ENHANCING USER EXPERIENCE DURING HANDOFFS IN WIRELESS COMMUNICATION

• US 20070207804A1
• Filed: 10/02/2006
• Published: 09/06/2007
• Est. Priority Date: 10/03/2005
• Status: Active Grant

• Current Assignee: Divitas Networks, Inc.
• Original Assignee: Divitas Networks, Inc.
• Inventors: Sharma, Vikas, Marder, Josh, Karia, Snehal, Solsona-Palomar, Marc, Athuluru, Srinivasa, Wang, Derek
• Granted Patent: US 7,546,125 B2
• Time in Patent Office: Days
• US Class Current: 455/436
• CPC Class Codes: H04L 61/2564 for a higher-layer protocol, e.g. for session initiation protocol [SIP]
• CPC Class Codes: H04L 61/2575 using address mapping retrieval, e.g. simple traversal of user datagram protocol through session traversal utilities for NAT [STUN]
• CPC Class Codes: H04L 61/2578 without involvement of the NAT server
• CPC Class Codes: H04L 63/029 Firewall traversal, e.g. tunnelling or, creating pinholes
• CPC Class Codes: H04L 63/20 for managing network security; network security policies in general filtering policies H04L63/0227
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1083 In-session procedures
• CPC Class Codes: H04L 65/1095 Inter-network session transfer or sharing
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/401 wherein the services involve a main real-time session and one or more additional parallel real-time or time sensitive sessions, e.g. white board sharing or spawning of a subconference
• CPC Class Codes: H04L 65/403 Arrangements for multi-party communication, e.g. for conferences data switching systems for conference H04L12/18; arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities H04M3/56; television conferencing systems H04N7/15
• CPC Class Codes: H04L 65/70 Media network packetisation
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/164 Adaptation or special uses of UDP protocol
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04W 36/02 Buffering or recovering information during reselection ; Modification of the traffic flow during hand-off
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/38 by fixed network equipment
• CPC Class Codes: H04W 4/16 Communication-related supplementary services, e.g. call-transfer or call-hold
• CPC Class Codes: H04W 8/02 Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks
• CPC Class Codes: H04W 8/04 : Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 8/08 : Mobility data transfer
• CPC Class Codes: H04W 80/04 : Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 92/02 : Inter-networking arrangements

Abstract

A method for performing a handoff for a mobile device from a first radio station to a second radio station. The method includes buffering a first media data set that is received through the first radio station. The method also includes cross-correlating a tail portion of the first media data set and a head portion of a second media data set to generate a cross-correlated media data set, if the second media data set is received through the second radio station. The method further includes synthesizing, using a modeled portion of the first media data set, a synthesized media data set, if no media data is received through the second radio station within a threshold. The method further includes extending the first media data set to generate an extended media data set, if no media data is received through the second radio station at the threshold.

Claims

1. A method for performing a handoff for a mobile device from a first radio station to a second radio station, the method comprising:

buffering a first media data set, the first media data set being received through the first radio station;

cross-correlating a tail portion of the first media data set and a head portion of a second media data set to generate a cross-correlated media data set, if the second media data set is received through the second radio station;

outputting the correlated media data set if the correlated media data set is generated;

synthesizing, using a modeled portion of the first media data set, a synthesized media data set, if no media data is received through the second radio station within a threshold, the threshold including at least one of a time threshold and a data amount threshold;

outputting the synthesized media data set if the synthesized media data set is synthesized;

extending at least a portion of the first media data set to generate an extended media data set, if no media data is received through the second radio station at the threshold; and

outputting the extended media data set if the extended media data set is generated.

2. The method of claim 1 wherein the step of buffering the first media data set is initiated upon imminence of the handoff, the imminence of the handoff being detected by at least one of the mobile device and a mobility server that contains information of the mobile device.

3. The method of claim 1 wherein the step of buffering the first media data set is initiated when the handoff starts.

4. The method of claim 1 wherein the first media data set contains at least one of silence, text, audio, and video signal data.

5. The method of claim 1 further comprising buffering the second media data set if the second media data set is received.

6. The method of claim 1 wherein the data amount threshold represents a predetermined number of missing data packets expected to be received from the second radio station.

7. The method of claim 1 wherein the extending includes inserting at least one silence packet into the at least a portion of the first media data set.

8. The method of claim 1 further comprising generating a transition media data set using at least one of the cross-correlated media data set, the synthesized media data set, and the extended media data set to perform at least one of modifying an overlap of media data in the handoff and filling a gap of media data in the handoff, the overlap of media data representing coexistence of the first media data set and the second media data set, the gap of media data representing a gap between an end of the first data set and a beginning of media data received through the second radio station.

9. The method of claim 8 further comprising adjusting a signal level of the transition media data set.

10. The method of claim 9 wherein the signal level of the transition media data set is adjusted to approximate a signal level of the first media data set.

11. The method of claim 1 further comprising adjusting a signal level of media data received through the second radio station to approximate a signal level of the first media data set.

12. A system for performing a handoff for a mobile device from a first radio station to a second radio station, the system comprising:

a buffer configured to buffer a first media data set, the first media data set being received through the first radio station;

a cross-correlation module configured to perform cross-correlation of a tail portion of the first media data set and a head portion of a second media data set to generate a cross-correlated media data set, if the second media data set is received through the second radio station;

a synthesizer module configured to synthesize, using a modeled portion of the first media data set, a synthesized media data set if no media data is received through the second radio station within a threshold, the threshold including at least one of a time threshold and a data amount threshold; and

an extension module configured to extend at least a portion of the first media data to generate an extended media data set if no media data is received through the second radio station at the threshold.

13. The system of claim 12 further comprising an adder module configured to generate a transition media data set using at least one of the cross-correlated media data set, the synthesized media data set, and the extended media data set to perform at least one of modifying an overlap of media data in the handoff and filling a gap of media data in the handoff, the overlap of media data representing coexistence of the first media data set and the second media data set, the gap of media data representing a gap between an end of the first data set and a beginning of media data received through the second radio station.

14. The system of claim 13 further comprising a signal level control module configured to adjust a signal level of the transition media data set.

15. The system of claim 12 further comprising a signal level control module configured to adjust a signal level of a transition media data set, the transition media data set including at least one media data packet that the system receives through the second radio station.

16. The system of claim 15 wherein the transition media data set further includes a function of at least one of the cross-correlated media data set, the synthesized media data set, and the extended media data set.

17. The system of claim 15 wherein the signal level of the transition media data set is adjusted to approximate a signal level of the first media data set.

18. The system of claim 12 wherein the buffer is further configured to buffer the second media data set if the system receives the second media data set.

19. The system of claim 12 further comprising at least one of a timer and a counter configured to measure at least one of a time duration and a missing data packet count between an end of the first media data set and a beginning of media data received through the second radio station, the at least one of the time duration and the missing data packet count to be compared against the threshold.

20. The system of claim 12 wherein the extension module is configured insert at least one silence packet into the at least a portion of the first media data.

21. The system of claim 12 wherein the extension module is configured periodically insert silence packets into the at least a portion of the first media data.