Gecikme ve enerji kısıtlı kablosuz ağlarda optimal kaynak özgüleme

In this thesis, the resource allocation in delay and energy constrained wireless networks is investigated. As the wireless applications and services in wireless networked control systems (WNCSs) and machine-to-machine communication (M2M) over cellular systems become widespread, energy and delay gain more importance in design of communication systems. Energy is one of the key concerns of communication system design since wireless sensors or devices mostly rely on batteries with limited capacity or energy harvesting techniques. Delay, on the other hand, is an important design metric since many wireless applications are time-critical in which timely delivery of information with high level of reliability is of paramount importance. First, we provide a novel framework for the joint optimization of controller and communication systems encompassing efficient abstractions of both systems for WNCSs, which may lead to broader adoption and real-world deployment. For the control system model, stochastic maximum allowable transfer interval and maximum allowable delay constraints are used as efficient abstractions considering wireless network induced imperfections. Communication system is presented via power consumption model and schedulability constraint using the control system parameters. Using both analytical analysis on the optimality conditions of the optimization problems and fast heuristics, energy efficient resource allocation methods are proposed for any power-related objective which is a non-decreasing function of the power consumptions of the nodes, different modulation schemes including MQAM and MFSK and scheduling algorithms. Second, we propose a new adaptivity metric for scheduling which exploits the periodic transmission nature of the sensor nodes in WNCSs. Using this metric, we provide a novel optimization approach with the objective of providing maximum adaptivity in schedule accommodating packet losses and changes in network topology while considering the constraints of the individual sensor nodes in terms of periodic data generation, transmission delay, energy and reliability. In order to solve the joint optimization problem fast and efficiently, we propose a design framework for heuristic scheduling algorithms. Third, we investigate the minimum length scheduling problem in wireless ad hoc networks considering packetized transmissions meaning that packet transmission of a node cannot be interrupted and divided into multiple chunks to be transmitted in different time slots due to impracticality and suboptimality reasons. Upon formulating the joint optimization problem and proving its NP-hardness, we show that the power control and rate adaptation problem can be separated from the scheduling problem. Then, we introduce a novel problem for the optimization of power control and rate adaptation where the time required for the concurrent transmission of a set of links each having an integer number of packets is minimized. Solving this problem allows formulation of the joint problem as a pure scheduling problem which is a large-scale Integer Programming (IP) problem. In order to solve this large-scale IP problem, we incorporate elegant Branch and Price Method and Column Generation method based heuristic algorithms. Fourth, we propose optimal power control and rate allocation strategies and fast scheduling algorithms based on column generation method for delay minimization and delay constrained energy minimization problems in Ultra Wide Band (UWB) wireless networks.