|
Researchers: Hong Li, Ph.D. student & Prof. Lorne Mason
Description:
Problem: Multipath routing in Service Overlay Networks is known to
be able to substantially reduce the network losses (especially
bursty losses) and delay jitters. Adaptive playback scheduling
is a technique used at the receiver to adjust the playback delay
adaptively to the network delay variation and to tradeoff the
playback delay and playback loss for the received voice signal.
Multipath selection for video streaming with multiple description
coding has been proposed. However, no work has
been reported on optimal multipath selection for Voice over
IP that cooperates with adaptive playback scheduling.
Approach: In order to maximize the quality for VoIP calls, we propose
a novel optimal multipath routing mechanism based on the
estimated R-factor. The advantage of our proposed mechanism
is that the selected optimal path not only maximizes the
R-factor for VoIP calls, but also automatically guarantees
a more stable quality for voice calls. The stability of the
optimal multipath comes from the fact that the proposed
end-to-end delay estimation method accounts for the network
delay variations by cooperating with the adaptive playback
scheduling at the receiver.
We propose a scheme whereby only feature vectors of the
network measurements are communicated and they are sent to
a data fusion center, where R-factor
on multipath are estimated and optimal multipath are selected.
Fig: Overlay nodes collect and pre-process network performance measurements,
then the pre-processed network performance feature vectors
are sent to data fusion center to make optimal multipath routing decisions.
Simulation Results:
Fig: R-factor on optimal multipath (upper line) VS R-factor on direct
path for a source-destination pair
Publications:
H. Li and L. Mason, "Optimal multipath routing with adaptive playback scheduling for VoIP in Service Overlay Networks", in Proc. IEEE Sarnoff, Apr. 2008, Princeton, NJ, USA.[pdf]
|
Return to QoS Routing for VoIP Projects