Optimization of packet transmission path

• US 20050249121A1
• Filed: 05/21/2003
• Published: 11/10/2005
• Est. Priority Date: 05/22/2002
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Matsunaga, Yasuhiko
• Granted Patent: US 10,069,714 B2
• Time in Patent Office: Days
• US Class Current: 370/238
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/12 Shortest path evaluation
• CPC Class Codes: H04L 63/04 for providing a confidential data exchange among entities communicating through data packet networks
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04W 12/03 Protecting confidentiality, e.g. by encryption
• CPC Class Codes: H04W 12/06 Authentication
• CPC Class Codes: H04W 40/02 Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service

Abstract

A method is disclosed for optimizing packet transmission paths in a mobile communication network (400) in which packets are transmitted and received between mobile stations (10-14) or between a mobile station and a fixed network (120) by way of a plurality of packet transmission device (60-64, 70-72, 80, and 81) and radio base stations (50-57). When a mobile station uses a service that is provided by a fixed network (300), imposed are applied on the packet transmission path such that packets pass by way of specific packet transmission devices (80 and 81) depending on the fixed network (external network) 300. When the mobile station uses a service that is provided by the mobile communication network (400), on the other hand, no restrictions are imposed on the packet transmission path, and the packet transmission path is thus set such that the link costs are a minimum.

Claims

1. A packet transmission path optimization method in a mobile communication network for transmitting and receiving packets between a mobile station and another mobile station or a fixed station by way of a plurality of packet transmission devices and radio base stations, wherein a packet transmission path is selected either by imposing restrictions on the packet transmission path such that packets pass by way of one or more specific packet transmission devices according to the type of service that is used by the mobile station or by not imposing restrictions on the packet transmission path such that the sum of link costs is minimized.

3. A method according to claim 1, wherein, when the radio base stations or packet transmission devices to which the mobile station is connected change due to movement of the mobile station, if there is a plurality of specific packet transmission devices through which packets are to pass, and if the sum of link costs is less for a packet transmission path that passes by way of specific packet transmission devices other than the specific packet transmission devices that were selected before movement, restrictions are imposed on the packet transmission path by reselecting the other specific packet transmission devices.

10. A method according to any claim 1, wherein said mobile communication network is a GPRS (General Packet Radio Service) network based on the TS 23.060 standards of the 3GPP (Third Generation Partnership Project), the packet transmission devices of the highest-ranked level are GGSN (Gateway GPRS Support Nodes), the packet transmission devices of the next level are SGSN (Serving GPRS Support Nodes), the packet transmission devices of the next level are BSC (Base Station Controllers) or RNC (Radio Network Controllers), radio base stations are arranged at the lowest-ranked level, and routers are arranged as necessary between the radio base stations and packet devices of each level.

11. A method according to claim 1, wherein said mobile communication network is a network based on the RFC (Request for Comments) 3220 Standards of the IETF (Internet Engineering Task Force), the packet transmission devices of the highest-ranked level are HA (Home Agents), radio base stations are arranged on the lowest-ranked level, and routers, which are the packet transmission devices of the intermediate levels, are arranged between the HA and the radio base stations.

12. A method according to claim 11, wherein when packets are transmitted from a communication partner of a mobile station to the mobile station, the packet transmission path is selected by either implementing tunneling and reverse tunneling such that a HA is included in the packet transmission path according to the type of service that the mobile station uses or by not imposing restrictions on the packet transmission path such that the sum of link costs is minimized.

2. A packet transmission path optimization method in a mobile communication network for transmitting and receiving packets between a mobile station and another mobile station or a fixed station by way of a plurality of packet transmission devices and radio base stations, wherein a packet transmission path is optimized either by imposing restrictions on the packet transmission path such that packets pass by way of one or more specific packet transmission devices when the mobile station uses a service that is provided by an external network, or by not imposing restrictions on the packet transmission path such that the sum of link costs is minimized when the mobile station uses a service that is provided by the mobile communication network to which the mobile station is directly connected.

4. A method according to claim 2, wherein, when the radio base stations or packet transmission devices to which the mobile station is connected change due to movement of the mobile station, if there is a plurality of specific packet transmission devices through which packets are to pass, and if the sum of link costs is less for a packet transmission path that passes by way of specific packet transmission devices other than the specific packet transmission devices that were selected before movement, restrictions are imposed on the packet transmission path by reselecting the other specific packet transmission devices.

5. A packet transmission path optimization method in a mobile communication network for transmitting and receiving packets between a mobile station and another mobile station or a fixed station by way of a plurality of packet transmission devices and radio base stations that are connected hierarchically after a packet transmission device has designated in advance a portion or all of the packet transmission path, wherein a packet transmission device, when designating the packet transmission path, selects either a path that passes by way of packet transmission devices that belong to a higher-ranked level than its own level or a path that passes by way of only packet transmission devices that belong to lower-ranked levels than its own level such that the sum of link costs is lower, and then establishes the packet transmission path.

6. A packet transmission path optimization method in a mobile communication network for transmitting and receiving packets between a mobile station and another mobile station or a host that is connected to an external network by way of a plurality of packet transmission devices and radio base stations that are connected hierarchically after a portion or all of the packet transmission path has been designated in advance, wherein, when a packet transmission device that belongs to a higher-ranked level detects after the packet transmission path has been established that a packet transmission path having a lower sum of link costs can be established in a lower-ranked level than its own level, the packet transmission device of the higher-ranked level instructs switching of the packet transmission path to packet transmission devices of the lower-ranked level such that the packet transmission path is established between packet transmission devices of the lower-ranked level.

7. A method according to claim 6, wherein when the packet transmission device of the higher-ranked level instructs switching of the packet transmission path to packet transmission devices of the lower-ranked level, the packet transmission device of the higher-ranked level transfers communication contexts that it possesses for mobile stations to packet transmission devices of the lower-ranked level.

8. A packet transmission path optimization method in a mobile communication network for transmitting and receiving packets between a mobile station and another mobile station or a host that is connected to an external network by way of a plurality of packet transmission devices and radio base stations that are hierarchically connected after a portion or all of the packet transmission path has been designated in advance, wherein;

when the radio base stations or packet transmission devices to which a mobile station is connected change due to movement of the mobile station after the packet transmission path has been established, a packet transmission device of a higher-ranked level determines whether the packet transmission path can be changed to a packet transmission path that passes by way of packet transmission devices of a more highly-ranked level than its own, and if a packet transmission path having lower costs can be established by way of packet transmission devices of the more highly-ranked level, the packet transmission device of the higher-ranked level instructs switching of the packet transmission path to the packet transmission devices of the more highly-ranked level.

9. A method according to claim 8, wherein when the packet transmission device of a higher-ranked level instructs switching of the packet transmission path to the packet transmission devices of the more highly-ranked level, the packet transmission device of the higher-ranked level transfers communication contexts that it possesses for mobile stations to the packet transmission devices of the more highly-ranked level.

13. A packet transmission device that constitutes a mobile communication network, characterized by means for identifying the type of service that a mobile station is to use based on information that is included in a request to establish a path that has been transmitted by said mobile station;

and

means for setting the packet transmission path either by imposing restrictions on the packet transmission path such that the path passes by way of one or more specific packet transmission devices according to the type of service that has been identified or by not imposing restrictions on the packet transmission path such that the sum of link costs is minimized.

14. A packet transmission device that constitutes a mobile communication network, characterized by means for identifying, based on information that is included in a request to establish a path that has been transmitted by a mobile station, whether the mobile station is to use a service that is provided by an external network or the mobile station is to use a service that is provided by the mobile communication network to which the mobile station is directly connected;

and

means for setting the packet transmission path either by imposing restrictions on the packet transmission path such that the packet transmission path passes by way of one or more specific packet transmission devices when the mobile station is to use a service that is provided by an external network, or by not imposing restrictions on the packet transmission path such that the sum of link costs is minimized when the mobile station is to use a service that is provided by the mobile communication network to which the mobile station is directly connected.

15. A packet transmission device according to claim 14, further comprising:

means for, when the radio base stations or packet transmission devices to which the mobile station is connected change due to movement by the mobile station, if there are a plurality of specific packet transmission devices through which packets are to pass, and if the packet transmission path that passes by way of specific packet transmission devices other than the specific packet transmission devices that were selected before the movement has a lower sum of link costs, imposing restrictions on the packet transmission path by reselecting the other specific packet transmission devices.

16. A packet transmission device that constitutes a mobile communication network, characterized by means for, when a portion or all of a packet transmission path has been designated in advance, selecting either a packet transmission path that passes by way of packet transmission devices that belong to a level that is more highly ranked than its own or a packet transmission path that passes by way of only packet transmission devices that belong to levels that are ranked equal to or lower than its own depending on which path has the lower sum of link costs;

and means for establishing the selected packet transmission path.

17. A packet transmission device that constitutes a mobile communication network, characterized by means for, after a packet transmission path has once been established, detecting whether a packet transmission path having lower link costs can be established between packet transmission devices of a lower-ranked level;

and

means for instructing a packet transmission device of a lower-ranked level to switch the packet transmission path such that a packet transmission path is established between packet transmission devices of the lower-ranked level.

18. A packet transmission device according to claim 17, further comprising:

means for, when instructing switching of the packet transmission path, transmitting communication contexts such as charge information and authentication information for mobile stations to the packet transmission device of a lower-ranked level.

19. A packet transmission device that constitutes a mobile communication network, characterized by:

means for, when the radio base stations or packet transmission devices to which a mobile station is connected change due to movement of the mobile station after a packet transmission path has once been established, determining whether the packet transmission path can be changed to pass by way of packet transmission devices of a level that is more highly-ranked than its own; and

means for instructing the packet transmission devices of the more highly-ranked level to switch the packet transmission path when it has been determined that a packet transmission path can be established that passes by way of the packet transmission devices of the more highly-ranked level and that has a lower sum of link costs.

20. A packet transmission device according to claim 19, further comprising means for, when instructing switching of the packet transmission path, transferring communication contexts for mobile stations to the packet transmission devices of the more highly-ranked level.

21. A program for causing a computer that constitutes a packet transmission device of a mobile communication network to function as:

means for identifying the type of service that a mobile station is to use based on information that is contained in a request to establish a path that has been transmitted by said mobile station; and

means for setting a packet transmission path by either imposing restrictions on the packet transmission path such that the path passes by way of one or more specific packet transmission devices according to the type of service that has been identified, or by not imposing restrictions on the packet transmission path such that the sum of link costs is minimized.

22. A program for causing a computer that constitutes a packet transmission device of a mobile communication network to function as:

means for identifying whether a mobile station is to use a service that is provided by an external network or a service that is provided by the mobile communication network to which the mobile station is directly connected based on information that is contained in a request to establish a path that has been transmitted from said mobile station; and

means for setting the packet transmission path either by imposing restrictions on the packet transmission path such that the path passes by way of one or more specific packet transmission devices when the mobile station is to use a service that is provided by an external network, or by not imposing restrictions on the packet transmission path such that the sum of link costs is minimized when the mobile station is to use a service that is provided by the mobile communication network to which the mobile station is directly connected.

23. A program according to claim 22, wherein said computer is further caused to function as means for, when radio base stations or packet transmission devices to which the mobile station is connected change as a result of movement by the mobile station, if there are a plurality of specific packet transmission devices through which packets are to pass, and if the packet transmission path that passes by way of specific packet transmission devices other than the specific packet transmission device that were selected before the movement has a lower sum of link costs, imposing restrictions on the packet transmission path by reselecting the other specific packet transmission devices.

24. A program for causing a computer that constitutes a packet transmission device of a mobile communication network to function as:

means for, when a portion or all of a packet transmission path has been designated in advance, selecting either a packet transmission path that passes by way of packet transmission devices that belong to a level that is more highly ranked than its own or a packet transmission path that passes by way of only packet transmission devices that belong to levels that are ranked equal to or lower than its own depending on which path has the lower sum of link costs; and

means for establishing the selected packet transmission path.

25. A program for causing a computer that constitutes a packet transmission device of a mobile communication network to function as:

means for, after a packet transmission path has once been established, detecting whether a packet transmission path having lower link costs can be established between packet transmission devices of a lower-ranked level; and

means for instructing a packet transmission device of a lower-ranked level to switch the packet transmission path such that a packet transmission path is established between packet transmission devices of the lower-ranked level.

26. A program according to claim 25 that further causes a computer to function as means for, when instructing switching of the packet transmission path, transmitting communication contexts such as charge information and authentication information for mobile stations to the packet transmission device of a lower ranked level.

27. A program for causing a computer that constitutes a packet transmission device of a mobile communication network to function as:

means for, when the radio base stations or packet transmission devices to which a mobile station is connected change due to movement of the mobile station after a packet transmission path has once been established, determining whether the packet transmission path can be changed to pass by way of packet transmission devices of a level that is more highly-ranked than its own; and

means for instructing the packet transmission devices of the more highly-ranked level to switch the packet transmission path when it has been determined that a packet transmission path can be established that passes by way of the packet transmission devices of the more highly-ranked level and that has a lower sum of link costs.

28. A program according to claim 27 wherein said computer is further caused to function as means for, when instructing switching of the packet transmission path, transferring communication contexts such as charge information and authentication information for mobile stations to the packet transmission devices of the more highly-ranked level.