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Chapter 1Introduction pminislots to be allocated for new arrivals and the second term (e.g. Var) refers to thenumber of contention minislots to be allocated to resolve collisions.In the Fix3 technique the headend allocates 3 contention minislots in each signallingframe, in the Var technique the headend allocates 3 contention minislots for everycollision registered in the previous signalling frame.In the Load technique, the headend allocated contention minislots, where depends on the current traffic load. From these techniques the author concluded thatthe dynamics of the Load-Var technique allowed the system to perform better thanthe other allocation strategies.For the DOCSIS protocol, the researchers of [73] also proposed different strategies toallocate the optimum number of contention slots in each signalling frame (namely S,E, Dbl, Exp, MeanSE and SE), where S and E represent the minimum and maximumnumber of contention minislots to be allocated, respectively. With Dld the headendallocates ‘max(2·o_Collisions, E)’ contention minislots in the following signallingframe. With Exp the number of contention minislots is given by ‘max(2 o_Collisions , E)’and with SE the headend allocates S contention minislots when there are nocollisions, and otherwise E. From all these strategies the best performance isobtained when the E, MeanSE and SE techniques are used. In the same reference,[73], the authors also approached the number of contention minislots to be allocatedin each signalling frame by changing the backoff window of the exponential backoffalgorithm.The researchers of [15] used a different approach to obtain the optimum number ofcontention minislots. The authors studied the performance of the DOCSIS protocolwhen the MAP size was changed from 1 to 10 ms and the number of contentionminislots was ranged from 2 to 16 minislots per MAP. Optimum results were foundwhen the MAP size was set to 2 ms (which contains 40 minislots of 16 bytes each),and the number of contention minislots per MAP was set to 6.c) Prioritisation and scheduling mechanisms: this field of research focuses on theclassification of data packets (by assigning different levels of priority) to gain accessto the upstream channel at the station premises. At the headend, reservation requests1-12