This paper addresses the problem of re-entry target identification using radar cross section (RCS) measurements obtained from distributed radars. Considering that the RCS pattern is subordinate to the target class and the aspect angle, the target identification problem is formulated as maximum a posteriori estimation associated with the multiple hypothesis of these two unknowns. Once each hypothesis is propagated through the approximate aspect angle dynamics, the corresponding hypothesis probability is evaluated by using the available RCS measurements and the pre-trained RCS distribution for the corresponding hypothesis. To improve the target identification performance, the RCS measurement likelihood is calculated by exploiting the geometric relation between the target and the multi-radar. Computer simulations are carried out to demonstrate the superiority and reliability of the proposed method over the existing machine-learning based algorithm.

In wireless mobile ad hoc networks, many important communications are based on the global broadcast that relies on a reliable 1-hop broadcasting in which a message from the source node is guaranteed to be delivered to all nodes within the source node's transmission range. Recently, a noble algorithm called CSMA/CN is proposed that utilizes collision notification to improve the network throughput. This paper presents an improved MAC protocol called ROB/CN (Reliable 1-Hop Broadcast Using Collision Notification) that achieves a guaranteed reliable 1-hop broadcast using CSMA/CN. In most previously proposed algorithms, if a transmission undergoes a collision, then the transmission should be restarted all over again, whereas in ROB/CN, the retransmission is not necessary if the collision is caused by only a small number of transmissions. Simulation results show the effectiveness of the proposed algorithm.

The route discovery and maintenance processes in wireless mobile networks are very expensive tasks due to the mobility of the host. Route discovery requires a considerable amount of resources and therefore it is wise to utilize the effort already invested in existing paths. This paper proposes a dynamic hybrid routing (DHR) protocol in ad hoc networks, which constructs paths only upon demand by taking attributes from both proactive and reactive algorithms. The goal of DHR is to re-use, whenever possible, portions of several existing paths when establishing a new path. The reusability is accomplished by using dynamic proactive zones (PZs), through which nearby existing path information is disseminated. By utilizing the information stored in PZs, considerable savings (in time and traffic) can be achieved over other on-demand routing algorithms that use flooding. In other route-finding algorithms, proactive zones are formed throughout the network and remain unchanged, whereas in DHR, routes are created and destroyed dynamically around the existing paths. Even though DHR may not find the shortest path between source and destination, it does reduce the amount of traffic needed to find a path and therefore increases the available bandwidth for data transfer.

Bluetooth ad hoc networks are formed by interconnecting Bluetooth enabled devices into piconets, and by interconnecting piconets into a scatternet. The existing protocols for scatternet formation expect all devices to be within transmission range of each other and there are no provisions yet for dynamic network reconfiguration in the process of devices joining or leaving the scatternet. We present a new distributed scatternet formation protocol designed to work in situations where all the devices are not necessarily within transmission range of each other. The protocol is a fault tolerant, semi proactive, randomized distributed protocol that adapts to the network topology and maintains connectivity within the scatternet, even under highly dynamic conditions without much reconfiguration.

Mobile ad hoc networks are composed of moving wireless hosts which, when within range of each other, form wireless networks. For communication to occur between hosts that are not within each other's range, routes involving intermediate nodes must be established; however, since the hosts may be in motion, a host that was part of a route may move away from its upstream and downstream partners, thus breaking the route. Our work shows that by utilizing only local geographic information (now a part of some route finding algorithms), a host can anticipate its neighbor's departure and, if other hosts are available, choose a host to bridge the gap, keeping the path connected. We present a distributed algorithm that anticipates route failure and performs preventative route maintenance using location information to increase a route lifespan. The benefits are that this reduces the need to find new routes (which is very expensive) and prevents interruptions in service. Simulation shows that as the density of nodes increase the chance to successfully utilize our route maintenance approach increases, and so does the savings.

A fault ring is a connection of only nonfaulty adjacent nodes and links such that the interior of the ring contains only faulty components. This paper proposes two wormhole routing algorithms that deal with more relaxed shapes of fault rings than previously known algorithms in the mesh networks. As a result, the number of components to be made disabled would be reduced considerably in some cases. First algorithm, called F4, uses four virtual channels and allows all four sides of fault rings to contain concave shapes. Second algorithm, F3, permits up to three sides to contain concave shapes using only three virtual channels. Both F3 and F4 are free of deadlock and livelock and guarantee the delivery of messages between any pair of nonfaulty and connected nodes in the network.

A new fault-tolerant all-to-all broadcasting algorithm in an n-dimensional hypercube with up to [n/2] faulty links is given. An extension of this algorithm that can tolerate up to [n/2] faulty nodes is also described. These algorithms assume a multiport I/O model, meaning each node can send and receive messages from all its adjacent nodes simultaneously. The total time steps taken by the proposed algorithms are near optimal, and they produce a factor of n less traffic than previously known algorithms.