On the influence of signal attenuation factors on packet dissemination in ad hoc wireless networks

Simulations show that signal attenuation factors like fading and shadowing improve the efficiency and speed of route discovery processes in ad hoc wireless networks that rely on the use of slotted ALOHA channel. On the other hand, the capture probability has been shown to be independent of the shadowing. While the detailed modeling of the route discovery packet dissemination in a network is rather complicated, it is possible to provide the “physical” reason for the positive influence of random signal attenuation factors. It turns out that, in a presence of n simultaneous transmitters, the probability of a successful packet reception from a given node conditioned on a reception from the same node in the previous time slot has a finite limit for n → ∞ (as opposed to the unconditional reception probability which scales as 1/n) and is lower for stronger shadowing environments. The latter property makes reception of different packets in successive slots more likely and improves route discovery performance.