AMOSAMOS is statistical software and it stands for analysis of a moment structures. AMOS is an added module, and is specially used for,. It is also known as analysis of covariance or causal modeling software. AMOS is a visual program for structural equation modeling (SEM). In AMOS, we can draw models graphically using simple drawing tools.
Spss22.0全称ibmspssstatistics 22，它虽然不是最新版的，但是它却可以说是该系列软件中最受欢迎的一款了。它可以前的版本一样，都是在刻个科学技术领域发挥着数据挖掘、预测分析、统计学分析运算的功能，但是和以前的版本相比它有新增加了倾向值分析、个案控制匹配等几项全新的分析方法，采用. An apparatus and methods are provided for sharing cell coverage information among devices in a cell network. Cell coverage information includes bitmap models of signal strength to enable intelligent handover decisions. Mobile terminals are able to receive cell coverage information over a broadband unidirectional broadcast network, such as a digital video broadcast network.
AMOS quickly performs the computations for SEM and displays the results.In calculation of coefficients, AMOS uses the following methods:. Maximum likelihood.
Unweighted least squares. Generalized least squares. Browne’s asymptotically distribution-free criterion. Scale-free least squaresConstruction of model in AMOS:First, we have to run AMOS. By clicking the “start” menu and selecting the “AMOS graphic” option, we can run the program. The moment AMOS starts running, a window appears called the “AMOS graphic.” In this window, we can manually draw our SEM model. Attaching Data: By selecting a file name from the data file option, we can attach data in AMOS for.
US1A1 - Methods and apparatus for sharing cell coverage information- Google Patents US1A1 - Methods and apparatus for sharing cell coverage information- Google Patents Methods and apparatus for sharing cell coverage informationInfo Publication number US1A1 US1A1 US11/064,934 US6493405A USA1 US 1 A1 US1 A1 US 1A1 US 6493405 A US6493405 A US 6493405A US A1 US A1 US A1 Authority US United States Prior art keywords cell mobile terminal cell coverage coverage information cci Prior art date 2004-02-27 Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) Granted Application number US11/064,934 Other versions Inventor Jani Vare Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)Nokia OyjOriginal Assignee Nokia Oyj Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.) 2004-02-27 Filing date 2005-02-25 Publication date 2005-02-27 Priority to US54873504P priority Critical 2005-02-25 Application filed by Nokia Oyj filed Critical Nokia Oyj 2005-02-25 Priority to US11/064,934 priority patent/US7369861B2/en 2005-02-25 Assigned to NOKIA CORPORATION reassignment NOKIA CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). An apparatus and methods are provided for sharing cell coverage information among devices in a cell network. Cell coverage information includes bitmap models of signal strength to enable intelligent handover decisions.
Mobile terminals are able to receive cell coverage information over a broadband unidirectional broadcast network, such as a digital video broadcast network. They are also able to receive cell coverage information from other mobile terminals via ad hoc wireless signalling.
Mobile terminals are also able to store and upload raw signal measurements to a cell coverage information center. Handover decisions for mobile terminals traveling through a wireless network are typically made based on factors such as cell coverage, mobile terminal location and terminal movement information. Mobile terminals include a variety of electronic devices, including cellular phones, mobile digital video broadcast (DVB) receivers, pagers, personal digital assistants, laptop computers, automobile computers, portable video players, and other devices which may move among multiple cells and which include equipment for receiving signals from a wireless network.
In addition to DVB receivers, mobile terminals may include mobile receivers of other digital unidirectional broadband broadcast systems. With a first conventional approach, handover decisions are based on location, cell coverage area and terminal movement vector information. The mobile terminal has means to know its exact location (e.g., GPS, AGPS) and measure the signal strength from available signals. 1 shows a mobile terminal 101 in the crossroads of cell signals A, B, and C, each of which is depicted by a border showing the outer reaches of a single minimum signal level. The movement and velocity of mobile terminal 101 is described by vector 102. Mobile terminal 101 is able to receive any of signals A, B, and C.
If mobile terminal 101 is presently receiving either signals B or C, then it executes a handover to signal A in order to continue reception of a signal in the future, assuming the same course and speed. 2 depicts a spherical rectangle 201 representation of cell signal A as used by some technical specifications, such as the Digital Video Broadcast (DVB) system. For cell signal A, spherical rectangle has a reference corner 202, typically located at the southwest corner of the rectangle. Reference corner 202 is specified by a specific longitude and latitude, or some other geographic designation. Call of chernobyl tool locations.
The extent of longitude 203 and the extent of latitude 204 describe the length and height of the bounding rectangle, which is sized to encompass the cell signal. The values associated with extents 203 and 204 are in the form of degrees, minutes and seconds, or spherical or planar vectors, or some other representation having a magnitude. While permitting relatively simple handoff calculations, the use of spherical rectangles is likely to be fraught with inaccuracies. 3 illustrates how the cell signals of FIG. 1 may be modeled using the conventional approach depicted in FIG. The cells are assumed to provide the same signal strength within rectangular areas.
Based on information provided to mobile terminal 101, the mobile terminal will either perform a handover to cell B, or keep the signal of cell B if already active. Given the signal strength of cell B in FIG. 1, such a determination is poor because of inaccurate cell signal representation, and a signal may be lost.
Although only a few shades are used to represent signal strengths, the infinite range of signal strengths varies depending on environmental conditions within the coverage area and other factors. Under a conventional approach, mobile terminal 101 will make a poor assumption selecting cell C as a handover destination from cell B.
Although cell C fully encompasses mobile terminal 101 moving along vector 102, the signal strength will decay if the mobile terminal maintains a connection to cell C. If the reception sensitivity of mobile terminal 101 were to be taken into account, the optimal choice in a handover situation would be to cell A, based on actual signal strengths. It should be noted that the Applicant is not suggesting that varying levels of signal strength have been used in conjunction with prior art handover procedures. With a second conventional approach, handover decisions are made based on a location determination that is estimated using signal strength information and cell coverage information. With this approach, a mobile terminal is not aware of its location (e.g., doesn't have a GPS system). 5 illustrates an example of this basic method utilizing only cell shape information (i.e., only one signal level used). Here, because mobile terminal 101 is able to detect signals from both cell A and cell C, it is able to determine that it is somewhere within shaded region 501.
6 depicts a similar method to detect approximate location using spherical rectangles. Here again, because signals from both cell A and cell C are detected, mobile terminal 101 is able to determine that it is somewhere within shaded area 601. Either method, while facilitating handover decisions, do so in a highly inaccurate manner, since the precise location within the shaded region is unknown. One or more of the above-mentioned needs in the art are satisfied by the disclosed methods and systems. Free field three dimensional models of signal levels may be created for a group of cells.
In one embodiment, the models are in the form of bitmaps. A mobile terminal can determine the inner area within the cell where it is located, based on the measured signal strength and maximum signal strength value (depending on the antenna sensitivity of the receiver and calibrated ‘free field’ signal strength) indicated in the bitmap information. This information may be used to execute handover procedures.
Aspects of the invention provide increased accuracy with respect to presenting the shape and quality of service in a cell. Embodiments of the invention provide systems and methods for distributing, receiving and sharing cell coverage information. In aspects of some embodiments, raw cell coverage data is measured by mobile terminals, identifying minimally a geographic location and signal strength. Raw cell coverage data may be used to calculate models of cell coverage information, including bitmaps. Raw cell coverage information and/or cell coverage models may be distributed using broadcast systems, shared by other mobile terminals, downloaded from the Internet, or otherwise sent and received among electronic devices.BRIEF DESCRIPTION OF THE DRAWINGS. In accordance with aspects of the invention, there is provided real-life free field three-dimensional plane models of signal levels existing for a given radio cell.
The models are developed in a well-defined area of adjustable size and resolution. Embodiments of the invention provide a signaling method which can be used to improve mobility in cell networks, including DVB-T/H networks. Specifically, determination and signaling of the coverage area of a cell, including the size of the cell and its location. Bitmap models of cell coverage may be created based on measurements of signal strength taken within the area of a cell.
7A shows a set of measurements of signal strength taken within a cell coverage area 701 according to one or more aspects of an embodiment of the invention. The signal strength values may be received from one or more terminals which may be mobile or remain in a fixed location. The received strength values are analyzed, for example statistically compared to values provided by other terminals and other measurement devices. The values are recorded as geographic locations, possibly using conventional longitude and latitude, along with signal strengths, possibly measured in decibels referenced to one milliwatt (dBm). Although the measured strength values shown in the figure are depicted as having only three signal levels (no/weak/strong), in certain embodiments the measured values may fall into a much broader range. The range of values could then be categorized using ranges. The number of ranges depends on several factors, including the desired size of the data file, the total extent of the range of values, and the need for more detailed strength measurements when making handover decisions.
In the case of a bitmap data file, the number of ranges (or colors) can greatly affect the size of the file. One signal strength would require one bit per pixel (0=no signal, 1=signal). Three signal strengths would require two bits per pixel (00=no signal, 01=weak signal, 10=average signal, 11=strong signal). Additional signal strengths would require additional bits, and subsequently increase the size of a data file such as a bitmap. Once regions are determined, a cell unit grid is effectively used to break the larger, more detailed interpolated cell coverage regions into a smaller, more manageable bitmap file.
For example, as shown in FIG. 7A, if the original cell coverage area was three kilometers by three kilometers, and the final bitmap file was set to have an area of 150 pixels by 150 pixels, then each pixel would represent 400 square meters (20 m by 20 m) (calculated by 9,000,000 m 2/22,500 pixels). The cell unit grid does not necessarily need squares or rectangles to break down cell coverage.
It may also use triangles or hexagons. When multiple regions intersect a particular cell unit, the pixel value may be decided by determining which region predominates within the cell unit. 8A and 8B show examples of mapping differently shaped signal coverage areas into bitmaps according to one or more aspects of an embodiment of the invention. 8A, cell coverage area 801 is mapped into cell unit grid 811.
8B, cell coverage area 802 is mapped into cell unit grid 812. For cell unit grids 811 and 812, depending on the size of their respective cell coverage areas 801 and 802, as well as other previously mentioned factors, each cell unit may encompass larger or smaller areas. In addition, the number of signal strength ranges may be varied as well. For example, cell unit grid 811 only uses two signal levels, whereas cell unit grid 812 uses three signal levels. When a mobile terminal receives bitmaps of cell coverage areas, it is able to make educated handover decisions with additional detail.
Rather than working with bulky rectangles, a mobile terminal works with highly detailed data files, perhaps in the form of bitmaps. In addition to being able to make more educated handover decisions, a mobile terminal lacking a GPS or other positioning system is able to make better guesses about its exact location. 9 depicts mobile terminal 101 moving in direction 102 is able to determine that it is somewhere within shaded region 901. This is based on being able to receive the stronger signal from Cell A at the same time as receiving the weaker signal from Cell C and knowing the boundaries of the stronger and weaker signals. Versionnumber: This 5-bit field is the version number of the sub-table. The versionnumber shall be incremented by 1 when a change in the information carried within the subtable occurs.
When it reaches value 31, it wraps around to 0. When the currentnextindicator is set to ‘1’, then the versionnumber shall be that of the currently applicable subtable defined by the tableid, platformid and actiontype. When the currentnextindicator is set to ‘0’, then the versionnumber shall be that of the next applicable subtable defined by the tableid, platformid and actiontype. 10 depicts a process for generating a cell description table or any other signaling item and transmitting it according to one or more aspects of an embodiment of the invention. In step 1001, the free field signal strengths for a particular cell are measured using either mobile or stationary devices. The devices may include mobile terminals capable of consuming cell signal content, and may also include dedicated measurement devices.
In step 1002, the measured strengths are converted into cell coverage bitmaps, such as described above. In step 1003, an entry in a cell description table is created for the cell, including within it metadata about the cell and its bitmap representation, as well as the bitmap itself. And in step 1004, the generated signaling item, such as the entry in the cell description table is transmitted for storage or use by mobile terminals. 11 shows a high level description of a process for bitmap information creation according to one or more aspects of an embodiment of the invention. Here, a computing unit 1101 resides within a mobile terminal, or within a server or other computing device. Computing unit 1101 takes input data 1102 about a cell coverage area, for example measurements of signal strength taken at various points around the cell.
Computing unit uses configuration parameters 1103 in transforming the input data into a data file 1104 representation of the cell coverage area, perhaps in the form of a bitmap. Configuration parameters 1103 may include the number of signal strength ranges that should be used, the size and shape of the cell units used to model the cell, and other relevant parameters which effect the creation of data file 1104. 12 shows one possible process for generating and transmitting a cell description table to a mobile terminal in a DVB network according to one or more aspects of an embodiment of the invention. Data file 1201, residing in server 1202, is used to create an entry in a CDT table 1203. Data file 1201 is made up of a bitmap file, or other file capable of providing cell unit strength values in a similar fashion. CDT table 1203, including one or more cell entries, is passed to multiplexer 1204 in a digital video broadcast network (DVB).
Multiplexer 1204 combines CDT tables with other digital content for broadcast as MPEG-TS transport streams from transmission station 1205. 13 shows a process for receiving a cell description table from a DVB network, parsing it, and using it in a mobile terminal according to one or more aspects of an embodiment of the invention. At step 1301, a mobile terminal receives a DVB-H/T signal including digital video broadcast content, as well as at least one signaling item, such as a CDT table entry. At step 1302, the mobile terminal parses the bitmap information from the signaling item received. At step 1303, a map of the cell coverage area is created, and optionally overlaid with other maps of surrounding cells. Adjustments may need to be made to the newly received map in order to integrate it into the multi-cell map, such as accounting for disparities in strength ranges and cell unit scales (in the case of a CDT type signaling item, these values may be parsed from the CDT metadata). At step 1304, signal availability is determined based on the multi-cell map created, and by analyzing movement of the device through space.
Finally, at step 1305, this information is used to make educated cell choices when needing to make a handover to an adjacent cell. Other methods for using signaling items such as a cell coverage bitmap to make educated cell handover decisions are available. 14 depicts a data structure for expressing vector information (e.g., vector 102 in FIG.
4), according to one or more aspects of an embodiment of the invention. Datagram 1400 comprises header information 1401 (such as the source IP address and the destination address) and data payload 1437. Also, datagram 1400 comprises geographical position information about a source device corresponding to a option type data field 1440, an option length data field 1441, a reserved data field 1449, a version data field 1451, a datum data field 1453, a latitude data field 1403, a longitude data field 1405, an altitude data fields 1407 and 1439, velocity data fields 1409, 1411, 1413, and 1415, location uncertainty data fields 1417, 1419, 1421, 1423, and 1425, velocity uncertainty data fields 1427, 1429, 1431, and 1433, and time data field 1435. Time data field 1435 is a 40-bit field that contains the current time and data in Coordinated Universal Time (UTC) and Modified Julian Date (MJD). Field 1435 is coded as 16 bits providing 16 LSBs of the MJD followed by 24 bits that represent 6 digits in a 4-bit Binary-Coded Decimal (BCD). In the exemplary embodiment, the geographical information is contained in a destination options header or in a hop-by-hop header, in compliance with RFC 2460. In the embodiment, a destination options header and a hop-by-hop header may be contained in the same datagram.
In the exemplary embodiment, version data field 1451 is an 8-bit field that indicates the version of the message header. Datum data field 1453 is an 8-bit field that indicates the used map datum (e.g., standard MIL-STD-2401) for determining the geographical position. Latitude data field 1403 is a 32-bit field that indicates the latitude value of the source device (e.g., corresponding to an approximate location of terminal node 107) presented in ANSI/IEEE Std 754-1985 format. Longitude data field 1405 is a 32-bit field that indicates the longitude value of the source device presented in ANSI/IEEE Std 754-1985 format. Alt indicator data field 1439 is a 1-bit field indicating the use of altitude information. Altitude data field is a 16-bit field that indicates the altitude value of the source device presented in ANSI/IEEE Std 754-1985 format.
Velocity indicator data field 1409 is a 1-bit field indicating the use of velocity information. If velocity information is included, this field is set to ‘1’. Otherwise this field is set to ‘0’. Heading data field 1411 is a 16-bit field that indicates the direction where the mobile node is moving.
If velocity indicator data field 1409 is set to ‘0’, this field is ignored. Otherwise, this field is included and is set to the angle of axis of horizontal velocity uncertainty, in units of 5.625 degrees, in the range from 0 to 84,375 degrees, where 0 degrees is True North and the angle increases toward the East. Vertical velocity data field 1413 is an 8-bit field, which indicates the vertical velocity of the mobile node. Vertical velocity data field 1413 is used if field 1409 is set to ‘1’. Horizontal velocity data field 1415 is a 16-bit field that indicates the horizontal velocity of the mobile node.
If velocity indicator is set to ‘1’, this field is in use. Once used, the horizontal speed is set in units of 0.25 m/s, in the range from 0 to 511.75 m/s. Otherwise this field is ignored.
LocUncH indicator data field 1417 is a 1-bit field which indicates the horizontal position uncertainty, including elliptical. If elliptical horizontal position uncertainty information is included in this response element, this field is set to ‘1’. Otherwise, this field is set to ‘0’. LocUnc angle data field 1419 (angle of axis of the standard error ellipse for horizontal position uncertainty) is a 8-bit field indicating the angle of axis of the standard error ellipse for horizontal position uncertainty. If LocUncH indicator field 1417 is set to ‘0’, this field is ignored.
Otherwise, this field is included and is set to angle of axis for horizontal position uncertainty, in units of 5.625 degrees, in the range from 0 to 84.375 degrees, where 0 degrees is True North and the angle increases toward the East. LocUnc A data field 1421 (standard deviation of error along angle specified for horizontal position uncertainty) is a 8-bit field indicating the Standard deviation of error along angle specified for horizontal position uncertainty. If LocUnc A data field 1421 is set to ‘0’, this field is ignored. Otherwise, this field is included and is set to represent the standard deviation of the horizontal position error along the axis corresponding to LocUnc angle data field 1419.
LocUnc P data field 1423 (standard deviation of error along angle specified for horizontal position uncertainty) is a 8-bit field indicating standard deviation of error along angle specified for horizontal position uncertainty. If LocUnc P data field 1423 is set to ‘0’, this field is ignored. Otherwise, this field is included and is set to represent the standard deviation of the horizontal position error perpendicular to the axis corresponding to LocUnc angle data field 1419. LocUnc vertical data field 1425 (standard deviation of vertical error for position uncertainty) is a 8-bit field indicating standard deviation of vertical error for position uncertainty.
VelUnc angle data field 1427 (angle of axis of standard error ellipse for horizontal velocity uncertainty) is a 8-bit field indicating the angle of axis of standard error ellipse for horizontal velocity uncertainty. If VelUnc angle data field 1427 is set to ‘0’, this field is ignored. Otherwise, this field is set to the angle of axis for horizontal velocity uncertainty, in units of 5.625 degrees, in the range from 0 to 84,375 degrees, where 0 degrees is True North and the angle increases toward the East. VelUnc A data field 1429 (standard deviation of error along angle specified for horizontal velocity uncertainty is a 8-bit field indicating standard deviation of error along angle specified for horizontal velocity uncertainty.
If velocity indicator data field 1409 is set to ‘1’, this field is included and is set to represent the standard deviation of the horizontal velocity error along the angle corresponding to VelUnc angle data field 1427. VelUnc P data field data field 1431 (standard deviation of error perpendicular to angle specified for horizontal velocity uncertainty) is a 8-bit field indicating standard deviation of error perpendicular to angle specified for horizontal velocity uncertainty. If velocity indicator data field 1409 is set to ‘1’, this field is included and is set to represent the standard deviation of the horizontal velocity error perpendicular to the angle corresponding to VelUnc angle data field 1427.
Otherwise, this field is ignored. VelUnc vertical data field 1433 (standard deviation of vertical velocity error) is an 8-bit field indicating the standard deviation of vertical velocity error. CCI may also be stored as individual bitmaps in a multi-cell map, or simply stored as individual files in memory or a file system.
Aspects of the invention provide that CCI may be stored using either one of two principles, although one skilled in the art will recognize that additional forms of cell coverage information may be used. Principle I data 1505 includes cell coverage data that has been analyzed and formatted into a bitmap or similar format, and includes cell coverage metadata. Principle I includes CCI stored in the previously described CDT table format. Principle II data 1506 includes raw point cell coverage data in the form of point locations (e.g., latitude and longitude) coupled with signal strengths (e.g., dBm).
Either form of cell coverage information may be stored and used by mobile terminal 101, although Principle II data 1506 requires more processing in order to be useful in handover decisions. Mobile terminal 101 may include multiple forms of reception and transmission functionality. Although three particular functions are shown, more or less may be used to take advantage of embodiments of the invention. GPS 1502 relies on signals received from satellites to determine the latitude and longitude of the mobile terminal's current location. Other positioning systems may provide alternatives to GPS 1502, including assisted GPS (AGPS).
RF component 1503 may be used to receive a primary signal of interest, for example a DVB-T/H broadcast signal. Mobile terminal 101 may, in addition to using CCI to find the strongest signal, may create its own Principle II CCI, recording location and signal strength throughout the cell coverage area. Other wireless components (not shown) may use short range radio or optical standards to communicate with nearby devices. For example, Bluetooth, WiFi, RFID, IrDA, Ultra-wideband (UWB) or another short range wireless communication standard may be used. Conventional mid to long range signalling such as cellular system 1504 can also be useful in sending and receiving CCI.
Cellular system 1504 may share resources and functionality with RF system 1503. In order to effectively utilize CCI, a mobile terminal 101 may be able to maintain data about multiple cells simultaneously. By examining surrounding cell coverage, and predicting the direction and speed of motion, mobile terminal 101 can perform handover operations that maintain continuous coverage and are less likely to fade. One method of maintaining data about multiple cells is to combine Principle I bitmap data into one large dynamic cell coverage map and tracking location and velocity of mobile terminal 101 on the map. 16A depicts mobile terminal 101 moving along vector 102 through a group of cell signals defined using bitmap cell coverage information according to one or more aspects of an embodiment of the invention. Mobile terminal 101 is leaving cell 1603 and must select a destination cell for a handover from among cell 1601 or cell 1602, or possibly even unknown cell 1610.
By using the map, mobile terminal 101 can predict its immediate destination and determine that it does not have Principle I CCI for the empty portion of unknown cell 1603. Mobile terminal 101 may be able to infer coverage if it had Principle II raw coverage points within the missing cell, but such calculations would require more time and processing power. 17 depicts a mobile terminal in communication with a selection of devices according to one or more aspects of an embodiment of the invention. Here, mobile terminal 101 needs missing CCI for a particular cell or geographic location, and it checks a series of potential sources, although not necessarily in the order set forth below. One possible source of CCI data is the broadcast stream coming from broadcast transmitter 1701, along path A. The signal delivered by transmitter 1701 (e.g., a DVB-T/H signal) may include Principle I CCI data for the current and neighboring cells. This CCI is sourced from cell coverage information center 1705, which includes server 1703 (or more likely multiple servers) and cell coverage database 1704 (CCD).
If the broadcast signal does not have the desired CCI, mobile terminal 101 may attempt to sense other mobile terminals, using a wireless communication scheme, such as Bluetooth, WiFi, IrDA, UWB, or some other ad hoc signaling method that allows peer-to-peer communications. Here, both mobile terminals 1605 and 1606 may be within range. Path B represents a wireless conversation between mobile terminal 101 and smaller mobile terminal 1605. Although mobile terminal 1605 may contain CCI for the cell in question, it may be of the wrong class, since the devices have different viewing dimensions and sizes.
(Class of signal may also depend on factors such as installed plug-ins, size of memory, and so forth) As such, the signal strengths in the memory of smaller mobile terminal 1605 may be of no use, since it actually receives a different signal than larger terminal 101. Path C represents a wireless conversation between mobile terminal 101 and similar mobile terminal 1606. If mobile terminal 1606 has the data desired, it can respond with the appropriate signaling item, such as a CDT table. If mobile terminal 1606 does not have the data, it may be able to provide mobile terminal 101 with a location for the information. For example, mobile terminal 1606 may be able to provide an IP address, username and password from which mobile terminal 101 can transfer the data (via PPP, FTP, HTTP, etc.).
Although not shown, mobile terminal 101 may communicate with another mobile terminal using a cellular data call, via the Internet, via SMS, or via some other indirect communication method. Messages to mobile terminals may also be sent via a broadcast network, such as a DVB-T/H network, where incoming messages are sent to the DVB-T/H network via SMS, MMS, Internet connection, or ad hoc signaling systems. These incoming messages are then forwarded via the broadcast signal to a recipient mobile terminal. If other mobile terminals do not have the cell coverage information sought, other communication routes may be available to mobile terminal 101. Path D represents a cellular conversation between mobile terminal 101 and cell coverage center 1705 via cell tower 1702.
Mobile terminal 101 may be able to make a data call, and download the proper CCI directly. Path E represents a conversation (either wired or wireless) between mobile terminal 101 and cell coverage center 1705 via a network 1706, such as the Internet or an intranet. A wireless conversation may take place via a cellular system or a WiFi connection. A wired conversation may take place via a sync cable or other direct connection with a computer or a network. As before, mobile terminal 101 may be able to download the proper CCI directly, perhaps using an IP address, username, and password previously provided by mobile terminal 1606. Other methods of communication between mobile terminal 101 and cell coverage information center 1705 are conceivable, both wired and wireless.
18 depicts mobile terminal 101 in communication with similar mobile terminal 1606 and CCI server 1703 according to one or more aspects of an embodiment of the invention. Turning now to the specific messages of conversations between mobile terminal 101 and other devices. Beginning with communication between mobile terminal 101 and similar mobile terminal 1606, the method of communication is not relevant, whether wireless, via the Internet, via broadcast, etc.
Assuming communication is possible using one of these methods, the individual messages are now in the spotlight. Message A represents an initial query or discovery, referred to as a CCI Discovery message. The components of the message are set forth in the table below.TABLE 3 CCI Discovery Message Field Name Description CCI Message Indicates the Type of Message: CCI Discovery Type CCI Discovery Indicates the desired CCI discovery method.
If the Method method requested is not available in the receiving terminal, then no method is indicated in the reply. Terminal Class Indicates the class of the requesting terminal. If the class of the receiving terminal does not match, then a “not available” status is provided in the reply.
Sending terminal can set this field to “any class” to prevent filtering. Geographical Contains the geographical range for the requested CCI Range metadata. “Not available” is sent in the reply if the receiving terminal has no CCI metadata for the given geographical range. The CCI Discovery message is received by mobile terminal 1606, which then replies with a standardized reply, Message B, also known as a CCI Reply. The components of this message are set forth below.TABLE 4 CCI Reply (to Discovery) Message Field Name Description CCI Message Indicates the Type of Message: CCI Reply Type Reply Type Indicates the type of the reply (i.e., whether it is a reply to a CCI Discovery or a CCI Request). CCI Type Indicates the types of CCI (e.g., Principle I, Principle II, CDT, etc.) that are available on the replying terminal, depending on discovery parameters.
Terminal Class Indicates the class of CCI metadata available on the replying terminal (e.g. Screen resolution, needed plugins, etc), depending on discovery parameters.
Geographical Contains the geographical range available on the Range replying terminal. “Not available” is sent in the reply if the replying terminal has no CCI metadata for the geographical range depending on discovery parameters. CCI Discovery Informs of parameters (e.g., IP address, user, password, Info and port) leading to the requested data on another device.
Once the reply to the discovery message is received, mobile terminal 101 may make a specific request, assuming similar mobile terminal 1606 had CCI metadata within the range sought by the discovery. Message C, also known as a CCI Request, is broken down below.TABLE 5 CCI Request Message Field Name Description CCI Message Indicates the Type of Message: CCI Request Type CCI Type Indicates the CCI type requested (e.g., Principle I, Principle II, CDT, etc.). Can also be set to “any type”, where priority is given to a particular type, but other types are acceptable if the primary is not available. Terminal Class Indicates the class of the requesting terminal (e.g.
Screen resolution, needed plugins, etc). If the class of the requesting and receiving terminals don't match, then “not available” status is provided in the reply. If the requesting terminal doesn't care about class, it can put an “any class” indicator in this field. Geographical Contains the geographical range available on the Range replying terminal. “Not available” is sent in the reply if the replying terminal has no CCI metadata for the geographical range depending on discovery parameters. Upon receiving the CCI Request, the receiving terminal 1606 responds with Message D, another CCI Reply, the components of which are set forth below.TABLE 6 CCI Reply (to Request) Message Field Name Description CCI Message Indicates the Type of Message: CCI Reply Type Reply Type Indicates the type of the reply (i.e., whether it is a reply to a CCI Discovery or a CCI Request). CCI Type Indicates the type of CCI (e.g., Principle I, Principle II, CDT, etc.) provided in this response.
Terminal Class Indicates the class of CCI metadata provided in the repsonse (e.g. Screen resolution, needed plugins, etc). Geographical Contains the geographical range provided in the Range response.
CCI Data The CCI data. To perform this operation, mobile terminal 101 uses a CCI Push message (Message F) to push the data to server 1703, where it can be stored, analyzed, converted to Principle I data, and forwarded to other mobile terminals. The substance of a CCI Push message is set forth below.TABLE 7 CCI Push Message Field Name Description CCI Message Indicates the Type of Message: CCI Push Type CCI Type Indicates the type of CCI (e.g., Principle I, Principle II, CDT, etc.) provided in this push, or that is available with CCI discovery parameters.
Terminal Class Indicates the class of CCI metadata provided in the push (e.g. Screen resolution, needed plug-ins, etc) or available with CCI discovery parameters. Geographical Contains the geographical range provided in this push, Range or available with CCI discovery parameters. CCI Discovery If this is a reply to a CCI discovery, informs of Info parameters (e.g., IP address, user, password, and port) for the CCI discovery.
Otherwise, field is left out. CCI Data The CCI data. 19 illustrates a process for issuing a cell coverage information request according to one or more aspects of an embodiment of the invention. At step 1901, available receivers, such as DVB-T/H receivers, are sought, whether via direct connections, such as ad hoc wireless standards, or via Internet or other indirect connections. If no receivers are available at decision 1902, then a timer is set for a specific period of time at step 1903. When the timer expires, control returns to step 1901, again seeking available receivers. If receivers, such as other mobile terminals, are available, then a CCI Discovery or CCI Request can be forwarded to the receiving device.
20 illustrates a process for issuing a cell coverage information reply according to one or more aspects of an embodiment of the invention. At step 2001, a listener is set up to wait for incoming CCI Discoveries or CCI Requests.
If no requests are forthcoming, at decision 2002, then control returns to step 2001. If a request is received, then processing of the request is handled at step 2003.
If the incoming message is a discovery, the appropriate information is assembled, and if the message is a request, likewise that information is assembled. At step 2004, the CCI Reply is transmitted back to the requesting terminal. 21 illustrates a process for issuing a cell coverage information push according to one or more aspects of an embodiment of the invention. At decision 2101, if a connection is needed, the server connection is created at step 2102. If the connection is successful at decision 2103, then at step 2104, the appropriate CCI data and metadata and/or discovery information are sent as a CCI Push. If no connection was needed at decision 2101, then step 2104 assembles the CCI Push in the same fashion. Once the CCI Push is issued, or if the connection attempt failed, control terminates normally.
While aspects of the invention have been described with respect specific examples, including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and techniques that fall within the spirit and scope of the invention as set forth in the appended claims. Aspects of the invention may also be used in other forms of wireless cellular networks, including digital video broadcasting (DVB), and in cellular telephony.Claims ( 20). A processor, configured to perform the steps of receiving cell coverage information via the receiver, storing at least the bitmap model of cell signal strengths in the memory, determining a travel vector based on changes in the longitude and latitude of the mobile terminal over time, and determining a destination cell for a handover based on the travel vector and at least the bitmap model of cell signal strengths.
Popular Posts
AMOSAMOS is statistical software and it stands for analysis of a moment structures. AMOS is an added module, and is specially used for,. It is also known as analysis of covariance or causal modeling software. AMOS is a visual program for structural equation modeling (SEM). In AMOS, we can draw models graphically using simple drawing tools.
Spss22.0全称ibmspssstatistics 22，它虽然不是最新版的，但是它却可以说是该系列软件中最受欢迎的一款了。它可以前的版本一样，都是在刻个科学技术领域发挥着数据挖掘、预测分析、统计学分析运算的功能，但是和以前的版本相比它有新增加了倾向值分析、个案控制匹配等几项全新的分析方法，采用. An apparatus and methods are provided for sharing cell coverage information among devices in a cell network. Cell coverage information includes bitmap models of signal strength to enable intelligent handover decisions. Mobile terminals are able to receive cell coverage information over a broadband unidirectional broadcast network, such as a digital video broadcast network.
AMOS quickly performs the computations for SEM and displays the results.In calculation of coefficients, AMOS uses the following methods:. Maximum likelihood.
Unweighted least squares. Generalized least squares. Browne’s asymptotically distribution-free criterion. Scale-free least squaresConstruction of model in AMOS:First, we have to run AMOS. By clicking the “start” menu and selecting the “AMOS graphic” option, we can run the program. The moment AMOS starts running, a window appears called the “AMOS graphic.” In this window, we can manually draw our SEM model. Attaching Data: By selecting a file name from the data file option, we can attach data in AMOS for.
US1A1 - Methods and apparatus for sharing cell coverage information- Google Patents US1A1 - Methods and apparatus for sharing cell coverage information- Google Patents Methods and apparatus for sharing cell coverage informationInfo Publication number US1A1 US1A1 US11/064,934 US6493405A USA1 US 1 A1 US1 A1 US 1A1 US 6493405 A US6493405 A US 6493405A US A1 US A1 US A1 Authority US United States Prior art keywords cell mobile terminal cell coverage coverage information cci Prior art date 2004-02-27 Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) Granted Application number US11/064,934 Other versions Inventor Jani Vare Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)Nokia OyjOriginal Assignee Nokia Oyj Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.) 2004-02-27 Filing date 2005-02-25 Publication date 2005-02-27 Priority to US54873504P priority Critical 2005-02-25 Application filed by Nokia Oyj filed Critical Nokia Oyj 2005-02-25 Priority to US11/064,934 priority patent/US7369861B2/en 2005-02-25 Assigned to NOKIA CORPORATION reassignment NOKIA CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). An apparatus and methods are provided for sharing cell coverage information among devices in a cell network. Cell coverage information includes bitmap models of signal strength to enable intelligent handover decisions.
Mobile terminals are able to receive cell coverage information over a broadband unidirectional broadcast network, such as a digital video broadcast network. They are also able to receive cell coverage information from other mobile terminals via ad hoc wireless signalling.
Mobile terminals are also able to store and upload raw signal measurements to a cell coverage information center. Handover decisions for mobile terminals traveling through a wireless network are typically made based on factors such as cell coverage, mobile terminal location and terminal movement information. Mobile terminals include a variety of electronic devices, including cellular phones, mobile digital video broadcast (DVB) receivers, pagers, personal digital assistants, laptop computers, automobile computers, portable video players, and other devices which may move among multiple cells and which include equipment for receiving signals from a wireless network.
In addition to DVB receivers, mobile terminals may include mobile receivers of other digital unidirectional broadband broadcast systems. With a first conventional approach, handover decisions are based on location, cell coverage area and terminal movement vector information. The mobile terminal has means to know its exact location (e.g., GPS, AGPS) and measure the signal strength from available signals. 1 shows a mobile terminal 101 in the crossroads of cell signals A, B, and C, each of which is depicted by a border showing the outer reaches of a single minimum signal level. The movement and velocity of mobile terminal 101 is described by vector 102. Mobile terminal 101 is able to receive any of signals A, B, and C.
If mobile terminal 101 is presently receiving either signals B or C, then it executes a handover to signal A in order to continue reception of a signal in the future, assuming the same course and speed. 2 depicts a spherical rectangle 201 representation of cell signal A as used by some technical specifications, such as the Digital Video Broadcast (DVB) system. For cell signal A, spherical rectangle has a reference corner 202, typically located at the southwest corner of the rectangle. Reference corner 202 is specified by a specific longitude and latitude, or some other geographic designation. Call of chernobyl tool locations.
The extent of longitude 203 and the extent of latitude 204 describe the length and height of the bounding rectangle, which is sized to encompass the cell signal. The values associated with extents 203 and 204 are in the form of degrees, minutes and seconds, or spherical or planar vectors, or some other representation having a magnitude. While permitting relatively simple handoff calculations, the use of spherical rectangles is likely to be fraught with inaccuracies. 3 illustrates how the cell signals of FIG. 1 may be modeled using the conventional approach depicted in FIG. The cells are assumed to provide the same signal strength within rectangular areas.
Based on information provided to mobile terminal 101, the mobile terminal will either perform a handover to cell B, or keep the signal of cell B if already active. Given the signal strength of cell B in FIG. 1, such a determination is poor because of inaccurate cell signal representation, and a signal may be lost.
Although only a few shades are used to represent signal strengths, the infinite range of signal strengths varies depending on environmental conditions within the coverage area and other factors. Under a conventional approach, mobile terminal 101 will make a poor assumption selecting cell C as a handover destination from cell B.
Although cell C fully encompasses mobile terminal 101 moving along vector 102, the signal strength will decay if the mobile terminal maintains a connection to cell C. If the reception sensitivity of mobile terminal 101 were to be taken into account, the optimal choice in a handover situation would be to cell A, based on actual signal strengths. It should be noted that the Applicant is not suggesting that varying levels of signal strength have been used in conjunction with prior art handover procedures. With a second conventional approach, handover decisions are made based on a location determination that is estimated using signal strength information and cell coverage information. With this approach, a mobile terminal is not aware of its location (e.g., doesn\'t have a GPS system). 5 illustrates an example of this basic method utilizing only cell shape information (i.e., only one signal level used). Here, because mobile terminal 101 is able to detect signals from both cell A and cell C, it is able to determine that it is somewhere within shaded region 501.
6 depicts a similar method to detect approximate location using spherical rectangles. Here again, because signals from both cell A and cell C are detected, mobile terminal 101 is able to determine that it is somewhere within shaded area 601. Either method, while facilitating handover decisions, do so in a highly inaccurate manner, since the precise location within the shaded region is unknown. One or more of the above-mentioned needs in the art are satisfied by the disclosed methods and systems. Free field three dimensional models of signal levels may be created for a group of cells.
In one embodiment, the models are in the form of bitmaps. A mobile terminal can determine the inner area within the cell where it is located, based on the measured signal strength and maximum signal strength value (depending on the antenna sensitivity of the receiver and calibrated ‘free field’ signal strength) indicated in the bitmap information. This information may be used to execute handover procedures.
Aspects of the invention provide increased accuracy with respect to presenting the shape and quality of service in a cell. Embodiments of the invention provide systems and methods for distributing, receiving and sharing cell coverage information. In aspects of some embodiments, raw cell coverage data is measured by mobile terminals, identifying minimally a geographic location and signal strength. Raw cell coverage data may be used to calculate models of cell coverage information, including bitmaps. Raw cell coverage information and/or cell coverage models may be distributed using broadcast systems, shared by other mobile terminals, downloaded from the Internet, or otherwise sent and received among electronic devices.BRIEF DESCRIPTION OF THE DRAWINGS. In accordance with aspects of the invention, there is provided real-life free field three-dimensional plane models of signal levels existing for a given radio cell.
The models are developed in a well-defined area of adjustable size and resolution. Embodiments of the invention provide a signaling method which can be used to improve mobility in cell networks, including DVB-T/H networks. Specifically, determination and signaling of the coverage area of a cell, including the size of the cell and its location. Bitmap models of cell coverage may be created based on measurements of signal strength taken within the area of a cell.
7A shows a set of measurements of signal strength taken within a cell coverage area 701 according to one or more aspects of an embodiment of the invention. The signal strength values may be received from one or more terminals which may be mobile or remain in a fixed location. The received strength values are analyzed, for example statistically compared to values provided by other terminals and other measurement devices. The values are recorded as geographic locations, possibly using conventional longitude and latitude, along with signal strengths, possibly measured in decibels referenced to one milliwatt (dBm). Although the measured strength values shown in the figure are depicted as having only three signal levels (no/weak/strong), in certain embodiments the measured values may fall into a much broader range. The range of values could then be categorized using ranges. The number of ranges depends on several factors, including the desired size of the data file, the total extent of the range of values, and the need for more detailed strength measurements when making handover decisions.
In the case of a bitmap data file, the number of ranges (or colors) can greatly affect the size of the file. One signal strength would require one bit per pixel (0=no signal, 1=signal). Three signal strengths would require two bits per pixel (00=no signal, 01=weak signal, 10=average signal, 11=strong signal). Additional signal strengths would require additional bits, and subsequently increase the size of a data file such as a bitmap. Once regions are determined, a cell unit grid is effectively used to break the larger, more detailed interpolated cell coverage regions into a smaller, more manageable bitmap file.
For example, as shown in FIG. 7A, if the original cell coverage area was three kilometers by three kilometers, and the final bitmap file was set to have an area of 150 pixels by 150 pixels, then each pixel would represent 400 square meters (20 m by 20 m) (calculated by 9,000,000 m 2/22,500 pixels). The cell unit grid does not necessarily need squares or rectangles to break down cell coverage.
It may also use triangles or hexagons. When multiple regions intersect a particular cell unit, the pixel value may be decided by determining which region predominates within the cell unit. 8A and 8B show examples of mapping differently shaped signal coverage areas into bitmaps according to one or more aspects of an embodiment of the invention. 8A, cell coverage area 801 is mapped into cell unit grid 811.
8B, cell coverage area 802 is mapped into cell unit grid 812. For cell unit grids 811 and 812, depending on the size of their respective cell coverage areas 801 and 802, as well as other previously mentioned factors, each cell unit may encompass larger or smaller areas. In addition, the number of signal strength ranges may be varied as well. For example, cell unit grid 811 only uses two signal levels, whereas cell unit grid 812 uses three signal levels. When a mobile terminal receives bitmaps of cell coverage areas, it is able to make educated handover decisions with additional detail.
Rather than working with bulky rectangles, a mobile terminal works with highly detailed data files, perhaps in the form of bitmaps. In addition to being able to make more educated handover decisions, a mobile terminal lacking a GPS or other positioning system is able to make better guesses about its exact location. 9 depicts mobile terminal 101 moving in direction 102 is able to determine that it is somewhere within shaded region 901. This is based on being able to receive the stronger signal from Cell A at the same time as receiving the weaker signal from Cell C and knowing the boundaries of the stronger and weaker signals. Versionnumber: This 5-bit field is the version number of the sub-table. The versionnumber shall be incremented by 1 when a change in the information carried within the subtable occurs.
When it reaches value 31, it wraps around to 0. When the currentnextindicator is set to ‘1’, then the versionnumber shall be that of the currently applicable subtable defined by the tableid, platformid and actiontype. When the currentnextindicator is set to ‘0’, then the versionnumber shall be that of the next applicable subtable defined by the tableid, platformid and actiontype. 10 depicts a process for generating a cell description table or any other signaling item and transmitting it according to one or more aspects of an embodiment of the invention. In step 1001, the free field signal strengths for a particular cell are measured using either mobile or stationary devices. The devices may include mobile terminals capable of consuming cell signal content, and may also include dedicated measurement devices.
In step 1002, the measured strengths are converted into cell coverage bitmaps, such as described above. In step 1003, an entry in a cell description table is created for the cell, including within it metadata about the cell and its bitmap representation, as well as the bitmap itself. And in step 1004, the generated signaling item, such as the entry in the cell description table is transmitted for storage or use by mobile terminals. 11 shows a high level description of a process for bitmap information creation according to one or more aspects of an embodiment of the invention. Here, a computing unit 1101 resides within a mobile terminal, or within a server or other computing device. Computing unit 1101 takes input data 1102 about a cell coverage area, for example measurements of signal strength taken at various points around the cell.
Computing unit uses configuration parameters 1103 in transforming the input data into a data file 1104 representation of the cell coverage area, perhaps in the form of a bitmap. Configuration parameters 1103 may include the number of signal strength ranges that should be used, the size and shape of the cell units used to model the cell, and other relevant parameters which effect the creation of data file 1104. 12 shows one possible process for generating and transmitting a cell description table to a mobile terminal in a DVB network according to one or more aspects of an embodiment of the invention. Data file 1201, residing in server 1202, is used to create an entry in a CDT table 1203. Data file 1201 is made up of a bitmap file, or other file capable of providing cell unit strength values in a similar fashion. CDT table 1203, including one or more cell entries, is passed to multiplexer 1204 in a digital video broadcast network (DVB).
Multiplexer 1204 combines CDT tables with other digital content for broadcast as MPEG-TS transport streams from transmission station 1205. 13 shows a process for receiving a cell description table from a DVB network, parsing it, and using it in a mobile terminal according to one or more aspects of an embodiment of the invention. At step 1301, a mobile terminal receives a DVB-H/T signal including digital video broadcast content, as well as at least one signaling item, such as a CDT table entry. At step 1302, the mobile terminal parses the bitmap information from the signaling item received. At step 1303, a map of the cell coverage area is created, and optionally overlaid with other maps of surrounding cells. Adjustments may need to be made to the newly received map in order to integrate it into the multi-cell map, such as accounting for disparities in strength ranges and cell unit scales (in the case of a CDT type signaling item, these values may be parsed from the CDT metadata). At step 1304, signal availability is determined based on the multi-cell map created, and by analyzing movement of the device through space.
Finally, at step 1305, this information is used to make educated cell choices when needing to make a handover to an adjacent cell. Other methods for using signaling items such as a cell coverage bitmap to make educated cell handover decisions are available. 14 depicts a data structure for expressing vector information (e.g., vector 102 in FIG.
4), according to one or more aspects of an embodiment of the invention. Datagram 1400 comprises header information 1401 (such as the source IP address and the destination address) and data payload 1437. Also, datagram 1400 comprises geographical position information about a source device corresponding to a option type data field 1440, an option length data field 1441, a reserved data field 1449, a version data field 1451, a datum data field 1453, a latitude data field 1403, a longitude data field 1405, an altitude data fields 1407 and 1439, velocity data fields 1409, 1411, 1413, and 1415, location uncertainty data fields 1417, 1419, 1421, 1423, and 1425, velocity uncertainty data fields 1427, 1429, 1431, and 1433, and time data field 1435. Time data field 1435 is a 40-bit field that contains the current time and data in Coordinated Universal Time (UTC) and Modified Julian Date (MJD). Field 1435 is coded as 16 bits providing 16 LSBs of the MJD followed by 24 bits that represent 6 digits in a 4-bit Binary-Coded Decimal (BCD). In the exemplary embodiment, the geographical information is contained in a destination options header or in a hop-by-hop header, in compliance with RFC 2460. In the embodiment, a destination options header and a hop-by-hop header may be contained in the same datagram.
In the exemplary embodiment, version data field 1451 is an 8-bit field that indicates the version of the message header. Datum data field 1453 is an 8-bit field that indicates the used map datum (e.g., standard MIL-STD-2401) for determining the geographical position. Latitude data field 1403 is a 32-bit field that indicates the latitude value of the source device (e.g., corresponding to an approximate location of terminal node 107) presented in ANSI/IEEE Std 754-1985 format. Longitude data field 1405 is a 32-bit field that indicates the longitude value of the source device presented in ANSI/IEEE Std 754-1985 format. Alt indicator data field 1439 is a 1-bit field indicating the use of altitude information. Altitude data field is a 16-bit field that indicates the altitude value of the source device presented in ANSI/IEEE Std 754-1985 format.
Velocity indicator data field 1409 is a 1-bit field indicating the use of velocity information. If velocity information is included, this field is set to ‘1’. Otherwise this field is set to ‘0’. Heading data field 1411 is a 16-bit field that indicates the direction where the mobile node is moving.
If velocity indicator data field 1409 is set to ‘0’, this field is ignored. Otherwise, this field is included and is set to the angle of axis of horizontal velocity uncertainty, in units of 5.625 degrees, in the range from 0 to 84,375 degrees, where 0 degrees is True North and the angle increases toward the East. Vertical velocity data field 1413 is an 8-bit field, which indicates the vertical velocity of the mobile node. Vertical velocity data field 1413 is used if field 1409 is set to ‘1’. Horizontal velocity data field 1415 is a 16-bit field that indicates the horizontal velocity of the mobile node.
If velocity indicator is set to ‘1’, this field is in use. Once used, the horizontal speed is set in units of 0.25 m/s, in the range from 0 to 511.75 m/s. Otherwise this field is ignored.
LocUncH indicator data field 1417 is a 1-bit field which indicates the horizontal position uncertainty, including elliptical. If elliptical horizontal position uncertainty information is included in this response element, this field is set to ‘1’. Otherwise, this field is set to ‘0’. LocUnc angle data field 1419 (angle of axis of the standard error ellipse for horizontal position uncertainty) is a 8-bit field indicating the angle of axis of the standard error ellipse for horizontal position uncertainty. If LocUncH indicator field 1417 is set to ‘0’, this field is ignored.
Otherwise, this field is included and is set to angle of axis for horizontal position uncertainty, in units of 5.625 degrees, in the range from 0 to 84.375 degrees, where 0 degrees is True North and the angle increases toward the East. LocUnc A data field 1421 (standard deviation of error along angle specified for horizontal position uncertainty) is a 8-bit field indicating the Standard deviation of error along angle specified for horizontal position uncertainty. If LocUnc A data field 1421 is set to ‘0’, this field is ignored. Otherwise, this field is included and is set to represent the standard deviation of the horizontal position error along the axis corresponding to LocUnc angle data field 1419.
LocUnc P data field 1423 (standard deviation of error along angle specified for horizontal position uncertainty) is a 8-bit field indicating standard deviation of error along angle specified for horizontal position uncertainty. If LocUnc P data field 1423 is set to ‘0’, this field is ignored. Otherwise, this field is included and is set to represent the standard deviation of the horizontal position error perpendicular to the axis corresponding to LocUnc angle data field 1419. LocUnc vertical data field 1425 (standard deviation of vertical error for position uncertainty) is a 8-bit field indicating standard deviation of vertical error for position uncertainty.
VelUnc angle data field 1427 (angle of axis of standard error ellipse for horizontal velocity uncertainty) is a 8-bit field indicating the angle of axis of standard error ellipse for horizontal velocity uncertainty. If VelUnc angle data field 1427 is set to ‘0’, this field is ignored. Otherwise, this field is set to the angle of axis for horizontal velocity uncertainty, in units of 5.625 degrees, in the range from 0 to 84,375 degrees, where 0 degrees is True North and the angle increases toward the East. VelUnc A data field 1429 (standard deviation of error along angle specified for horizontal velocity uncertainty is a 8-bit field indicating standard deviation of error along angle specified for horizontal velocity uncertainty.
If velocity indicator data field 1409 is set to ‘1’, this field is included and is set to represent the standard deviation of the horizontal velocity error along the angle corresponding to VelUnc angle data field 1427. VelUnc P data field data field 1431 (standard deviation of error perpendicular to angle specified for horizontal velocity uncertainty) is a 8-bit field indicating standard deviation of error perpendicular to angle specified for horizontal velocity uncertainty. If velocity indicator data field 1409 is set to ‘1’, this field is included and is set to represent the standard deviation of the horizontal velocity error perpendicular to the angle corresponding to VelUnc angle data field 1427.
Otherwise, this field is ignored. VelUnc vertical data field 1433 (standard deviation of vertical velocity error) is an 8-bit field indicating the standard deviation of vertical velocity error. CCI may also be stored as individual bitmaps in a multi-cell map, or simply stored as individual files in memory or a file system.
Aspects of the invention provide that CCI may be stored using either one of two principles, although one skilled in the art will recognize that additional forms of cell coverage information may be used. Principle I data 1505 includes cell coverage data that has been analyzed and formatted into a bitmap or similar format, and includes cell coverage metadata. Principle I includes CCI stored in the previously described CDT table format. Principle II data 1506 includes raw point cell coverage data in the form of point locations (e.g., latitude and longitude) coupled with signal strengths (e.g., dBm).
Either form of cell coverage information may be stored and used by mobile terminal 101, although Principle II data 1506 requires more processing in order to be useful in handover decisions. Mobile terminal 101 may include multiple forms of reception and transmission functionality. Although three particular functions are shown, more or less may be used to take advantage of embodiments of the invention. GPS 1502 relies on signals received from satellites to determine the latitude and longitude of the mobile terminal\'s current location. Other positioning systems may provide alternatives to GPS 1502, including assisted GPS (AGPS).
RF component 1503 may be used to receive a primary signal of interest, for example a DVB-T/H broadcast signal. Mobile terminal 101 may, in addition to using CCI to find the strongest signal, may create its own Principle II CCI, recording location and signal strength throughout the cell coverage area. Other wireless components (not shown) may use short range radio or optical standards to communicate with nearby devices. For example, Bluetooth, WiFi, RFID, IrDA, Ultra-wideband (UWB) or another short range wireless communication standard may be used. Conventional mid to long range signalling such as cellular system 1504 can also be useful in sending and receiving CCI.
Cellular system 1504 may share resources and functionality with RF system 1503. In order to effectively utilize CCI, a mobile terminal 101 may be able to maintain data about multiple cells simultaneously. By examining surrounding cell coverage, and predicting the direction and speed of motion, mobile terminal 101 can perform handover operations that maintain continuous coverage and are less likely to fade. One method of maintaining data about multiple cells is to combine Principle I bitmap data into one large dynamic cell coverage map and tracking location and velocity of mobile terminal 101 on the map. 16A depicts mobile terminal 101 moving along vector 102 through a group of cell signals defined using bitmap cell coverage information according to one or more aspects of an embodiment of the invention. Mobile terminal 101 is leaving cell 1603 and must select a destination cell for a handover from among cell 1601 or cell 1602, or possibly even unknown cell 1610.
By using the map, mobile terminal 101 can predict its immediate destination and determine that it does not have Principle I CCI for the empty portion of unknown cell 1603. Mobile terminal 101 may be able to infer coverage if it had Principle II raw coverage points within the missing cell, but such calculations would require more time and processing power. 17 depicts a mobile terminal in communication with a selection of devices according to one or more aspects of an embodiment of the invention. Here, mobile terminal 101 needs missing CCI for a particular cell or geographic location, and it checks a series of potential sources, although not necessarily in the order set forth below. One possible source of CCI data is the broadcast stream coming from broadcast transmitter 1701, along path A. The signal delivered by transmitter 1701 (e.g., a DVB-T/H signal) may include Principle I CCI data for the current and neighboring cells. This CCI is sourced from cell coverage information center 1705, which includes server 1703 (or more likely multiple servers) and cell coverage database 1704 (CCD).
If the broadcast signal does not have the desired CCI, mobile terminal 101 may attempt to sense other mobile terminals, using a wireless communication scheme, such as Bluetooth, WiFi, IrDA, UWB, or some other ad hoc signaling method that allows peer-to-peer communications. Here, both mobile terminals 1605 and 1606 may be within range. Path B represents a wireless conversation between mobile terminal 101 and smaller mobile terminal 1605. Although mobile terminal 1605 may contain CCI for the cell in question, it may be of the wrong class, since the devices have different viewing dimensions and sizes.
(Class of signal may also depend on factors such as installed plug-ins, size of memory, and so forth) As such, the signal strengths in the memory of smaller mobile terminal 1605 may be of no use, since it actually receives a different signal than larger terminal 101. Path C represents a wireless conversation between mobile terminal 101 and similar mobile terminal 1606. If mobile terminal 1606 has the data desired, it can respond with the appropriate signaling item, such as a CDT table. If mobile terminal 1606 does not have the data, it may be able to provide mobile terminal 101 with a location for the information. For example, mobile terminal 1606 may be able to provide an IP address, username and password from which mobile terminal 101 can transfer the data (via PPP, FTP, HTTP, etc.).
Although not shown, mobile terminal 101 may communicate with another mobile terminal using a cellular data call, via the Internet, via SMS, or via some other indirect communication method. Messages to mobile terminals may also be sent via a broadcast network, such as a DVB-T/H network, where incoming messages are sent to the DVB-T/H network via SMS, MMS, Internet connection, or ad hoc signaling systems. These incoming messages are then forwarded via the broadcast signal to a recipient mobile terminal. If other mobile terminals do not have the cell coverage information sought, other communication routes may be available to mobile terminal 101. Path D represents a cellular conversation between mobile terminal 101 and cell coverage center 1705 via cell tower 1702.
Mobile terminal 101 may be able to make a data call, and download the proper CCI directly. Path E represents a conversation (either wired or wireless) between mobile terminal 101 and cell coverage center 1705 via a network 1706, such as the Internet or an intranet. A wireless conversation may take place via a cellular system or a WiFi connection. A wired conversation may take place via a sync cable or other direct connection with a computer or a network. As before, mobile terminal 101 may be able to download the proper CCI directly, perhaps using an IP address, username, and password previously provided by mobile terminal 1606. Other methods of communication between mobile terminal 101 and cell coverage information center 1705 are conceivable, both wired and wireless.
18 depicts mobile terminal 101 in communication with similar mobile terminal 1606 and CCI server 1703 according to one or more aspects of an embodiment of the invention. Turning now to the specific messages of conversations between mobile terminal 101 and other devices. Beginning with communication between mobile terminal 101 and similar mobile terminal 1606, the method of communication is not relevant, whether wireless, via the Internet, via broadcast, etc.
Assuming communication is possible using one of these methods, the individual messages are now in the spotlight. Message A represents an initial query or discovery, referred to as a CCI Discovery message. The components of the message are set forth in the table below.TABLE 3 CCI Discovery Message Field Name Description CCI Message Indicates the Type of Message: CCI Discovery Type CCI Discovery Indicates the desired CCI discovery method.
If the Method method requested is not available in the receiving terminal, then no method is indicated in the reply. Terminal Class Indicates the class of the requesting terminal. If the class of the receiving terminal does not match, then a “not available” status is provided in the reply.
Sending terminal can set this field to “any class” to prevent filtering. Geographical Contains the geographical range for the requested CCI Range metadata. “Not available” is sent in the reply if the receiving terminal has no CCI metadata for the given geographical range. The CCI Discovery message is received by mobile terminal 1606, which then replies with a standardized reply, Message B, also known as a CCI Reply. The components of this message are set forth below.TABLE 4 CCI Reply (to Discovery) Message Field Name Description CCI Message Indicates the Type of Message: CCI Reply Type Reply Type Indicates the type of the reply (i.e., whether it is a reply to a CCI Discovery or a CCI Request). CCI Type Indicates the types of CCI (e.g., Principle I, Principle II, CDT, etc.) that are available on the replying terminal, depending on discovery parameters.
Terminal Class Indicates the class of CCI metadata available on the replying terminal (e.g. Screen resolution, needed plugins, etc), depending on discovery parameters.
Geographical Contains the geographical range available on the Range replying terminal. “Not available” is sent in the reply if the replying terminal has no CCI metadata for the geographical range depending on discovery parameters. CCI Discovery Informs of parameters (e.g., IP address, user, password, Info and port) leading to the requested data on another device.
Once the reply to the discovery message is received, mobile terminal 101 may make a specific request, assuming similar mobile terminal 1606 had CCI metadata within the range sought by the discovery. Message C, also known as a CCI Request, is broken down below.TABLE 5 CCI Request Message Field Name Description CCI Message Indicates the Type of Message: CCI Request Type CCI Type Indicates the CCI type requested (e.g., Principle I, Principle II, CDT, etc.). Can also be set to “any type”, where priority is given to a particular type, but other types are acceptable if the primary is not available. Terminal Class Indicates the class of the requesting terminal (e.g.
Screen resolution, needed plugins, etc). If the class of the requesting and receiving terminals don\'t match, then “not available” status is provided in the reply. If the requesting terminal doesn\'t care about class, it can put an “any class” indicator in this field. Geographical Contains the geographical range available on the Range replying terminal. “Not available” is sent in the reply if the replying terminal has no CCI metadata for the geographical range depending on discovery parameters. Upon receiving the CCI Request, the receiving terminal 1606 responds with Message D, another CCI Reply, the components of which are set forth below.TABLE 6 CCI Reply (to Request) Message Field Name Description CCI Message Indicates the Type of Message: CCI Reply Type Reply Type Indicates the type of the reply (i.e., whether it is a reply to a CCI Discovery or a CCI Request). CCI Type Indicates the type of CCI (e.g., Principle I, Principle II, CDT, etc.) provided in this response.
Terminal Class Indicates the class of CCI metadata provided in the repsonse (e.g. Screen resolution, needed plugins, etc). Geographical Contains the geographical range provided in the Range response.
CCI Data The CCI data. To perform this operation, mobile terminal 101 uses a CCI Push message (Message F) to push the data to server 1703, where it can be stored, analyzed, converted to Principle I data, and forwarded to other mobile terminals. The substance of a CCI Push message is set forth below.TABLE 7 CCI Push Message Field Name Description CCI Message Indicates the Type of Message: CCI Push Type CCI Type Indicates the type of CCI (e.g., Principle I, Principle II, CDT, etc.) provided in this push, or that is available with CCI discovery parameters.
Terminal Class Indicates the class of CCI metadata provided in the push (e.g. Screen resolution, needed plug-ins, etc) or available with CCI discovery parameters. Geographical Contains the geographical range provided in this push, Range or available with CCI discovery parameters. CCI Discovery If this is a reply to a CCI discovery, informs of Info parameters (e.g., IP address, user, password, and port) for the CCI discovery.
Otherwise, field is left out. CCI Data The CCI data. 19 illustrates a process for issuing a cell coverage information request according to one or more aspects of an embodiment of the invention. At step 1901, available receivers, such as DVB-T/H receivers, are sought, whether via direct connections, such as ad hoc wireless standards, or via Internet or other indirect connections. If no receivers are available at decision 1902, then a timer is set for a specific period of time at step 1903. When the timer expires, control returns to step 1901, again seeking available receivers. If receivers, such as other mobile terminals, are available, then a CCI Discovery or CCI Request can be forwarded to the receiving device.
20 illustrates a process for issuing a cell coverage information reply according to one or more aspects of an embodiment of the invention. At step 2001, a listener is set up to wait for incoming CCI Discoveries or CCI Requests.
If no requests are forthcoming, at decision 2002, then control returns to step 2001. If a request is received, then processing of the request is handled at step 2003.
If the incoming message is a discovery, the appropriate information is assembled, and if the message is a request, likewise that information is assembled. At step 2004, the CCI Reply is transmitted back to the requesting terminal. 21 illustrates a process for issuing a cell coverage information push according to one or more aspects of an embodiment of the invention. At decision 2101, if a connection is needed, the server connection is created at step 2102. If the connection is successful at decision 2103, then at step 2104, the appropriate CCI data and metadata and/or discovery information are sent as a CCI Push. If no connection was needed at decision 2101, then step 2104 assembles the CCI Push in the same fashion. Once the CCI Push is issued, or if the connection attempt failed, control terminates normally.
While aspects of the invention have been described with respect specific examples, including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and techniques that fall within the spirit and scope of the invention as set forth in the appended claims. Aspects of the invention may also be used in other forms of wireless cellular networks, including digital video broadcasting (DVB), and in cellular telephony.Claims ( 20). A processor, configured to perform the steps of receiving cell coverage information via the receiver, storing at least the bitmap model of cell signal strengths in the memory, determining a travel vector based on changes in the longitude and latitude of the mobile terminal over time, and determining a destination cell for a handover based on the travel vector and at least the bitmap model of cell signal strengths.
...'>Specificindirecteffects Plugin Estimands Amos 23 Free Downlloads(23.03.2020)AMOSAMOS is statistical software and it stands for analysis of a moment structures. AMOS is an added module, and is specially used for,. It is also known as analysis of covariance or causal modeling software. AMOS is a visual program for structural equation modeling (SEM). In AMOS, we can draw models graphically using simple drawing tools.
Spss22.0全称ibmspssstatistics 22，它虽然不是最新版的，但是它却可以说是该系列软件中最受欢迎的一款了。它可以前的版本一样，都是在刻个科学技术领域发挥着数据挖掘、预测分析、统计学分析运算的功能，但是和以前的版本相比它有新增加了倾向值分析、个案控制匹配等几项全新的分析方法，采用. An apparatus and methods are provided for sharing cell coverage information among devices in a cell network. Cell coverage information includes bitmap models of signal strength to enable intelligent handover decisions. Mobile terminals are able to receive cell coverage information over a broadband unidirectional broadcast network, such as a digital video broadcast network.
AMOS quickly performs the computations for SEM and displays the results.In calculation of coefficients, AMOS uses the following methods:. Maximum likelihood.
Unweighted least squares. Generalized least squares. Browne’s asymptotically distribution-free criterion. Scale-free least squaresConstruction of model in AMOS:First, we have to run AMOS. By clicking the “start” menu and selecting the “AMOS graphic” option, we can run the program. The moment AMOS starts running, a window appears called the “AMOS graphic.” In this window, we can manually draw our SEM model. Attaching Data: By selecting a file name from the data file option, we can attach data in AMOS for.
US1A1 - Methods and apparatus for sharing cell coverage information- Google Patents US1A1 - Methods and apparatus for sharing cell coverage information- Google Patents Methods and apparatus for sharing cell coverage informationInfo Publication number US1A1 US1A1 US11/064,934 US6493405A USA1 US 1 A1 US1 A1 US 1A1 US 6493405 A US6493405 A US 6493405A US A1 US A1 US A1 Authority US United States Prior art keywords cell mobile terminal cell coverage coverage information cci Prior art date 2004-02-27 Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) Granted Application number US11/064,934 Other versions Inventor Jani Vare Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)Nokia OyjOriginal Assignee Nokia Oyj Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.) 2004-02-27 Filing date 2005-02-25 Publication date 2005-02-27 Priority to US54873504P priority Critical 2005-02-25 Application filed by Nokia Oyj filed Critical Nokia Oyj 2005-02-25 Priority to US11/064,934 priority patent/US7369861B2/en 2005-02-25 Assigned to NOKIA CORPORATION reassignment NOKIA CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). An apparatus and methods are provided for sharing cell coverage information among devices in a cell network. Cell coverage information includes bitmap models of signal strength to enable intelligent handover decisions.
Mobile terminals are able to receive cell coverage information over a broadband unidirectional broadcast network, such as a digital video broadcast network. They are also able to receive cell coverage information from other mobile terminals via ad hoc wireless signalling.
Mobile terminals are also able to store and upload raw signal measurements to a cell coverage information center. Handover decisions for mobile terminals traveling through a wireless network are typically made based on factors such as cell coverage, mobile terminal location and terminal movement information. Mobile terminals include a variety of electronic devices, including cellular phones, mobile digital video broadcast (DVB) receivers, pagers, personal digital assistants, laptop computers, automobile computers, portable video players, and other devices which may move among multiple cells and which include equipment for receiving signals from a wireless network.
In addition to DVB receivers, mobile terminals may include mobile receivers of other digital unidirectional broadband broadcast systems. With a first conventional approach, handover decisions are based on location, cell coverage area and terminal movement vector information. The mobile terminal has means to know its exact location (e.g., GPS, AGPS) and measure the signal strength from available signals. 1 shows a mobile terminal 101 in the crossroads of cell signals A, B, and C, each of which is depicted by a border showing the outer reaches of a single minimum signal level. The movement and velocity of mobile terminal 101 is described by vector 102. Mobile terminal 101 is able to receive any of signals A, B, and C.
If mobile terminal 101 is presently receiving either signals B or C, then it executes a handover to signal A in order to continue reception of a signal in the future, assuming the same course and speed. 2 depicts a spherical rectangle 201 representation of cell signal A as used by some technical specifications, such as the Digital Video Broadcast (DVB) system. For cell signal A, spherical rectangle has a reference corner 202, typically located at the southwest corner of the rectangle. Reference corner 202 is specified by a specific longitude and latitude, or some other geographic designation. Call of chernobyl tool locations.
The extent of longitude 203 and the extent of latitude 204 describe the length and height of the bounding rectangle, which is sized to encompass the cell signal. The values associated with extents 203 and 204 are in the form of degrees, minutes and seconds, or spherical or planar vectors, or some other representation having a magnitude. While permitting relatively simple handoff calculations, the use of spherical rectangles is likely to be fraught with inaccuracies. 3 illustrates how the cell signals of FIG. 1 may be modeled using the conventional approach depicted in FIG. The cells are assumed to provide the same signal strength within rectangular areas.
Based on information provided to mobile terminal 101, the mobile terminal will either perform a handover to cell B, or keep the signal of cell B if already active. Given the signal strength of cell B in FIG. 1, such a determination is poor because of inaccurate cell signal representation, and a signal may be lost.
Although only a few shades are used to represent signal strengths, the infinite range of signal strengths varies depending on environmental conditions within the coverage area and other factors. Under a conventional approach, mobile terminal 101 will make a poor assumption selecting cell C as a handover destination from cell B.
Although cell C fully encompasses mobile terminal 101 moving along vector 102, the signal strength will decay if the mobile terminal maintains a connection to cell C. If the reception sensitivity of mobile terminal 101 were to be taken into account, the optimal choice in a handover situation would be to cell A, based on actual signal strengths. It should be noted that the Applicant is not suggesting that varying levels of signal strength have been used in conjunction with prior art handover procedures. With a second conventional approach, handover decisions are made based on a location determination that is estimated using signal strength information and cell coverage information. With this approach, a mobile terminal is not aware of its location (e.g., doesn\'t have a GPS system). 5 illustrates an example of this basic method utilizing only cell shape information (i.e., only one signal level used). Here, because mobile terminal 101 is able to detect signals from both cell A and cell C, it is able to determine that it is somewhere within shaded region 501.
6 depicts a similar method to detect approximate location using spherical rectangles. Here again, because signals from both cell A and cell C are detected, mobile terminal 101 is able to determine that it is somewhere within shaded area 601. Either method, while facilitating handover decisions, do so in a highly inaccurate manner, since the precise location within the shaded region is unknown. One or more of the above-mentioned needs in the art are satisfied by the disclosed methods and systems. Free field three dimensional models of signal levels may be created for a group of cells.
In one embodiment, the models are in the form of bitmaps. A mobile terminal can determine the inner area within the cell where it is located, based on the measured signal strength and maximum signal strength value (depending on the antenna sensitivity of the receiver and calibrated ‘free field’ signal strength) indicated in the bitmap information. This information may be used to execute handover procedures.
Aspects of the invention provide increased accuracy with respect to presenting the shape and quality of service in a cell. Embodiments of the invention provide systems and methods for distributing, receiving and sharing cell coverage information. In aspects of some embodiments, raw cell coverage data is measured by mobile terminals, identifying minimally a geographic location and signal strength. Raw cell coverage data may be used to calculate models of cell coverage information, including bitmaps. Raw cell coverage information and/or cell coverage models may be distributed using broadcast systems, shared by other mobile terminals, downloaded from the Internet, or otherwise sent and received among electronic devices.BRIEF DESCRIPTION OF THE DRAWINGS. In accordance with aspects of the invention, there is provided real-life free field three-dimensional plane models of signal levels existing for a given radio cell.
The models are developed in a well-defined area of adjustable size and resolution. Embodiments of the invention provide a signaling method which can be used to improve mobility in cell networks, including DVB-T/H networks. Specifically, determination and signaling of the coverage area of a cell, including the size of the cell and its location. Bitmap models of cell coverage may be created based on measurements of signal strength taken within the area of a cell.
7A shows a set of measurements of signal strength taken within a cell coverage area 701 according to one or more aspects of an embodiment of the invention. The signal strength values may be received from one or more terminals which may be mobile or remain in a fixed location. The received strength values are analyzed, for example statistically compared to values provided by other terminals and other measurement devices. The values are recorded as geographic locations, possibly using conventional longitude and latitude, along with signal strengths, possibly measured in decibels referenced to one milliwatt (dBm). Although the measured strength values shown in the figure are depicted as having only three signal levels (no/weak/strong), in certain embodiments the measured values may fall into a much broader range. The range of values could then be categorized using ranges. The number of ranges depends on several factors, including the desired size of the data file, the total extent of the range of values, and the need for more detailed strength measurements when making handover decisions.
In the case of a bitmap data file, the number of ranges (or colors) can greatly affect the size of the file. One signal strength would require one bit per pixel (0=no signal, 1=signal). Three signal strengths would require two bits per pixel (00=no signal, 01=weak signal, 10=average signal, 11=strong signal). Additional signal strengths would require additional bits, and subsequently increase the size of a data file such as a bitmap. Once regions are determined, a cell unit grid is effectively used to break the larger, more detailed interpolated cell coverage regions into a smaller, more manageable bitmap file.
For example, as shown in FIG. 7A, if the original cell coverage area was three kilometers by three kilometers, and the final bitmap file was set to have an area of 150 pixels by 150 pixels, then each pixel would represent 400 square meters (20 m by 20 m) (calculated by 9,000,000 m 2/22,500 pixels). The cell unit grid does not necessarily need squares or rectangles to break down cell coverage.
It may also use triangles or hexagons. When multiple regions intersect a particular cell unit, the pixel value may be decided by determining which region predominates within the cell unit. 8A and 8B show examples of mapping differently shaped signal coverage areas into bitmaps according to one or more aspects of an embodiment of the invention. 8A, cell coverage area 801 is mapped into cell unit grid 811.
8B, cell coverage area 802 is mapped into cell unit grid 812. For cell unit grids 811 and 812, depending on the size of their respective cell coverage areas 801 and 802, as well as other previously mentioned factors, each cell unit may encompass larger or smaller areas. In addition, the number of signal strength ranges may be varied as well. For example, cell unit grid 811 only uses two signal levels, whereas cell unit grid 812 uses three signal levels. When a mobile terminal receives bitmaps of cell coverage areas, it is able to make educated handover decisions with additional detail.
Rather than working with bulky rectangles, a mobile terminal works with highly detailed data files, perhaps in the form of bitmaps. In addition to being able to make more educated handover decisions, a mobile terminal lacking a GPS or other positioning system is able to make better guesses about its exact location. 9 depicts mobile terminal 101 moving in direction 102 is able to determine that it is somewhere within shaded region 901. This is based on being able to receive the stronger signal from Cell A at the same time as receiving the weaker signal from Cell C and knowing the boundaries of the stronger and weaker signals. Versionnumber: This 5-bit field is the version number of the sub-table. The versionnumber shall be incremented by 1 when a change in the information carried within the subtable occurs.
When it reaches value 31, it wraps around to 0. When the currentnextindicator is set to ‘1’, then the versionnumber shall be that of the currently applicable subtable defined by the tableid, platformid and actiontype. When the currentnextindicator is set to ‘0’, then the versionnumber shall be that of the next applicable subtable defined by the tableid, platformid and actiontype. 10 depicts a process for generating a cell description table or any other signaling item and transmitting it according to one or more aspects of an embodiment of the invention. In step 1001, the free field signal strengths for a particular cell are measured using either mobile or stationary devices. The devices may include mobile terminals capable of consuming cell signal content, and may also include dedicated measurement devices.
In step 1002, the measured strengths are converted into cell coverage bitmaps, such as described above. In step 1003, an entry in a cell description table is created for the cell, including within it metadata about the cell and its bitmap representation, as well as the bitmap itself. And in step 1004, the generated signaling item, such as the entry in the cell description table is transmitted for storage or use by mobile terminals. 11 shows a high level description of a process for bitmap information creation according to one or more aspects of an embodiment of the invention. Here, a computing unit 1101 resides within a mobile terminal, or within a server or other computing device. Computing unit 1101 takes input data 1102 about a cell coverage area, for example measurements of signal strength taken at various points around the cell.
Computing unit uses configuration parameters 1103 in transforming the input data into a data file 1104 representation of the cell coverage area, perhaps in the form of a bitmap. Configuration parameters 1103 may include the number of signal strength ranges that should be used, the size and shape of the cell units used to model the cell, and other relevant parameters which effect the creation of data file 1104. 12 shows one possible process for generating and transmitting a cell description table to a mobile terminal in a DVB network according to one or more aspects of an embodiment of the invention. Data file 1201, residing in server 1202, is used to create an entry in a CDT table 1203. Data file 1201 is made up of a bitmap file, or other file capable of providing cell unit strength values in a similar fashion. CDT table 1203, including one or more cell entries, is passed to multiplexer 1204 in a digital video broadcast network (DVB).
Multiplexer 1204 combines CDT tables with other digital content for broadcast as MPEG-TS transport streams from transmission station 1205. 13 shows a process for receiving a cell description table from a DVB network, parsing it, and using it in a mobile terminal according to one or more aspects of an embodiment of the invention. At step 1301, a mobile terminal receives a DVB-H/T signal including digital video broadcast content, as well as at least one signaling item, such as a CDT table entry. At step 1302, the mobile terminal parses the bitmap information from the signaling item received. At step 1303, a map of the cell coverage area is created, and optionally overlaid with other maps of surrounding cells. Adjustments may need to be made to the newly received map in order to integrate it into the multi-cell map, such as accounting for disparities in strength ranges and cell unit scales (in the case of a CDT type signaling item, these values may be parsed from the CDT metadata). At step 1304, signal availability is determined based on the multi-cell map created, and by analyzing movement of the device through space.
Finally, at step 1305, this information is used to make educated cell choices when needing to make a handover to an adjacent cell. Other methods for using signaling items such as a cell coverage bitmap to make educated cell handover decisions are available. 14 depicts a data structure for expressing vector information (e.g., vector 102 in FIG.
4), according to one or more aspects of an embodiment of the invention. Datagram 1400 comprises header information 1401 (such as the source IP address and the destination address) and data payload 1437. Also, datagram 1400 comprises geographical position information about a source device corresponding to a option type data field 1440, an option length data field 1441, a reserved data field 1449, a version data field 1451, a datum data field 1453, a latitude data field 1403, a longitude data field 1405, an altitude data fields 1407 and 1439, velocity data fields 1409, 1411, 1413, and 1415, location uncertainty data fields 1417, 1419, 1421, 1423, and 1425, velocity uncertainty data fields 1427, 1429, 1431, and 1433, and time data field 1435. Time data field 1435 is a 40-bit field that contains the current time and data in Coordinated Universal Time (UTC) and Modified Julian Date (MJD). Field 1435 is coded as 16 bits providing 16 LSBs of the MJD followed by 24 bits that represent 6 digits in a 4-bit Binary-Coded Decimal (BCD). In the exemplary embodiment, the geographical information is contained in a destination options header or in a hop-by-hop header, in compliance with RFC 2460. In the embodiment, a destination options header and a hop-by-hop header may be contained in the same datagram.
In the exemplary embodiment, version data field 1451 is an 8-bit field that indicates the version of the message header. Datum data field 1453 is an 8-bit field that indicates the used map datum (e.g., standard MIL-STD-2401) for determining the geographical position. Latitude data field 1403 is a 32-bit field that indicates the latitude value of the source device (e.g., corresponding to an approximate location of terminal node 107) presented in ANSI/IEEE Std 754-1985 format. Longitude data field 1405 is a 32-bit field that indicates the longitude value of the source device presented in ANSI/IEEE Std 754-1985 format. Alt indicator data field 1439 is a 1-bit field indicating the use of altitude information. Altitude data field is a 16-bit field that indicates the altitude value of the source device presented in ANSI/IEEE Std 754-1985 format.
Velocity indicator data field 1409 is a 1-bit field indicating the use of velocity information. If velocity information is included, this field is set to ‘1’. Otherwise this field is set to ‘0’. Heading data field 1411 is a 16-bit field that indicates the direction where the mobile node is moving.
If velocity indicator data field 1409 is set to ‘0’, this field is ignored. Otherwise, this field is included and is set to the angle of axis of horizontal velocity uncertainty, in units of 5.625 degrees, in the range from 0 to 84,375 degrees, where 0 degrees is True North and the angle increases toward the East. Vertical velocity data field 1413 is an 8-bit field, which indicates the vertical velocity of the mobile node. Vertical velocity data field 1413 is used if field 1409 is set to ‘1’. Horizontal velocity data field 1415 is a 16-bit field that indicates the horizontal velocity of the mobile node.
If velocity indicator is set to ‘1’, this field is in use. Once used, the horizontal speed is set in units of 0.25 m/s, in the range from 0 to 511.75 m/s. Otherwise this field is ignored.
LocUncH indicator data field 1417 is a 1-bit field which indicates the horizontal position uncertainty, including elliptical. If elliptical horizontal position uncertainty information is included in this response element, this field is set to ‘1’. Otherwise, this field is set to ‘0’. LocUnc angle data field 1419 (angle of axis of the standard error ellipse for horizontal position uncertainty) is a 8-bit field indicating the angle of axis of the standard error ellipse for horizontal position uncertainty. If LocUncH indicator field 1417 is set to ‘0’, this field is ignored.
Otherwise, this field is included and is set to angle of axis for horizontal position uncertainty, in units of 5.625 degrees, in the range from 0 to 84.375 degrees, where 0 degrees is True North and the angle increases toward the East. LocUnc A data field 1421 (standard deviation of error along angle specified for horizontal position uncertainty) is a 8-bit field indicating the Standard deviation of error along angle specified for horizontal position uncertainty. If LocUnc A data field 1421 is set to ‘0’, this field is ignored. Otherwise, this field is included and is set to represent the standard deviation of the horizontal position error along the axis corresponding to LocUnc angle data field 1419.
LocUnc P data field 1423 (standard deviation of error along angle specified for horizontal position uncertainty) is a 8-bit field indicating standard deviation of error along angle specified for horizontal position uncertainty. If LocUnc P data field 1423 is set to ‘0’, this field is ignored. Otherwise, this field is included and is set to represent the standard deviation of the horizontal position error perpendicular to the axis corresponding to LocUnc angle data field 1419. LocUnc vertical data field 1425 (standard deviation of vertical error for position uncertainty) is a 8-bit field indicating standard deviation of vertical error for position uncertainty.
VelUnc angle data field 1427 (angle of axis of standard error ellipse for horizontal velocity uncertainty) is a 8-bit field indicating the angle of axis of standard error ellipse for horizontal velocity uncertainty. If VelUnc angle data field 1427 is set to ‘0’, this field is ignored. Otherwise, this field is set to the angle of axis for horizontal velocity uncertainty, in units of 5.625 degrees, in the range from 0 to 84,375 degrees, where 0 degrees is True North and the angle increases toward the East. VelUnc A data field 1429 (standard deviation of error along angle specified for horizontal velocity uncertainty is a 8-bit field indicating standard deviation of error along angle specified for horizontal velocity uncertainty.
If velocity indicator data field 1409 is set to ‘1’, this field is included and is set to represent the standard deviation of the horizontal velocity error along the angle corresponding to VelUnc angle data field 1427. VelUnc P data field data field 1431 (standard deviation of error perpendicular to angle specified for horizontal velocity uncertainty) is a 8-bit field indicating standard deviation of error perpendicular to angle specified for horizontal velocity uncertainty. If velocity indicator data field 1409 is set to ‘1’, this field is included and is set to represent the standard deviation of the horizontal velocity error perpendicular to the angle corresponding to VelUnc angle data field 1427.
Otherwise, this field is ignored. VelUnc vertical data field 1433 (standard deviation of vertical velocity error) is an 8-bit field indicating the standard deviation of vertical velocity error. CCI may also be stored as individual bitmaps in a multi-cell map, or simply stored as individual files in memory or a file system.
Aspects of the invention provide that CCI may be stored using either one of two principles, although one skilled in the art will recognize that additional forms of cell coverage information may be used. Principle I data 1505 includes cell coverage data that has been analyzed and formatted into a bitmap or similar format, and includes cell coverage metadata. Principle I includes CCI stored in the previously described CDT table format. Principle II data 1506 includes raw point cell coverage data in the form of point locations (e.g., latitude and longitude) coupled with signal strengths (e.g., dBm).
Either form of cell coverage information may be stored and used by mobile terminal 101, although Principle II data 1506 requires more processing in order to be useful in handover decisions. Mobile terminal 101 may include multiple forms of reception and transmission functionality. Although three particular functions are shown, more or less may be used to take advantage of embodiments of the invention. GPS 1502 relies on signals received from satellites to determine the latitude and longitude of the mobile terminal\'s current location. Other positioning systems may provide alternatives to GPS 1502, including assisted GPS (AGPS).
RF component 1503 may be used to receive a primary signal of interest, for example a DVB-T/H broadcast signal. Mobile terminal 101 may, in addition to using CCI to find the strongest signal, may create its own Principle II CCI, recording location and signal strength throughout the cell coverage area. Other wireless components (not shown) may use short range radio or optical standards to communicate with nearby devices. For example, Bluetooth, WiFi, RFID, IrDA, Ultra-wideband (UWB) or another short range wireless communication standard may be used. Conventional mid to long range signalling such as cellular system 1504 can also be useful in sending and receiving CCI.
Cellular system 1504 may share resources and functionality with RF system 1503. In order to effectively utilize CCI, a mobile terminal 101 may be able to maintain data about multiple cells simultaneously. By examining surrounding cell coverage, and predicting the direction and speed of motion, mobile terminal 101 can perform handover operations that maintain continuous coverage and are less likely to fade. One method of maintaining data about multiple cells is to combine Principle I bitmap data into one large dynamic cell coverage map and tracking location and velocity of mobile terminal 101 on the map. 16A depicts mobile terminal 101 moving along vector 102 through a group of cell signals defined using bitmap cell coverage information according to one or more aspects of an embodiment of the invention. Mobile terminal 101 is leaving cell 1603 and must select a destination cell for a handover from among cell 1601 or cell 1602, or possibly even unknown cell 1610.
By using the map, mobile terminal 101 can predict its immediate destination and determine that it does not have Principle I CCI for the empty portion of unknown cell 1603. Mobile terminal 101 may be able to infer coverage if it had Principle II raw coverage points within the missing cell, but such calculations would require more time and processing power. 17 depicts a mobile terminal in communication with a selection of devices according to one or more aspects of an embodiment of the invention. Here, mobile terminal 101 needs missing CCI for a particular cell or geographic location, and it checks a series of potential sources, although not necessarily in the order set forth below. One possible source of CCI data is the broadcast stream coming from broadcast transmitter 1701, along path A. The signal delivered by transmitter 1701 (e.g., a DVB-T/H signal) may include Principle I CCI data for the current and neighboring cells. This CCI is sourced from cell coverage information center 1705, which includes server 1703 (or more likely multiple servers) and cell coverage database 1704 (CCD).
If the broadcast signal does not have the desired CCI, mobile terminal 101 may attempt to sense other mobile terminals, using a wireless communication scheme, such as Bluetooth, WiFi, IrDA, UWB, or some other ad hoc signaling method that allows peer-to-peer communications. Here, both mobile terminals 1605 and 1606 may be within range. Path B represents a wireless conversation between mobile terminal 101 and smaller mobile terminal 1605. Although mobile terminal 1605 may contain CCI for the cell in question, it may be of the wrong class, since the devices have different viewing dimensions and sizes.
(Class of signal may also depend on factors such as installed plug-ins, size of memory, and so forth) As such, the signal strengths in the memory of smaller mobile terminal 1605 may be of no use, since it actually receives a different signal than larger terminal 101. Path C represents a wireless conversation between mobile terminal 101 and similar mobile terminal 1606. If mobile terminal 1606 has the data desired, it can respond with the appropriate signaling item, such as a CDT table. If mobile terminal 1606 does not have the data, it may be able to provide mobile terminal 101 with a location for the information. For example, mobile terminal 1606 may be able to provide an IP address, username and password from which mobile terminal 101 can transfer the data (via PPP, FTP, HTTP, etc.).
Although not shown, mobile terminal 101 may communicate with another mobile terminal using a cellular data call, via the Internet, via SMS, or via some other indirect communication method. Messages to mobile terminals may also be sent via a broadcast network, such as a DVB-T/H network, where incoming messages are sent to the DVB-T/H network via SMS, MMS, Internet connection, or ad hoc signaling systems. These incoming messages are then forwarded via the broadcast signal to a recipient mobile terminal. If other mobile terminals do not have the cell coverage information sought, other communication routes may be available to mobile terminal 101. Path D represents a cellular conversation between mobile terminal 101 and cell coverage center 1705 via cell tower 1702.
Mobile terminal 101 may be able to make a data call, and download the proper CCI directly. Path E represents a conversation (either wired or wireless) between mobile terminal 101 and cell coverage center 1705 via a network 1706, such as the Internet or an intranet. A wireless conversation may take place via a cellular system or a WiFi connection. A wired conversation may take place via a sync cable or other direct connection with a computer or a network. As before, mobile terminal 101 may be able to download the proper CCI directly, perhaps using an IP address, username, and password previously provided by mobile terminal 1606. Other methods of communication between mobile terminal 101 and cell coverage information center 1705 are conceivable, both wired and wireless.
18 depicts mobile terminal 101 in communication with similar mobile terminal 1606 and CCI server 1703 according to one or more aspects of an embodiment of the invention. Turning now to the specific messages of conversations between mobile terminal 101 and other devices. Beginning with communication between mobile terminal 101 and similar mobile terminal 1606, the method of communication is not relevant, whether wireless, via the Internet, via broadcast, etc.
Assuming communication is possible using one of these methods, the individual messages are now in the spotlight. Message A represents an initial query or discovery, referred to as a CCI Discovery message. The components of the message are set forth in the table below.TABLE 3 CCI Discovery Message Field Name Description CCI Message Indicates the Type of Message: CCI Discovery Type CCI Discovery Indicates the desired CCI discovery method.
If the Method method requested is not available in the receiving terminal, then no method is indicated in the reply. Terminal Class Indicates the class of the requesting terminal. If the class of the receiving terminal does not match, then a “not available” status is provided in the reply.
Sending terminal can set this field to “any class” to prevent filtering. Geographical Contains the geographical range for the requested CCI Range metadata. “Not available” is sent in the reply if the receiving terminal has no CCI metadata for the given geographical range. The CCI Discovery message is received by mobile terminal 1606, which then replies with a standardized reply, Message B, also known as a CCI Reply. The components of this message are set forth below.TABLE 4 CCI Reply (to Discovery) Message Field Name Description CCI Message Indicates the Type of Message: CCI Reply Type Reply Type Indicates the type of the reply (i.e., whether it is a reply to a CCI Discovery or a CCI Request). CCI Type Indicates the types of CCI (e.g., Principle I, Principle II, CDT, etc.) that are available on the replying terminal, depending on discovery parameters.
Terminal Class Indicates the class of CCI metadata available on the replying terminal (e.g. Screen resolution, needed plugins, etc), depending on discovery parameters.
Geographical Contains the geographical range available on the Range replying terminal. “Not available” is sent in the reply if the replying terminal has no CCI metadata for the geographical range depending on discovery parameters. CCI Discovery Informs of parameters (e.g., IP address, user, password, Info and port) leading to the requested data on another device.
Once the reply to the discovery message is received, mobile terminal 101 may make a specific request, assuming similar mobile terminal 1606 had CCI metadata within the range sought by the discovery. Message C, also known as a CCI Request, is broken down below.TABLE 5 CCI Request Message Field Name Description CCI Message Indicates the Type of Message: CCI Request Type CCI Type Indicates the CCI type requested (e.g., Principle I, Principle II, CDT, etc.). Can also be set to “any type”, where priority is given to a particular type, but other types are acceptable if the primary is not available. Terminal Class Indicates the class of the requesting terminal (e.g.
Screen resolution, needed plugins, etc). If the class of the requesting and receiving terminals don\'t match, then “not available” status is provided in the reply. If the requesting terminal doesn\'t care about class, it can put an “any class” indicator in this field. Geographical Contains the geographical range available on the Range replying terminal. “Not available” is sent in the reply if the replying terminal has no CCI metadata for the geographical range depending on discovery parameters. Upon receiving the CCI Request, the receiving terminal 1606 responds with Message D, another CCI Reply, the components of which are set forth below.TABLE 6 CCI Reply (to Request) Message Field Name Description CCI Message Indicates the Type of Message: CCI Reply Type Reply Type Indicates the type of the reply (i.e., whether it is a reply to a CCI Discovery or a CCI Request). CCI Type Indicates the type of CCI (e.g., Principle I, Principle II, CDT, etc.) provided in this response.
Terminal Class Indicates the class of CCI metadata provided in the repsonse (e.g. Screen resolution, needed plugins, etc). Geographical Contains the geographical range provided in the Range response.
CCI Data The CCI data. To perform this operation, mobile terminal 101 uses a CCI Push message (Message F) to push the data to server 1703, where it can be stored, analyzed, converted to Principle I data, and forwarded to other mobile terminals. The substance of a CCI Push message is set forth below.TABLE 7 CCI Push Message Field Name Description CCI Message Indicates the Type of Message: CCI Push Type CCI Type Indicates the type of CCI (e.g., Principle I, Principle II, CDT, etc.) provided in this push, or that is available with CCI discovery parameters.
Terminal Class Indicates the class of CCI metadata provided in the push (e.g. Screen resolution, needed plug-ins, etc) or available with CCI discovery parameters. Geographical Contains the geographical range provided in this push, Range or available with CCI discovery parameters. CCI Discovery If this is a reply to a CCI discovery, informs of Info parameters (e.g., IP address, user, password, and port) for the CCI discovery.
Otherwise, field is left out. CCI Data The CCI data. 19 illustrates a process for issuing a cell coverage information request according to one or more aspects of an embodiment of the invention. At step 1901, available receivers, such as DVB-T/H receivers, are sought, whether via direct connections, such as ad hoc wireless standards, or via Internet or other indirect connections. If no receivers are available at decision 1902, then a timer is set for a specific period of time at step 1903. When the timer expires, control returns to step 1901, again seeking available receivers. If receivers, such as other mobile terminals, are available, then a CCI Discovery or CCI Request can be forwarded to the receiving device.
20 illustrates a process for issuing a cell coverage information reply according to one or more aspects of an embodiment of the invention. At step 2001, a listener is set up to wait for incoming CCI Discoveries or CCI Requests.
If no requests are forthcoming, at decision 2002, then control returns to step 2001. If a request is received, then processing of the request is handled at step 2003.
If the incoming message is a discovery, the appropriate information is assembled, and if the message is a request, likewise that information is assembled. At step 2004, the CCI Reply is transmitted back to the requesting terminal. 21 illustrates a process for issuing a cell coverage information push according to one or more aspects of an embodiment of the invention. At decision 2101, if a connection is needed, the server connection is created at step 2102. If the connection is successful at decision 2103, then at step 2104, the appropriate CCI data and metadata and/or discovery information are sent as a CCI Push. If no connection was needed at decision 2101, then step 2104 assembles the CCI Push in the same fashion. Once the CCI Push is issued, or if the connection attempt failed, control terminates normally.
While aspects of the invention have been described with respect specific examples, including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and techniques that fall within the spirit and scope of the invention as set forth in the appended claims. Aspects of the invention may also be used in other forms of wireless cellular networks, including digital video broadcasting (DVB), and in cellular telephony.Claims ( 20). A processor, configured to perform the steps of receiving cell coverage information via the receiver, storing at least the bitmap model of cell signal strengths in the memory, determining a travel vector based on changes in the longitude and latitude of the mobile terminal over time, and determining a destination cell for a handover based on the travel vector and at least the bitmap model of cell signal strengths.
...'>Specificindirecteffects Plugin Estimands Amos 23 Free Downlloads(23.03.2020)