Network selection by wireless terminals

Claiming priority under section 119 of section 35 USC

This application claims priority to provisional patent application number 60/780391, entitled "NETWORK SELECTION BY WIRELESS TERMINALS", filed March 7, 2006, transferred to the assignee hereof and expressly incorporated herein by reference.

DESCRIPTION

TECHNICAL FIELD

The present disclosure relates generally to communication, and more specifically to techniques for selecting a wireless network for gripping by a wireless terminal.

BACKGROUND

Wireless networks are networks with wireless capabilities that allow wireless terminals communicate without cables or wires. Wireless networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, etc. These wireless networks may be wireless global communications networks (WWAN), such as cellular networks, wireless metropolitan area networks (WMAN) and wireless local area networks (WLAN).

A wireless terminal (e.g., cellular phone) may be capable of receiving service from one or more wireless networks. After switching, the terminal may search for a wireless network that is within range and from which a terminal may receive services. If such a wireless network is found, the terminal can capture wireless network and attempt to register with the wireless network. During registration, the terminal may be authenticated and authorized for the requested service wireless network, or perhaps the home network if the user is roaming. The terminal may then communicate with the wireless network to receive the desired service (services), for example, to issue or receive calls, to access email, to obtain Internet services, etc.

The terminal may not have any knowledge of its operating environment when it is initially turned on and may not know which wireless networks, if any, can be captured. In addition, the terminal may have a list of preferred networks whose selection by the terminal is preferred when the home network is unavailable, for example when the user moves to a roaming or is temporarily not within the coverage of the home network. Wireless networks in the preferred list may be selected based on business arrangements between the home network operator and other network operators, service offerings, for reasons of efficiency and reliability, the preferred payment, security and privacy considerations, etc.

When the terminals may be within the coverage of zero or more wireless networks that may or may not be in the preferred list. In this case, the terminal may search for an extended period of time to look for one of the preferred networks. The search can be more difficult if the terminal supports multiple radio technologies and / or a plurality of frequency bands, so how can there be a greater number of combinations of radio technologies and frequency ranges to search. During this time, the search of the user may not be able to issue or receive services such as voice calls, email, and short messages.

Therefore, in the prior art there is a need for methods that allow the terminal to reduce the length of time for capturing a wireless network, especially when the terminal has little or no prior knowledge of which networks may be available.

SUMMARY OF THE INVENTION

Hereinafter, a method for efficiently performing network selection using information stored in the terminal. According to an aspect an apparatus is described which includes a memory that stores coverage information for previously detected wireless networks and a processor that selects a wireless network to attempt acquisition based on the stored coverage information. The coverage information may be given in various formats, as described below.

According to another aspect, an apparatus is described which includes a memory that stores information for previously detected cells in wireless networks and a processor that obtains information for current location of the terminal and selects a wireless network to attempt acquisition based on the information for the current location and the stored Information for previously detected cells.

According to another aspect, an apparatus is described which includes a memory that stores usage information for wireless networks to which it was previously accessed and a processor that selects a wireless network to attempt acquisition based on the stored usage information.

According to another aspect of the apparatus is described which includes a memory that stores availability information for previously detected wireless networks and a processor that selects a wireless network to attempt acquisition based on the stored availability information.

According to another aspect of the apparatus is described which includes a memory that stores almanac information (team information) for cells in wireless networks and a processor that selects a wireless network to attempt acquisition based on the almanac information. The almanac information may comprise information on cells available at different locations and information for capturing cells.

Various aspects and features of the disclosure are described in further detail below.

BRIEF DESCRIPTION OF DRAWINGS

1 illustrates an environment with multiple wireless networks.

Figure 2 illustrates the use of stored information to expedite network selection.

3 illustrates an environment with multiple cells in different wireless networks

Figure 4 shows a process for network selection using coverage information.

5 shows a process for network selection using usage information and / or availability.

6 shows a process for network selection using cell information.

7 shows a process for network selection using almanac information.

8 illustrates a block diagram of a terminal, base station and system controller.

Detailed description

1 illustrates an exemplary network environment 100 in which are present a plurality of wireless networks. In this example there are four wireless networks 110a, 110b, 110c and 110d, indicated as Network A, B, C and D respectively. In general, each wireless network may have any coverage area (service), and the coverage area of ​​some or all wireless networks may overlap. In the example shown in Figure 1, wireless networks A, B and C overlap in area 114, which shows a cross-superposition.

In general, each wireless network 110 may implement any radio technology such as Global System for Mobile Communications (GSM), wideband CDMA (W-CDMA), Long Term Evolution (LTE), CDMA2000 1X, High Rate Packet Data (HRPD), IEEE 802.16, IEEE 802.20, IEEE 802.11, Hiperlan, Flash-OFDM® etc. GSM, W-CDMA, LTE, CDMA2000 1X, HRPD, and Flash-OFDM® are radio technologies for WWAN. W-CDMA is part of the Universal Mobile Telecommunications System (UMTS). CDMA2000 1X and HRPD are part of cdma2000, which is also referred to as a code division multiple access channels (CDMA). IEEE 802.16 and IEEE 802.20 are two families of standards from the Institute of Electrical and Electronics Engineers (IEEE) for WMAN, IEEE 802.16 being commonly referred to as WiMAX. IEEE 802.11 is a family of standards from other IEEE for WLAN and commonly referred to as Wi-Fi. Hiperlan is another radio technology for WLAN, these various radio technologies are known in the art.

In general, a wireless network may implement one or more radio technologies. For simplicity, the following description assumes that each wireless network implements one radio technology, even though a plurality of wireless networks with different radio technologies may be assigned the same network identifier, and / or they may be supported by a common set of base stations and / or other common network elements. In the example used in the description below, network 110a is a network GSM, network 110b is a UMTS network that may implement W-CDMA, network 110c is a network of CDMA, which may implement CDMA2000 1X or HRPD, and network 110d is an IEEE 802.11 network . IEEE 802.11 network may implement any standard in the IEEE 802.11 family of standards such as 802.11a, 802.11b, 802.11g, 802.11n, etc. In the description herein "802.11" generally covers any standard in the IEEE 802.11 family of standards.

The multi-mode terminal 120 may be capable of communicating with wireless networks of different radio technologies. For example, terminal 120 may support GSM, W-CDMA, CDMA 1X, HRPD, 802.11, etc., or any combination thereof. Terminal 120 may be stationary or mobile and may also be referred to as a user equipment (UE), mobile station, access terminal, a mobile equipment, a subscriber unit, a station, etc. Terminal 120 may be a cellular phone, a personal digital assistant (PDA), a wireless device, a wireless modem, a handheld device, a laptop computer, a cordless phone, etc.

Terminal 120 may be located in an area 114 and may be able to receive GSM network 110a, UMTS network 110b, and CDMA network 110c. However, terminal 120 may prefer to use UMTS instead of GSM and CDMA, e.g., for better service and / or greater coverage. For terminal 120 there may be preferences for various network operators and their associated services. For example, the operator for network 110a may be preferred over the operator for network 110b, which may be advantageous for the network operator to 110c. However, taking into consideration radio technology and network operator preferences, terminal 120 may prefer UMTS network 110b as a GSM network 110a, and CDMA network 110c. Terminal 120 may thus have a prioritized list of preferred network operator and technology combinations. In general, a prioritized list may be formed on the basis of network operator preferences, radio technology preferences and the preferences of the network operator and radio technology, etc.

Terminal 120 may be able to receive (signal from) a plurality of wireless networks of different radio technologies at a particular location. There may be only one or a few preferred network operators for terminal 120 among all the available networks. Terminal 120 may perform a search to find a preferred network operator and / or a preferred radio technology. During the search, terminal 120 may tune its receiver to each frequency that can be used by the wireless network and determine whether any wireless network at that frequency. For each frequency, terminal 120 may detect the signal from a wireless network at that frequency, capture timing and / or frequency of any detected signals, demodulate the broadcasted information from any of the captured signal, identifying the wireless network operator based on the broadcast information, and decide whether to choose the wireless network. Search network each radio technology may be performed in accordance with a procedure applicable for that radio technology.

Terminal 120 may have a list of preferred network operators or a list of preferred combinations of operator-network technology. Entries in the preferred list may be prioritized to ensure that terminal 120 selects the home network operator when in service, and during roaming selects certain other network operators with whom the operator home network may have a business relationship, and / or They offer advantages for the home network operator and / or user terminal. Terminal 120 then may perform a full search in order to identify all preferred network operators or combinations of all network operator-technology, which can be accessed at the current location. Terminal 120 may then select the most preferred network operator or a combination of network technology operator to use.

Terminal 120 may spend a long time to capture a preferred network, for example, when the terminal is switched to a new location (for example, after the airplane flight) or loses coverage area (e.g., moving through a long tunnel) and needs to re-capture the service area location in comfort. In many cases, the wireless network that terminal 120 used previously may not be available, and terminal 120 may have little or no knowledge of the networks available at the new location. Terminal 120 may perform a full search to find all available networks. For a complete search user may not be able to call or receive any services.

Terminal 120 may search for a preferred network at power-up or after loss of coverage. Terminal 120 may also search for a more preferred network when receiving service, or from a less preferred network or not a preferred network, which may have been selected initially because a more preferred network was not available at the previous location. It is desirable to quickly find a preferred network in all of these scenarios.

In one aspect, terminal 120 may store information for cells and / or wireless networks and may use the stored information to more quickly and efficiently perform network selection. Terminal 120 may store information for only preferred networks, or any available networks, or preferred networks plus available networks wherever preferred networks are not available, or some other combination of networks. In the following description, "written" network is a wireless network to which the terminal 120 has stored information that can be used for network selection. Recorded network may be preferred network or available network that may have been previously detected, or that appeal to the terminal 120.

In general, terminal 120 may store any type of information for a given network. For example, terminal 120 may store information used to capture network, such as, for example, frequency band, frequency channel, radio technology, scrambling code, etc. Terminal 120 may also store information regarding where the network might be detected, the likelihood of detecting the network, etc. Terminal 120 may update the stored information as new networks are discovered and / or when the identified new coverage area or capabilities recorded networks. Terminal 120 may be able to obtain a comprehensive database for cells and / or networks via a time through the ability to self-learning.

Terminal 120 may perform network selection at a particular time, and may not know which wireless networks may be available, for example because the terminal 120 joined to a new location. Terminal 120 may then search for a preferred network based on the stored information. For example, terminal 120 may search for preferred network operators or combinations of network operators and radio technologies in a prioritized order. Terminal 120 may use the stored information to determine which one (s), range (s) and frequency radio technology to try to capture a given preferred network.

In one embodiment, terminal 120 may store usage information for wireless networks to which the terminal previously handled. Terminal 120 may store information regarding the degree of use (e.g., the total access time) for each frequency band and radio technology used by each recorded network and / or other network usage statistics. Usage information could be used to determine which networks are normally available over a period of time. A higher degree of prior usage for a given network may be indicative of a greater probability of capture of the network in the future. Terminal 120 may determine the search order based on the usage information and may search one or more networks in frequency bands and radio technologies having higher levels of prior usage.

In another design, terminal 120 may store information about the availability in the past for networks previously detected but have not been accessed terminal. Terminal 120 may store information on the percentage of time and / or the number of times each network was detected and / or other availability statistics. Most of the earlier availability for a given network may be indicative of a greater probability of detection of the network in the future.

In yet another design, terminal 120 may store coverage information for networks previously detected by the terminal, the coverage information may indicate where these networks were detected previously by terminal 120 and may be provided in various formats. In the first scheme, the coverage information may comprise geographic description (e.g., latitude and longitude coordinates) of specific locations where each network was detected. Terminal 120 may store information, such as identification information of each network, radio technology and frequency information for each network, geographic description of the locations where each network was detected, etc. Terminal 120 may store network information and the service area for all locations visited by the terminal. Alternatively, terminal 120 may store information for locations that may be located remotely to at least some minimum distance (e.g., at least one kilometer), which may reduce the amount of coverage information in storage. Terminal 120 may omit information for locations in which the terminal was present for only brief periods of time (e.g., when the terminal user was moving) in order to further reduce the amount of storage space. For areas in which terminal 120 was present for extended periods of time (e.g., home, in neighborhoods, in the work place, the preferred areas in which make a purchase, home friends and relatives, etc.), terminal 120 may store information on a more detailed basis for locations that may be positioned more closely together.

In the second scheme, the coverage information may comprise geographic description of a visited coverage area where each network was previously detected by terminal 120. Visited network coverage is part of the coverage area of ​​the network that was visited by terminal 120. This scheme allows the terminal 120 may combine information about the service area networks, how to reduce the amount of memory and processing time in carrying out search of the stored information. The coverage information for a network may comprise location coordinates along the perimeter of the visited coverage area for that network. Alternatively, terminal 120 may approximate the visited coverage area of ​​geometric shape such as circle, ellipse, n-sided polygon, etc. For example, a visit to the coverage area can be approximated by (i) the terms specified center and radius, or (ii) by an ellipse specified by the center, the length of the small and the main axis and the direction of the main axis. Terminal 120 may select an appropriate geometric shape and / or determine parameters of the selected geometric shape based on location coordinates obtained for the network. The coverage information may also be specified in other geographic shapes and formats.

Terminal 120 may store coverage information for recorded networks in various manners. Terminal 120 may store coverage information and associate detected networks to the coverage area information. For example, terminal 120 may store different coverage areas (e.g., geographic shapes) and a set of networks detected in each coverage area. Networks in the set associated with the particular coverage area, can be specified in order of preference. The new coverage area may be defined whenever a different set of networks is detected in the area. Alternatively, terminal 120 may store a list of detected networks and the coverage area for each network in the list. Service area (coverage) for each network can be set to one or more geographic shapes, a set of location coordinates, etc. Terminal 120 may update the visited coverage area for each network appropriately.

Terminal 120 may use the coverage information for the previously detected networks to efficiently perform network selection. Terminal 120 may determine its current location based on any positioning method, e.g. autonomous position determination method, which is independent of wireless network support, such as a GPS (Global Positioning System). For the first scheme, terminal 120 may determine the closest previously visited location for which stored information is available for networks. Terminal 120 may retrieve stored information for the networks detected at this closest location and may search for these networks in a suitable order so that a preferred network may be found as quickly as possible. For the second scheme, terminal 120 may first determine its current location and then determine whether the current location is within the visited coverage area for any previously detected network. Terminal 120 may identify networks with coverage area overlapping the current location and may search for these networks in a desired order.

Terminal 120 may also use information broadcast by wireless networks for network selection. For example, the base stations (or access points) in a wireless broadcast network can carry out its location coordinates. The terminal 120 can recognize the location of these base stations based on the broadcast information. Terminal 120 may then find out his location based on the locations of all received base stations and may identify networks available at this location based on the stored information. Terminal 120 may also use information broadcast by base stations to assist in saving the information for the networks detected at each location, e.g., if terminal 120 could not or preferred not to get its location by other means due to cost or other reasons.

2 illustrates a structure of using stored information to expedite network selection. Table 1 contains several types of information that may be stored by terminal 120 for each network and provides a short description for each type of information.

Table 1Tip informatsiiOpisaniePredpochtenie setiUkazyvaet preferred wireless setiRadiotehnologiyaUkazyvaet radio technology used by wireless setyuInformatsiya of chastoteUkazyvaet frequency (f) range (s) and / or frequency channels used by wireless setyuInformatsiya about ispolzovaniiUkazyvaet degree or magnitude of previous use of wireless setiInformatsiya about last dostupnostiUkazyvaet available wireless networks in proshlomInformatsiya Zone obsluzhivaniyaUkazyvaet where the wireless network can be detected

Table 1 contains various types of information that can be stored for each network. Different and / or other types of information may also be stored. For example, terminal 120 may store only usage information, only information about the availability in the past, only coverage information, both usage information and a service area, etc.

Information in Table 1 may be supported for a given network as follows. Network preference can be specified based on a scale from 1 to N, where 1 is the most preferred and N being the least preferred, where N may be any value. The preference may be determined by the operator of the home network and is provided at terminal 120. The frequency information may indicate one or more frequency bands, one or more frequency channels, one or more broadcast channels, etc., used by the wireless network, and can be updated, when a new service frequency bands and / or channels are discovered for the wireless network. Terminal 120 may use the radio technology and frequency information to search for wireless networks. Usage information may indicate how often the wireless network accessed in the past and may be updated whenever the wireless network is selected for use. Reachability information in the past may indicate how often the wireless network was detected in the past and may be updated whenever the wireless network is detected. The coverage information may convey the visited coverage area for a wireless network and may be updated whenever a terminal moves to a new area.

Terminal 120 may maintain a table for storing information. In one embodiment, the table may include an entry for each wireless network previously detected or accessed by terminal 120. addressed new record may be added in the table when a new network is found by terminal 120. The entry for each network may include fields for any type of information, for example, as shown in Table 1. Each field for each network may be updated as new information is gathered for that network.

In yet another design, terminal 120 may store information for cells as well as networks previously detected by the terminal. The term "cell" (cell) can refer to a base station (or access point) and / or its coverage area (service) depending on the context in which the term is used. The coverage area of ​​a base station may be partitioned into multiple smaller areas that may be referred to as sector or cell sector. For simplicity, much of the following description assumes that networks are not sectorized and that cells are the smallest unit of coverage. The methods described herein can also be used for sectorized networks in which sectors or cell-sectors are the smallest unit of coverage.

3 illustrates an exemplary network environment 300 in which terminal 120 may be within the coverage of multiple cells in multiple wireless networks. In this example, terminal 120 is within the coverage of cells 310a and 310b in UMTS network 110b, and also cell 310c in CDMA network 110c. Cells 310a, 310b and 310c are also denoted as cells B1, B2 and C1, respectively, and are served by base stations 312a, 312b and 312c, respectively. Cells B1, B2 and C1 overlap in area 314, which is shown in Figure 3, a cross-superposition.

Terminal 120 may store identification information for cells detected at a particular location. The identification information for each cell may be obtained from, and may be associated with the transmission from the base station, an access point, a repeater, etc. Cell identification information may be globally unique identification and may be given in different formats for different radio technologies. For example, identification information for a cell in GSM or UMTS may comprise a country code for mobile communication (MCC), mobile network code (MNC), location area code (LAC) and cell identity (CI). The identification information for a sector in CDMA 1X may comprise a system identification information (SID), network identity (NID) and the identifier BaseID base station, which may be composed of a cell identifier and sector identifier CELL_ID SECTOR_ID. Identification information for the sector in HRPD may comprise a 128-bit subnet ID. The identification information for an access point in IEEE 802.11 network address may comprise Medium Access Control (MAC), the designated access point and used to identify its coverage area. The globally unique identification for each cell may be transmitted from the broadcasting base station and / or repeater serving that cell. Similarly, each access point can to broadcast their MAC addresses in frames "beacon." Terminal 120 may receive the globally unique identification for a given cell whenever the terminal comes within the coverage area of ​​the base station or repeater for that cell. The terminal may also receive a given MAC-address of the access point whenever the terminal comes within the coverage area of ​​the access point. Identification information for a given cell, sector or access point may also be called as a global cell identification information (G_ID).

Terminal 120 may also store other information for each detected cell. For example, for each detected cell, terminal 120 may store identification information of the network (the ID of the network) to the wireless network, which the cell belongs if this network ID is not contained in or implied by the identification information of the cell, the preference or priority of the wireless network or a combination of network and radio technology, frequency information for the cell, radio technology used by the cell, etc. Terminal 120 may store information for each detected cell only once, if possible, to reduce the amount of data storage for cells detected at different locations.

For each detected cell, terminal 120 may store information for other associated cells and / or networks that were also detected by terminal 120 within the visited coverage area of ​​this cell. The stored information may comprise radio technology and frequency information for each network, the preference or priority of the network identification information associated cells, etc. Terminal 120 may also store signal strength information for cells and / or networks. For example, terminal 120 may flag cells with weak flag of the received signal strength and / or networks with weak cell reception. Information can be collected and updated at all or some locations, on a continuous time basis or at discrete time intervals, whenever cells detected by terminal 120 or when the received signal strength for cells exceeds a particular threshold.

The cell may have a certain normal coverage area in which its received signal strength will normally be high and in which the cell can be accessed to receive the service from its associated network. The cell may also have an extended coverage area (e.g., the area surrounding the normal coverage area) in which the cell can be detected by terminal 120 but, due to the low level signal may not be able to effectively serve the terminal. By associating cells from different networks, terminal 120 may employ both the normal and extended coverage areas of each cell to increase the number of other cells associated with that cell. In this case, the signal levels of the associated cells for a given cell may not always be high, and throughout the normal or extended coverage area of ​​that given cell signal level associated cell may be consistently high or consistently low or may vary between low and high values ​​at different locations. Such information about the level of the signal can also be stored for each cell associated with any given cell.

Terminal 120 may also store association between signal levels for cells. For example, the signal level or range of signal levels for a given associated cell may be stored for any cell for locations at which the signal associated cell is high (e.g., in the normal coverage area of ​​the associated cell) and separately for other locations where the signal level associated cell is low (e.g., in the extended coverage area of ​​the associated cell). Terminal 120 may later detect a particular cell and obtain the signal level of the cell in its current location. Terminal 120 may then determine based on the identification information as the cell and the signal level, which other cells may be captured at its current location and which of these cells have higher signal strengths and thus will be suitable for use with a greater probability. Based on the preference order for the networks associated with the cells with higher signal strength, terminal 120 may first attempt to acquire the cell with the highest network preference and, if not acquired, may attempt to acquire other cells according to the network preference order.

The stored information for cells and / or networks may be linked such that terminal 120 can quickly identify all cells that might be taken whenever a given cell is detected. For each detected cell (or access point), information for that detected cell and / or its network may be linked to other cells and / or networks that might also be accepted. This linking of information may also reduce the amount of duplicate information for cells and / or networks. If more than one cell in a given network can be detected at a particular location, then terminal 120 may store the cell with the strongest signal or the detected set of strongest cells, or all detected cells together with an indication of their relative levels of the received signal. Saving may be repeated (e.g., at other locations) whenever changes are observed in the detected cells.

Terminal 120 may reduce the amount of information storage, passing the cells that were detected for only short periods. Terminal 120 may move on the area when these cells were detected and may be less likely to return to these cells for any significant period of time. Terminal 120 may also note cells found through an extensive search. For example, the user can enable the terminal 120 upon arrival at the airport, and an extensive search can be performed to capture the preferred network. Terminal 120 may store more information in this case and may use this information to expedite network selection on the next visit of the same airport.

Terminal 120 may use the stored cell information for network selection. Terminal 120 may revisit or come close to the location where the cells have been previously detected, and the information has been saved for these cells. Terminal 120 may detect a cell at this location, receive and decode the broadcasted information from this detected cell, identify the detected cell based on the broadcast information, and determine other cells and networks (if any) associated with a detected cell for which stored information is available. Terminal 120 may then determine the appropriate procedure for the search of wireless networks, designated as the stored information available at this location. The search order may be determined based on the preferences or priorities of the wireless networks, as indicated by the stored information. Terminal 120 may then search for one wireless network at a time, starting with the most preferred network. For each wireless network, terminal 120 may search for any cell in the network or specific cells identified by stored information.

In the example shown in Figure 3, terminal 120 may first detect cell B1 in network B, while in the region 314, and may determine that cells B2 and C1 in networks B and C, respectively, may also be taken at that location, based on the stored information linking cell B1 with cells B2 and C1. Terminal 120 may then determine the desired order of searching for networks B and C. Terminal 120 may attempt to grab a network C first and may search or any cell in network C (e.g., using the radio technology and frequency information stored for network C), or a specific cell C1 that is associated with the first detected cell B1.

Terminal 120 may detect a given cell x in multiple locations and may store information associating cell x with multiple sets of other cells available at these locations and their networks. Terminal 120 may thereafter revisit one of these multiple locations and detect cell x first. Terminal 120 may then obtain the multiple sets of cells associated with the first detected cell x, combine these sets of cells and their networks, and search the combined cells and / or networks in a desired order. Alternatively, the terminal 120 may use information regarding the signal strength for the associated cells (if previously stored) and search for cells with the highest recorded signal strength. In another alternative embodiment, terminal 120 may detect one of the cells (cell y), associated with cell x. Terminal 120 may then obtain other cells associated with the second detected cell y and their network from the stored information. Terminal 120 may then search first (or only) cells or networks that are associated with both cells x and y.

In general, terminal 120 may initially detect any number of cells, determine other cells associated with each detected cell, and search first (or only) from the cells or networks that are associated with all initially detected cells or the greatest number of initially detected cells. If a plurality of cells initially detected, the terminal 120 may combine the information for the networks for all detected cells to determine a smaller or larger set of available networks from which to perform network selection. Terminal 120 may obtain (i) a larger set based on combining networks associated with the initial detected cells or (ii) a smaller set based on the intersection of these networks. Terminal 120 may also select networks that are more likely to be available based on other criteria such as received signal strength and recorded signal strength for these networks, usage information, availability information in the past, etc.

Tables 2-5 provide an example of cell information that may be stored by terminal 120. In this example, cells in three wireless networks were detected by terminal 120 when operating in the small region. The specific values ​​in these tables are only for illustrative purposes and may not correspond to any actual networks.

Table 2 stores information for the three wireless networks detected by terminal 120. The information stored in Table 2 may be common for all cells in each network. In this example, Table 2 stores, for each network, an internal identifier (e.g., A) for the network, an external global identity (e.g., MCC and MNC), assigned to the network preference network frequency band and radio technology used by the network, and a pointer to dependent specific network table for the network. For example, for network A MCC-MNC is 200-56, the preference is 1 (meaning that the network A is the most preferred network), the frequency range is 1900 MHz, a radio technology - GSM, and Table 3 stores the cell information for network A. Terminal 120 may create an internal network identifier in order to facilitate any layered reference to the information in Table 2. The external global identity for each network information can be obtained from information broadcast by each cell in the network. It depends on the particular network table for each network may store information for each cell previously detected in that network.

Table 2 - Information on setiSetMSS-MNCPredpochtenieChastotny diapazonRadiotehnologiyaUkazatel on the table at the table setiA200-5611900 MGtsGSMUkazatel 3V200-762850 MGtsW-CDMAUkazatel 4S200-4931900 MGtsCDMAUkazatel on the table at the table 5

Tables 3, 4 and 5 stored information for networks A, B and C respectively. In this example, each table stores, for each cell an internal identity (e.g., A1) for the cell, an external identity for the cell, a frequency channel for the cell, the network to which the cell belongs, and internal identities of other cells in the same or other networks having overlapping service areas that cell. Internal identification information of the cell can be used as a pointer to the table entry for the cell. External identification information of each cell may be obtained from information broadcast by that cell. The frequency channel is indicative of the frequency used by the cell and can be absolute radio frequency channel number (ARFCN) in GSM, UTRA ARFCN (UARFCN) in W-CDMA, a channel number in CDMA, etc. Each table may also store other information that may be specific to a particular radio technology. For example, Tables 4 and 5 may store scrambling code information for W-CDMA and CDMA, respectively.

As an example, in Table 3 from the inner cell A1 identity was discovered before the terminal identification information 120. The outer cell A1 is defined location area code (LAC) 230 and identification information cells (CI) 120. The cell A1 has been broadcasting on channel 960, and belongs to a network A. Cell A1 is associated with cell A2 in network A and cell C2 in network C. The associated cells A2 and C2 may be detected by terminal 120 when located within the coverage of cell A1.

Table 3 - Information of the cell network AYacheykaLAC-CIKanalSetAssotsiirovannye yacheykiA1230-120960AA2, S2A2230-121900AA1, S2A3230-122700AV3, C3

Table 4 - Information cell network BYacheykaLAC-CIKanalSetAssotsiirovannye yacheykiV1232-24800VV2, S1V2232-25750VV1, S1V3232-26650VA3, C3

Table 5 - Information for the cell-network CYacheykaLAC CIKanalSetAssotsiirovannye yacheykiS125-98120SV1, V2S225-97140SA1, A2S325-96160SA3, B3

Information about the network cell and in Tables 2-5 may also be stored in other ways. For example, one table may have one entry for each cell, wherein each record comprises inner and outer cell identification information, identification information of an external network bandwidth and a channel number and identification information associated inner cells in other networks. This single table may contain all of the information from the tables 2-5.

Terminal 120 may use the information about the network and the cell in Tables 2-5 for network selection as follows. Terminal 120 may be turned on and may first detect a cell with the value of LAC-CI, equal to 25-96, with the value of the network MCC-MNC, equal 200-49. Terminal 120 may scan the cell-related tables for any cell with the LAC-CI value of 25-96. In this example, terminal 120 may find this LAC-CI value for cell C3 in Table 5. Terminal 120 may then checks whether the detected MCC-MNC value of 200-49 to the MCC-MNC value for network C, to which cell C1 belongs. In this example, Table 5 indicates that cell C1 belongs to the network C, and Table 2 indicates that network C has a value of MCC-MNC 200-49, which corresponds to the detected value of the MCC-MNC. Terminal 120 may thus confirm that the detected cell is indeed cell C3, and can detect from Table 5 that there are two associated cells A3 and B3 with overlapping coverage areas to cell C3.

By using Tables 2 and 5, terminal 120 may detect the networks for cells A3, B3 and C3 and may then set their network preferences. In this example, detected cell C3 belongs in network C with preference 3, while associated cells A3 and B3 belong in networks A and B with preferences 1 and 2, respectively. Since network A has the highest preference, terminal 120 may attempt to detect cell A3 first. Tables 2 and 3 indicate that the cell A3 is a GSM cell operating in the frequency range 1900 MHz channel 700, and has a value assigned LAC-CI, equal to 230-122. Terminal 120 may use this information to quickly capture cell A3 without painstaking search. If cell A3 captured, the terminal 120 may attempt to access the network through the A cell. If cell A3 is not captured, the terminal 120 may attempt to appeal to cell B3 in network B, which has the next highest preference value. If cell B3 is not successfully captured, the terminal 120 can go back to the original cell C3 detected on the network C. Terminal 120 may then be found on the ground of absence of other associated cells in Table 5 for the cell C3, that there is no need to look for any other network.

The terminal 120 and / or other terminals may send the network operator (eg operator serving or home network) information collected by these terminals, using self-learning methods and suitable for use for network selection. For example, terminal 120 may send information for cells and / or networks previously detected in different geographic areas or locations, cells and / or networks associated with the detected cells, identification information of the detected cells and networks, frequencies and radio technologies used by detected networks, and etc. Terminal 120 may accumulate information over some time period and send the information when necessary. Terminal 120 may also send smaller amounts of information more frequently, for example, information for cells and networks detected by terminal 120 at its current location. Terminal 120 may also send information when and as requested by the network operator. As a specific example, terminal 120 may send the information in Tables 2-5 to the network operator. The network operator may combine information received from different terminals in different locations to obtain more comprehensive information on cells and networks in a large geographic area. The network operator may provide all or portions of this comprehensive information to individual terminals to assist with network selection.

The network operator (e.g., a serving or a home operator network) may also provide information that can be used by terminal 120 for network selection. The issued information may be the same, similar or more extensive, accurate and reliable than the information gathered by the terminal 120 through the methods of self-training. Reports information can improve network selection in locations that terminal 120 has not previously visited, or for which insufficient information was previously collected and stored. Software (issued), information may be for cells and / or networks available in different geographic areas or locations, cells and / or networks associated with different cells, identification information of cells and networks, frequencies and radio technologies used by networks and so on. d. Provision of information can be given in the formats described above (e.g., as shown in Tables 2-5), or some other format.

In one embodiment, the network operator may provide information in the form of a base station almanac (BSA), which may support other capabilities such as positioning terminal 120. BSA typically includes various types of information on base stations to support location services and positioning. For example, BSA may provide for each cell (or each base station), the geographic coordinates of the base station antenna used for that cell, the frequency band for the cell, the frequency and / or circuit hopping used for broadcast and / or other channels sent by the cell , other cells in the same or other networks that may be found within the cell, transmission timing or pilot phase differences between the signals of the cell and other cells detected within the cell etc. It may be captured by a broadcast channel to obtain broadcast information that may be used to verify the identification information of the cell measurement for determining the location, etc.

BSA may be modified and / or extended to include information used to maintain the network selection. BSA may include information on cells (or base stations) available at different locations, associations between cells with overlapping coverage areas, the identification information and preferences of networks to assist with network selection, radio technology and frequency information to assist in the capture, information to maintain positioning, etc. BSA may also include information on other cells and / or networks, which may be selected within the area covered by the cells included in the BSA.

Each cell may broadcast almanac information to implement that can be accepted and used by the terminals within the coverage area of ​​the cell. Given cell may also send almanac information directly to a given terminal, e.g., when and as required by the Terminal. For example, almanac information may be provided to the terminal 120 by the network operator (eg operator serving or home network) and store in the terminal 120 for future use.

Almanac or other information used to assist with network selection may be extensive if covering all cells for all networks in a large geographic area, such as nationwide. The volume of almanac information to send and subsequently store may be reduced in various ways.

In one embodiment, the terminal 120 may receive only almanac information applicable for terminal 120, e.g., only almanac information for networks utilizing radio technologies and frequency bands supported by terminal 120. For example, terminal 120 may support GSM and W-CDMA and may receive only the information Almanac for networks utilizing GSM and W-CDMA, and not for networks utilizing other radio technologies such as CDMA, IEEE 802.11, etc.

In another embodiment, the almanac information may be provided for individual cells within an area geographically close to terminal 120 belonging to all or some networks with the zone in the area.

In another embodiment, the almanac information may be provided for groups of cells instead of individual cells. For example, almanac information may be provided for GSM location areas, which are explicitly defined and identified groups of cells. The almanac information may also be provided for many or all cells in a particular network (e.g., when these cells have the same or similar information) and may comprise a superset of information for all of these cells.

In another embodiment, almanac information may be provided for networks (e.g., preferred networks) over a large area (e.g., nationwide), and not in cooperation with the cells of other networks. The almanac information may include the radio technologies supported by each network, frequency information for each network, etc. The almanac information may also be reduced by providing information for only cells or groups of cells with coverage at locations where network selection may be difficult, for example at major airports.

Terminal 120 and / or other terminals may also send to a network operator information collected by these terminals and suitable for use as almanac information, such as information for identifying the cell information used frequency Observed synchronization or phase difference of the pilot signals between associated cells and etc. Terminal 120 may collect information for cells detected by the terminal for a certain period of time and may send the collected information, e.g., when convenient or required. Terminal 120 may also send information (e.g., more frequently) for only cells detected at its current location. Terminal 120 may also send its location (or measurements used to determine its location) at which information was collected. The network operator can use this information from the terminal 120 to display the locations of base stations for the detected cells. The network operator may also combine information received from different terminals to obtain more comprehensive almanac information and may then issue the appropriate parts on individual terminals to assist with network selection.

4 illustrates a method 400 performed by a terminal for network selection using information on the service area. The coverage information for previously detected wireless networks may be collected and stored in the terminal (step 412). The coverage information may be for all previously detected wireless networks, only wireless networks in a preferred list, etc. The current location of the terminal can be determined (step 414). A wireless network to attempt acquisition may be selected based on the current location of the terminal and the stored coverage information for the previously detected wireless networks (block 416).

The coverage information may comprise various types of information. For example, information about the service area of ​​each previously detected wireless network may comprise location coordinates where the wireless network was previously detected. These coordinate locations may be separated by at least a particular minimum distance. For block 414, wireless networks previously detected at locations within a particular distance of the current location can be identified, and one of the identified wireless networks may be selected to attempt acquisition.

The coverage information for each previously detected wireless network may also comprise (i) a set of location coordinates defining a visited coverage area of ​​the previously detected wireless network, (ii) a set of parameters for a geometric shape approximating the visited coverage area, or (iii) some other geographic Description visited coverage area. For block 414, previously detected wireless network by visiting the coverage areas that overlap the current location may be identified, and one of the identified wireless networks may be selected to attempt acquisition.

The coverage information for each previously detected wireless network may also comprise measurement results received signal strength for cells in the wireless network. These measurements can be used to identify wireless networks available at the current location.

5 illustrates a method 500 performed by a terminal for network selection using usage information and / or availability. Usage information for wireless networks that was previously accessed and / or availability information for previously detected wireless networks may be collected and stored in the terminal (step 512). Usage information for each wireless network to which previously have been accessed, may indicate the length of time during which the wireless network previously accessed. Availability information for each previously detected wireless network may indicate the length of time or number of times the wireless network was previously detected.

A wireless network to attempt acquisition may be selected based on the stored usage information for wireless networks that was previously accessed and / or the stored availability information for previously detected wireless networks (block 514). For example, a wireless network that has been accessed, and that has been available for the greatest number of times in the past, may be selected to capture the first, then the wireless network to which you applied, or that has been available for the second greatest number of times in the past, may be selected to capture etc.

6 illustrates a method 600 performed by a terminal for network selection using cell information. Information for previously detected cells in wireless networks may be collected by the terminal and stored in the terminal (step 612). Information for the current location of the terminal may be obtained (block 614). Information for the current location may comprise identification information of a cell obtained based on broadcast information received from the cell, a position estimate for the current location of the terminal, and / or some other information. A wireless network to attempt acquisition may be selected based on information for the current location and the stored information for the previously detected cells (block 616).

The stored information for the previously detected cells may comprise radio technology and frequency information used to capture these cells, wireless networks to which these cells belong, preferences for these wireless networks, the identification information cells associated with each previously detected cell (e.g., cells, that were detected in the same location as the previously detected cell), location information for each previously detected cell, and / or other information. This information may be stored in the first table of information for wireless networks (e.g., Table 2), and, for each wireless network, a second table of information for the previously detected cells in that wireless network (e.g., Table 3). The first table may store information for a network identifier, preferences, radio technology and frequency band for each wireless network. The second table for each wireless network may store information for a cell identity, a frequency channel, a network identifier, and associated cells for each set of at least one previously detected cell in that wireless network. This information can also be stored in other formats, such as one large table.

All or a portion of the stored information for the previously detected cells may be sent to a designated wireless network, such as the serving network or a home network (step 618). Information for other cells may also be received from the designated wireless network (block 620).

7 illustrates a method 700 performed by a terminal for network selection using almanac information. The almanac information for cells in wireless networks may be received from the designated wireless network, such as the serving network or a home network (step 712) and stored (step 714). The almanac information may comprise information on cells available at different locations and information for capturing cells. The almanac information may also comprise information linking cells with overlapping coverage areas and belonging to different wireless networks, information only wireless networks utilizing radio technologies supported by the terminal, information for groups of cells instead of individual cells, information for cells in designated areas (e.g., airports ) etc. A wireless network to attempt acquisition may be selected based on the almanac information (block 716). Information for previously detected cells may be collected (step 718). Collected information that is suitable for use as almanac information may be sent to the designated wireless network (block 720).

8 illustrates a block diagram of a design of terminal 120, base station 312 and system controller 320. Base station 312 may be one of the base stations in Figure 3. System controller 320 may be a single network entity or a collection of network entities such as radio network controller (RNC), a mobile switching center (MSC), etc.

On the uplink or reverse link, data and signaling to be sent by terminal 120 are processed (e.g., formatted, encoded, and interleaved) by the encoder 822 and further processed (e.g., modulated, channelized (formed in the channel), and scrambled) by a modulator ( MOD) 824 to generate an output signal elements. A transmitter (TMTR) 832 then leads to the desired conditions (e.g., converts to analog, filters, amplifies, and frequency upconverts) the elements of the output signal and generates an uplink signal, which is transmitted via an antenna 834. On the downlink or forward link, antenna 834 receives a downlink signal transmitted by base station 312. A receiver (RCVR) 836 results in desired conditions (e.g., filters, amplifies, downconverts, and digitizes) the received signal from antenna 834 and provides samples. A demodulator (DEMOD) 826 processes (e.g., descrambles, forms a channel, and demodulates) the samples and provides symbol estimates. A decoder 828 further processes (e.g., deinterleaves and decodes) the symbol estimates and provides decoded data. Encoder 822, modulator 824, demodulator 826 and decoder 828 may be implemented by a modem processor 820. These units may perform processing in accordance with the radio technology (e.g., GSM, W-CDMA, CDMA 1X, HRPD, IEEE 802.11, etc.) used by the wireless network, received by terminal 120 or with which the terminal currently communicates. Terminal 120 may also receive signals from satellites 330 (e.g., GPS satellites) and may obtain a position estimate for its current location based on measurements for satellites and / or base stations using a suitable positioning method.

Controller / processor 840 controls the operation at terminal 120. Controller / processor 840 may perform processing 400 according to Figure 4, process 500 according to Figure 5, process 600 according to Figure 6, process 700 of Figure 7 and / or other processes for the selection network. Memory 842 stores program code and data for terminal 120 and may also store information used for network selection.

8 also shows the structure of a base station 312 and system controller 320. Base station 312 includes a controller / processor 850 that performs various functions for communication with the terminals, a memory 852 that stores program codes and data for base station 312 and the transceiver 854 that supports radio communication with the terminals. The system controller 320 includes a controller / processor 860 that performs various functions to support communication for the terminals and a memory 862 that stores program codes and data for system controller 320. Controller / processor 860 may send almanac and / or information to the terminals and / or may receive almanac and / or cell information from the terminals. Memory 862 may store cell information and / or almanac.

Those of skill would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips which can be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described herein with reference to the disclosure herein may be implemented as electronic hardware, software, or a combination thereof. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the current disclosure.

The various illustrative logical blocks, modules, and circuits described in connection with the disclosure herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine, A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with DSP core, or any other such configuration.

The steps of a method or algorithm described with reference to the disclosure herein may be embodied directly in hardware, in a software module executed by a processor, or a combination thereof. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, registers, hard disk, a removable disk, CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In an alternative embodiment, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. ASIC may reside in a terminal. In the alternative, the processor and the storage medium may reside as discrete components in the terminal.

The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the description is not intended to be limited to the examples described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed therein.