Avoiding data loss and reducing registration overhead in packet networks

• US 7,688,786 B2
• Filed: 09/17/2003
• Issued: 03/30/2010
• Est. Priority Date: 03/17/2003
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Ho, Duncan, Abrol, Nischal
• Primary Examiner(s): Appiah; Charles N
• Assistant Examiner(s): Karikari; Kwasi
• Application Number:
  US10/665,929
• Publication Number:
  US 20040184436A1
• Time in Patent Office: 2,386 Days
• Field of Search: 370/331, 370/335, 370/324, 370/328, 455/432.1, 455/436
• US Class Current: 370/331
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support

Abstract

Techniques for avoiding data loss and reducing registration overhead in a wireless packet data communication system are disclosed. In one embodiment, a mobile station adds each connection to a connection list following registration with the PCF. The mobile station need not reregister a connection included in the connection list when it again enters the PCF'"'"'s coverage area. In another embodiment, a PDSN maintains a connection table, with one or more connections for each mobile station. The PDSN transmits data to the mobile station along one of the connections. In yet another embodiment, a PDSN transmits on an active connection, if one exists. In yet another embodiment, connections in a connection list or connection table are removed when a corresponding inactivity timer expires. Various other embodiments are also presented. Benefits include allowing mobile stations to travel between PCFs without re-registering, which reduces registration overhead and increases system capacity, and avoidance of data loss from network initiated data directed to a mobile station, resulting in timely delivery of the data and reduction of system resources allocated to retransmission of data.

Claims

1. A wireless communication device, comprising:

a connection table for storing one or more connection identifiers, wherein a connection identifier corresponds to a Packet Coordination Function (PCF) that has been previously visited by the wireless communication device, the connection table indicating whether a connection between the wireless communication device and each PCF is active;

a receiver for receiving a connection identifier;

a processor for determining if the received connection identifier is contained in the connection table, and for delivering the received connection identifier to the connection table for storing when the received connection identifier is not contained in the connection table;

a transmitter for sending a registration in response to the received connection identifier when the received connection identifier is not contained in the connection table; and

a first inactivity timer associated with the connection identifier, wherein the processor removes the connection identifier from the connection table in response to an expiration of the first inactivity timer, the first inactivity timer configured to expire before a second inactivity timer maintained in a Packet Data Serving Node (PDSN) to which the wireless communication device is connected via the PCF and which is also associated with the connection identifier;

wherein the processor resets the first inactivity timer in response to activity on a connection corresponding to the connection identifier, and

wherein the processor is further operable to determine that the registration is not needed if the processor determines that received connection identifier is contained in the connection table.

2. The wireless communication device of claim 1, wherein the processor clears the connection table when a connection is received corresponding to a Packet Data Serving Node (PDSN) that is different from a PDSN corresponding to a previously stored connection.

3. The wireless communication device of claim 1, wherein the processor clears the connection table when a clear table message is received by the receiver.

4. A Packet Data Serving Node (PDSN), operable with a plurality of Packet Coordination Functions (PCFs) via a corresponding plurality of connections, each PCF operable to communicate with one or more wireless communication devices, the PDSN further operable with a network for directing data for transmission to one or more wireless communication devices, comprising:

a connection table for storing a plurality of connection sets, each connection set comprising one or more connections associated with a wireless communication device, wherein a first timer in the PDSN and a second timer in the wireless communication device correspond to each of the connections and wherein the first timer is set to expire after the second timer;

a processor for selecting a connection from the one or more connections in a connection set associated with a wireless communication device for which data is directed from the network; and

a buffer for receiving data from the network that is designated for delivery to a wireless communication device, storing the received data until the wireless communication device is located, based on an active connection, on one of the connections in the connection set and transmitting the stored data on the selected connection to the wireless communication device.

5. The Packet Data Serving Node (PDSN) of claim 4, wherein an active connection identifier is stored in the connection table to identify zero or one active connection for each wireless communication device.

6. The Packet Data Serving Node (PDSN) of claim 5, wherein the processor selects all of the connections associated with a wireless communication device for transmission to the wireless communication device when no connection for the wireless communication device is identified as active.

7. The Packet Data Serving Node (PDSN) of claim 5, wherein the processor selects a subset of the connections associated with a wireless communication device for transmission to the wireless communication device when no connection for the wireless communication device is identified as active.

8. The Packet Data Serving Node (PDSN) of claim 5, wherein the processor selects the most recent active connection from the connections associated with a wireless communication device for transmission to the wireless communication device when no connection for the wireless communication device is identified as active.

9. The Packet Data Serving Node (PDSN) of claim 5, wherein the processor selects one or more connections randomly from the connections associated with a wireless communication device for transmission to the wireless communication device when no connection for the wireless communication device is identified as active.

10. The Packet Data Serving Node (PDSN) of claim 4, further comprising a plurality of timers corresponding to the plurality of stored connections, wherein the processor removes a connection from the connection table upon expiration of one of the plurality of timers associated with the connection.

11. The Packet Data Serving Node (PDSN) of claim 10, wherein the processor resets one of the plurality of timers in response to an activity indicator associated with the mobile station on the corresponding connection.

12. A method of registering and maintaining connections, comprising:

receiving a connection identifier at a wireless communication device;

determining if the received connection identifier is contained in a connection table, and registering a connection in response to a received connection not contained in the connection table;

storing the received connection identifier in the connection table when the connection is not contained in the connection table, wherein the connection identifier corresponds to a Packet Coordination Function (PCF) that has been previously visited by the wireless communication device and indicates whether a connection between the PCF and the wireless communication device is active;

determining that the registration is not needed if the received connection identifier is in the connection table; and

removing the connection identifier from the connection table in response to expiration of a first inactivity timer associated with the connection identifier and maintained by the wireless communication device, the first inactivity timer configured to expire before a second inactivity timer maintained in a Packet Data Serving Node (PDSN) to which the wireless communication device is connected via the POF and which is also associated with the connection identifier;

wherein the first inactivity timer is reset in response to activity on the connection corresponding to the connection identifier.

13. The method of claim 12, further comprising:

receiving a clear table message; and

clearing the connection table in response to the clear table message.

14. A method of registering and maintaining connections, comprising:

establishing one or more connections with one or more Packet Coordination Functions (PCFs);

storing a plurality of connection sets in a connection table, each connection set comprising one or more connections with a POF and associated with a wireless communication device;

buffering received data from a network that is designated to a wireless communication device, storing the received data until the wireless communication device is located, based on an active connection, on one of the connections in the connection set;

selecting a connection from the one or more connections in a connection set associated with a wireless communication device for which data is directed and transmitting the stored data on the selected connection to the wireless communication device; and

maintaining a plurality of first timers that correspond to each of the connections and wherein each of the plurality of first timers are set to expire after each of a plurality of second timers in the wireless communication device.

15. The method of claim 14, further comprising maintaining a plurality of timers corresponding to the plurality of stored connections and removing a connection from the connection table upon expiration of one of the plurality of timers associated with the connection.

16. An apparatus, comprising:

means for receiving a connection identifier at a wireless communication device;

means for storing the received connection identifier in a connection table when the connection is not contained in the connection table, wherein a connection identifier corresponds to a Packet Coordination Function (PCF) that has been previously visited by the apparatus and indicates whether a connection between the PCF and the wireless communication device is active;

means for determining if the received connection identifier is contained in a connection table, and

means for registering a connection in response to a received connection not contained in the connection table;

means for determining that the registration is not needed if the received connection identifier is in the connection table; and

means for removing the connection identifier from the connection table in response to expiration of a first inactivity timer associated with the connection identifier and maintained by the wireless communication device, the first inactivity timer configured to expire before a second inactivity timer maintained in a Packet Data Serving Node (PDSN) to which the wireless communication device is connected via the PCF and which is also associated with the connection identifier;

wherein the first inactivity timer is reset in response to activity on the connection corresponding to the connection identifier.

17. An apparatus, comprising:

means for establishing one or more connections with one or more Packet Coordination Functions (PCFs);

means for storing a plurality of connection sets in a connection table, each connection set comprising one or more connections with a PCFs and associated with a wireless communication device, wherein a first timer in the apparatus and a second timer in the wireless communication device correspond to each of the connections and wherein the first timer is set to expire after the second timer;

means for buffering received data from a network that is designated to a wireless communication device;

means for storing the received data until the wireless communication device is located, based on an active connection, on one of the connections in the connection set;

means for selecting a connection from the one or more connections in a connection set associated with a wireless communication device for which data is directed; and

means for transmitting the stored data on the selected connection to the wireless communication device.