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Chapter 6Optimisation of CRA using adaptive CSAs pIn order to make a direct comparison among the components of delays involved in thetransmission of data packets, we can analyse the situation when only IP traffic isdelivered. From Figure 6.19, on high traffic loads, the splitting tree algorithm requireson average 10 ms to transmit successfully a reservation request (this corresponds to themean contention delay curve in Figure 6.19b), in comparison to approximately 19 msrequired by the exponential backoff algorithm (Figure 6.19a.). This variation of 9 msmakes a difference in system performance, because having a large service time(comprised of the mean contention delay plus the mean grant delay) results in packetsbeing queued for a longer period of time as the offered load increases further, which inturn results in large mean access delays.Components of Delay (ms)1201101009080706050403020100a) Exponential Backoff Algorithm b) Splitting Tree AlgorithmMeanwaitingdelayMeangrantdelayMeancontentiondelay42 43 44 45 46 47 48 49 50 51 52umber of Active StationsMeanwaitingdelay48 49 50 51 52 53 54 55 56 57 58 59 60umber of Active StationsMeangrantdelayMeancontentiondelayFigure 6.19 – Components of delay, Exponential backoff vs. splitting tree algorithmfor IP traffic.6-26