Can QoS guarantees be supported for live video over ATM networks?

Abstract

Bangalox-560012 INDIA Abstrucr4merging B-ISDN networks which use Asynchronous Transfer Mode (ATM) as a backbone network, need to provide Quality of Service(QoS) to various multimedia traffic classes such as live video, high resolution images, video on demand, etc. Since live video is expected to dominate multimedia traffic, guaranteeing QoS for live video is complex hecause of no U priori knowledge of the video stream and hence requires a good understanding of such video sources. This paper investigates a complete framework for transporting live video over ATM networks with QoS guarantees. The proposed framework comprises of a source model, call admission controller and a scheduler. The source model uses Enbopy as a measure to characterize the live video traffic. A Murkov Chain model is developed based on this measure. The source model aids in reserving resources for the admitted sessions. The algorithm developed for call admission guarantees a minimum bandwidth throughout the duration of the session. Two new scheduling algorithms viz Guaranteed Bandwidth Schedule and Guaranteed Delay Schedule optimize the bandwidth utilization of all active sessions. Using this framework for transporting live video a cell loss probability of 4.87 x lo-' and a best effort bandwidth utilization of 80% is obtained.

Harmony — An Architecture for Providing Quality of Service in Mobile Computing Environments

“…Thus F& (t) specifies the bandwidth at time t for the real-time VBR stream. Based on our earlier study of various real-time VBR streams 6 , Fb(t) has a domain 0 < t < 00 and range 0 < Fb(t) < 231 Mbps. The first frame rate specified by the user is the initial state in the Markov chain.…”

“…Network guarantees over ATM networks are provided based on the Entropy model 6 . We extend this model here to determine the network traffic profile over the wireless channels.…”

Design space exploration for providing QoS within the HARMONY framework

“…Network guarantees are provided based on the Entropy model proposed in [7] over ATh4 networks. A synthetic traffic profile with the same statistical properties as those of traffic in a wireless environment is generated by modulating traffic in wireline domain with white gaussian noise.…”

“…A synthetic traffic profile with the same statistical properties as those of traffic in a wireless environment is generated by modulating traffic in wireline domain with white gaussian noise. This synthetic traffic is modeled using the Entropy model with 21 states of unequal extents in a Markov chain [7]. Each state in the Markov chain represents a bandwidth regime.…”

“…In HARMONY network resources are reserved based on the Entropy Model [7], and compute guarantees are provided by off-loading tasks from the mobile units to compute servers in the backbone network. A load-balancing scheme redistributes loads across all compute servers so that these are equally loaded.…”