JP4388394B2 - Integrated wireless system network - Google Patents

Description

The present invention relates to network integration radio system including a plurality of radio access systems.

  The conventional integrated wireless system is designed to enable basic services such as outgoing / incoming calls, location notification, authentication, and discovery / selection / switching of wireless access systems in order to realize seamless services among multiple wireless access systems. A control protocol called BAS) is used. In this conventional integrated wireless system, when switching from one wireless access system to another wireless access system, a control signal for switching to another wireless access system is transmitted using BAS. As a method of transmitting the BAS between the user and the network, there is a method of overlaying on an existing wireless access system (for example, Non-Patent Document 1).

Inoue, Mahmoud, Murakami, Hasegawa, Morikawa "RAN Overlay MIRAI System (1) Overview" IEICE, 2003 General Conference, B-5-131, March 2003

  By the way, in a conventional integrated wireless system, for example, a PHS wireless access network used for communication between a terminal and a node, for example, a wireless LAN wireless access network for switching communication, and a BAS regarding switching of a wireless access system are used. For example, when three radio access networks are different from the radio access network of the second generation mobile communication system, for example, when performing handover between different radio access networks, three different radio access networks are used. It is necessary to communicate with the network. In particular, in order to switch the radio access network seamlessly (without causing a momentary interruption), the terminal transmits a BAS control signal required for switching to the second while performing communication with the PHS radio access network. It is necessary to establish communication connection with the wireless access network of the wireless LAN to be switched by communicating with the wireless access network of the next generation mobile communication system and exchanging between the servers.

  Therefore, in the conventional integrated radio system, a BAS control signal for controlling switching (handover) between different radio access networks is transmitted in addition to the radio access network that switches communication with the radio access network that is communicating. In this case, since it is necessary to communicate with three different radio access networks at the time of handover, there is a problem that the scale of the terminal increases.

The present invention has been made to solve the above-described problems, and when performing a handover, the terminal only needs to be connected to the radio access network to which the terminal is currently communicating and the switching destination radio access network, there is no need to connect to other wireless access networks, and to provide a network for integrated radio system that can realize a seamless handover.

An integrated radio system network according to the present invention includes a plurality of radio access systems for forming a data communication path between a terminal and a node, a communication network for connecting the node and the plurality of radio access networks, in the network integration radio system including a server for communicating control signals for handover between the plurality of radio access network to the terminal through the communication network and said plurality of radio access networks, one wireless A radio access network used for transmitting a control signal for handover to the server based on a radio access network switching instruction instructing a terminal connected to the access network to change the connection destination to another radio access network Route selector that instructs to change Further comprising the server to switch the radio access network to be used for transmission of control signals for handover from said one radio access network based on the change instruction from the path selection unit to the other radio access network It is characterized by.

  According to the present invention, when performing handover, the terminal only needs to connect to the radio access network that is currently communicating with the radio access network of the switching destination, and does not need to be connected to other radio access networks, Seamless handover can be realized.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of an integrated radio system according to the present invention. The integrated radio system shown in FIG. 1 connects a plurality of radio access systems 2 to 5 for forming a data communication path between the terminal 1 and the node 8, and a node 8 and a plurality of radio access networks 2 to 5. A communication signal for handover between the plurality of radio access networks 2 to 5 to the terminal 1 via the Internet network 6 as a communication network for communication and the Internet network 6 and the plurality of radio access networks 2 to 5. And a route selection unit 14 that instructs the server 7 to change the radio access network used for transmission of the control signal for handover based on the radio access network switching instruction from the terminal 1. The server 7 manages the switching of the radio access network. It has been made to switch the radio access network 2-5 for use in transmission of control signals for handover based on the change instruction.

  In addition, the terminal 1 communicates a control signal for handover with a communication function unit 11 for wireless communication with a plurality of wireless access systems, and a server 7 on the network side of the integrated wireless system via the communication function unit 11. Unit 12 and a handover control unit 13 for instructing a change of a radio access network used for communication.

  Here, the radio access network 2 is a PHS radio access network, the radio access network 3 is a radio LAN (IEEE802.11b) radio access network, the radio access network 4 is a radio access network of the second generation mobile communication system, and radio access The network 5 is a radio access network of the third generation mobile communication system, and the radio access networks 4 and 5 include base stations.

  In the terminal 1, the communication function unit 11 provides a function of wirelessly connecting the terminal 1 and a base station of each radio access network based on an instruction from the BAS control unit 12 or the handover control unit 13. Furthermore, the communication function unit 11 has a function of performing wireless connection simultaneously with base stations of different radio access networks.

  Further, the BAS control unit 12 executes communication of a control signal regarding switching between different radio access networks depending on the BAS protocol, and transmits the control information to the handover control unit 13. The communication between the BAS control unit 12 and the server 7 is realized via the communication function unit 11 and one of the radio access networks 2 and 5 and the Internet network 6. Further, the BAS control unit 12 receives an instruction relating to a change of the radio access network used for communication from the handover control unit 13 and controls the communication function unit 11 based on the instruction. Furthermore, it has a function of transmitting control information from the handover control unit 13 to the server 7 via the communication function unit 11, the radio access networks 2 to 5, and the Internet network 6 according to the BAS control protocol.

  Further, the path selection unit 14 on the server 7 side manages (records) which radio access network is used as the radio access network in which the terminal 1 transmits the BAS. Further, when a request for switching the radio access network used for communication is received, the terminal is connected via the server 7, the Internet network 6, one radio access network among the radio access networks 2 to 5, and the communication function unit 11 of the terminal 1. 1 BAS controller 12 is instructed to change the radio access network used for communication and the radio access network that transmits the BAS.

  Next, the operation of the integrated wireless system having the above-described configuration will be described. Here, based on FIGS. 2A and 2B, during the data communication between the terminal 1 and the node 8 in the PHS wireless access network 2, the terminal 1 leads the data communication to the wireless LAN wireless access network 4. A case where the radio access network to be performed is switched will be described. In the following, the PHS radio access network 2 is denoted as RAN2, and the radio LAN radio access network 3 is denoted as RAN3. The procedure is the same even when a radio access network other than the above RAN2 and RAN3 is used as the radio access network to be used. In this case, the terminal 1 performs data communication with the node 8 via the RAN 2 and the Internet network 6. Furthermore, the terminal 1 communicates control information related to handover with the server 7 via the RAN 2 and the Internet network 6 based on the BAS control protocol.

  Switching between radio access networks is performed according to the following procedures (1) to (9). (1) The handover control unit 13 of the terminal 1 accepts a request to switch the radio access network for data communication from RAN2 to RAN3 (execution of handover). The handover execution request is a request from the user input of the terminal 1 or an application on the terminal 1. The handover control unit 13 instructs the communication function unit 11 to activate the communication function of the RAN3.

  (2) When the handover function unit 13 is instructed to activate the communication function of the RAN 3, the communication function unit 11 activates the communication function of the RAN 3 while continuing the data communication and the BAS communication with the RAN 2. The base station detection, synchronization, location registration, and other processes necessary for connection with the RAN 3 are performed to establish a connection with the RAN 3. This connection with RAN3 is established based on a procedure specific to RAN3. As a result, the terminal 1 is connected to the two radio access networks RAN2 and RAN3. When the connection with the RAN 3 is established, the communication function unit 11 notifies the BAS control unit 12 and the handover control unit 13 of the connection establishment with the RAN 3.

  (3) The handover control unit 13 that has received the report of the connection establishment from the communication function unit 11 to the RAN 3 instructs the BAS control unit 12 to switch the radio access network that transmits the BAS from the RAN 2 to the RAN 3. .

  (4) The BAS control unit 12 that has received an instruction to switch the radio access network that transmits the BAS from the RAN 2 to the RAN 3 from the handover control unit 13 receives the server side route selection unit via the RAN 2, the Internet network 6, and the server 7. 14 is instructed to switch the radio access network transmitting the BAS.

  (5) When the server-side route selection unit 14 receives an instruction to switch the radio access network transmitting the BAS from the RAN 2 to the RAN 3 from the BAS control unit 12 of the terminal 1, the terminal 1 recorded in the route selection unit 14 The record of the radio access network used for the transmission of BAS is changed from RAN2 to RAN3. Further, the server 7 is instructed to change the radio access network used for BAS transmission from RAN2 to RAN3.

  (6) When the route selection unit 14 is instructed to change the radio access network used for BAS transmission from RAN2 to RAN3, the server 7 changes the radio access network used for BAS transmission from RAN2 to RAN3. change. Further, the server 7 changes the radio access network used for BAS transmission from the RAN 2 to the RAN 3 for the BAS control unit 12 of the terminal 1 via the Internet network 6, the RAN 3 and the communication function unit 11 of the terminal 1. Notify completion of.

  (7) The BAS controller 12 that has received the completion of the change from the RAN 2 to the RAN 3 of the radio access network used for BAS transmission from the server 7 transmits the BAS to the handover controller 13 on the terminal 1 side. Report the completion of switching of the radio access network used for. After receiving this report, the handover control unit 13 and the server 7 switch the data communication path between the terminal 1 and the node 8 from RAN2 to RAN3.

  (8) After the switching of the radio access network for data communication is completed, the handover control unit 13 instructs the communication function unit 11 to stop the communication function with the RAN2.

  (9) Upon receiving the instruction to stop the communication function with RAN2, the communication function unit 11 stops the communication function with RAN2.

  Therefore, according to the first embodiment, even when the radio access system for performing data communication is switched (handovered), the terminal 1 is only connected to the radio access network that is currently communicating and the radio access network that is the switching destination. It only needs to be connected, and there is no need to connect to any other radio access network. Therefore, seamless handover can be realized only by connecting to a maximum of two radio access networks.

  In the procedure (2), the communication function unit 11 activates the RAN3 wireless communication function in response to an instruction from the route selection unit 14, but the communication function unit 11 may activate the RAN3 wireless communication function in advance. The effect of this invention is not impaired. Further, in the procedure (8), the handover control unit 13 instructs the communication function unit 11 to stop the communication function with the RAN2, but does not instruct the communication function unit 11 to stop the communication function of the RAN2. Even when the communication function of RAN2 in 9) is not stopped, the effect of the present invention is not impaired.

  In the first embodiment, the case where the handover is performed from the PHS radio access network 2 to the radio LAN radio access network 3 has been described. However, the same effect can be obtained in handover between other radio access networks. In the first embodiment, the case of PHS, wireless LAN, second generation mobile communication system, and third generation mobile communication system is shown as the radio access network connected to the Internet network 6. If two or more radio access networks are connected to the Internet, the same effect can be obtained at the time of handover between the two or more radio access networks.

  Further, in the first embodiment, the case where the Internet network 6 is used between the wireless access networks and between the server 7 and the node 8 is shown. However, a communication network other than the Internet is connected between the wireless access networks and between the server 7 and the node 8. The same effect can be achieved even when used for connection. Further, in the first embodiment, the case of the node 8 connected to the Internet network 6 as the data communication partner of the terminal 1 has been described. However, the communication partner of the terminal 1 can be connected to another wired network via the Internet network 6. The same effect can be obtained even when connected or with other terminals connected to the radio access network.

Embodiment 2. FIG.
FIGS. 3A to 3C illustrate the operation of the integrated radio system according to Embodiment 2 of the present invention. In the integrated radio system shown in FIG. A procedure for switching the wireless access network that performs data communication to the wireless access network 3 of the wireless LAN led by the node 8 during data communication between the nodes 8 will be described. The procedure is the same even when a radio access network other than RAN2 and RAN3 is used as the radio access network to be used. In addition, the constituent elements in the figure are the same as those described in FIGS. In this case, the terminal 1 performs data communication with the node 8 via the RAN 2 and the Internet network 6. Further, the terminal 1 communicates control information related to handover with the server 7 via the RAN 2 and the Internet network 6 based on the BAS control protocol.

Switching between radio access networks is performed according to procedures (1) to (12).
(1) When a user input or an application in the node 8 generates a request for switching from the RAN2 to the RAN3 of the radio access network for data communication, the node 8 switches the radio access network from the RAN2 to the RAN3 to the server 7. Instruct.

  (2) Upon receiving the instruction to switch the radio access network from RAN2 to RAN3, the server 7 uses the BAS control protocol to the BAS control unit 12 via the Internet network 6, the RAN2, and the communication function unit 11 of the terminal 1. An instruction to switch the radio access network from RAN2 to RAN3 is transmitted.

  (3) Upon receiving an instruction to switch the radio access network from RAN2 to RAN3 using the BAS control protocol, the BAS controller 12 issues a request to the handover controller 13 to switch the radio access network from RAN2 to RAN3. 13 is transmitted.

  (4) The handover control unit 13 of the terminal 1 accepts a request to switch the radio access network for data communication from RAN2 to RAN3 (execution of handover). The handover execution request is a user input of the terminal 1 or a request from an application on the terminal 1. The handover control unit 13 instructs the communication function unit 11 to activate the communication function of the RAN 3.

  (5) When the activation of the RAN3 communication function is instructed by the handover control unit 13, the communication function unit 11 activates the RAN3 communication function while continuing the data communication with the RAN2 and the BAS communication. The base station detection, synchronization, location registration, and other processes necessary for connection with the RAN 3 are performed to establish a connection with the RAN 3. This connection with RAN3 is established based on a procedure specific to RAN3. As a result, the terminal 1 is connected to the two radio access networks RAN2 and RAN3. When the connection with the RAN 3 is established, the communication function unit 11 notifies the BAS control unit 12 and the handover control unit 13 of the connection establishment with the RAN 3.

  (6) The handover control unit 13 that has received the report of the connection establishment from the communication function unit 11 to the RAN 3 instructs the BAS control unit 12 to switch the radio access network that transmits the BAS from the RAN 2 to the RAN 3. .

  (7) Upon receiving an instruction to switch the radio access network that transmits the BAS from the handover control unit 13 to the RAN 3, the BAS control unit 12 passes through the RAN 2, the Internet network 6, and the server 7, and the server side route selection unit 14 is instructed to switch the radio access network transmitting the BAS.

  (8) When the server side route selecting unit 14 receives an instruction from the BAS control unit 12 of the terminal 1 to switch the radio access network transmitting the BAS from RAN2 to RAN3, the terminal 1 recorded in the route selecting unit 14 Changes the record of the radio access network used for BAS transmission from RAN2 to RAN3. Further, the server 7 is instructed to change the radio access network used for BAS transmission from RAN2 to RAN3.

  (9) When the route selection unit 14 is instructed to change the radio access network used for BAS transmission from RAN2 to RAN3, the server 7 changes the radio access network used for BAS transmission from RAN2 to RAN3. change. Further, the server 7 changes the radio access network used for BAS transmission from the RAN 2 to the RAN 3 to the BAS control unit 12 of the terminal 1 via the Internet network 6, the RAN 3 and the communication function unit 11 of the terminal 1. Notify completion.

  (10) The BAS control unit 12 that has received the completion of the change from the RAN 2 to the RAN 3 of the radio access network used for the BAS transmission from the server 7 transmits the BAS to the handover control unit 13 on the terminal 1 side. Report the completion of switching of the radio access network to be used. After receiving this report, the handover control unit 13 and the server 7 switch the data communication path between the terminal 1 and the node 8 from RAN2 to RAN3.

  (11) After the switching of the radio access network for data communication is completed, the handover control unit 13 instructs the communication function unit 11 to stop the communication function with the RAN2.

  (12) Upon receiving the instruction to stop the communication function with RAN2, the communication function unit 11 stops the communication function with RAN2.

  Therefore, according to the second embodiment, even when the radio access system for performing data communication is switched (handovered), the terminal 1 is connected only to the radio access network currently performing communication and the radio access network to which switching is performed. And it is not necessary to connect to any other radio access network. Therefore, seamless handover can be realized only by connecting to a maximum of two radio access networks.

  In the procedure (5), the communication function unit 11 activates the RAN3 wireless communication function in response to an instruction from the handover control unit 13, but the communication function unit 11 activates the RAN3 wireless communication function in advance. However, the effect of the present invention is not impaired. Furthermore, in the procedure (11), the handover control unit 13 instructs the communication function unit 11 to stop the communication function with the RAN2, but does not instruct the communication function unit 11 to stop the communication function of the RAN2. Even when the communication function of RAN2 in 9) is not stopped, the effect of the present invention is not impaired.

  In the second embodiment, the case where the handover is performed from the PHS radio access network 2 to the radio LAN radio access network 3 has been described. However, the same effect can be obtained in handover between other radio access networks. . In the second embodiment, the case of PHS, wireless LAN, second generation mobile communication system, and third generation mobile communication system has been shown as the radio access network connected to the Internet network. If two or more radio access networks are connected to the Internet, the same effect can be obtained during handover between the two or more radio access networks.

  In the second embodiment, the Internet network 6 is used between the wireless access networks and between the server and the node. However, a communication network other than the Internet is used between the wireless access networks and between the server and the node. Even in this case, the same effect can be achieved. In the second embodiment, the case of the node 8 connected to the Internet network as the data communication partner of the terminal 1 has been described. However, the communication partner of the terminal 1 is connected to another wired network via the Internet network 6. The same effect can be obtained even when the terminal is connected or other terminals connected to the wireless access network.

It is a block diagram which shows the structure of the integrated radio | wireless system which concerns on this invention. FIG. 6 is a diagram illustrating an operation of integrated wireless system integration according to Embodiment 1 of the present invention, and is a diagram illustrating a procedure in the case of switching a radio access network led by a terminal. It demonstrates the operation | movement of integrated radio | wireless system integration which concerns on Embodiment 2 of this invention, and is a figure which shows the procedure in the case of switching a radio access network led by a node.

Explanation of symbols

  1 terminal, 2 PHS radio access network, 3 wireless LAN radio access network, 4 second generation mobile communication system radio access network, 5 third generation mobile communication system radio access network, 6 Internet network, 7 server , 8 nodes, 11 communication function unit, 12 BAS control unit, 13 handover control unit, 14 route selection unit.

Claims (1)

A plurality of wireless access systems for forming a data communication path between the terminal and the node;
A communication network for connecting the node and a plurality of radio access networks;
A network for an integrated radio system comprising: a server for communicating a control signal for handover between the plurality of radio access networks to a terminal via the communication network and the plurality of radio access networks;
A terminal connected to one radio access network is used to transmit a control signal for handover to the server based on a radio access network switching instruction instructing another radio access network to change the connection destination. A route selection unit for instructing to change the radio access network;
The server switches a radio access network used for transmission of a control signal for handover from the one radio access network to the other radio access network based on a change instruction from the route selection unit. Integrated wireless system network.

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