Quality of Service in TDMA MANETs using Prioritised Time Slot Assignment

Abstract

Mobile ad hoc networks (MANETs) find use in a wide variety of areas, which include defence-based applications, disaster relief operations, commercial applications and sensor networks. The increase in multimedia applications creates the need for a wireless network to provide Quality of Service (QoS) guarantees to provide effective communication of real-time traffic. MANETs have limited wireless resources and a time-varying topology, which makes it difficult to provide QoS in Time Division Multiple Access (TDMA)-based networks. In TDMA each user is allocated a time slot within each time frame. Therefore a scheduling algorithms is required to schedule traffic by optimally allocating time slots in TDMA. The TDMA scheduling algorithm is an optimisation problem on a directed graph (the MANET). This research applies the Dining Philosophers' (DP) problem to the time slot assignment in TDMA-based MANETs. The DP model of the MANET is represented as a Petri net. A variant of that assignment problem is developed in which priorities within nodes are provided such that nodes with multimedia traffic will have higher priority. The doorway concept is used to handle starvation, required to solve the Prioritised Dining Philosophers' (PDP) problem. The pseudo-code of the algorithm describes in detail how it finds the solution.