Adaptive Playout Scheduling for Voice over IP: Event-Triggered Control Policy
(English)In: IEEE Multimedia, ISSN 1070-986X, E-ISSN 1941-0166Article in journal (Other academic) Submitted
We study adaptive-playout scheduling for Voice over IP using the frame-work of stochastic impulse control theory. We use the Wiener process tomodel the fluctuation of the buffer length in the absence of control. In thiscontext, the control signal consists of length units that correspond to insert-ing or dropping a pitch cycle. We define an optimality criterion that hasan adjustable trade-off between average buffering delay and average controlsignal (the length of the pitch cycles added plus the length of the pitch cyclesdropped), and show that a band control policy is optimal for this criterion.The band control policy maintains the buffer length within a band regionby imposing impulse control (inserted or dropped pitch cycles) whenever thebounds of the band are reached. One important property of the band controlpolicy is that it incurs no packet-loss through buffering if there are no out-of-order packet-arrivals. Experiments performed on both synthetic and realnetwork-delay traces show that the proposed playout scheduling algorithmoutperforms two recent algorithms in most cases.
Playout scheduling, jitter buffer, impulse control
IdentifiersURN: urn:nbn:se:kth:diva-24218OAI: oai:DiVA.org:kth-24218DiVA: diva2:345497
QS 2011 QS 201203262010-08-252010-08-252012-03-26Bibliographically approved