Apparatus, and an associated method, for preserving communication service quality levels during hand-off of communications in a radio communication system
View Patent ↗Apparatus, and an associated method, that preserves the service quality level of data communications in a radio communication system in which communications are handed off between access points, or other fixed-site entities. Data stuffing operations are performed by a data sequence expander prior to effectuation of hand over period during a service interruption during the handoff of communications of a data, containing the extra data is played out in real time, and the service interruption is less noticeable.
1. In a communication system having a mobile node that communicates a first sequence of communication data symbols pursuant to effectuation of a communication service with a network part, the network part having a serving access point with which the mobile node initially communicates and at least a first target access point with which communications continue subsequent to hand-off of communication thereto, an apparatus for facilitating improved perceived service quality levels of communication during hand-off of the communication from the serving access point to the target access point, said apparatus comprising:
a data sequence expander adapted to receive indications of pendency of the hand-off of the communications and to receive representations of the first sequence of the communication data symbols communicated pursuant to the effectuation of the communication service, said data sequence expander adding expanded data symbols to the first sequence of the communication data symbols responsive to detections of the indications of the pendency of the hand-off of the communications, thereby to form a first expanded sequence;
wherein the data sequence expander approximates an amount of time prior to occurrence of the hand-off and selects a number of expanded data symbols to add to the first sequence so that the selected number of expanded data symbols causes a delay that corresponds to the amount of time prior to occurrence of the hand-off.
2. The apparatus of claim 1 wherein the first sequence of the communication data is organized at the mobile node, and wherein said data sequence expander is embodied at the mobile node.
3. The apparatus of claim 1 wherein the network part comprises a proxy device and wherein said data sequence expander is embodied at the proxy device.
4. The apparatus of claim 1 wherein the communication service in effectuated between the mobile node and the correspondent node, wherein the first sequence of the communication data symbols is originated at the correspondent node, and wherein said data sequence expander is positioned remote from the correspondent node.
5. The apparatus of claim 4 wherein said data sequence expander is embodied at the mobile node.
6. The apparatus of claim 4 wherein the network part comprises a proxy device and wherein said data sequence expander is embodied at the proxy device.
7. The apparatus of claim 1 further comprising a resampler adapted to receive the representation of the first sequence of the communication data symbols, said resampler selectably for resampling selected portion of the first sequence of the communication data symbol and for forming the expanded data symbols therefore.
8. The apparatus of claim 7 wherein selected symbols of the first sequence of the communication data symbols define silence periods and wherein the expanded data symbols are of symbols values corresponding to values of the selected symbols that define the silence periods.
9. The apparatus of claim 8 wherein the expanded data symbols formed by said resampler are concatenated to the data symbols of the first sequence of the communication data symbols that define the silence periods.
10. The apparatus of claim 1 wherein a second sequence of communication data symbols is further communicated pursuant to the effectuation of the communication service, the second sequence forming a second expanded sequence and wherein said apparatus further comprises a data sequence contractor adapted to receive representations of the second sequence of the communication data symbols, said data sequence contractor selectably for removing expanded data symbols out of the second sequence.
11. The apparatus of claim 10 wherein said data sequence contractor is further adapted to receive the indications of the pendency of the hand-off of the communications, the expanded data symbols removed out of the second sequence responsive to detection of the indications of the pendency of the hand-off of the communication.
12. The apparatus of claim 11 wherein said data sequence contractor is embodied at the mobile node.
13. The apparatus of claim 11 wherein the network part comprises a proxy device and wherein said data sequence expander is embodied at the proxy device.
14. The apparatus of claim 1 wherein the communication service is effectuated with a correspondent node and wherein the hand-off of communications, indications of the pendency thereof are provided to said data sequence expander, is effectuated free of interaction with the correspondent node.
15. In a radio communication system having at least a first communication station for communicating a first sequence of data, the data being a selected multiple of a first data length and of a second data length, the first data length a fractional portion of the second data length, a method for operating upon the data at an RLP (Radio Link Protocol) logical layer of at least the first communication station, said method comprising:
detecting pendency of the hand-off of the communication from the serving access point to the first target access point;
approximating an amount of time prior to occurrence of the hand-off;
selecting a number of expanded data symbols to add to the first sequence such that the selected number of expanded data symbols will cause a delay that corresponds to the amount of time prior to occurrence of the hand-off; and
adding the expanded data symbols to the first sequence of the communication data responsive to detection of the pendency of the hand-off of communications, thereby to form a first expanded data sequence.
16. The method of claim 15 wherein the expanded data symbols are added during said operation of selectably adding to increase the first sequence to be of a length at least corresponding to an anticipated hand-off interruption period.
17. The method of claim 15 further comprising the operation of removing the expanded data symbols added to the first sequence during said operation of selectably adding.
18. The method of claim 15 further comprising the operation of buffering the first expanded sequence at a jitter buffer.
19. The method of claim 18 further comprising the operation of retrieving the first expanded sequence the jitter buffer to effectuate the communication service during hand-off of the communications to the target access point.
20. The method of claim 15 wherein the communication system comprises an IEEE 802.11 compliant communication system and wherein the first sequence of the data to which the expanded data symbols comprise packet data, formatted pursuant to a packet formatting scheme permitted to be communicated in the IEEE 802.11 compliant communication system.