It is well known that IEEE 802.11 provides a physical layer multi-rate capability. In this paper, we propose a novel MAC layer relay-enabled point coordination function (PCF) protocol, called rPCF, to exploit this capability. With multiple data rates in response to different channel conditions, if the direct link has low data rate, data packets may be delivered faster through a relay node. To e...

We propose a novel multicast scheme that can provide qualityof-service (QoS) to multicast service over IEEE 802.11 wireless LANs by utilizing medium access control (MAC) layer relay. It is well known that IEEE 802.11 provides a physical layer multi-rate capability in response to different channel conditions, and hence packets may be delivered at a higher data rate through a relay node than thro...

We investigate the symmetric degrees of freedom (DoF) of the K-pair (2K users) two-way relay Multiple-Input Multiple-Output (MIMO) Gaussian interference channel for K = 2, 3 where each user is equipped with M antennas and the relay node is equipped with N antennas. The two users of each pair communicate with each other via the help of the relay only. Expressing the DoF characterization as a fun...

This paper establishes the utility of user cooperation in facilitating secure wireless communications. In particular, the four-terminal relay-eavesdropper channel is introduced and an outer-bound on the optimal rate-equivocation region is derived. Several cooperation strategies are then devised and the corresponding achievable rate-equivocation region are characterized. Of particular interest i...

The large-scale mobile Underwater Wireless Sensor Network (UWSN) is a useful networking paradigm to explore underwater environments. The characteristics of mobile UWSNs, such as low communication bandwidth, large propagation delay, and floating node mobility are significantly different from wireless sensor networks. In this paper, we propose a new efficient routing protocol, called multi-path r...

Up to now a considerable number of studies have been conducted on the localization methods for stationary wireless sensor networks (WSNs). However little attention has been given to the localization scheme for a mobile wireless sensor network (MWSN) where all sensor nodes are moving. In this paper, we propose a self-localization scheme with relay nodes which transmit the information from an anc...

The transmission of signals in a hybrid satellite-terrestrial system (HSTS) in the presence of co-channel interference (CCI) is considered in this study. Specifically, we examine the problem of amplify-and-forward (AF)-based relaying in a hybrid satellite-terrestrial link, where the relay node is operating in the presence of a dominant co-channel interferer. It is assumed that direct connection...

Cooperative diversity is a communication technique where a relay node provides signal diversity to the destination by retransmitting the signal received from the source. To find an optimal relay and maximize the resulting performance, a relay selection procedure is used with channel state information as a selection metric. In this paper, we model cooperative diversity with relay selection as a ...

We investigate two distinct problems in military radio networking. In the first problem, we study a mobile airborne multi-hop wireless network. The mobility of the nodes leads to dynamic link capacities requiring changes to the topology by adding and removing links. Changes are intended to minimize maximum link load. Mixed integer linear programming is used to periodically find topological modi...