| The challenge in the design of a protocol architecture for Mobile Ad Hoc Networks (MANETs) is to efficiently convey information using an unreliable physical channel within a dynamic connected set of mobile limited-range limited-energy radios without the support of any infrastructure. Since a MANET is a dynamic, distributed entity, the optimal control of such a system should also be dynamic and adaptive. The global optimal solution for the coordination of a dynamic distributed network (i.e., centralized control) can be achieved by continuously monitoring the global network status, which is not realizable, or at least not scalable, due to the overhead required to obtain such information. Although distributed coordination is realizable and practical, due to the lack of reliable coordination, its performance becomes unstable as the network load increases and it cannot avoid the waste of valuable resources such as bandwidth and energy.; My thesis is that a protocol architecture for MANETs that coordinates channel access through an explicit collective decision process based on available local information will outperform completely distributed approaches under a wide range of operating conditions in terms of throughput and energy efficiency without sacrificing the practicality and scalability of the architecture, unlike centralized approaches.; This dissertation presents the Time Reservation using Adaptive Control for Energy Efficiency (TRACE) family of protocol architectures that achieve such coordinated channel access in a distributed manner for real-time data broadcasting in MANETs. The TRACE protocols include SH-TRACE, a time-frame based MAC protocol for single-hop networks; MH-TRACE, which adds coordination in a multi-hop environment to the SH-TRACE protocol; NB-TRACE, which incorporates network-wide broadcasting into the TRACE framework, and MC-TRACE, which extends the TRACE framework to multicasting and unicasting.; Extensive simulations and theoretical analysis have shown that the TRACE protocols outperform distributed network protocols in terms of energy efficiency without sacrificing the spatial reuse efficiency and the quality of service requirements of the application layer. Indeed, the TRACE protocols approach theoretical performance limits. |
