Adnan Agbaria

Extrapolation-based and QoS-aware real-time communication in wireless mobile ad hoc networks

In mobile ad hoc networks (MANETs), it is increasingly important to devote attention to real-time and quality of service (QoS) issues. We present here a novel extrapolation-based and QoS-aware technology for providing soft real-time services in MANETs. The proposed technology combines elements of proactive and location-based techniques. Each node maintains a global view, which is periodically updated through state exchange among all the nodes. At any time, a node is able to extrapolate the location of a given node based on its velocity vector. Resource management, dynamic scheduling, velocity-based extrapolation, and multipath search techniques are employed to meet the realtime and QoS requirements despite network contention and frequent topology changes. We demonstrate this technology by presenting a real-time and QoS routing protocol. We evaluate the performance of the protocol and compare it to the performance of other well-known routing protocols.

A bandwidth management approach for quality of service support in mobile ad hoc networks

Bandwidth management is a key feature for providing quality of service (QoS) in contemporary mobile ad hoc networks (MANETs). In this paper, we present a novel approach to bandwidth reservation which is designed for highly mobile environments. In this scheme, a node takes into account the bandwidth requirements of its 2-hop neighbors. The design of this scheme does not depend on any routing protocol. We evaluate the proposed approach by incorporating it in the well known AODV protocol. The comparison between the original AODV and its extended version, with our approach, shows that the latter achieves a significantly lower latency and higher reliability.

Improvements and Reconsideration of Distributed Snapshot Protocols

Distributed snapshots are an important building block for distributed systems, and, among other applications, are useful for constructing efficient checkpointing protocols. In addition to the imposed overhead of the existing distributed snapshot protocols, those protocols are not trivially applicable (if at all) in many of todays distributed systems, e.g., grid, mobile, and sensors systems. After presenting the shortages and the inapplicability of the most popular existing distributed snapshot protocols, this paper discusses improvement directions for the protocols. In addition, it presents a new and an important improvement for the most popular distributed snapshot protocol, which was presented by Chandy and Lamport in 1985. Although the proposed improvement is simple and easy to implement, it has significant benefits in reducing the software and hardware overheads of distributed snapshots. Then, the paper presents proofs for the safety and progress of the new protocol. Lastly, it presents a performance analysis of the protocol using stochastic models