Traffic Operations and Management

The paper presents the performance advantage of wireless token ring protocol (WTRP) versus IEEE 802.11 in DCF mode. WTRP is a medium access control (MAC) protocol and is designed to provide quality of service in WLANs. WTRP supports guaranteed QoS in terms of bounded latency and reserved bandwidth which are crucial constraints of the real time applications and inapplicable in an IEEE 802.11 network. WTRP is a distributed MAC protocol and partial connection is enough for full connectivity. The stations take turn to transmit and are forced to suspend the transmission after having the medium...

A real time, highly decentralized, adaptive traffic signal optimization method, ALLONS-D, based on the rolling horizon dynamic programming technique, is presented. We describe the basic architecture, the system model, and the optimization scheme of ALLONS-D. We compare ALLONS-D with other approaches to signal control via several sets of simulation results. The margins of improvement are significant when compared with the standard Webster's criteria for signal setting. The feasibility of on-line implementation of ALLONS-D is discussed as well as on-going evaluations and extensions.

We consider the problem of adjusting transmission power for vehicle-to-vehicle broadcast safety communication in vehicular ad hoc networks. Given a target communication range designated by a vehicle safety application, the power control algorithm is designed to select a transmission power no greater than necessary for the targeted range. The power control algorithm results in higher communication reliability since collisions are minimized for safety communications. Our main idea is to add a power tuning feedback beacon during each safety message exchange. Our simulation results show that...

Techniques for pursuit-evasion games and search missions have been studied widely in the research community in the past few years but most of the emphasis has been laid on the control strategies for these missions. These have been shown to work for small scale missions, but attempts at their application to large scale missions have suffered from the lack of scalability and robustness of these systems. Hence we believe that for large systems implementing these missions, there is a need to lay emphasis on proper network architecture for these systems to make them scalable and robust to...