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Unformatted text preview: 1 I I t E k p t Î» = âˆ´ = = âˆ’ = Purdue University Compare the schemes Compare the schemes Â¾ Let Â¾ Throughput comparison( normalized by t I ) Stop and wait 1-p a Go back n 1-p 1+(a-1)p Selective repeat (1-p) 1 > âˆ´ + = = a t t t t t a I I out I T 3 Purdue University Compare the schemes Compare the schemes Â¾ Note: 1. If a is small (ie. a ~ 1), all schemes are basically the same. This means transmission time dominates propagation delay. 2. If a is large but p is very small such that ap << 1 i. Stop and wait is bad but, ii. Go back n and selective repeat have comparable performance 3. If ap ~ 1 or ap > 1, then selective repeat is much better than go back n Â¾ Identify regimes in which each scheme is the best Â¾ Selective repeat is best in terms of throughput Â¾ Selective repeat is most complex to implement...
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- Spring '09
- Purdue University, selective repeat