JP2009164785A - Communication control method and radio communication system - Google Patents

Abstract

To provide a communication control method and a wireless communication system capable of assigning hierarchically configured IDs to each node even in a system in which the node configuration varies.
A communication control method according to the present invention includes an activation notification transmission step in which a newly activated base station 4 transmits an activation notification including its own contact information to a core network node 1A, and a core that has received the activation notification. The network node 1A includes a node-specific ID region in which its own node ID and a unique ID newly assigned to the base station 4 are combined, and an ID allocation region to a lower-order node of the base station 4 An ID assigning step of assigning the converted node ID to the base station 4.
[Selection] Figure 1

Description

  The present invention relates to a communication control method and a radio communication system for assigning hierarchically configured IDs to each node.

  When performing a handover, the mobile communication terminal acquires the ID of a cell that is a candidate for the handover destination by monitoring the common channel, and reports this cell ID to an upper node such as an RNC (Radio Network Controller). Then, the RNC determines a handover destination based on the reported cell ID. In addition, a path for transmitting a handover request and an IP address for transmitting signaling from the cell ID configured as “MMS / xGSN ID”, “RNC ID”, “BTS ID”, and “CELL ID” And an SCTP port are derived (for example, Patent Document 1 below).

  For example, when a terminal performs handover to a cell under a different BTS in the same RNC, the RNC has the same BRN (cell) as the handover destination because the “RNC ID” included in the cell ID is the same at the source and destination. Since it can be determined that it is under its control, the IP address and SCTP port derivation processing is performed by itself. When performing handover to a BTS (cell) existing under a different RNC, since the “RNC ID” included in the cell ID is different, an Iur connection is established via the core network node, and an IP address or SCTP is established. Deriving ports and the like.

JP 2001-024700 A

  However, the configuration of the cell ID in the above prior art can be applied to a system such as 3G having a fixed hierarchical structure in which the route from the core network node to the cell is configured by RNC / BTS / cell. It cannot be applied to a system in which nodes constituting a route from a network node to a cell are not fixed. That is, there is a problem that when the nodes constituting the route fluctuate, the cell ID cannot be configured by a combination of IDs for each node.

  In the above conventional technique, since the RNC statically manages the adjacent node information, when the number of nodes increases or decreases, the operator needs to manage the update of the adjacent node information. For this reason, for example, when the number of nodes increases due to the downsizing of cells or the like, there is a problem that an increase in management cost is expected.

  The present invention has been made in view of the above, and even in a system in which the node configuration fluctuates, it is possible to assign a hierarchically configured ID to each node, and regardless of operator management. An object is to obtain a communication control method and a wireless communication system capable of managing node information.

  In order to solve the above-described problems and achieve the object, the present invention provides a startup notification transmission step in which a newly started new node transmits a startup notification including its own contact information to an upper node, and the startup notification is received. The higher-order node includes a node-specific ID area in which its own node ID and a unique ID newly assigned to the new node are combined, and an ID assignment area to a lower-order node of the new node An ID assigning step of assigning a hierarchical node ID to the new node.

  According to the present invention, there is an effect that a hierarchical ID can be configured even in a system in which nodes constituting a path from a core node to a cell are not fixed.

  Embodiments of a wireless communication system 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 1 FIG.
FIG. 1 is a diagram showing a configuration example of a first embodiment of a wireless communication system according to the present invention. The wireless communication system of FIG. 1 includes a core network node 1A, a concentrator 2A that is a radio base station aggregation device such as an RNC, and base stations (eNodeBs) 3 to 6. In addition, the mobile communication terminal 20 is located in this system. In addition, the ellipses in the figure represent the cells 100 and 101 under the base station 3, the cell 102 under the base station 4, the cell 103 under the base station 5, and the cell 104 under the base station 6, respectively.

  In FIG. 1, the core network node 1A is connected to a core network (not shown) that is a large-capacity communication line. Here, hierarchical IDs are assigned to lower nodes. The concentrator 2A couples a plurality of communication channels to one transmission line.

  The core network node 1A holds information about lower nodes (lower node ID, contact information, etc.) as a lower node list. In addition, each node other than the core network node 1A holds information regarding nodes adjacent to itself as an adjacent node list. These lists are dynamically updated according to the increase / decrease of nodes, and the latest state is maintained.

  In the wireless communication system configured as described above, the operation when the node configuration changes will be described by taking the case where the base station 4 is activated as an example.

  When the base station 4 is activated, it notifies the core network node 1A, which is an upper node, of an activation notification indicating that fact together with contact information such as its own IP address and SCTP port number. The core network node 1A that has received the activation notification newly adds the base station 4 to the lower node list. In addition, an ID corresponding to the system configuration is assigned to the base station 4, and the ID is returned as a response to the activation notification. Further, the lower node list held by the core network node 1A is also notified by this response.

  For example, when the ID of the core network node 1A is “0x1234”, the ID assigned to the base station 4 is “0x123401 ** (* is Don't care), and the ID assigned to the base station 3 is“ 0x123402 * ”. * (* Is Don't care). Here, “01” and “02” after “1234” are unique ID portions newly assigned to the base stations 4 and 3 operating as lower nodes of the core network node 1A. Further, the ID assigned to the concentrator 2A is, for example, “0x12348 ***” (* is Don't care), which leaves the ID assignment area for the base stations 5 and 6 existing in the lower level. Therefore, the ID assigned to the base station 5 is “0x123481 ** (* is Don't care), and the ID assigned to the base station 6 is“ 0x123482 ** (* is Don't care). Here, “8” after “1234” is a unique ID portion newly assigned to the concentrator 2A operating as a lower node of the core network node 1A. Further, “1” and “2” after “12348” are unique ID portions newly assigned to the base stations 5 and 6 that operate as lower nodes of the concentrator 2A.

  The base station 4 that acquired the ID by the response to the activation notification activates the concentrator 2A described in the lower node list notified from the core network node 1A, including its own ID and contact information based on the contact information. Send notifications.

  The concentrator 2A that has received the activation notification from the base station 4 adds the ID and contact information of the base station 4 included in the activation notification to its adjacent node information. In addition, as a response to the activation notification, the base station 4 is notified by including its own ID and contact information in a response message. Then, the base station 4 that has received this response message adds the ID and contact information of the concentrator 2A included in the response message to its adjacent node list.

  By the above operation, the lower node list and the adjacent node list are dynamically managed so as to be always the latest.

  Next, the operation when performing handover in the wireless communication system constructed by the above operation will be described.

  For example, when the mobile communication terminal 20 moves from the cell 100 to the cell 103, the mobile communication terminal 20 detects that the quality of the monitored common channel is higher in the cell 103 than in the cell 100 Thus, the base station 3 that provides the cell 100 is requested to perform handover to the cell 103. The base station 3 that has received the handover request searches its own adjacent node list and determines that there is no base station that provides the handover destination cell 103 as an adjacent node. On the other hand, the base station 3 determines that it is necessary to notify the handover destination to the handover destination via its own upper node, and transfers the handover request to the core network node 1A that is the upper node.

  Next, the core network node 1A that has received the handover request refers to the lower node list and determines that there is a base station 5 that provides the cell 103 to the lower node. Then, based on the contact information, the handover request is transferred to the concentrator 2A, which is the upper node of the base station 5.

  Next, the concentrator 2A that has received the handover request refers to its own adjacent node list and determines that there is a base station 5 that provides the cell 103 to a lower node. Then, a handover request is transferred to the base station 5 based on the contact information.

  With the above operation, the base station 5 that finally received the handover request recognizes that the mobile communication terminal 20 requests handover with the cell 100 as the movement source and the cell 103 as the movement destination. Thereafter, each of the above devices returns a response to the handover request through a route opposite to the handover request, and the handover by the mobile communication terminal 20 is realized.

  As described above, in this embodiment, hierarchical IDs according to the system configuration are dynamically assigned to the nodes configuring the wireless communication system. That is, the ID is configured by a combination of IDs for each node. As a result, a hierarchical ID can be configured even in a system in which nodes constituting a path from a core node to a cell are not fixed. In addition, since the lower-level node list and the adjacent node list are dynamically updated, for example, even when the number of nodes constituting the system increases or decreases, the list can be managed regardless of the operator's management. Routing efficiency.

  In the present embodiment, as an example of the ID assignment process, for example, the ID assignment method shown in FIG. 2 or 3 may be adopted. Even when these ID allocation methods are employed, the same effects as described above can be obtained.

  FIG. 2 is a diagram illustrating an example of an ID assignment method. In this example, it is assumed that the core network node 1A assigns “0x12345070” as an ID value and “0xFFFFF0F0” as a bit mask to a specific lower node. In this case, the ID of the specific lower node is “0x12345070” masked by the bit mask. Further, when assigning an ID to a lower node, the unmasked area 200 can be used as a newly assignable area.

  FIG. 3 is a diagram showing an example of an ID assignment method different from that in FIG. In this example, the core network node 1A notifies the specific lower node of the ID value and the prefix length as information indicating the ID area. Therefore, when the core network node 1A assigns “0x12345670” as the ID value and “28 bits” as the prefix length, the ID of the specific lower node is “0x1234567” in the range specified by the prefix length. Further, when assigning an ID to a lower node, the area 300 not designated by the prefix length can be used as a newly assignable area.

Embodiment 2. FIG.
In the first embodiment, the ID allocation process for dynamically assigning hierarchical IDs to lower nodes and the efficiency of routing by dynamically updating the lower node list and the adjacent node list have been described. In the present embodiment, ID allocation and routing are further improved in efficiency. Hereinafter, processing different from that of the first embodiment will be described.

  FIG. 4 is a diagram illustrating a configuration example of a second embodiment of the wireless communication system according to the present invention. This wireless communication system includes a core network node 1B and base stations 7-9. Also, the ellipses in the figure represent cells 105 and 106 under the base station 7, cells 107 and 108 under the base station 8, and cells 109 and 110 under the base station 9, respectively.

  In addition, the core network node 1B holds information on lower nodes as a lower node list, similarly to the core network node 1A described above. In addition, each base station holds information regarding nodes adjacent to itself as an adjacent node list, as in the base station of the first embodiment described above. These lists are dynamically updated according to the increase / decrease of nodes, and the latest state is maintained.

  Next, the operation when the node configuration varies in the wireless communication system configured as described above will be described.

  For example, it is assumed that the base station 9 is newly activated while the base stations 7 and 8 are already activated. In this case, the base station 9 is the upper node for contact information such as its own IP address and SCTP port number, and a start notification including “2” as the number of cells that can be provided (upper limit value). Notify the core network node 1B. In the core network node 1B, according to the content of the activation notification, the base station 9 is assigned an ID having an area where an ID can be assigned to two lower cells. When this ID is assigned to the base station 9, it is assigned by the method described in the first embodiment.

  If there is no vacant ID assigned to the base station 9, the core network node 1B provides information on the number of necessary IDs to the base station 7 and the base station 8 that are already assigned lower IDs. In addition, a request for returning a free ID is notified. The base station 7 and the base station 8 notified of this request return unnecessary IDs to the core network node 1B. The core network node 1B assigns the returned ID to the base station 9. As described above, even when there is no available ID to be allocated, it is possible to cope with a case where the number of nodes further increases by requesting other nodes to return unnecessary IDs.

  In addition, for example, when stopping the base station 8 that is being activated, the core network node 1B is notified that the ID assigned to itself and its lower nodes (here, cells) can be returned. To do. In the core network node 1B, the ID notified that it can be returned is registered as an ID that can be reused when notified of a new activation request, and information about the base station 8 is deleted from the lower-level node list. . In addition to the notification to the core network node 1B, the base station 8 notifies the base station 7, which is an adjacent node, that it will stop. Thereby, the base station 7 deletes the information regarding the base station 8 from its own adjacent node list.

  As described above, in this embodiment, since a predetermined lower node notifies the core network node of the number of lower nodes of itself, further efficiency of ID allocation and routing is realized. be able to. In addition, when the ID is insufficient, it is requested to return the already assigned ID, and when the active base station stops, it is notified that the ID can be returned. Management becomes possible.

Embodiment 3 FIG.
In this embodiment, a case will be described in which there is a cell that cannot accommodate a mobile communication terminal. In the following, processing different from that of the first and second embodiments will be described.

  FIG. 5 is a diagram illustrating a configuration example of a third embodiment of the wireless communication system according to the present invention. The wireless communication system includes a core network node 1C that performs the same operation as the core network node 1A or the core network node 1A described above, a concentrator 2A, and base stations 10 to 12. In addition, the mobile communication terminal 30 is located in this system. Also, the ellipses in the figure respectively accommodate the cells 111 and 112 under the base station 10 that can accommodate the mobile communication terminal 30, the cell 113 under the base station 11 that can accommodate the mobile communication terminal 30, and the mobile communication terminal 30. The cells 114 and 115 under the base station 12 that cannot be performed are shown.

  Next, a handover operation in the radio communication system configured as described above will be described. Here, it is assumed that the base stations 10 to 12 are all activated, and ID assignment and various node list updates have already been completed. Further, it is assumed that the base station 10 recognizes that the base station 12 is a base station that cannot accommodate the mobile communication terminal 30 by exchanging with the core network node 1C at the time of activation.

  In this state, the base station 10 notifies the mobile communication terminal 30 located in the cell 111 of a cell list indicating cells under the base station that cannot accommodate the mobile communication terminal 30. Specifically, not the cell ID assigned to the cells 114 and 115 but the ID of the base station 12 is notified as the cell list.

  The mobile communication terminal 30 that has received the ID of the base station 12 as the cell list removes all the cells under the base station 12 from the candidates for the destination cell when performing a handover, Select the destination from the cell.

  As described above, in the present embodiment, when a cell that cannot accommodate a mobile communication terminal exists in the system, a base station that provides the cell is notified to the mobile communication terminal in advance, and handover is performed. Sometimes, all cells under the base station are excluded from the destination cell candidates. Thereby, it is possible to reduce the amount of communication at the time of handover, and efficient handover is possible.

  As described above, the communication control method according to the present invention is useful for a mobile communication system in which the node configuration varies, and in particular, for a system that assigns hierarchically configured IDs to each node constituting the system. Is suitable.

It is a figure which shows the structural example of Embodiment 1 of the radio | wireless communications system concerning this invention. It is a figure which shows an example of an ID allocation method. It is a figure which shows an example of the ID allocation method different from the said FIG. It is a figure which shows the structural example of Embodiment 2 of the radio | wireless communications system concerning this invention. It is a figure which shows the structural example of Embodiment 3 of the radio | wireless communications system concerning this invention.

Explanation of symbols

1A, 1B, 1C Core network node 2A Concentrator 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 Base station 20, 30 Mobile communication terminal 100, 101, 102, 103, 104, 105, 106 , 107, 108, 109, 110, 111, 112, 113, 114, 115 cells

Claims (12)

A communication control method in a wireless communication system in which a hierarchical structure is formed by a plurality of nodes, and node IDs are hierarchized between nodes,
An activation notification transmission step in which a newly activated new node transmits an activation notification including its own contact information to an upper node;
The upper node that has received the activation notification has a node-specific ID area in which its own node ID and a unique ID newly assigned to the new node are combined, and an ID allocation area to a lower-order node of the new node An ID assigning step of assigning the hierarchical node ID including the new node to the new node;
The communication control method characterized by including. The upper node holds node information including the node ID and contact information of the lower node as a lower node list,
further,
A lower node list update step in which the node dynamically adds node information of the new node to a lower node list;
The communication control method according to claim 1, further comprising: Each node constituting the system holds node information of adjacent nodes as an adjacent node list,
further,
A node information notifying step in which the upper node notifies the new node of node information of an adjacent node adjacent to the new node;
The new node transmits its node information to the adjacent node based on the node information received from the upper node, and the adjacent node returns its node information to the new node. An adjacent node list update step of updating the mutual adjacent node list;
The communication control method according to claim 2, further comprising:   When a wireless communication terminal in communication with a specific node performs a handover, a transfer path of a handover control message transmitted / received between the movement source node and the movement destination node is determined by the node receiving the message from the adjacent node list or 4. The communication control method according to claim 3, wherein the determination is autonomously based on the lower node list.   In the case of assigning the hierarchical node ID, the upper node sets an area masked by a predetermined bit mask as an ID area unique to the node, and sets an area not masked by the predetermined bit mask as an area of the new node. The communication control method according to any one of claims 1 to 4, further comprising an ID allocation area for a lower node.   When assigning the hierarchical node ID, the upper node notifies the prefix length as information indicating the ID area unique to the node, and sets an area not specified by the prefix length to a lower level of the new node. The communication control method according to any one of claims 1 to 4, wherein an ID allocation area is assigned to a node. In the activation notification transmission step, the activation notification is transmitted including the upper limit value of the number of cells that can be provided by itself,
The communication control method according to any one of claims 1 to 6, wherein, in the ID assignment step, the hierarchical node IDs are assigned in consideration of the upper limit value.   In the ID allocation step, if there is no available node ID to be allocated to the new node, the upper node requests another lower node to which a node ID has already been allocated to return an empty ID and is returned. 8. The communication control method according to claim 7, wherein a node ID assigned to the new node is assigned. The lower node to stop notifies the upper node that the node ID assigned to itself and its lower node can be returned,
In the upper node, the node ID notified that it can be returned is registered as an ID that can be reused when a new activation request is notified, and the node information of the lower node to be stopped from the lower node list The communication control method according to claim 7, wherein the communication control method is deleted. The lower node to stop further notifies the adjacent node that it will stop,
The communication control method according to claim 9, wherein the adjacent node deletes node information of the subordinate node to be stopped from the adjacent node list.   When there is a cell that cannot accommodate a mobile communication terminal in the system, the node ID of the base station that provides the cell is notified to the mobile communication terminal, and all cells under the base station are moved during handover. The communication control method according to claim 1, wherein the communication control method is excluded from candidates for the previous cell. A wireless communication system in which a hierarchical structure is formed by a plurality of nodes, and node IDs are hierarchized between nodes,
Subordinate node that sends a startup notification including its own contact information when newly started,
When receiving a startup notification, a node-specific ID area that combines its own node ID and a unique ID newly assigned to the lower node, and an ID allocation area to a lower node of the lower node, An upper node that assigns the hierarchical node ID including the lower node, and
A wireless communication system comprising:

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