Modelling of a Hybrid MAC Protocol for M2M Communications

Machine-to-machine (M2M) communications is one of the enabling technologies for connecting massive number of devices to the Internet of Things (IoT). M2M communications have different characteristics than human-to-human (H2H) communications. In this work, we propose a scalable, hybrid MAC protocol that will satisfy user quality-of-service (QoS) requirements. We model both periodic and nonperiodic traffic. The proposed MAC protocol organizes transmissions into superframes consisting of a number of frames. A machine is assumed to generate a one or zero packet per its period. The machines have been divided into several types according to their packet generation probabilities. The generated packets are classified into different traffic classes according to their tolerance to packet losses and served by a subframe. Further, each subframe is divided into two sub-periods one serving contention and the other reserved traffic of that traffic class. We formulated an optimization problem that minimizes frame length subject to QoS user requirements. Then, we derived packet loss probability for each class as well as total packet loss probability for the optimization. Formulation resulted in a nonlinear optimization problem, but numerical results show that an LP approximation provides a nearly optimal solution. The work also considered the proposed protocol under user mobility. The packet arrival process under user mobility has been derived. Then the performance of the protocol has been evaluated with the contention service under this arrival process. The contention service with and without packet losses have been considered. A priority queueing mechanism also has been studied for M2M communication. The results of this thesis may be useful in the design of M2M communication system

Proposal of a Cognitive Based MAC Protocol for M2M Environments

The radio resource shortage is one of the most important issues to be taken into account when deploying modern wireless communication systems. A novel communication paradigm named cognitive radio, has been introduced in the last years for a more efficient exploitation of the limited available spectrum and cope with the inefficiency in the spectrum usage. Its main aim is to allow the co-existence of different wireless systems on the same spectral resources by limiting the mutual interference. The aim of this paper is to design a cognitive networking environment where the primary network is based on the OFDMA principle. The proposed Medium Access Control (MAC) technique for the secondary network, named Data Aided Cognitive Technique (DACT), aims to exploit the framing information broadcast by the primary network in order to setup transparently an independent network with a particular focus on Machine to Machine (M2M) communications