Packet core function and method of selecting a packet data service node/foreign agent in a packet data network

• US 6,834,050 B1
• Filed: 09/08/2000
• Issued: 12/21/2004
• Est. Priority Date: 03/10/2000
• Status: Expired due to Fees

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Segura, Louis, Madour, Lila, Shafik, Karim
• Primary Examiner(s): LEE, CHI HO A
• Application Number:
  US09/658,432
• Time in Patent Office: 1,565 Days
• Field of Search: 370/210.1, 370/310.2, 370/313, 370/328, 370/331, 370/338, 370/349, 370/389, 370/392, 370/400, 370/401, 370/410, 370/465, 455/432.1, 455/436, 455/439, 455/440, 455/445
• US Class Current: 370/392
• CPC Class Codes: H04M 15/00 Arrangements for metering, time-control or time indication ; Metering, charging or billing arrangements for voice wireline or wireless communications, e.g. VoIP
• CPC Class Codes: H04M 15/31 Distributed metering or calculation of charges
• CPC Class Codes: H04M 15/43 Billing software details
• CPC Class Codes: H04M 15/8038 Roaming or handoff
• CPC Class Codes: H04M 2215/204 UMTS; GPRS
• CPC Class Codes: H04M 2215/22 Bandwidth or usage-sensitve billing
• CPC Class Codes: H04M 2215/32 Involving wireless systems
• CPC Class Codes: H04M 2215/34 Roaming
• CPC Class Codes: H04M 2215/7442 Roaming
• CPC Class Codes: H04M 2215/96 Distributed calculation of charges, e.g. in different nodes like for mobiles between HLR and VLR, or between the terminal and the billing function
• CPC Class Codes: H04W 36/12 Reselecting a serving backbone network switching or routing node
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 8/06 Registration at serving network Location Register, VLR or user mobility server

Abstract

A Packet Core Function (PCF) and method of consistently selecting a Packet Data Service Node (PDSN) from a plurality of PDSNs in a packet data network to host a data session for a Mobile Node (MN). In a first embodiment, a static lookup table in the PCF is used to associate a list of identifiers for MNs and a list of the plurality of PDSNs in the network. The PCF obtains an identifier for the MN and utilizes the lookup table and a hash function to associate the identifier for the MN with a PDSN. The PDSN is then selected by the PCF to host the data session for the MN. In another embodiment, the PCF also includes a cache timer and a cache memory that stores the identifier for the MN and the IP address of the selected PDSN for a predetermined time period following the handoff of the MN to another PCF. If the MN returns to the PCF within the predetermined period of time, the PCF reselects the same PDSN to host the data session. In another embodiment, following the initial selection of a PDSN to host the data session, the EP address of the PDSN is sent to the MN which then passes the IP address of the PDSN to any subsequent PCFs where the MN roams. A PDSN zone ID may be utilized in lieu of the fill IP address.

Claims

1. A method of consistently selecting a particular Packet Data Service Node (PDSN) from a plurality of PDSNs in a packet data network to host a data session for a Mobile node (MN), said method comprising the steps of:

storing a static lookup table in a Packet Core Function (PCF), said table including a list of identifiers for MNs and an associated list of the plurality of PDSNs in the network;

utilizing the lookup table by the PCF to associate an identifier for the MN with the particular PDSN;

selecting the particular PDSN by the PCF to host the data session for the MN;

storing in a cache memory of the PCF, an identifier for the MN and an Internet Protocol (IP) address for the particular PDSN for a predetermined period of time after handing off the MN to another PCF;

determining whether the MN returned to the PCF within the predetermined Period of time; and

reselecting the particular PDSN to host the data session if the MN returned to the PCF within the predetermined period of time.

2. The method of consistently selecting a particular PDSN of claim 1 wherein the network includes a plurality of PCFs, and the step of storing a static lookup table in a PCF includes storing the lookup table in every PCF in the network.

3. The method of consistently selecting a particular PDSN of claim 2 further comprising the steps of:

performing a dormant handoff procedure to hand off the MN from a source PCF to a target PCF in the network, said dormant handoff procedure including the step of passing the identifier for the MN to the target PCF;

utilizing the lookup table by the PCF to associate the an identifier for the MN with the selected PDSN; and

connecting the MN to the selected PDSN by the target PCF.

4. The method of claim 2, the method further comprising the steps of:

initially selecting, by the PCF, the particular PDSN to host the data session;

sending an information message from the PCF to the MN via a Base Station Controller (BSC) with an indication of the IP address of the particular PDSN; and

passing the IP address of the particular PDSN from the MN to at least another PCF where the MN roams in the network.

5. The method of claim 1 includes the step of

obtaining by the PCF, an identifier for the MN before

utilizing the lookup table by the PCF to associate the identifier for the MN with the particular PDSN.

6. The method of consistently selecting the particular PDSN of claim 4 wherein the indication of the IP address of the selected PDSN is a PDSN zone ID.

7. A Packet Core Function (PCF) that consistently selects a particular Packet Data Service Node (PDSN) from a plurality of PDSNs in a packet data network to host a data session for a Mobile Node (MN), said PCF comprising:

a static lookup table that includes a list of identifiers for MNs and an associated list of the plurality of PDSNs in the network;

means for associating the identifier for the MN with the particular PDSN utilizing the lookup table, and selecting the particular PDSN to host the data session for the MN;

a cache memory that stores the identifier for the MN and an Internet Protocol (IP) address for the particular PDSN for a predetermined period of time after handing off the MN to another PCF;

a cache timer for determining when the predetermined time period has expired; and

means for reselecting the particular PDSN to host the data session if the MN returns to the PCF within the predetermined period of time.