Admission control methods for quality of service assurances in wireless ad-hoc networks.

摘要

Multimedia applications have quality of service (QoS) needs typically expressed in terms of maximum allowed time delays and/or minimum required data rates. It is imperative that next generation wireless ad-hoc networks have mechanisms that provide multimedia applications with QoS assurances. Until recently, wireless ad-hoc networks were composed of nodes that are equipped with single omnidirectional antennas. However, due to advances in technology, it is now possible to build wireless nodes with more than one antenna. Multiple antennas provide wireless ad-hoc networks with significantly more capabilities than single antennas. The main goal of this dissertation is to develop methods that efficiently exploit the capabilities of multiple antennas to better meet the QoS requirements of multimedia applications.; Specifically, this dissertation develops a theoretical framework to regulate the available resources and control the admissibility of multimedia applications in multiple antenna based wireless ad-hoc networks. It develops a set of sufficient conditions to verify whether the required data rates of given multimedia applications can be satisfied. The key features of the admission control methods developed in this dissertation are as follows. First, the conditions are distributed in the sense that wireless nodes can implement them by relying only on local information. Second, they are efficient in the sense that the network rejects a new application "almost" only when doing so violates the data rates of one or more of the previously accepted applications. Third, they account for cross-layer effects among different layers of the network protocol stack.; To demonstrate the use of the developed admission control conditions, the dissertation proposes an energy-efficient routing scheme for applications with data rate constraints. The routing scheme increases the lifetime of wireless ad-hoc networks by conserving the energy resources while meeting the data rate requirements of all applications.; The end result of this dissertation is a set of effective methods that exploit the capabilities of emerging wireless ad-hoc networks to meet needs of envisioned applications.