CWminContention Window Minimum
Copyright 1988-2018, All rights reserved.
References in periodicals archive ?
Contention window become CWmin when the transmission completed successfully which is 7, while collision occur, it was doubled till CWmax (1024) was reached.
CWmin has been adapted to the size of the network; both values 31 and 63 have been used.
Figures 32 and 33 show the default and optimized values, respectively, for CWmin and CWmax.
Gannoune, "A Non-linear Dynamic Tuning of the Minimum Contention Window (CWmin) for Enhanced Service Differentiation in IEEE 802.11 ad-hoc Networks," IEEE 63rd Vehicular Technology Conference, Melbourne Vic, pp.
Very few works dealing with the optimization of the minimum contention window values CWmin were presented in the literature.
Data Traffic Types and Parameters Data Traffic Types Priority CWmin ([upsilon]) Voice Traffic [upsilon] = 1 (aCWmin+1)/4-1 Video Traffic [upsilon] = 2 (aCWmin+1)/2-1 Best Effort Traffic [upsilon] = 3 aCWmin Background Traffic [upsilon] = 4 aCWmin Data Traffic Types CWmax (u) x([upsilon]) Voice Traffic (aCWmin+1)/2-1 2 Video Traffic aCWmin 2 Best Effort Traffic aCWmax 3 Background Traffic aCWmax 7
Parameters Values Channel frequeney 24 GHz Channel bit rate 1 Mbit/s PHY header 192 bits MAC header 224 bits LlcSnap header 64 bits ACK 112 bits Packet payload (Ldata) 8192 bits CWmin 31 CWmax 1023 Retransmission limit (m) 5 Propagation delay ([delta]) 1 [mu]s Slot time ([sigma]) 20 [mu]s SIFS 10 [mu]s DIFS (=2[sigma] + SIFS) 50 [mu]s tdata 8672 [mu]s tack 304 [mu]s Table 3: Module load status.
To reduce the computational complexity in this proposed method use a lookup table to speed up the best CWmin selection based on the number of opponents is being suggested.
IEEE 802.11e EDCA parameters [3] Priority AC AIFS CWmin CWmax Service 0,1,2 0 2 31 1023 BE 3 1 1 31 1023 Video 4, 5 2 1 31 63 Video 6,7 3 1 7 15 Voice Table 2.