SEAMLESS MOBILITY FOR A MULTIPLE INTERFACE DEVICE IN A CO-LOCATED WIRELESS ENVIRONMENT

• US 20070041350A1
• Filed: 08/22/2005
• Published: 02/22/2007
• Est. Priority Date: 08/22/2005
• Status: Active Grant

• Current Assignee: Telcordia Legacy Inc.
• Original Assignee: Telcordia Incorporated, Toshiba America Research Inc (Toshiba Corporation)
• Inventors: FAMOLARI, David
• Granted Patent: US 7,711,369 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04L 1/1809 Selective-repeat protocols
• CPC Class Codes: H04L 2001/0092 Error control systems characterised by the topology of the transmission link
• CPC Class Codes: H04W 36/02 Buffering or recovering information during reselection ; Modification of the traffic flow during hand-off
• CPC Class Codes: H04W 36/1446 wherein at least one of the networks is unlicensed
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

Data packets are transmitted from a first access network to a first interface of a multiple interface device (MID), and identical data packets are transmitted concurrently from a second access network to a second interface of the MID. Some of the data packets that are transmitted to the MID from the first access network are not received by the first interface. The MID inspects identifiers of data packets from the first and second interfaces in order to send to the application a stream including all of the data packets. For example, the MID sends to the application the data packets from the first interface, buffers the data packets from the second interface, and sends data packets from the buffer to the application upon detecting that data packets in the buffer were transmitted to the first interface but not received by the first interface.

Claims

1. A method of enabling seamless mobility for a multiple interface device in a co-located wireless environment in which data packets are transmitted to the multiple interface device from a first access network and identical data packets are transmitted concurrently to the multiple interface device from a second access network, the data packets including identifiers for identifying the data packets, the method comprising:

(a) the multiple interface device receiving a first stream of the data packets from the first access network at a first interface and receiving a second stream of the data packets from the second access network at a second interface, wherein some of the data packets that are transmitted to the multiple interface device from the first access network are not received by the first interface and are therefore missing from the first stream of the data packets; and

(b) the multiple interface device inspecting the identifiers of data packets in the first stream and identifiers of data packets in the second stream in order to combine data packets from the first stream with data packets from the second stream to produce a third stream of data packets received by an application of the multiple interface device, the third stream of data packets including said some of the data packets that are transmitted to the multiple interface device from the first access network and are not received by the first interface and are therefore missing from the first stream of the data packets.

2. The method as claimed in claim 1, which includes the multiple interface device forwarding the data packets received from the first access network at the first interface to the application, storing in a buffer data packets received from the second access network at the second interface, and forwarding at least one data packet from the buffer to the application upon detecting that said at least one data packet is missing from the first stream of the data packets received from the first access network at the first interface.

3. The method as claimed in claim 2, wherein said at least one data packet is detected to be missing from the first stream of data packets when said at least one data packet has not been received at the first interface for more than a certain period of time after it has been received at the second interface.

4. The method as claimed in claim 2, which includes responding to receipt of said at least one data packet at the second interface by checking whether said at least one data packet has already been received at the first interface, and upon finding that said at least one data packet has not already been received at the first interface, starting a timer, and wherein said at least one data packet is forwarded from the buffer to the application upon expiration of the timer.

5. The method as claimed in claim 2, wherein the identifiers specify a sequence of the data packets, and said at least one data packet is detected to be missing from the first stream of data packets when the identifiers of data packets received at the first interface indicate that said at least one data packet is missing from the first stream of data packets received from the first access network at the first interface.

6. The method as claimed in claim 2, wherein the first interface is programmed to return a retransmission request to the first access network for a data packet that has been found to be missing from the first stream of data packets for a certain period of time unless the first interface is requested not to return a retransmission request for the data packet that has been found to be missing from the first stream of data packets for the certain period of time, and wherein the method includes requesting the first interface not to return a retransmission request for said at least one data packet upon finding that said at least one data packet is missing from the first stream of data packets.

7. The method as claimed in claim 2, which includes detecting that the data packets are being received at the second interface before the data packets are being received at the first interface, and upon detecting that the data packets are being received at the second interface before the data packets are being received at the first interface, passing the data packets received at the second interface to the application without storing the data packets received at the second interface in a buffer, and storing data packets received at the first interface in a buffer.

8. The method as claimed in claim 1, which includes the multiple interface device detecting that the second interface is failing to receive so many more of the data packets than the first interface that it is undesirable for the second access network to transmit the data packets from the second access network to the multiple interface device, and upon detecting that the second interface is failing to receive so many more of the data packets than the first interface that it is undesirable for the second access network to transmit the data packets from the second access network to the multiple interface device, sending a request to the first access network or the second access network to terminate transmission of the data packets from the second access network to the multiple interface device.

9. A method of enabling seamless mobility for a multiple interface device in a co-located wireless Internet Protocol (IP) network environment in which IP data packets are transmitted to the multiple interface device from a first access network and identical IP data packets are transmitted concurrently to the multiple interface device from a second access network, the method comprising:

(a) the multiple interface device receiving a first stream of the IP data packets from the first access network at a first interface and receiving a second stream of the IP data packets from the second access network at a second interface, wherein some of the IP data packets that are transmitted to the multiple interface device from the first access network are not received by the first interface; and

(b) the multiple interface device forwarding the IP data packets received from the first access network at the first interface to the application, storing in a buffer IP data packets received from the second access network at the second interface, and upon detecting that IP data packets in the buffer are missing from the first stream of the IP data packets received from the first access network at the first interface, forwarding the missing IP data packets from the buffer to the application.

10. The method as claimed in claim 9, wherein at least one IP data packet in the buffer is detected to be missing from the first stream of IP data packets when said at least one IP data packet has not been received at the first interface for more than a certain period of time after said at least one IP data packet has been received at the second interface.

11. The method as claimed in claim 9, which includes responding to receipt of at least one IP data packet at the second interface by checking whether said at least one IP data packet has already been received at the first interface, and upon finding that said at least one IP data packet has not already been received at the first interface, starting a timer, and wherein said at least one IP data packet is forwarded from the buffer to the application upon expiration of the timer.

12. The method as claimed in claim 9, wherein the IP data packets include information specifying a sequence of the IP data packets, and at least one of the IP data packets is detected to be missing from the first stream of IP data packets when the specified sequence of the IP data packets indicates that said at least one of the IP data packets is missing from the first stream of IP data packets received from the first access network at the first interface.

13. The method as claimed in claim 9, wherein the first interface is programmed to return a retransmission request to the first access network for an IP data packet that has been found to be missing from the first stream of IP data packets for a certain period of time unless the first interface is requested not to return a retransmission request for the IP data packet that has been found to be missing from the first stream of IP data packets for the certain period of time, and wherein the method includes requesting the first interface not to return a retransmission request for at least one IP data packet upon finding that said at least one IP data packet is missing from the first stream of IP data packets and is found in the buffer.

14. A multiple interface device having seamless mobility in a co-located wireless network environment in which data packets are transmitted to the multiple interface device from a first access network and identical data packets are transmitted concurrently to the multiple interface device from a second access network, wherein some of the data packets that are transmitted to the multiple interface device from the first access network are not received by the multiple interface device, said multiple interface device comprising:

at least one processor programmed for executing an application;

a first wireless transceiver for receiving a first stream of the data packets from the first access network; and

a second wireless transceiver for receiving a second stream of the data packets from the second access network;

wherein said at least one processor is further programmed for forwarding the data packets received by the first wireless transceiver to the application, for storing in a buffer data packets received by the second wireless transceiver, and upon detecting that data packets in the buffer are missing from the first stream of the data packets received by the first wireless transceiver, forwarding the missing data packets from the buffer to the application.

15. The multiple interface device as claimed in claim 14, wherein said at least one processor is programmed to detect that at least one data packet in the buffer is missing from the first stream of data packets when said at least one data packet has not been received by the first wireless transceiver for more than a certain period of time after said at least one IP data packet has been received at the second wireless transceiver.

16. The multiple interface device as claimed in claim 14, wherein said at least one processor is programmed to respond to receipt of at least one data packet by the second wireless transceiver by checking whether said at least one data packet has already been received by the first wireless transceiver, and upon finding that said at least one data packet has not already been received by the first wireless transceiver, starting a timer, and forwarding said at least one data packet from the buffer to the application upon expiration of the timer.

17. The multiple interface device as claimed in claim 14, wherein data packets have identifiers that specify a sequence of the data packets, and said at least one processor is programmed for detecting that at least one of the data packets is missing from the first stream of data packets when the identifiers of data packets received by the first wireless transceiver indicate that said at least one of the data packets is missing from the first stream of data packets received by the first wireless transceiver.

18. The multiple interface device as claimed in claim 14, wherein said at least one processor is programmed to return a retransmission request to the first access network for a data packet that has been found to be missing from the first stream of data packets for a certain period of time unless said data packet that has been found to be missing from the first stream of data packets for a certain period of time is found in the buffer.

19. The multiple interface device as claimed in claim 14, wherein said at least one processor is programmed for detecting that the data packets are being received by the second wireless transceiver before the data packets are being received by the first wireless transceiver, and upon detecting that the data packets are being received by the second wireless transceiver before the data packets are being received by the first wireless transceiver, passing the data packets received by the second wireless transceiver to the application without storing the data packets received by the second wireless transceiver in a buffer, and storing data packets received by the first wireless transceiver in a buffer.

20. The multiple interface device as claimed in claim 14, wherein said at least one processor is programmed for detecting that the second wireless transceiver is failing to receive so many more of the data packets than the first wireless transceiver that it is undesirable for the second access network to transmit the data packets from the second access network to the multiple interface device, and upon detecting that the second wireless transceiver is failing to receive so many more of the data packets than the first wireless transceiver that it is undesirable for the second access network to transmit the data packets from the second access network to the multiple interface device, sending a request to the first access network or the second access network to terminate transmission of the data packets from the second access network to the multiple interface device.