Sudarshan Vasudevan

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Neighbor discovery is one of the first steps in the initialization of a wireless ad hoc network. In this paper, we design and analyze practical algorithms for neighbor discovery in wireless networks. We first consider an ALOHA-like neighbor discovery algorithm in a synchronous system, proposed in an earlier work. When nodes do not have a collision detection(More)
Leader election is a very important problem, not only in wired networks, but in mobile, ad hoc networks as well. Existing solutions to leader election do not handle frequent topology changes and dynamic nature of mobile networks. We present a leader election algorithm that is highly adaptive to arbitrary (possibly concurrent) topological changes and is(More)
We consider the problem of neighbor discovery in static wireless ad hoc networks with directional antennas. We propose several probabilistic algorithms in which nodes perform random, independent transmissions to discover their one-hop neighbors. Our neighbor discovery algorithms are classified into two groups, viz. Direct-Discovery Algorithms in which nodes(More)
The performance experienced by wireless clients in IEEE 802.11 wireless networks heavily depends on the clients' ability to identify the Access Point (AP) that will offer the best service. The current AP affiliation mechanism implemented in most wireless clients is based on signal strength measurements received by the client from all the APs in its(More)
Neighbor discovery is one of the first steps in configuring and managing a wireless network. Most existing studies on neighbor discovery assume a single-packet reception model where only a single packet can be received successfully at a receiver. In this paper, motivated by the increasing prevalence of multipacket reception (MPR) technologies such as CDMA(More)
We consider the problem of secure leader election and propose two cheat-proof election algorithms : Secure Extrema Finding Algorithm (SEFA) and Secure Preference-based Leader Election Algorithm (SPLEA). Both algorithms assume a synchronous distributed system in which the various rounds of election proceed in a lock-step fashion. SEFA assumes that all(More)
We investigate the scalability of a class of algorithms that exploit the dynamics of wireless fading channels to achieve secret communication in a large wireless network of <i>n</i> randomly located nodes. We describe a construction in which nodes transmit <i>artificial noise</i> to suppress eavesdroppers whose locations are unknown and ensure secrecy of(More)
The secure transmission of information in wireless networks without knowledge of eavesdropper channels or locations is considered. Two key mechanisms are employed: artificial noise generation from system nodes other than the transmitter and receiver, and a form of multi-user diversity that allows message reception in the presence of the artificial noise. We(More)
The ability to transmit a message securely in the presence of eavesdroppers in a dense wireless network is considered. As with a number of recent schemes, system nodes other than the transmitter and receiver are chosen to generate noise that confuses the eavesdropper. By exploiting the dynamics of the fading, significantly improved performance is achieved(More)
For many wireless communication links, such as those employing turbo codes or sequentially-decoded convolutional codes, the power consumption of the decoder at the receiver depends on the received signal power and, hence, on the transmitted signal power. By transmitting a signal at a power higher than the minimum required for successful reception, the(More)