Strategic Location Planning for Broadband Access Networks under Cooperative Transmission

To achieve a cost-effective network deployment, employing state-of-art technical advances provides a practical and effective way to enhance system performance and quality of service provisioning. Cooperative transmission has been recognized as one of the most effective paradigms to achieve higher system performance in terms of lower bit-error rate, higher throughput, larger coverage, more efficient energy utilization, and higher network reliability. This dissertation studies the location planning for the deployment of broadband access networks and explores the great potential of cooperative transmission in the context of single-cell cooperative relaying and multi-cell cooperative transmission, respectively. The placement problem is investigated in two categories of network deployment environment, i.e., an existing wireless access network and a perspective broadband access network, respectively. In an existing wireless access network, to solve some practical problems such as the requirements of capacity enhancement and coverage extension, relay stations (RSs) are introduced in the network architecture. We propose two optimization frameworks with the design objectives of maximizing cell capacity and minimizing number of RSs for deployment, respectively. Mathematical formulations are provided to precisely capture the characteristics of the placement problems. The corresponding solution algorithms are developed to obtain the optimal (or near-optimal) results in polynomial time. Numerical analysis and case studies are conducted to validate the performance benefits due to RS placement and the computation efficiency of the proposed algorithms. To deploy a new metropolitan-area broadband access network, we explore the integration of passive optical network (PON) and wireless cooperative networks (WCN) under the multi-cell cooperative transmission technology. An optimization framework is provided to solve the problem of dimensioning and site planning. The issues of node placement, BS-user association, wireless bandwidth and power breakdown assignment are jointly considered in a single stage to achieve better performance. We also propose a solution to the complex optimization problem based on decomposition and linear approximation. Numerical analysis and case studies are conducted to verify the proposed framework. The results demonstrate the performance gains and economic benefits. Given a set of network parameters, the proposed optimization frameworks and solutions proposed in this dissertation can provide design guidelines for practical network deployment and cost estimations. And the constructed broadband access networks show a more cost-effective deployment by taking advantage of the cooperative transmission technology

An Efficient Wireless Extension Point Placement Algorithm in Urban Rectilineal WLANs

Abstract — With a small amount of software modification, wireless Extension Points (EPs), which are now commercially available, can be used to improve the throughput capacity of a Wireless Local Area Network (WLAN). An EP is an immobile device that has access to the power supply or is equipped with a high capacity battery but does not have direct access to the Internet. They relay data wirelessly between the Access Point (AP) and the mobile hosts. In this paper, we investigate the optimal placement of EPs such that the throughput capacity of an urban rectilineal WLAN can be maximized. Two channel models are studied, based on the Shannon capacity bound and IEEE 802.11 specifications. We first formulate a solution for the optimal EP placement problem in a general network scenario as a non-linear programming problem, then we propose an efficient algorithm that determines the optimal locations of a fixed number of EPs in a rectilineal network. Our results show that, for a wide range of system parameters, the optimally placed EPs can significantly increase the network throughput capacity. Moreover, we study how the number of EPs, transmission power, path loss exponent, channel models and traffic characteristics affect the optimal EP placement and expected throughput capacity of the network. Index Terms — wireless local area networks, access point, extension point, optimal placement, capacity improvement, mathematical programming/optimization. I