JP2008205743A - Control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid occurrence of interference between both communication systems even when a WiMAX (Worldwide Interoperability for Microwave Access) system using a frequency band which is adjacent to a frequency band used in an existing satellite mobile communication system, is introduced in an ambient where the existing system is being introduced. <P>SOLUTION: The control device 10 of the invention is provided with a position information acquisition unit 11 which is composed to acquire the position information of a communication terminal 50 for satellite communication, and a channel assignment unit 16 which is composed so that a channel for satellite communication is assigned out of channels in the frequency band for satellite communication based on the interference area information which shows an interference area where interference due to WiMAX communication occurs in the satellite communication system and the position information of the communication terminal 50. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention provides a first communication system that performs first communication using a channel in a first frequency band, and a second communication channel that uses a channel in a second frequency band adjacent to the first frequency band. The present invention relates to a control device used in a mobile communication system including a second communication system that performs the above communication.

  Conventionally, as shown in FIG. 1, a satellite mobile communication system is known that is performed using a satellite communication space station 30, a satellite communication earth station 10, and a satellite communication mobile station 50.

  In such a satellite mobile communication system, as shown in FIG. 2, a part or all of the frequency band of 2500 MHz to 2535 MHz is used for downlink communication from the satellite communication space station 30 to the satellite communication mobile station 50. A part or all of the frequency band of 2655 MHz to 2690 MHz is used for uplink communication from the satellite communication mobile station 50 to the satellite communication space station 30.

  In recent years, “WiMAX (World Wide Interoperability for Microwave Access)” has been defined as a standard for fixed wireless communication.

As shown in FIG. 1, it is assumed that WiMAX communication base station 70 and WiMAX communication mobile station 90 are installed to perform WiMAX communication in an environment where the above-described satellite communication is performed.
Japanese Patent Laid-Open No. 11-510992

  However, in the above-described examination, it is assumed that a frequency band of 2535 MHz to 2605 MHz is used for WiMAX communication, and therefore, there are a frequency band used in WiMAX communication and a frequency band used in downlink communication in the satellite communication described above. As a result of being adjacent, there is a problem in that interference occurs between both communications (specifically, between downlink communications and WiMAX communications in satellite communications).

  Therefore, the present invention has been made in view of the above-described problems, and uses a frequency band adjacent to a frequency band used in an existing satellite mobile communication system in an environment where the existing satellite mobile communication system is introduced. An object of the present invention is to provide a control device that can avoid the occurrence of interference between both communication systems even when a WiMAX communication system is introduced.

  According to a first aspect of the present invention, there is provided a first communication system that performs a first communication using a channel in a first frequency band, and a channel in a second frequency band adjacent to the first frequency band. And a second communication system that performs second communication using the control device, and is configured to acquire position information of a communication terminal that performs the second communication. In the second frequency band, based on interference area information indicating an interference area in which interference from the first communication occurs in the second communication system and position information of the communication terminal. And a channel allocation unit configured to allocate the second communication channel from among the channels.

  In the first feature of the present invention, the channel allocating unit calculates a distance between a control device in the first communication system and a communication terminal in the second communication system, using position information of the communication terminal. Based on the calculated distance, the second communication channel may be allocated from the channels in the second frequency band.

  According to this invention, in an environment where the first communication system and the second communication system are mixed, the interference between the two communication systems can be measured without measuring the interference state in the second communication system. Occurrence can be avoided.

  In the first aspect of the present invention, the channel allocation unit is configured to sequentially allocate the second communication channel from a channel closer to the first frequency band within the second frequency band. May be.

  According to this invention, based on the position information and interference area information of the communication terminal (satellite communication mobile station) that performs the second communication, the communication terminal generates interference from the first communication (WiMAX communication). When the second communication channel (satellite communication channel) is allocated from the channel closer to the first frequency band when it does not exist in the interference area, the first communication described above is performed. In an environment where the system and the second communication system coexist, it is possible to avoid the occurrence of interference between the two communication systems and to realize efficient frequency utilization.

  In the first aspect of the present invention, the apparatus includes a moving speed acquisition unit configured to acquire a moving speed of the communication terminal, and the channel allocation unit is configured to perform the first operation based on the moving speed of the communication terminal. The second communication channel may be allocated from among the channels in the two frequency bands.

  According to this invention, when the communication terminal that performs the second communication moves at a high speed, the communication terminal enters the interference area before the completion of the second communication, as compared with the case where the communication terminal is stationary. In consideration of the high possibility, the channel for the second communication can be allocated.

  In the first feature of the present invention, the channel allocating unit is configured to select the second communication from the channels in the second frequency band based on whether the communication terminal is a portable type or a fixed type. May be configured to allocate a dedicated channel.

  According to this invention, when the communication terminal that performs the second communication is portable, there is a possibility that the communication terminal may enter the interference area before the second communication is completed, compared to the case where the communication terminal is fixed. Therefore, the second communication channel can be allocated.

  In the first feature of the present invention, the channel allocating unit, based on an interference situation in the communication terminal, can be selected from the channels in the second frequency band when the location information of the communication terminal is not acquired. The second communication channel may be allocated.

  According to this invention, in the environment where the first communication system and the second communication system described above are mixed, even if the position information of the communication terminal performing the second communication cannot be acquired, both communication Interference between systems can be avoided.

  In the first feature of the present invention, the channel allocator, from the channel on the side away from the first frequency band in the second frequency band, when the location information of the communication terminal is not acquired. The second communication channel may be sequentially assigned.

  According to this invention, in the environment where the first communication system and the second communication system described above are mixed, when the position information of the communication terminal performing the second communication cannot be acquired, the communication terminal Since it cannot be determined whether or not it exists in the interference area, the occurrence of interference between the two communication systems is avoided by assigning a channel that is not easily affected by interference from the channel in the first frequency band. Can do.

  As described above, according to the present invention, a WiMAX communication system using a frequency band adjacent to a frequency band used in an existing satellite mobile communication system is introduced in an environment where the existing satellite mobile communication system is installed. Even in this case, it is possible to provide a control device that can avoid the occurrence of interference between the two communication systems.

(Mobile communication system according to the first embodiment of the present invention)
With reference to FIG. 1 thru | or FIG. 7, the structure of the mobile communication system which concerns on the 1st Embodiment of this invention is demonstrated.

  As shown in FIG. 1, the mobile communication system according to the present embodiment includes a satellite mobile communication system (second communication) including a satellite communication space station 30, a satellite communication earth station 10, and a satellite communication mobile station 50. The WiMAX communication system (first communication system) including the WiMAX communication base station 70 and the WiMAX communication mobile station 90 is introduced into the environment in which the system is installed.

  Here, the satellite mobile communication system according to the present embodiment enables communication via a geostationary satellite, and applies an FDMA (Frequency Division Multiple Access) method and an SCPC (Single Channel Per Carrier) method. is doing.

  That is, in the satellite mobile communication system in the present embodiment, when each user performs communication using the satellite communication mobile station 50, one channel multiplexed by the FDMA method is assigned to such communication. It is configured.

  In such satellite communication, as shown in FIG. 2, the frequency band (second frequency band) of 2500 MHz to 2535 MHz is used for downlink communication from the satellite communication space station 30 to the satellite communication mobile station 50. In the upstream communication from the satellite communication mobile station 50 to the satellite communication space station 30, a frequency band of 2655 MHz to 2690 MHz is used.

  On the other hand, the WiMAX communication system according to the present embodiment enables fixed wireless communication in accordance with the standard “WiMAX” defined by WiMAX Forum, and applies a multi-carrier scheme (OFDMA: Orthogonal Division Multiple Access) scheme. is doing.

  That is, in the WiMAX communication system according to the present embodiment, when each user performs communication using the satellite communication mobile station 50, one or a plurality of channels multiplexed by the OFDMA method are assigned to the communication. It is configured as follows.

  The “channel” used in the present specification may be at least frequency-divided, and may be frequency-divided and further time-divided or code-divided.

  In such WiMAX communication, as shown in FIG. 2, the downlink communication from the WiMAX communication base station 70 to the WiMAX communication mobile station 90 and the uplink from the WiMAX communication mobile station 90 to the WiMAX communication base station 70 are performed. A frequency band (first frequency band) of 2535 MHz to 2655 MHz is used for both communications.

  In such WiMAX communication, the above-described frequency band of 2535 MHz to 2655 MHz is divided into 20 MHz band modes that are divided and used for each 20 MHz band, 10 MHz band mode that is divided and used for each 10 MHz band, and divided into 5 MHz bands. The 5 MHz band mode to be used is switched and used.

  The satellite communication earth station 10 according to the present embodiment is a control device configured to allocate a channel for satellite communication used for communication by the mobile station 90 for satellite communication, as shown in FIG. It includes a position information acquisition unit 11, a moving speed acquisition unit 12, a mobile station information management unit 13 for satellite communication, a base station information management unit 14 for WiMAX communication, a margin management unit 15, and a channel allocation unit 16. ing.

  The position information acquisition unit 11 is configured to acquire position information of the satellite communication mobile station 50 (a communication terminal that performs second communication). Specifically, the position information acquisition unit 11 may be configured to acquire the position information of the satellite communication mobile station 50 using the GPS function.

  The moving speed acquisition unit 12 is configured to acquire the moving speed of the satellite communication mobile station 50.

  Specifically, the moving speed acquisition unit 12 acquires the moving speed of the satellite communication mobile station 50, and sets the acquired moving speed of the satellite communication mobile station 50 to “stationary”, “quasi-stationary”, and “low-speed movement”. ”Or“ high-speed movement ”, and the classification result is recorded in the satellite communication mobile station information management unit 13 as the movement state of the satellite communication mobile station 50. .

  For example, the movement speed acquisition unit 12 may be configured to determine the movement speed of the satellite communication mobile station 50 based on the movement distance in the past predetermined period. The mobile communication station 50 may be configured to determine the moving speed of the satellite communication mobile station 50 based on the amount of channel fluctuation established in the above, or the satellite communication mobile station 50 type (portable or fixed type). The moving speed of the satellite communication mobile station 50 may be determined based on the above.

  As shown in FIG. 4, the satellite communication mobile station information management unit 13 associates a “mobile station ID”, “position information”, “type”, “movement state”, and “interference state”. It is configured to manage communication mobile station information.

  “Mobile station ID” indicates identification information of the mobile station for satellite communication, “Position information” indicates position information of the mobile station for satellite communication acquired by the position information acquisition unit 11, and “Type” indicates The type (for example, portable type or fixed type) of the mobile station for satellite communication is shown.

  The “movement state” is a movement state classified based on the movement speed of the mobile station for satellite communication acquired by the movement speed acquisition unit 11 (for example, “stationary”, “quasi-stationary”, “low-speed movement”, “ Fast movement ").

  The “interference state” indicates a channel in which interference occurs in the satellite communication mobile station among the channels in the second frequency band.

  As shown in FIG. 5, the WiMAX communication base station information management unit 14 includes a “base station ID”, “position information”, “transmission power”, “tilt angle”, “beam direction”, “ It is configured to manage WiMAX communication base station information associating “frequency band used”, “maximum antenna gain”, and “use of multiple antennas”.

  “Base station ID” indicates identification information of the WiMAX communication base station, “Position information” indicates position information of the WiMAX communication base station, and “Transmission power” indicates the antenna of the WiMAX communication base station. The “tilt angle” indicates the tilt angle of the beam transmitted from the antenna of the WiMAX communication base station, and the “beam direction” indicates the beam transmitted from the antenna of the WiMAX communication base station. Indicates the direction.

  “Used frequency band” indicates a frequency band used by the WiMAX communication base station, “Maximum antenna gain” indicates a maximum value of the antenna gain in the WiMAX communication base station, and for the WiMAX communication It may be determined in consideration of antenna gain and antenna directivity in the base station.

  “Use of multi-antenna” indicates whether or not a multi-antenna (MIMO, AAS, etc.) is used in the WiMAX communication base station.

  As shown in FIG. 6, the margin management unit 15 is configured to manage the “movement state” and the “margin” in association with each other.

  The channel allocation unit 16 is configured to allocate a channel for satellite communication (second communication) from channels in the second frequency band.

  Specifically, the channel allocation unit 16 includes interference area information indicating an interference area where interference from WiMAX communication (first communication) occurs in the satellite communication system (second communication system) and the mobile station 50 for satellite communication. On the basis of the position information, a channel for satellite communication (second communication) is allocated from channels usable in the second frequency band.

  Here, the “usable channel” indicates a channel that is unused in a target area to which a channel for satellite communication is allocated and that satisfies the criteria of received power and interference amount.

  Further, the channel allocator 16 sets the distance X between a WiMAX communication base station 70 (a control device in the first communication system), which will be described later, and a satellite communication mobile station 50 (a communication terminal in the second communication system). Based on this, the channel for satellite communication may be allocated from the channels in the second frequency band.

  Further, the channel allocation unit 16 may be configured to allocate a channel for satellite communication from channels in the second frequency band based on the moving speed of the mobile station 50 for satellite communication.

  Further, the channel allocating unit 16 selects a channel for satellite communication from among the channels in the second frequency band based on the type of the mobile station 50 for satellite communication (that is, whether it is a portable type or a fixed type). May be configured to be assigned.

  Here, the channel allocation unit 16 sets the “transmission power”, “tilt angle”, “beam direction”, “maximum antenna gain”, and “use of multi-antenna” recorded in the base station management unit 14 for WiMAX communication. Accordingly, the size of the interference area is estimated.

  Further, the channel assignment unit 16 uses the position information of the satellite communication mobile station 50, and the WiMAX communication base station 70 (control device in the first communication system) and the satellite communication mobile station 50 (second communication system). The distance X to the communication terminal) is calculated.

  Further, the channel allocation unit 16 is configured to extract a margin corresponding to the moving speed (moving state) of each satellite communication mobile station 50 from the margin management unit 15.

  Then, the channel allocation unit 16 determines that the calculated distance X between the WiMAX communication base station 70 and the satellite communication mobile station 50 is the extracted margin and the WiMAX communication base for all the WiMAX communication base stations 70. Whether or not the satellite communication mobile station 50 exists within the interference area of the specific WiMAX communication base station 70 as to whether or not it is larger than the sum of the size of the interference area centered on the position of the station 70. Determine whether or not.

  The channel allocating unit 16 determines that the calculated distance X between the WiMAX communication base station 70 and the satellite communication mobile station 50 is the extracted margin and the WiMAX communication base station 70 for all the WiMAX communication base stations 70. In other words, it is determined that the satellite communication mobile station 50 does not exist within the interference area of any WiMAX communication base station 70. In this case, the channel for satellite communication is sequentially allocated from the channel closer to the first frequency band within the second frequency band.

  On the other hand, for the specific WiMAX communication base station 70, the channel allocation unit 16 calculates the distance X between the calculated WiMAX communication base station 70 and the satellite communication mobile station 50 as the extracted margin and the WiMAX communication base. When it is determined that it is not larger than the sum of the size of the interference area centered on the position of the station 70, that is, the satellite communication mobile station 50 exists in the interference area by the specific WiMAX communication base station 70. If it is determined, the channel for satellite communication is sequentially allocated from the channel on the side away from the first frequency band within the second frequency band.

  Further, when the location information of the satellite communication mobile station 50 is not acquired, the channel allocation unit 16 performs satellite communication from the channels in the second frequency band based on the interference state in the satellite communication mobile station 50. May be configured to allocate a dedicated channel.

  In addition, when the position information of the satellite communication mobile station 50 is not acquired, the channel allocation unit 16 selects a satellite communication channel from a channel on the side away from the first frequency band within the second frequency band. You may be comprised so that it may allocate sequentially.

  The channel assignment unit 16 is configured to notify the satellite communication mobile station 50 of the assigned satellite communication channel via the control channel. Note that such a control channel is a channel in a frequency band that is not easily affected by interference from WiMAX communication.

  Note that the channel allocating unit 16 considers the interference state in the satellite communication mobile station 50 even if the position information of the satellite communication mobile station 50 has been acquired, and the channel within the second frequency band. May be configured to allocate a channel for satellite communication from among them.

  When the interference situation in the satellite communication mobile station 50 is not taken into account, the propagation situation greatly changes due to the influence of topography, buildings, and the like. Even when the interference situation in the mobile station 50 is taken into consideration, it is set to be larger than the margin.

  As shown in FIG. 7, the satellite communication mobile station 50 according to the present embodiment includes a position information acquisition unit 51A, a position information transmission unit 51B, a movement speed acquisition unit 52A, a movement speed transmission unit 52B, and a channel assignment. A request unit 53 and a communication unit 54 are provided.

  The position information acquisition unit 51A is configured to acquire the position information of the satellite communication mobile station 50 using GPS or the like.

  The position information transmitting unit 51B is configured to transmit the position information of the satellite communication mobile station 50 to the satellite communication earth station 10 via the access channel at a predetermined timing. Note that such an access channel is a channel in a frequency band that is not easily affected by interference from WiMAX communication.

  The moving speed acquisition unit 52A is configured to acquire the moving speed of the satellite communication mobile station 50 using GPS or the like.

  The moving speed transmission unit 52B is configured to transmit the moving speed of the satellite communication mobile station 50 to the satellite communication earth station 10 via the access channel at a predetermined timing.

  The moving speed transmission unit 52 transmits, as the moving speed of the satellite communication mobile station 50, the movement distance in the past predetermined period, the channel fluctuation amount established with the satellite communication earth station 10, and the like. It may be configured to.

  The channel assignment request unit 53 is configured to transmit a channel assignment request for requesting the satellite communication earth station 10 to assign a channel for satellite communication via the access channel.

  The communication unit 54 is configured to perform satellite communication using a channel assigned by the satellite communication earth station 10.

(Operation of the mobile communication system according to the first embodiment of the present invention)
Hereinafter, the operation of the mobile communication system according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 8, in step S <b> 101, the channel assignment unit 16 of the satellite communication earth station 10 receives the channel assignment request transmitted from the satellite communication mobile station 50.

  In step S102, the channel allocation unit 16 refers to the satellite communication mobile station information management unit 13 and determines whether or not the position information of the satellite communication mobile station 50 has been acquired.

  If acquired, the operation proceeds to steps S103 to S105. If not acquired, the operation proceeds to step S107.

  In step S103, the channel allocating unit 16 calculates the distance X between all the WiMAX communication base stations 70 and the satellite communication mobile station 50 using the position information of the satellite communication mobile station 50, In step S104, the interference area by all the WiMAX communication base stations 70 is estimated with reference to the WiMAX communication base station management unit 14, and in step S105, the moving speed (movement state) of the mobile station 50 for satellite communication is estimated. Is extracted from the margin management unit 15.

  In step S106A, the channel allocation unit 16 determines whether or not the condition of (distance X)> (interference area size) + (margin) is satisfied for all the WiMAX communication base stations 70.

  If the channel allocation unit 16 determines that the above-mentioned condition is satisfied for all the WiMAX communication base stations 70, in step S106B, the channel allocation unit 16 changes the first frequency band from the unused channels in the second frequency band. The channel having the closest frequency is assigned to the mobile station 50 for satellite communication.

  On the other hand, when determining that the above condition is not satisfied for all the WiMAX communication base stations 70, the channel allocating unit 16 selects the first channel from the unused channels in the second frequency band in step S106C. A channel having a frequency farthest from the frequency band is assigned to the mobile station 50 for satellite communication.

  In step S107, the channel allocation unit 16 refers to the interference status of the satellite communication mobile station 50 in the satellite communication mobile station information management unit 13, and selects one of the channels in which no interference from WiMAX communication has occurred. And assigned to the satellite communication mobile station 50.

  In step S108, the channel allocation unit 16 notifies the allocated channel to the satellite communication mobile station 50.

  In step S109, the communication unit 54 of the satellite communication mobile station 50 starts satellite communication using the notified channel.

(Operations and effects of the mobile communication system according to the first embodiment of the present invention)
According to the mobile communication system according to the present embodiment, in an environment where a WiMAX communication system and a satellite communication system are mixed, the occurrence of interference between both communication systems can be achieved without measuring the interference state in the satellite communication system. It can be avoided.

  According to the mobile communication system according to the present embodiment, based on the position information and interference area information of the satellite communication mobile station 50, the satellite communication mobile station 50 is present in an interference area where interference from WiMAX communication occurs. If not, since the channel for satellite communication is allocated from the channel closer to the first frequency band, in a mixed environment of WiMAX communication systems and satellite communication systems, the communication systems In addition to avoiding the occurrence of interference, efficient frequency utilization can be realized.

  According to the mobile communication system according to the present embodiment, when the satellite communication mobile station 50 is moving at a high speed, it enters the interference area before the satellite communication is completed, compared with the case where the satellite communication mobile station 50 is stationary. In consideration of the high possibility that the channel for satellite communication will be allocated.

  According to the mobile communication system according to the present embodiment, when the satellite communication mobile station 50 is portable, it enters the interference area before the satellite communication is completed, compared to the case where it is fixed. In consideration of the high possibility, channel assignment for such satellite communication can be performed.

  According to the mobile communication system according to the present embodiment, even in the environment where the WiMAX communication system and the satellite communication system are mixed, even if the position information of the satellite communication mobile station 50 cannot be acquired, Interference can be avoided in

  According to the mobile communication system according to the present embodiment, in the environment where the WiMAX communication system and the satellite communication system are mixed, if the position information of the mobile station for satellite communication 50 cannot be acquired, the mobile station for satellite communication is used. Since it is impossible to determine whether or not 50 exists in the interference area, the occurrence of interference between both communication systems is avoided by assigning a channel that is not easily affected by interference from the channel of the first frequency band. can do.

(Modification 1)
With reference to FIG. 9, the mobile communication system according to the first modification will be described.

  As shown in FIG. 9, in step S <b> 201, the channel assignment unit 16 of the satellite communication earth station 10 receives the channel assignment request transmitted from the satellite communication mobile station 50.

  In step S202, the channel allocation unit 16 refers to the interference state of the satellite communication mobile station 50 in the satellite communication mobile station information management unit 13, and extracts a channel in which no interference from WiMAX communication occurs.

  In step S203, the channel allocation unit 16 refers to the satellite communication mobile station information management unit 13 and determines whether or not the position information of the satellite communication mobile station 50 has been acquired.

  If acquired, the operation proceeds to steps S204 to S206. If not acquired, the operation proceeds to step S208.

  In step S204, the channel allocation unit 16 calculates the distance X between all the WiMAX communication base stations 70 and the satellite communication mobile station 50 using the position information of the mobile station 50 for satellite communication. In step S205, the WiMAX communication base station management unit 14 is referred to, and interference areas of all the WiMAX communication base stations 70 are estimated. In step S206, the moving speed (movement state) of the satellite communication mobile station 50 is estimated. Is extracted from the margin management unit 15.

  In step S207A, the channel allocation unit 16 determines whether or not the condition of (distance X)> (interference area size) + (margin) is satisfied for all the WiMAX communication base stations 70.

  If the channel allocation unit 16 determines that the above-described condition is satisfied for all the WiMAX communication base stations 70, in step S207B, the channel allocation unit 16 selects from the unused channels in the second frequency band extracted in step S202. A channel having a frequency closest to the first frequency band is assigned to the mobile station 50 for satellite communication.

  On the other hand, if the channel allocation unit 16 determines that the above condition is not satisfied for all the WiMAX communication base stations 70, in step S207C, the unused channel in the second frequency band extracted in step S202. The channel having the frequency farthest from the first frequency band is allocated to the mobile station 50 for satellite communication.

  In step S208, the channel allocation unit 16 moves the channel having the frequency farthest from the first frequency band from the unused channels in the second frequency band extracted in step S202, to the satellite communication mobile. Assign to station 50.

  In step S209, the channel assignment unit 16 notifies the satellite communication mobile station 50 of the assigned channel.

  In step S210, the communication unit 54 of the satellite communication mobile station 50 starts satellite communication using the notified channel.

(Modification 2)
With reference to FIG. 10, the mobile communication system according to the second modification will be described.

  As shown in FIG. 10, in step S <b> 301, the channel assignment unit 16 of the satellite communication earth station 10 receives the channel assignment request transmitted from the satellite communication mobile station 50.

  In step S302, the channel allocation unit 16 refers to the satellite communication mobile station information management unit 13 and determines whether or not the position information of the satellite communication mobile station 50 has been acquired.

  If acquired, the operation proceeds to steps S303 to S305. If not acquired, the operation proceeds to step S308.

  In step S303, the channel allocation unit 16 calculates the distance X between all the WiMAX communication base stations 70 and the satellite communication mobile station 50 using the position information of the satellite communication mobile station 50, In step S304, the WiMAX communication base station management unit 14 is referred to, and interference areas of all the WiMAX communication base stations 70 are estimated. In step S305, the moving speed (movement state) of the mobile station 50 for satellite communication is estimated. Is extracted from the margin management unit 15.

  In step S306, the channel allocation unit 16 determines whether or not the condition of (distance X)> (interference area size) + (margin) is satisfied for all the WiMAX communication base stations 70.

  If the channel allocation unit 16 determines that the above condition is satisfied for all the WiMAX communication base stations 70, the interference amount is equal to or less than a predetermined threshold value among the unused channels in the second frequency band in step S307A. And a channel having a frequency closest to the first frequency band is assigned to the mobile station 50 for satellite communication.

  On the other hand, if the channel allocation unit 16 determines that the above condition is not satisfied for all the WiMAX communication base stations 70, in step S307B, the channel allocation unit 16 determines the amount of interference from the unused channels in the second frequency band. Is assigned to the satellite communication mobile station 50, the channel having the frequency farthest from the first frequency band.

  In step S308, the channel allocation unit 16 refers to the interference status of the satellite communication mobile station 50 in the satellite communication mobile station information management unit 13, and selects one of the channels in which no interference from WiMAX communication has occurred. And assigned to the satellite communication mobile station 50.

  In step S309, the channel allocation unit 16 notifies the allocated channel to the satellite communication mobile station 50.

  In step S310, the communication unit 54 of the satellite communication mobile station 50 starts satellite communication using the notified channel.

(Modification 3)
In the third modification, the channel allocation unit 16 of the earth station 10 for satellite communication uses the determination result in step S106A in FIG. 8, the determination result in step S207A in FIG. 9, or the determination result in step S306 in FIG. This is configured to notify the mobile station 50 for use.

  Then, the satellite communication mobile station 50 performs channel selection processing (see steps S106B and S106C in FIG. 8, steps S207B and S207C in FIG. 9, and steps S307A and S307B in FIG. 10) based on the determination result and the interference state. Configured to do.

  Thereafter, the satellite communication mobile station 50 notifies the satellite communication earth station 10 of the selected channel, and the satellite communication earth station 10 assigns the notified channel. Here, the channel selected by the satellite communication mobile station 50 may be a plurality of channel candidates.

  Although the present invention has been described in detail using the above-described embodiments, it is obvious to those skilled in the art that the present invention is not limited to the embodiments described in this specification. The present invention can be implemented as modified and changed modes without departing from the spirit and scope of the present invention defined by the description of the scope of claims. Therefore, the description of the present specification is for illustrative purposes and does not have any limiting meaning to the present invention.

1 is an overall configuration diagram of a mobile communication system according to a first embodiment of the present invention. It is a figure which shows the frequency utilization condition in the mobile communication system which concerns on the 1st Embodiment of this invention. It is a functional block diagram of the earth station for satellite communications concerning a 1st embodiment of the present invention. It is a figure which shows an example of the mobile station information for satellite communications managed in the earth station for satellite communications concerning the 1st Embodiment of this invention. It is a figure which shows an example of the base station information for WiMAX communication managed in the earth station for satellite communications which concerns on the 1st Embodiment of this invention. It is a figure which shows an example of the margin information managed in the earth station for satellite communications concerning the 1st Embodiment of this invention. It is a functional block diagram of the mobile station for satellite communication which concerns on the 1st Embodiment of this invention. FIG. 3 is a sequence diagram showing an operation of the mobile communication system according to the first embodiment of the present invention. It is a sequence diagram which shows operation | movement of the mobile communication system which concerns on the modification 1 of this invention. It is a sequence diagram which shows operation | movement of the mobile communication system which concerns on the modification 2 of this invention.

Explanation of symbols

1, 2, 3, ... area 10, satellite communication earth station 11, position information acquisition unit 12, movement speed acquisition unit 13, satellite communication mobile station information management unit 14, WiMAX communication base station information management unit 15, margin management Unit 16 ... Channel allocation unit 30 ... Space station for satellite communication 50 ... Mobile station for satellite communication 51A ... Position information acquisition unit 51B ... Position information transmission unit 52A ... Movement speed acquisition unit 52B ... Movement speed transmission unit 53 ... Channel allocation request unit 54 ... Communication unit 70 ... WiMAX communication base station 90 ... WiMAX communication mobile station

Claims (7)

A first communication system that performs a first communication using a channel in the first frequency band and a second communication that uses a channel in a second frequency band adjacent to the first frequency band A control device used in a mobile communication system comprising a second communication system,
A position information acquisition unit configured to acquire position information of a communication terminal that performs the second communication;
Based on interference area information indicating an interference area in which interference from the first communication occurs in the second communication system and position information of the communication terminal, the first of the channels in the second frequency band. And a channel allocating unit configured to allocate two communication channels.   The channel allocating unit calculates a distance between the control device in the first communication system and the communication terminal in the second communication system using the position information of the communication terminal, and based on the calculated distance The control device according to claim 1, wherein the control device is configured to allocate the second communication channel from among the channels in the second frequency band. Comprising a moving speed acquisition unit configured to acquire the moving speed of the communication terminal;
The channel allocating unit is configured to allocate the second communication channel from channels in the second frequency band based on a moving speed of the communication terminal. Item 3. The control device according to Item 1 or 2.   The channel allocating unit is configured to allocate the second communication channel from among the channels in the second frequency band based on whether the communication terminal is portable or fixed. The control device according to claim 1, wherein the control device is provided.   If the location information of the communication terminal is not acquired, the channel allocating unit selects the second communication channel from among the channels in the second frequency band based on an interference state in the communication terminal. The control device according to claim 1, wherein the control device is configured to be assigned.   The channel allocation unit, when the location information of the communication terminal is not acquired, selects the second communication channel from a channel on the side away from the first frequency band within the second frequency band. The control device according to any one of claims 1 to 4, wherein the control device is configured to be assigned sequentially.   The channel allocating unit is configured to sequentially allocate the second communication channel from a channel closer to the first frequency band within the second frequency band. Item 5. The control device according to any one of Items 1 to 4.

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