Delay-constrained utility maximisation in multi-hop random access networks

Multi-hop random access networks have received much attention because of their distributed nature which facilitates deploying many new applications over the sensor and computer networks. Recently, utility maximisation framework is applied in order to optimise performance of such networks; however, proposed algorithms result in large transmission delays. In this study, the authors will analyse delay in random access multi-hop networks and solve the delay-constrained utility maximisation problem. We define the network utility as a combination of rate utility and energy cost functions and solve the following two problems: 'optimal medium access control with link delay constraint' and, 'optimal congestion and contention control with end-to-end delay constraint'. The optimal tradeoff between delay, rate and energy is achieved for different values of delay constraint and the scaling factors between rate and energy. Eventually, linear and super-linear distributed optimisation solutions are proposed for each problem and their performance are compared in terms of convergence and complexity.