Interference and SINR coverage in spatial non-slotted Aloha networks

TL;DR

This paper develops analytical models for interference in non-slotted Aloha networks, providing insights into SINR coverage and comparing performance with slotted Aloha using stochastic geometry.

Contribution

It introduces two new tractable stochastic-geometric models for interference in pure Aloha, extending analysis beyond slotted Aloha and accounting for dynamic interference variations.

Findings

Derived closed-form Laplace transforms of interference

Analyzed SINR outage probability in pure Aloha

Compared non-slotted and slotted Aloha performance

Abstract

In this paper we propose two analytically tractable stochastic-geometric models of interference in ad-hoc networks using pure (non-slotted) Aloha as the medium access. In contrast the slotted model, the interference in pure Aloha may vary during the transmission of a tagged packet. We develop closed form expressions for the Laplace transform of the empirical average of the interference experienced during the transmission of a typical packet. Both models assume a power-law path-loss function with arbitrarily distributed fading and feature configurations of transmitters randomly located in the Euclidean plane according to a Poisson point process. Depending on the model, these configurations vary over time or are static. We apply our analysis of the interference to study the Signal-to-Interference-and-Noise Ratio (SINR) outage probability for a typical transmission in pure Aloha. The results are used to compare the performance of non-slotted Aloha to the slotted one, which has almost exclusively been previously studied in the same context of mobile ad-hoc networks.