ARQ protocols with adaptive block size perform better over a wide range of bit error rates

“…If selective repeat algorithm is use then several segments are stored at the receiver side. In general the formula for channel throughput is following [6]:…”

Section: Single Hop Casementioning

confidence: 99%

Optimal segment size for transmission in Multi-hop system

Ukhanova

Luo²,

Turlikov³

2008

2008 International Conference on Telecommunications

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“…The throughput achievable with a hybrid ARQ protocol can be maximized by dynamic adaptation of the channel coding parameters. In many adaptive ARQ-based protocols [18][19][20], the code-rate is selected in response to the actual channel state, which can be estimated by counting the number of erroneous frames; but an accurate estimation of channel state requires the analysis of many frames, so this is slow. A somewhat different adaptive hybrid ARQ model, due to Yang and Hossain [21], is based on the assumption that the channel state (in terms of symbol error rate) can be estimated on a frame-by-frame basis from the signal-to-noise ratio (SNR) fed back by the receiver.…”

Section: Related Workmentioning

confidence: 99%

A Hybrid Error Recovery scheme for Scalable Video Transmission over 3G Cellular Broadcast Networks

2007

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The cdma2000 1xEV-DO mobile communication system provides broadcast and multicast services (BCMCS) to meet an increasing demand for multimedia data services. But the servicing of video streams over a BCMCS network faces a challenge from the unreliable and error-prone nature of the radio channel. BCMCS uses Reed-Solomon coding integrated with the MAC protocol for error recovery. We show that this is not effective for mobiles moving at the edge of service area, where the channel condition is bad, resulting in significantly lower video quality. To improve the playback quality of an MPEG-4 FGS (fine granularity scalability) video stream, we propose a hybrid error recovery scheme incorporating a packet scheduler, which uses slots saved by reducing the Reed-Solomon coding overhead. Packets to be retransmitted are prioritized by a utility function which reduces the packet error-rate in the application layer within a fixed retransmission budget by considering of the map of the error control block at each mobile node. Our error recovery scheme also uses the characteristics of MPEG-4 FGS to improve the video quality even for a slowmoving mobile which is experiencing a high error-rate in the physical channel because of error bursts.

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“…For example, in [5] Martins and Alves sought for the instantaneous bit error rate (BER) of the system in the context of an adaptive packet size ARQ scheme. Channel estimation techniques may also include signal power measurements and pilot tone transmissions [6].…”

Section: Introductionmentioning

confidence: 99%