JP2012015898A - Base station device, communication system, and method for controlling call connection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base station device capable of controlling call connection considering load balancing for a plurality of radio communication schemes when supporting the schemes.SOLUTION: A base station device supporting a plurality of radio communication schemes comprises: a first radio-communication-scheme-related processing section 3 and a second radio-communication-scheme-related processing section 4 both for performing prescribed radio communication processing according to respective radio communication schemes including management of radio resources; and a radio resource management section 2 for acquiring usage information of radio resources for the respective radio communication schemes from the first radio-communication-scheme-related processing section 3 and the second radio-communication-scheme-related processing section 4, and selecting a radio communication scheme to be used for call connection of a terminal based on the information when a call connection request is received from the terminal.

Description

  The present invention relates to a base station apparatus, a communication system, and a call connection control method.

  Currently, development of LTE (Long Term Evolution) standard, which is the successor standard of 3G (3rd Generation), is underway. LTE is aiming for a higher-speed, larger-capacity wireless communication system than before, and there is a demand for optimization of radio resource allocation control in accordance with the communication capability and service of a user terminal (UE: User Equipment) ( Non-patent document 1 below).

3GPP (3rd Generation Partnership Project), 3GPP TS 36.101 V8.7.0 “3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) radio transmission and reception (Release 8) ", 2009-09

  However, in LTE, the cell radius is narrower than 3G, and since there are terminals that support only 3G at the beginning of introduction, it is expected that both 3G and LTE wireless communication systems will be used together. Is done. On the other hand, a femto base station installed in a general home is required to support both wireless communication systems with a single device in order to reduce the installation area and power consumption.

  When the base station is compatible with both 3G and LTE, conventionally, the operations of the respective wireless communication systems are individually performed. Therefore, in the process of one radio communication system, it was impossible to grasp the number of terminals located in the cell corresponding to the other radio communication system and the availability of radio resources of the other radio communication system. For this reason, when the 3G and LTE wireless communication methods are used together in the conventional method, the load balance between the wireless communication methods is not taken into consideration, and call connection control such as selection of the wireless communication method by which the terminal performs call connection is not performed. There was a problem that it was not optimized throughout. If the load balance is not taken into account, for example, communication may be concentrated on one of the wireless communication methods, especially in femto base stations installed in ordinary homes, etc. There is also a possibility.

  The present invention has been made in view of the above, and in the case of supporting a plurality of wireless communication schemes, a base station apparatus and communication capable of performing call connection control considering the load balance between the wireless communication schemes It is an object to obtain a system and a call connection control method.

  In order to solve the above-described problems and achieve the object, the present invention provides a base station apparatus that supports a plurality of radio communication schemes, and for each radio communication scheme, predetermined radio communication based on the radio communication scheme. A wireless communication processing unit that performs processing and performs wireless resource management based on the wireless communication method; obtains information indicating a use state of the wireless resource for each wireless communication method from the wireless communication processing unit; A radio resource management unit that selects a radio communication method for performing call connection of the terminal based on the information when requested.

  Advantageous Effects of Invention According to the present invention, there is an effect that call connection control can be performed in consideration of load balance between wireless communication methods when supporting a plurality of wireless communication methods.

FIG. 1 is a diagram illustrating a functional configuration example of a base station apparatus. FIG. 2 is a chart showing an example of a call connection control procedure.

  Embodiments of a base station apparatus, a communication system, and a call connection control method according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment.
FIG. 1 is a diagram illustrating a functional configuration example of an embodiment of a base station apparatus according to the present invention. As shown in FIG. 1, the base station apparatus 1 according to the present embodiment includes a radio resource management unit 2, a first radio communication scheme processing unit 3, and a second radio communication scheme processing unit 4. The The first wireless communication system processing unit 3 includes a wireless resource control processing unit 31, a call connection control processing unit 32, a wireless connection control processing unit 33, and a data transfer processing unit 34. The second wireless communication system processing unit 4 includes a wireless resource control processing unit 41, a call connection control processing unit 42, a wireless connection control processing unit 43, and a data transfer processing unit 44. The first wireless communication method processing unit 3 and the second wireless communication method processing unit 4 can be considered as wireless communication processing units that perform wireless communication processing according to each wireless communication method.

  The base station apparatus 1 according to the present embodiment corresponds to two communication methods, a first wireless communication method and a second wireless communication method. For example, the first wireless communication method can be a 3G wireless communication method, and the second wireless communication method can be an LTE wireless communication method. The first wireless communication method and the second wireless communication method are not limited to these, and any wireless communication method may be used as long as it is a wireless communication method for performing call connection with a terminal.

  The first wireless communication system processing unit 3 performs communication processing according to the first wireless communication system. Specifically, for example, the following processing is performed. Based on the first wireless communication method with the terminal, the wireless connection control processing unit 33 performs terminal wireless connection such as connection start processing with a terminal within its communicable area and data transmission / reception processing with the terminal. Implement control. The radio resource control processing unit 31 controls and manages radio resources used between the terminal wirelessly connected to itself and the terminal via the radio connection control processing unit 33. The radio resource control processing unit 31 performs any radio resource control and management method. For example, when a terminal is wirelessly connected to itself, the radio resource is allocated to the terminal and the radio resource being allocated is allocated. Hold.

  The call connection control processing unit 32 performs call connection of a call originating from a terminal wirelessly connected to itself and a call originating from a terminal wirelessly connected to itself. Note that it is assumed that the call connection control processing unit 32 manages the number of calls (number of calls) of a terminal connected to the own apparatus using the first wireless communication method. In addition, the data transfer processing unit 34 transfers data received from the terminal via the wireless connection control processing unit 33 to a core network (not shown) to which the data transfer processing unit 34 is connected, and data addressed to the terminal received from the core network or the like. Is transferred to the destination terminal via the wireless connection control processing unit 33.

  Further, the second wireless communication system processing unit 4 performs communication processing according to the second wireless communication system. The operations of the radio resource control processing unit 41, the call connection control processing unit 42, the radio connection control processing unit 43, and the data transfer processing unit 44 are performed in accordance with the second radio communication method instead of the first radio communication method. The operations are the same as those of the radio resource control processing unit 31, the call connection control processing unit 32, the radio connection control processing unit 33, and the data transfer processing unit 34, except for the above.

  The configurations of the first wireless communication system processing unit 3 and the second wireless communication system processing unit 4 can perform wireless communication processing including call control and wireless resource management based on the corresponding wireless communication system. Any configuration is possible as long as the configuration is not limited to the configuration shown in FIG.

The radio resource management unit 2
(A) The amount of radio resources used in each of the first radio communication system and the second radio communication system (b) A call that is being connected by a call according to each of the first radio communication system and the second radio communication system Number (c) Capability of the terminal during call connection (whether the first wireless communication method or the second wireless communication method can be used, or both the first wireless communication method and the second wireless communication method are used) Possible)
(D) Manage the transmission rate of the connected call.

  Specifically, for (a), the radio resource management unit 2 determines the radio resource amount used in the first radio communication method from the radio resource control processing unit 31 of the first radio communication method processing unit 3. Acquire, acquire the radio resource amount used in the second radio communication method from the radio resource control processing unit 41 of the second radio communication method processing unit 4, and hold each radio resource amount as radio resource information .

  In addition, for (b), the radio resource management unit 2 obtains the number of calls connected by the first radio communication method from the call connection control processing unit 32 of the first radio communication method processing unit 3, The number of calls connected by the second wireless communication method is acquired from the call connection control processing unit 42 of the second wireless communication method processing unit 4, and each number of calls is held as call number information.

  In addition, the radio resource management unit 2 (c) is a terminal (terminal identification information) that can be wirelessly connected by the first wireless communication method from the wireless connection control processing unit 33 of the first wireless communication method processing unit 3. And a terminal that can be wirelessly connected by the second wireless communication method is acquired from the wireless connection control processing unit 43 of the second wireless communication method processing unit 4. Then, based on the acquired information, each terminal can be connected by the first wireless communication method, can be connected by the second wireless communication method, both the first wireless communication method and the second wireless communication method. Is stored as terminal capability information. Note that, for example, the wireless connection control processing unit 33 and the wireless connection control processing unit 43 hold the terminals (terminal identification information) for which the wireless connection control processing unit 33 has performed wireless connection processing as terminals that can be connected by the corresponding wireless communication method. Alternatively, the wireless connection control processing unit 33 and the wireless connection control processing unit 43 may acquire information on a connectable wireless communication method from the terminal.

  In addition, for (d), the radio resource management unit 2 acquires the transmission rate of a call that is being connected by the first radio communication method from the data transfer processing unit 34 of the first radio communication method processing unit 3, The transmission rate of the call being connected by the second wireless communication method is acquired from the data transfer processing unit 44 of the second wireless communication method processing unit 4, and these transmission rates are held as transmission rate information. The data transfer processing unit 34 and the data transfer processing unit 44 can grasp the transmission rate for each call based on the data to be transferred, for example, and hold this transmission rate for each call of the terminal.

  In addition, in order to acquire the information of (a)-(d), the radio | wireless resource management part 2 regularly acquires (for example, in the case of (a), the radio | wireless resource control processing part 31 and the radio | wireless resource control processing part) 41) may be requested to acquire information, or the information may be read from a storage unit or the like in which the acquisition source holds such data. The acquisition source may notify the radio resource management unit 2 of information when the information is changed. Further, the radio resource management unit 2 may not acquire these pieces of information and may acquire the information from the acquisition source when the information becomes necessary.

  Next, the call connection control method of this embodiment will be described. In the base station apparatus 1, when the radio connection control processing unit 33 receives a request (radio resource allocation request) for making a new call connection from a terminal in the first radio communication method, the radio resource management unit 2 Notify Upon receiving this notification, the radio resource management unit 2 has a radio resource amount used in the first radio communication scheme based on the radio resource information held therein being equal to or greater than a predetermined radio resource threshold, and The free resource amount of the other wireless communication method (second wireless communication method) is equal to or greater than a predetermined free resource threshold, and the terminal also supports the second wireless communication method based on the terminal capability information. If it is determined that the connection is rejected, a connection rejection message for notifying connection to the new call connection request by the second wireless communication method is transmitted to the terminal that is the source of the call connection request via the wireless connection control processing unit 33. To do. Note that the radio resource management unit 2 knows the total amount of radio resources allocated to the first radio communication scheme and the second radio communication scheme, and based on this total amount and the radio resource amount in use. Thus, free resources for each wireless communication method are obtained.

  Similarly, when the wireless connection control processing unit 43 receives a request for making a new call connection (wireless resource allocation request) from the terminal in the second wireless communication method, the wireless connection control processing unit 43 notifies the wireless resource management unit 2 to that effect. To do. Then, similarly to the above, the radio resource management unit 2 has a radio resource amount used in the second radio communication scheme equal to or greater than a predetermined radio resource threshold, and the other radio communication scheme (first In the first wireless communication system), when it is determined that the terminal is also compatible with the first wireless communication system based on the terminal capability information. A connection rejection message for notifying connection is transmitted to the transmission source terminal. Note that the radio resource threshold values of the first radio communication scheme and the second radio communication scheme may be the same value, but are generally set independently. In addition, the vacant resource threshold values of the first wireless communication method and the second wireless communication method may be the same value, but are generally set independently.

  By performing such processing, when a new call connection request is received, it is possible to adjust the radio resource usage of the first radio communication method and the second radio communication method, and the first radio communication method can be adjusted. It becomes possible to achieve load balance between the communication method and the second wireless communication method.

  FIG. 2 is a chart showing an example of a call connection control procedure according to the present embodiment. In the example of FIG. 2, as an example, the first wireless communication method is 3G, and the second wireless communication method is LTE. In this case, the terminal transmits a “RRC (Radio Resource Control) Connection Request” message for requesting a new call connection by LTE (step S1). This terminal is assumed to be a terminal that can support both the first wireless communication system and the second wireless communication system.

  In the base station apparatus 1, when the radio connection control processing unit 43 receives this “RRC (Radio Resource Control) Connection Request” message, it notifies the radio resource management unit 2 to that effect. Based on this notification, the radio resource management unit 2 determines that the radio resource amount used in the second radio communication scheme (in this case, LTE) is a predetermined radio resource threshold based on the held radio resource information. And the free resource amount of the other wireless communication system (in this case, 3G) is greater than or equal to a predetermined free resource threshold, and the terminal also supports the second wireless communication system Suppose that In this case, the radio resource management unit 2 stores the 3G standby frequency in the Redirection info (transfer information) portion, which is OP (optional) information, in the connection rejection (RRC Connection Reject) message of the LTE standby frequency. Transmit (step S2).

  When the terminal receives this connection rejection message, it determines that switching from LTE to 3G is performed based on this message (step S3), and uses the stored standby frequency to send an “RRC Connection Request” message by 3G. Transmit (step S4). In the base station apparatus 1, when the radio connection control processing unit 43 receives this “RRC Connection Request” message, it notifies the radio resource management unit 2 to that effect. In this case, the radio resource amount of the first radio communication system (in this case, 3G) is less than the predetermined radio resource threshold value, and the connection rejection message is not transmitted. Therefore, the radio resource control processing unit 31 transmits the “RRC Connection Setup” message to the terminal as usual (step S5). Thereafter, 3G transmission processing is performed between the first wireless communication system processing unit 3 and the terminal (step S6).

  In the example of FIG. 2, the call control request and the connection refusal for this are notified using the “RRC Connection Request” message and the “RRC Connection Request” message, but these messages are examples and other You may make it notify in a format. In the example of FIG. 2, the standby frequency of the other wireless communication method is notified as Redirection info. However, the present invention is not limited to this, and any method can be used as long as it is a method of notifying the wireless communication method of the switching destination. It may be used.

  When all the connected calls are made by the first wireless communication method, the resource management unit 2 uses the notification information or the like to notify the second wireless communication method processing unit 4 The terminal may be controlled to transmit an instruction to perform standby using the first wireless communication method to a terminal that is in the standby state using the wireless communication method, and the transmission power of the second wireless communication method processing unit 4 may be reduced. Thereby, when the call by the 2nd radio | wireless communication system is not performed, the low power consumption of the base station apparatus 1 is attained. As described above, when it is necessary to hand over the connected terminal to the first wireless communication method, for example, because the transmission rate of a connected call is increased in a state where power consumption is reduced. In this case, the terminal can be handed over to the second wireless communication system by increasing the transmission power of the second wireless communication system processing unit 4. The above operation is the same when the first wireless communication system and the second wireless communication system are reversed.

  Here, based on the number of calls that are being communicated by the first wireless communication system (or the second wireless communication system), whether or not all connected calls are made by the first wireless communication system. However, the present invention is not limited to this, and it may be determined whether or not the first wireless communication system is used based on the amount of radio resources. Since the number of calls is an index representing the radio resource usage status in each radio communication system as well as the radio resource amount, the radio resource amount can be used instead of the number of calls as the radio usage status.

  Further, when a call being connected exists in both the first wireless communication method and the second wireless communication method, all terminals that are communicating in the first wireless communication method are in the second wireless communication method. If the second wireless communication system processing unit 4 can support the transmission rate of the connected call of the first wireless communication system, all calls are transmitted to the second wireless communication system. Control may be performed so as to perform switching as in the method. For this switching, for example, a conventional handover procedure between LTE and 3G can be used. Further, even when all connected calls are performed by the second wireless communication method, this switching may be performed when the radio resources of the second wireless communication method do not exceed a predetermined threshold. By performing such control, the function of the first wireless communication system processing unit 3 can be stopped, and the power consumption can be reduced while satisfying the communication request of the terminal. The above operation is the same when the first wireless communication system and the second wireless communication system are reversed.

  In the present embodiment, a case has been described in which the base station apparatus 1 supports two wireless communication systems, the first wireless communication system and the second wireless communication system. However, the present invention is not limited to this, and three or more wireless communication systems are used. The operation of this embodiment may be applied when the communication method is supported. In this case, a wireless communication system processing unit is provided for each wireless communication system, and the wireless resource management unit 2 acquires information corresponding to (a) to (d) from each wireless system processing unit, and performs call connection control and the like. carry out. In this case, since there is not one other communication method, one of the other communication methods is selected. For example, when there is a new call connection request and the amount of radio resources used in the wireless communication method for which the connection request has been made is greater than or equal to a predetermined radio resource threshold, A connection rejection message is used to notify the terminal that the terminal is compatible and that the call connection is to be established in the wireless communication system having the largest amount of free resources.

  As described above, in the present embodiment, the radio resource management unit 2 acquires the radio resource amounts used from the first radio communication method processing unit 3 and the second radio communication method processing unit 4, respectively, Based on the respective radio resource amount and free resource amount of the first radio communication method processing unit 3 and the second radio communication method processing unit 3, the radio communication method for performing call connection with the terminal is selected. . Therefore, when supporting a plurality of wireless communication systems, it is possible to select a wireless communication system for performing call connection based on the usage status of each wireless communication system, and to implement new call admission control in consideration of the overall load balance Can do.

  Further, the radio resource management unit 2 obtains the number of calls communicating with each of the first radio communication system processing unit 3 and the second radio communication system processing unit 4 so that all the connected calls are one of them. When the wireless communication system is used, the transmission power of the other wireless communication system is reduced. Thereby, the power consumption of the base station apparatus 1 can be reduced.

  In addition, when there is a call connected to both radio communication systems, the radio resource management unit 2 causes a terminal communicating with one radio communication system to be handed over to the other radio communication system. Also good. As a result, the function of the wireless communication system processing unit of the wireless communication system in which there is no connected call can be stopped, and the power consumption of the base station apparatus 1 can be reduced.

  As described above, the base station apparatus and the call connection control method according to the present invention are useful for a base station apparatus that supports a plurality of wireless communication schemes, and are particularly suitable for femto base stations installed in general homes and the like. Yes.

DESCRIPTION OF SYMBOLS 1 Base station apparatus 2 Radio | wireless resource management part 3 1st radio | wireless communication system process part 4 2nd radio | wireless communication system process part 31,41 Radio | wireless resource control process part 32,42 Call connection control process part 33,43 Radio | wireless connection control process 34, 44 Data transfer processing unit

Claims (7)

A base station device supporting a plurality of wireless communication systems,
A wireless communication processing unit that performs predetermined wireless communication processing based on the wireless communication method for each wireless communication method, and performs wireless resource management based on the wireless communication method;
Radio communication that acquires information indicating the usage status of radio resources for each radio communication method from the radio communication processing unit, and performs call connection of the terminal based on the information when a call connection request is received from the terminal A radio resource management unit for selecting a method;
A base station apparatus comprising: The information includes the amount of radio resources used for each radio communication method,
The radio resource management unit holds the radio communication scheme that can be handled for each terminal as terminal capability information, and when there is the call connection request, the radio resource management unit uses the radio communication scheme used in the call connection request. There is a free wireless communication system that is a wireless communication system in which the wireless resource amount is equal to or greater than a predetermined threshold and the free resource amount obtained based on the wireless resource amount is less than the predetermined free resource threshold. And, when it is determined that the transmission source terminal that is the transmission source of the connection request is compatible with the vacant wireless communication scheme based on the terminal capability information, a wireless communication scheme that performs call connection of the transmission source terminal Selecting the free wireless communication method as
The base station apparatus according to claim 1. The information further includes the number of calls during call connection for each wireless communication method,
When there is an unused wireless communication system that is a wireless communication system that is determined that there is no call being connected based on the number of calls for each wireless communication system, the wireless resource management unit Instructing a terminal in a standby state according to the system to shift to a standby state in the wireless communication system in which a call being connected exists, and reducing the transmission power of the unused wireless communication system Instruct the communication processor
The base station apparatus according to claim 2. The radio resource management unit reduces the transmission power of the unused radio communication method when performing call connection by the unused radio communication method when the transmission power of the unused radio communication method is reduced. Instructing the wireless communication processing unit to return to the value before
The base station apparatus according to claim 3. The information further includes a transmission rate for each call,
The radio resource management unit selects one or more of these radio communication schemes as non-use radio communication schemes when there are two or more radio communication schemes during a call connection. Then, the call connection using the non-use wireless communication method is switched to a call connection using the wireless communication method other than the non-use wireless communication method using the wireless communication method in which a call being connected exists, and the non-use wireless communication method Control to stop the function that performs processing corresponding to
The base station apparatus according to claim 2, 3, or 4. A communication system comprising a base station device corresponding to a plurality of wireless communication systems, and a terminal wirelessly connected to the base station device,
The base station device
A wireless communication processing unit that performs predetermined wireless communication processing based on the wireless communication method for each wireless communication method, and performs wireless resource management based on the wireless communication method;
Wireless communication that acquires information indicating a usage state of a wireless resource for each wireless communication method from the wireless communication processing unit, and performs call connection of the terminal based on the information when a call connection request is received from the terminal A radio resource management unit for selecting a method;
A communication system comprising: A call connection control method in a base station apparatus corresponding to a plurality of wireless communication methods,
A wireless communication processing step for performing predetermined wireless communication processing based on the wireless communication method for each wireless communication method, and performing wireless resource management based on the wireless communication method;
An information acquisition step of acquiring information indicating a use status of a radio resource for each radio communication method from the radio communication processing unit;
When there is a call connection request from a terminal, a radio resource management step of selecting a radio communication method for performing call connection of the terminal based on the information;
A call connection control method.

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