Method and associated apparatus for distributed dynamic paging area clustering under heterogeneous access networks

• US 7,937,096 B2
• Filed: 06/28/2002
• Issued: 05/03/2011
• Est. Priority Date: 10/03/2001
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Takeshita, Atsushi, Funato, Daichi
• Primary Examiner(s): Appiah; Charles N
• Assistant Examiner(s): Peaches; Randy
• Application Number:
  US10/185,240
• Publication Number:
  US 20030143999A1
• Time in Patent Office: 3,231 Days
• Field of Search: 455/458, 455/456.1, 455/435, 455/63.2, 455/426.1, 379/59, 379/60, 379/54, 709/229
• US Class Current: 455/458
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition

Abstract

In a telecommunication system, paging areas may be automatically reconfigured as required. Paging areas can be adaptively reconfigured in accordance with changes in movement traffic of mobile hosts. The system and method work under a constraint that only a limited number of area IDs are permitted for each paging unit area. Also, the system and method work over heterogeneous access networks. Thus, according to the presently disclosed embodiments, paging areas reconfigure themselves according to changes in movement traffic of mobile hosts.

Claims

1. A last hop router configured for use in a telecommunication system, the last hop router comprising:

a paging area clustering agent to receive movement reports from mobile hosts in the telecommunication system, to determine dynamic clustering of paging areas based upon statistical mobility information derived from the movement reports, and to send paging messages to local paging agent clusters to page a mobile host;

a dormant monitoring agent to detect delivery of packets addressed to a mobile host in dormant mode and activate the paging area clustering agent to send a paging message to the local paging agent clusters to page the mobile host; and

a local paging agent for sending paging signals to mobile hosts identifying a paging area associated with the last hop router,

wherein the paging area clustering agent performs the following processes;

a probability map update process, wherein the probability map update process receives a registration signal from a mobile host, calculates statistics of mobile host movement and updates the probability map, and determines frequencies of mobile host movements and notifies the clustering process;

a clustering process, wherein the clustering process locates and determines paging areas to be joined or disjoined from other paging areas and updates the cluster maps of the paging area and other paging areas; and

a paging forwarding process, wherein the paging forward process receives a paging trigger packet from the dormant monitoring agent and queries the cluster map to determine to which area a packet should be delivered, forwards the paging trigger packet to the area, and notifies the clustering process of frequencies of paging trigger packets received.

2. A paging forwarding process operative in conjunction with a telecommunication system including a plurality of access points capable of radio communication with a plurality of mobile hosts, the paging forwarding process comprising:

clustering map discovery means for determining in a clustering map to which paging areas of the telecommunication system packets should be delivered to in response to a received paging trigger packet;

paging forwarding means for forwarding the paging trigger to a paging area determining by the clustering map discovery means; and

paging notification means for tracking frequencies of receipt of paging trigger packets.

3. A join method for clustering of paging areas in a telecommunication system, the join method comprising:

at one access point of the telecommunication system, detecting another access point to join;

sending a request to join the other access point;

after joining, at the one access point, substituting branch clustering information for default clustering information; and

specifying the other access point as a root wherein detecting another access point to join comprises;

storing a probability map of information about movement of mobile hosts in the telecommunication system; and

based on the probability map, identifying paging areas to be joined.

4. A join method for clustering of paging areas in a telecommunication system, the join method comprising:

at a leaf access point of a paging area cluster of access points of the telecommunication system, receiving from a joining access point a request to join the paging area cluster, wherein the paging area cluster includes a paging area for each of the access points of the paging area cluster;

within the paging area cluster, forwarding the request through one or more predecessor access points to a root access point;

at the root access point, determining if joining is permitted;

if joining is permitted, sending a reply from the root access point through the one or more predecessor access points to the leaf access point for communication to the joining access point.

5. A cluster merge method for clustering of paging areas in a telecommunication system, the cluster merge method comprising:

at a first paging area cluster of access points, receiving a request to merge from a second paging area cluster of access points;

forwarding the request to a root of the first paging area cluster;

determining at the root if the request to merge may be granted;

returning a reply to the second paging area cluster; and

after merging the first paging area cluster and the second paging area cluster, at access points of the first paging area cluster of access points, updating stored clustering data to reflect the merging.

6. A cluster prune method for clustering of paging areas in a telecommunication system, the cluster prune method comprising:

at one access point of a paging area cluster of access points, originating a request to prune to other access points of the paging area cluster of access points;

receiving a reply from the other access points; and

severing one set of access points of the paging area cluster of access points from another set of access points.

7. The cluster prune method of claim 6 wherein originating a request to prune comprises:

identifying one or more access points to sever from the paging area cluster to form a new cluster; and

identifying an access point of the one or more access points to become a root of the new cluster.

8. A cluster devolution method for clustering of paging areas in a telecommunication system, the cluster devolution method comprising:

at a root access point of a paging area cluster of access points, originating a request to devolve to other access points of the paging area cluster of access points, the request including information defining a tree structure of the paging area cluster;

receiving a reply at the root access point; and

in response to the reply, severing from the paging area cluster.

9. The cluster devolution method of claim 8 further comprising:

receiving the request at a second access point;

sending the reply to the root access point; and

after the severing, notifying other access points of the paging area cluster that the second access point is a new root access point.