JP2015136028A - Wireless communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that it takes time longer than necessary, when a MS performs cell search according to a scanning rage or a frequency step defined by a wireless communication system.SOLUTION: When the destination area of a MS is specified, the MS receives a frequency list of the BS belonging to the destination area, before disconnecting a network. Depending on the content of that frequency list, the MS calculates a range to be scanned and the frequency step, and then creates and saves some search configurations. When arriving at the destination area and performing cell search, the MS shortens the time required for cell search significantly, by performing cell search using the search configurations thus created.

Description

  The present invention relates to a radio communication technique, and more particularly to a technique for speeding up cell search in a radio communication system.

  In general, when a wireless mobile station (hereinafter referred to as “MS” or “Mobile Station”) performs wireless communication, a network entry (“MS” refers to wireless communication) to a wireless communication system via a wireless base station (hereinafter referred to as “BS” or “Base Station”). Process for establishing a connection to the system network). Since network entry is performed via the BS, the MS performs a cell search and checks whether there is a BS having a communicable center frequency before executing the network entry. The MS scans radio waves in a predetermined frequency width (frequency step) within a scanning range (from a start frequency to an end frequency) assigned to the wireless communication system. If a BS with a communicable center frequency is detected during scanning, the MS synchronizes with that BS and then starts processing network entries.

  However, the width of the frequency step scanned by the MS is generally smaller than the width between the center frequencies used by the BS. For this reason, the cell search when scanning all the frequencies within the scanning range requires a very long time. For this reason, for example, in Patent Document 1, the scanning range is divided into a plurality of groups, the electric field strength is measured for each group, and the group with the strongest electric field strength is preferentially set as the object of scanning, so that We are proposing a technology to reduce time.

JP 2011-182148 A

  In the cell search, if the scanning range and frequency step are not devised, the MS may take more time than necessary for the cell search. In a wireless communication system that requires high reliability, it is better that the time until the MS starts communication is shorter. Therefore, the time required for the cell search of the MS needs to be as short as possible.

  AeroMACS (Aeronautical Mobile Airport Communication System) built on the basis of Mobile WiMAX (Worldwide Interoperability for Microwave Access) is one of the target wireless communication systems. AeroMACS is applicable to airports. AeroMACS provides high-speed mobile communication systems for aviation. Aviation operations are mission critical tasks that involve even human life. In order to realize quick and appropriate communication, it is desirable to shorten the time required for starting communication as much as possible.

  As an example of cell search in AeroMACS, when scanning all the frequencies in the scanning range, the start frequency is 5095 MHz, the end frequency is 5145 MHz, the frequency step is 250 kHz, so the MS is in order from 5095 MHz to 5145 MHz in 250 kHz steps Perform cell search with. Since the width between the center frequencies of BS used in AeroMACS is 5 MHz (BS center frequency is selected from 5095 MHz, 5100 MHz, 5105 MHz, ..., 5145 MHz), cells in very fine frequency steps A search will be performed. In the case of the above condition, when the center frequency used by the BS to be connected is 5095 MHz, the MS completes the cell search in one scan. However, when the center frequency used by the BS to be connected is 5145 MHz, the MS needs 201 scans for cell search. This difference in the number of scans may cause a difference of several tens of seconds. Compared to the network entry processing time (several seconds), the worst case cell search processing time is very long.

In order to solve the above-described problems, in the present invention,
At least one first radio base station installed at the first airport, at least one second radio base station installed at the second airport, and at least one of the first radio base station and the second radio base station A wireless communication system including a wireless mobile station that communicates wirelessly with a frequency management device,
The frequency management device includes a control unit that transmits and receives messages, a center frequency used by a second radio base station installed at a second airport, and information on a runway of the second airport that is covered by the second radio base station. And a storage unit that stores the information in association with each other,
The wireless mobile station includes a mobile station controller that transmits and receives messages,
When the radio mobile station heads from the first airport to the second airport, the mobile station control unit sends a message requesting information on the center frequency used by the second radio base station installed in the second destination airport, When the message is received, the control unit of the frequency management device uses the second radio base station installed at the second airport stored in the storage unit and transmits it to the frequency management device via the first radio base station. Provided is a radio communication system for transmitting a center frequency and information on a runway of the second airport covered by a second radio base station to a radio mobile station via the first radio base station.

  According to the present invention, the time for cell search by MS can be shortened.

It is a figure which shows the structure of an AeroMACS network. It is a block diagram which shows the structure of MS. It is a block diagram which shows the structure of a frequency management server. It is a sequence diagram which shows the process which updates a frequency list. It is a figure which shows the example of an own airport frequency list. It is a figure which shows the example of another airport frequency list. It is a sequence diagram which shows a process when MS receives a frequency list. It is a flowchart which shows the process which produces a runway search configuration. It is a flowchart which shows the process which produces an airport search config. It is a figure which shows the example of a search list. It is a figure which shows the cover area of the airplane and the BS installed in the airport before landing at the airport. It is a flowchart which shows the process which performs a cell search using a runway search configuration. It is a flowchart which shows the process which performs a cell search using an airport search config. It is an image figure at the time of performing a cell search using runway search configuration A. It is an image figure at the time of performing a cell search using runway search configuration B. It is an image figure at the time of performing a cell search using an airport search config. It is an image figure at the time of performing a cell search using default search configuration.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment of the present invention is merely an embodiment, and the present invention is not limited to this embodiment.

  FIG. 1 is a diagram showing a configuration of an AeroMACS network in the present embodiment. The AeroMACS network includes an ASN (Access Service Network) 109, a CSN (Connectivity Service Network) 110, and a frequency management server 108. The ASN 109 provides a physical layer and MAC layer connection function such as a wireless connection function with the MS 101 and wireless resource management. The ASN 109 is composed of BSs 102 to 104 that are radio base stations and an ASN-GW (Access Service Network Gateway) 105. The CSN 110 provides IP connection functions such as IP address distribution to the MS 101 and communication record processing. The CSN 110 includes an AAA (Authentication Authorization Accounting) server 106 and an HA (Home Agent) server 107 that provide these functions.

  In this wireless communication system, the MS 101 is a wireless mobile station installed in an airplane that moves from the A airport 111 to the B airport 121, for example. The MS 101 is connected to the frequency management server 108 and the Internet via the BSs 102 to 104 while at the A airport 111. Also, when taking off from A airport 111, the connection with BS102-104 is cut off, and when it arrives at destination B airport 121, a new cell search is performed, and BS112-114 installed at B airport 121 Check if there is a BS with a center frequency that can be communicated. Specifically, the MS 101 scans radio waves with a frequency range (frequency step) in which a predetermined scanning range (from the start frequency to the end frequency) is determined based on the search configuration. If a BS having a communicable center frequency is detected during scanning, the MS 101 synchronizes with the BS and subsequently performs network entry processing.

  The description of the network configuration of the B airport 121 that can communicate via the A airport 111 and the Internet 122 is the same as the network configuration of the A airport 111, and therefore will be omitted. In FIG. 1, only one MS is shown, but naturally a plurality of MSs can be connected to each BS. In addition, the frequency management servers 108 and 118 are configured to be installed separately at the airport A 111 and the airport B 121, but instead of being installed at each airport, for example, a centralized frequency management server is provided on the Internet 122. It is good also as a structure to install.

  FIG. 2 is a block diagram showing the configuration of the MS. The MS 201 includes a wireless communication unit 205 for communicating with the BS, a baseband unit 204 for performing radio signal modulation and demodulation processing, a search list creating unit 202 for creating a search list, a recording unit 208 for recording data, and the MS 201 It is comprised from the control part 203 which performs each control of these. The radio unit 205 includes a radio transmission unit 206 that transmits radio signals and a radio reception unit 207 that receives radio signals. The storage unit 208 holds a search list 209 and a frequency list 210.

  FIG. 3 is a block diagram showing the configuration of the frequency management server. The frequency management server 301 includes a communication unit 302 for communicating with a BS connected to a network, a recording unit 305 for recording data, a frequency list updating unit 304 for updating a frequency list included in the recording unit 305, and frequency management It is comprised from the control part 303 which performs each control of a server. The recording unit 305 includes a local airport frequency list 306 including information on a center frequency used by a BS installed at its own airport, and another airport frequency list including information on a center frequency used by a BS installed at another airport. Hold 307.

  FIG. 5 is a diagram illustrating an example of the own airport frequency list managed by the frequency management server. This example is the own airport frequency list 306 managed by the frequency management server 108 of the A airport 111. The own airport frequency list 306 stores information on the BSs 102 to 104 installed at the airport A 111, and “BSID”, which is a BS identifier for identifying each BS, and information on the airport where the BS is installed. "Airport" indicating the field, "Runway" indicating the information of the runway covered by the BS as a communication area, and "Center frequency" indicating the information of the center frequency used by the BS.

  FIG. 6 is a diagram illustrating an example of another airport frequency list managed by the frequency management server. This example is the other airport frequency list 307 managed by the frequency management server 108 of the A airport 111. The other airport frequency list 307 stores information on BSs installed at airports other than airport A 111. Like the own airport frequency list, “BSID”, “airport”, “runway”, “center frequency” ] Field. In this example, information on airports B, C, and D connected to airport A via the Internet is stored.

  FIG. 4 is a sequence diagram illustrating processing for updating a frequency list managed by the frequency management server. The control unit 303 of the frequency management server 118 creates an update confirmation message 401 including the own airport frequency list 306 read from the storage unit 305, and transmits the update confirmation message 401 to the BSs 112 to 114 installed at the own airport via the communication unit 302. . The update confirmation message 401 is transmitted to confirm whether the center frequency used by each BS has changed.

  With the reception of the update confirmation message 401, the BSs 112 to 114 refer to this list and confirm whether the center frequency used by the BS 112 to 114 has changed. If the center frequency to be used has changed, the BS transmits an update message 402 including information on the new center frequency to the frequency management server 118.

  The control unit 303 of the frequency management server 118 receives the update message 402 via the communication unit 302, and instructs the frequency list update unit 304 to update the own airport frequency list 306 included in the storage unit 305. . The frequency list updating unit 304 updates the own airport frequency list 306 included in the storage unit 305 using information on the new center frequency in accordance with an instruction from the control unit 303.

  After the update of the own airport frequency list is completed, the control unit 303 of the frequency management server 118 of the B airport 121 creates a server update message 403 including the own airport frequency list 306 read from the storage unit 305, and the communication unit 302 To the frequency management server 108 of the airport A 111.

  The control unit 303 of the frequency management server 108 receives the server update message 403 via the communication unit 302, and instructs the frequency list update unit 304 to update the other airport frequency list 307 included in the storage unit 305. To do. The frequency list updating unit 304 updates the other airport frequency list 307 included in the storage unit 305 using the information of the own airport frequency list 306 transmitted from the frequency management server 118 of the B airport 121 according to the instruction of the control unit 303. .

  In FIG. 4, the description has been made on the assumption that the frequency management servers are installed separately at the airport A 111 and the airport B 121. However, for example, a centralized frequency management server is installed on the Internet 122. It does not matter. In that case, the centralized frequency management server transmits the update confirmation message 401 to each of the BSs 102 to 104 of the airport A 111 and the BSs 112 to 114 of the airport B 121, and receives the update message 402 from each. . In this case, since the centralized frequency management server collectively manages the frequency list of each airport without distinguishing between its own airport and other airports, it is not necessary to transmit the server update message 403. Also in the embodiments described below, the present invention can be applied by replacing the frequency management server installed at each airport with a centralized frequency management server.

  FIG. 7 is a sequence diagram showing processing when the MS receives a frequency list. When the destination airport is determined, the control unit 203 of the MS 101 at the airport A 111 creates a message 701 for requesting a frequency list including information on the center frequency used by the base station installed at the destination airport, and the baseband The data is transmitted to the frequency management server 108 via the unit 204 and the wireless transmission unit 206. BS 103 relays frequency list request message 701 and transmits frequency list request message 702 to frequency management server 108.

  The control unit 303 of the frequency management server 108 receives the frequency list request message 702 via the communication unit 302. Then, the control unit 303 extracts the requested destination airport information (for example, all records related to the airport B) from the other airport frequency list 307 in the storage unit 305, and creates a frequency list response message 703 based on the information. To do. The control unit 303 transmits the created frequency list response message 703 via the communication unit 302.

  BS 103 relays frequency list response message 703 and transmits frequency list transmission message 704 to MS 101.

  The control unit 203 of the MS 101 receives the frequency list response message 703 via the wireless reception unit 207 and the baseband unit 204. The control unit 203 stores the received information in the frequency list 210 of the storage unit 208. The frequency list 210 has the same configuration as the other airport frequency list 307 described with reference to FIG. 6 and includes fields of “BSID”, “airport”, “runway”, and “center frequency”. When the destination is B airport, all records in which the “airport” field is “B airport” in the other airport frequency list 307 of FIG.

  After storing the destination airport information in the frequency list 210, the control unit 203 of the MS 101 sends a DREG-REQ (De-registration request) message 705 for requesting deregistration to the radio base station that is currently communicating. It is created and transmitted to the BS 103 via the baseband unit 204 and the wireless transmission unit 206. Upon receiving the DREG-REQ message 705, the BS 103 transmits a DREG-CMD (DREG command) message 706 indicating a deregistration command to the MS 101, and disconnects the MS 101 connection.

  FIG. 8 is a flowchart showing a process in which the MS creates a runway search configuration based on the frequency list 210. The search list creation unit 202 of the MS 101 reads out a frequency list related to a BS that covers a predetermined runway of a destination airport as a communication area from the frequency list 210 of the storage unit 208 (step 802). The search list creation unit 202 determines a search configuration creation method to be created according to the number of BSs including the read predetermined runway as a cover area (step 803). For example, referring to the frequency list of FIG. 6, it is determined that there is one BS that covers the runway A of the airport B, and that there are two BSs that cover the runway B of the airport B.

When there are a plurality of BSs covering the predetermined runway in step 803, the search list creation unit 202 sets the start frequency, end frequency, and frequency step size as in the following (A-1) to (A-3). Define and create a search config for use in cell search (step 804).
(A-1) The minimum center frequency is set as the start frequency among the center frequencies used by a plurality of read BSs.
(A-2) Set the maximum center frequency as the end frequency among the center frequencies used by multiple read BSs.
(A-3) Set the frequency step size to 5 MHz.

  Note that the frequency step size of (A-3) may be determined as appropriate according to the width between the center frequencies of the BS employed in the wireless communication system, and AeroMACS is assumed as the wireless communication system as in this embodiment. If so, set the frequency step size to 5 MHz. When there are a plurality of wireless networks to be connected, search list creating section 202 sets a frequency step size according to the width between the center frequencies of BSs defined by the wireless network. However, in the present embodiment, since the MS is connected only to the AeroMACS network, the search list creation unit 202 sets the frequency step size to a fixed value (5 MHz).

On the other hand, when there is only one BS covering the predetermined runway in step 803, the search list creation unit 202 starts the start frequency, end frequency, and frequency step as in the following (B-1) to (B-2). Define the size and create a search config (step 805).
(B-1) Set the center frequency used by one read BS as the start frequency and end frequency.
(B-2) The frequency step size is not set (since there is only one BS for cell search execution).

  In this way, in steps 804 and 805, the search list creation unit 202 creates a search configuration (runway search configuration) for each runway at the destination airport, and holds it in the search list 209 of the storage unit 208. An example of the search list 209 will be described later with reference to FIG.

  The search list creation unit 202 confirms whether or not BS frequency information has been read for all runways included in the destination airport (step 806). If there is BS information of the runway that has not been read yet, the process returns to step 802, the frequency information of the BS covering another runway is read, and a search configuration for the runway is created (steps 803 to 805). Thus, a runway search configuration is created for every runway at the destination airport and stored in the search list 209 of the storage unit 208.

  FIG. 9 is a flowchart showing a process in which the MS creates an airport search configuration based on the frequency list 210. The search list creation unit 202 of the MS 101 reads a frequency list related to the BS installed at the destination airport from the frequency list 210 of the storage unit 208 (step 902). The search list creation unit 202 determines a search configuration creation method to be created according to the number of BSs including the destination airport as a cover area (or a BS installed at the destination airport) (step 903). For example, taking the frequency list in FIG. 6 as an example, it is determined that there are three BSs covering the airport B.

When there are a plurality of BSs installed at the destination airport in step 903, the search list creation unit 202 sets the start frequency, end frequency, and frequency step size as in the following (C-1) to (C-3). A search configuration is defined and used for cell search (step 904).
(C-1) Among the center frequencies used by the read multiple BSs, the minimum center frequency is set as the start frequency.
(C-2) Set the maximum center frequency as the end frequency among the center frequencies used by multiple read BSs.
(C-3) Set the frequency step size to 5 MHz.

  Similar to the runway search configuration, the frequency step size may be appropriately determined according to the width between the center frequencies of the BS employed in the wireless communication system.

On the other hand, when there is only one BS installed at the destination airport in step 903, the search list creation unit 202 performs start frequency, end frequency, and frequency step as in the following (D-1) to (D-2). Define the size and create a search config (step 905).
(D-1) Set the center frequency used by one read BS as the start frequency and end frequency.
(D-2) The frequency step size is not set (since there is only one BS for cell search execution).

  In this way, in steps 904 and 905, search list creating section 202 creates a destination airport search configuration (airport search configuration) and stores it in search list 209 of storage section 208.

  FIG. 10 is a diagram showing an example of the search list 209 held by the MS 101. As shown in FIG. Search list 209 includes runway search config A1001 and runway search config B1002 created in the flow of FIG. 8, airport search config 1003 created in the flow of FIG. 9, and default search config 1004, and the MS is the destination. Used when performing cell search at airport B. As described with reference to FIGS. 8 and 9, each search configuration includes fields for scanning (from a start frequency to an end frequency) and a frequency step size.

  The control unit 203 of the MS 101 preferentially uses the runway search configuration A1001 when landing on the runway A1102 of the destination B airport B121. When the cell search using the runway search configuration A1001 fails, the control unit 203 of the MS101 performs a cell search using the default search configuration 1004 as a recovery measure.

  The control unit 203 of the MS 101 preferentially uses the runway search configuration B1003 when landing on the runway B1103. When the cell search using the runway search configuration B 1003 fails, the control unit 203 of the MS 101 performs a cell search using the default search configuration 1004 as a recovery measure.

  The default search configuration 1004 is defined by a scanning range and a frequency step size defined in the wireless communication system, and is stored in the search list 209 in advance. In this embodiment, AeroMACS is assumed as the wireless communication system. Therefore, when performing a cell search using the default search configuration 1004, the MS 101 performs a cell search between 5095 MHz and 5145 MHz with a frequency step size of 250 kHz. Run.

  Since only the AeroMACS network is targeted in this embodiment, there is only one default search configuration in the search list 209. If the MS 101 is a terminal connected to a plurality of wireless communication systems, the search list 209 includes as many default search configurations as the number of wireless communication systems.

  FIG. 11 is a diagram showing the airplane 1101 before landing at the destination B airport 121 and the cover areas 1104 to 1106 of the BSs 112 to 114 installed at the B airport 121. Cover areas 1104 to 1106 indicate ranges in which BSs 112 to 114 installed at B airport 121 can be connected to the MS. For example, in order for the MS installed in the airplane 1101 to communicate with the BS 112, it must be inside the cover area 1104. Runway A1102 is included in the cover area 1104 of BS112. A part of runway B1103 is included in a cover area 1105 of BS113 and a cover area 1106 of BS114. That is, the MS communicates with the BS 112 when traveling on the runway A1102, and communicates with the BS 113 and BS 114 when traveling on the runway B1103.

  FIG. 12 is a flowchart showing a process for executing a cell search using a runway search configuration at an airport to which the MS is destined. After determining the runway to land at the destination airport, the control unit 203 of the MS 101 reads the runway search configuration and the default search configuration of the runway to land from the search list 209 of the storage unit 208 (step 1202).

  The control unit 203 determines whether or not it has entered the cover area of the BS installed at the airport (step 1203). When the MS enters the cover area, the control unit 203 executes a cell search using the runway search configuration (step 1204). The control unit 203 confirms whether or not the BS has been detected using the runway search configuration (step 1205). If it cannot be detected, the control unit 203 performs a cell search using the default search configuration (step 1206). The control unit 203 confirms whether or not a BS has been detected using the default search configuration (step 1207). The control unit 203 continues to execute the cell search using the default search configuration until the BS is continuously detected. When the control unit 203 of the MS 101 detects a communicable BS in step 1205 or step 1207, the cell search process is completed (step 1208), and synchronization with the detected BS is performed, followed by the network entry process. Start.

  It is desirable that the control unit 203 uses the runway search configuration only at the stage before the network entry executed for the first time after landing at the airport. Once the network entry is made, the control unit 203 of the MS 101 executes a cell search using the airport search configuration 1003 when disconnected from the network and connected again to the BS installed in the airport.

  FIG. 13 is a flowchart showing a process for executing a cell search using an airport search configuration. When the network entry is completed by the process of FIG. 12 (step 1302), the control unit 203 of the MS 101 reads the airport search configuration and default search configuration of the landing airport from the search list 209 of the storage unit 208 (step 1303).

  The control unit 203 checks whether the MS 101 is disconnected from the network after the network entry of the MS 101 is completed (step 1304). When the network entry is made again after the MS 101 is disconnected from the network, the control unit 203 executes a cell search using the airport search configuration 1003 (1305). The control unit 203 confirms whether or not the BS has been detected using the airport search configuration 1003 (step 1306). If the BS cannot be detected, the control unit 203 performs a cell search using the default search configuration 1004 (step 1307). The control unit 203 continues to execute the cell search using the default search configuration 1004 until the BS is continuously detected. In step 1306 or step 1308, when the MS 101 detects a communicable BS, the cell search process is completed (step 1309), synchronization with the detected BS is performed, and then network entry process is started.

  It should be noted that the control unit 203 of the MS 101 executes the cell search using the airport search configuration 1003 or the default search configuration 1004 until the next destination airport of the MS 101 is determined and the aircraft takes off.

  Here, a cell search executed at the time of handover will be described. As a cell search method performed at the time of handover, a cell search method defined by mobile WiMAX is adopted. After the network entry is completed, the MS 101 receives an NBR-ADV (Neighbor Advertisement) message from the BS as broadcast information. The NBR-ADV message includes the center frequency used by the adjacent BS as information. When switching the BS to be connected (when handing over), the mobile WiMAX standard stipulates that only this center frequency be cell-searched.

  FIG. 14 is an execution image diagram when a cell search is performed by runway search configuration A1001. MS101 scans only 5095MHz. The MS101 scans only once.

  FIG. 15 is an execution image diagram when the cell search is performed by the runway search configuration B1002. The MS101 scans from 5100 MHz to 5105 MHz with a frequency step of 5 MHz. The number of times MS101 scans is at most twice.

  FIG. 16 is an execution image diagram when a cell search is performed with the airport search configuration 1003. The MS101 scans from 5095 MHz to 5105 MHz with a frequency step of 5 MHz. The MS101 scans at most three times.

  FIG. 17 is an execution image diagram when a cell search is performed with the default search configuration 1004. The MS101 scans between 5095 MHz and 5145 MHz with a frequency step of 250 kHz. In the worst case, the MS101 scans 201 times.

  Execution of cell search using the default search configuration is a recovery measure when cell search using the runway search configuration and airport search configuration fails. The MS performs a cell search using the runway search configuration and airport search configuration only once. After that failure, the MS performs a cell search using the default search configuration. The MS 101 repeatedly performs a cell search using the default search configuration until a communicable BS is detected.

  As can be seen from the examples of FIGS. 14 to 17, when the cell search is executed using the runway search configuration and the airport search configuration, the cell search is executed as compared with the case where the cell search is executed using the default search configuration. The number of scans required for the search is greatly reduced. Therefore, the time required for cell search can be greatly shortened.

  As described above, according to the present embodiment, before the MS performs a cell search at a destination, the center frequency used by the BS subject to cell search is given to the MS in advance, so Time can be shortened. Further, since the MS has a function of changing the frequency step size, the present invention can be applied to an MS connected to a plurality of wireless communication systems having different widths between center frequencies used by the BS. Is possible.

  In the present embodiment, the wireless communication system at the airport has been described as an example. However, the present invention can be applied to a scene where the MS disconnects from the network and moves to another area even outside the airport. In that case, when the destination area is specified, the MS receives a frequency list of BSs belonging to the destination area before disconnecting the network. Depending on the contents of the frequency list, the MS calculates the scanning range and frequency step, and creates and saves several search configurations. When performing a cell search in that area, the MS performs a cell search using the created search config and attempts to speed up the cell search. If the BS cannot be detected within the scanning range defined in the search configuration, the MS searches the BS by scanning the scanning range defined in the wireless communication system with fine frequency steps as a recovery measure.

  Further, the scope of application of the present invention is not limited to AeroMACS. For example, the present invention can be applied to all wireless communication networks such as LTE (Long Term Evolution) and WiMAX that are currently in practical use and wireless communication networks that are expected to be used in the future.

  101: MS, 102-104, 112-114: BS, 105, 115: ASN-GW, 106, 116: AAA server, 107, 117: HA server, 108, 118: Frequency management server, 109, 119: ASN, 110, 120: CSN, 111: Airport A, 121: Airport B, 122: Internet, 201: MS, 202: Search list creation unit, 203: Control unit, 204: Baseband unit, 205: Wireless communication unit, 206: Wireless transmission unit, 207: Radio reception unit, 208: Recording unit, 209: Search list, 210: Frequency list, 301: Frequency management server, 302: Communication unit, 303: Control unit, 304: Frequency list update unit, 305: Recording unit, 306: Own airport frequency list, 307: Other airport frequency list, 1101: Airplane, 1102: Runway A, 1103: Runway B 1104~1106: BS coverage area of

Claims (12)

At least one first radio base station installed at the first airport, at least one second radio base station installed at the second airport, the first radio base station, and the second radio base station. A wireless communication system including a wireless mobile station that communicates with at least one wirelessly and a frequency management device,
The frequency management device includes:
A control unit for sending and receiving messages;
A storage unit that associates and stores a center frequency used by a second radio base station installed at the second airport and information on a runway of the second airport that is covered by the second radio base station;
With
The wireless mobile station is
A mobile station controller that sends and receives messages,
When the wireless mobile station heads from the first airport to the second airport,
The mobile station control unit sends a message requesting information on a center frequency used by the second radio base station installed at the second airport to the destination to the frequency management device via the first radio base station. Send
When the control unit of the frequency management device receives the message, the control unit stores the central frequency used by the second radio base station installed in the second airport and stored in the storage unit, and the second radio base station A wireless communication system, wherein information on the runway of the second airport to be covered is transmitted to the wireless mobile station via the first wireless base station. The wireless communication system according to claim 1,
The wireless mobile station further includes:
A mobile station storage unit that stores a search configuration for performing a cell search,
When the mobile station control unit receives information on the center frequency and the runway from the frequency management device and determines that there are a plurality of the second radio base stations covering the runway, Among the center frequencies used by one second radio base station, the minimum center frequency and the maximum center frequency are set as a start frequency and an end frequency, respectively, and a predetermined frequency width is set as a frequency step during scanning. A wireless communication system, characterized in that a runway search configuration is created and stored in the mobile station storage unit. The wireless communication system according to claim 2,
When the mobile station control unit determines that the number of the second radio base stations covering the runway is one, the mobile station control unit scans the center frequency used by the one second radio base station by a cell search. A wireless communication system, characterized in that a runway search configuration having a start frequency and an end frequency is created and stored in the mobile station storage unit. A wireless communication system according to claim 3,
The mobile station control unit, when receiving information on a plurality of runways from the frequency management device, creates the runway search configuration for each runway. The wireless communication system according to claim 4,
When the wireless mobile station moves from the first airport to the second airport and enters a coverage area of the second wireless base station that covers a predetermined runway to land,
The radio communication system, wherein the mobile station control unit performs a cell search using a runway search configuration of the predetermined runway stored in the mobile station storage unit. The wireless communication system according to claim 5,
The mobile station storage unit stores a default search configuration used in the wireless communication system,
The mobile station control unit performs a cell search using the runway search configuration of the predetermined runway, and when the second radio base station is not detected, performs a cell search using the default search configuration. A wireless communication system, characterized in that: The wireless communication system according to claim 6,
The mobile station control unit receives information on the center frequency and the runway from the frequency management device, and determines that there are a plurality of the second radio base stations installed at the second airport, Among the center frequencies used by the plurality of second radio base stations, the minimum center frequency and the maximum center frequency are respectively set as a start frequency and an end frequency for scanning by cell search, and a predetermined frequency width is a frequency step at the time of scanning. A wireless communication system, wherein an airport search configuration is created and stored in the mobile station storage unit. The wireless communication system according to claim 7,
If the mobile station control unit determines that there is one second radio base station installed at the second airport, a cell search is performed for a center frequency used by the one second radio base station. A radio communication system, characterized in that an airport search configuration having a start frequency and an end frequency to be scanned is created and stored in the mobile station storage unit. A wireless communication system according to claim 8,
After the wireless mobile station performs a cell search using the runway search configuration or the default search configuration, detects the second wireless base station and performs network entry, the wireless mobile station If you are disconnected from the network,
The mobile station control unit performs a cell search using the airport search config stored in the mobile station storage unit. The wireless communication system according to claim 9, wherein
The mobile station control unit performs a cell search using the airport search config and performs a cell search using the default search config when the second radio base station is not detected. Wireless communication system. A wireless communication system according to any one of claims 1 to 10,
The frequency management device is a first frequency management device installed at the first airport, and a second radio base station installed at the second airport from the second frequency management device installed at the second airport. A wireless communication system characterized by receiving information on a center frequency used by and storing the information in the storage unit. A wireless communication system according to claim 11, wherein
The second frequency management device transmits a confirmation message inquiring whether or not a center frequency to be used is updated to the second radio base station, and notifies the updated center frequency from the second radio base station. When a response message is received, an update message including the updated center frequency is transmitted to the first frequency management device.

Images