Table 1 Definition of system parameters

r

The maximum value of the backoff stage

m

The maximum value of the contention window

size

N _s (N _h )

The number of sender (helper) nodes

τ

CRTS frame transmission probability on a

wireless channel

p _m (p _d )

Control (DATA) frame transmission error

probability due to a bad wireless channel

p _c

CRTS frame transmission failure probability due

to collision

p _sr

Helper node selection success probability

p _fr

Helper node selection failure probability

R _i

Data transmission rate in Mbps

for i=1,2,5.5,11

r _i

Maximum distance (m) for each R _i

p _i

Probability for transmitting DATA at R _i

p _h

Cooperation probability that at least one

candidate helper node is in cooperation

p _r

Probability that a receiver node is located within

its sender node’s transmission range