Identification of unused resources in a packet data network

• US 20020167905A1
• Filed: 04/30/2002
• Published: 11/14/2002
• Est. Priority Date: 05/08/2001
• Status: Active Grant

• Current Assignee: Ericsson AB (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Chowdhury, Kuntal, Wenzel, Peter
• Granted Patent: US 7,139,829 B2
• Time in Patent Office: Days
• US Class Current: 370/249
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 69/28 Timers or timing mechanisms used in protocols
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04W 72/51 based on terminal or device properties
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 76/30 Connection release
• CPC Class Codes: H04W 88/14 Backbone network devices

Abstract

A packet data service node is formed to establish an “always on” connection with a mobile terminal by way of a packet control function card or device with the ability to determine when a mobile terminal no longer requires a previously established point-to-point protocol communication link. More specifically, the PDSN formed according to one embodiment of the present invention, includes an inactivity timer and corresponding logic to prompt it to generate an LCP Echo Request to the mobile terminal after expiration of the inactivity timer. Each time data or control signals are received from the mobile terminal, the inactivity timer is reset. Upon expiration of the timer, the PDSN generates the LCP Echo Request. In one embodiment of the invention, the LCP Echo Request is generated at least once and a total of three times prior to the release of network resources responsive to not receiving an LCP Echo Reply from the mobile terminal, which it should have generated had it received the LCP Echo Request generated by the PDSN. Logic defined by the PDSN and its corresponding method of operation facilitates the release of resources being wasted by a mobile terminal that no longer needs as determined by failure of the mobile terminal to respond with an LCP Echo Reply

Claims

1. A packet data serving node (PDSN), comprising:

a bus coupled to the processor for transmitting computer instructions and control signals to and from the processor within the PDSN;

memory coupled to the bus, the memory including computer instructions that define operational logic for causing the PDSN to generate a Link Control Protocol (LCP) Echo Request signal to a mobile terminal upon specified conditions; and

a processor for executing computer instructions wherein the processor retrieves the computer instructions from the memory over the bus and executes the computer instructions to generate a first LCP Echo Request signal.

2. The PDSN of claim 1 wherein the computer instructions stored within the memory define logic to prompt the processor to set an inactivity timer and to generate the first LCP Echo Request signal upon expiration of the inactivity timer.

3. The PDSN of claim 2 wherein the computer instructions define logic to prompt the processor reset the inactivity timer every time the data packet or control signal is received from the mobile terminal.

4. The PDSN of claim 3 wherein the computer instructions define logic to set the inactivity timer to a value that is equal to or exceeds one hour.

5. The PDSN of claim 1 wherein the computer instructions stored within the memory further define operational logic to prompt the processor to generate a second LCP Echo Request if a reply is not received from the mobile terminal within a specified period after the first LCP Echo Request was generated.

6. The PDSN of claim 1 wherein the processor generates at least three LCP Echo Requests if a reply is not received for either a first or a second LCP Echo Request that was generated.

7. The PDSN of claim 6 wherein the computer instructions further define operational logic to prompt the processor to set a response timer each time one of the at least three LCP Echo Request is transmitted wherein the processor does not either retransmit another LCP Echo Request or determine to tear down the point-to-point protocol communication link established with the mobile terminal until expiration of the response timer.

8. A communication network including a wireless communication network portion for establishing “

always on”

type communication links for transmitting data, the network comprising;

radio transceiver circuitry for establishing a radio frequency (RF) communication link with a mobile terminal;

a base station controller/access network controller (BSC/ANC) for establishing and controlling the RF communication link, the BSC/ANC coupled to communicate with the radio transceiver circuitry and to transmit and receive communication signals thereto and therefrom, respectively;

a packet control function (PCF) network element coupled to the BSC/ANC, the PCF for converting data between an IP protocol and a wireless network protocol; and

a packet data serving node (PDSN) coupled to the PCF, the PDSN for establishing a connection between a packet data network and the PCF, the PDSN further including logic to generate an inactivity timer and to generate an LCP Echo Request upon expiration of the inactivity timer.

9. The communication network of claim 8 wherein the PDSN further includes logic to tear down a communication link if the PDSN does not receive an LCP Echo Reply from the mobile terminal within a specified period after generation of the LCP Echo Request.

10. The communication network of claim 9 wherein the PDSN does not tear down the communication link unless an LCP Echo Reply was not received after the LCP Echo request was generated a plurality of times.

11. The communication network of claim 10 wherein the plurality of times comprises at least three times.

12. The communication network of claim 13 wherein the inactivity timer is set to a value that is equal to or exceeds one hour.

14. The communication network of claim 8 wherein the inactivity timer is set to a value that is within a range of magnitude of approximately three hours.

16. The method of claim 15 further including resetting the inactivity timer if a reply is received from the mobile terminal.

17. The method of claim 16 further including generating a second ping if the reply is not received within a specified reply time.

18. The method of claim 17 further including generating a third ping if the reply is not received within the specified reply time.

19. The method of claim 18 further including determining to tear down the communication link if the reply was not received to any one of the first, second or third generated pings.

20. The method of claim 15 wherein generating the ping comprises generating an LCP Echo Request signal and the reply comprises receiving an LCP Echo Reply signal originated by the mobile terminal.

15. A method for determining to tear down a communication link with a mobile terminal in a wireless network, comprising:

creating the communication link;

setting an inactivity timer after creating the communication link;

resetting the inactivity timer each time a signal is received from the mobile terminal; and

upon expiration of the inactivity timer, generating a ping to the mobile terminal to determine if the communication link should be torn down.