Costas Busch

Learn More
A MAC protocol specifies how nodes in a sensor network access a shared communication channel. Desired properties of such MAC protocol are: it should be distributed and contention-free (avoid collisions); it should self-stabilize to changes in the network (such as arrival of new nodes), and these changes should be contained, i.e., affect only the nodes in(More)
Link reversal algorithms provide a simple mechanism for routing in communication networks whose topology is frequently changing, such as in mobile ad hoc networks. A link reversal algorithm routes by imposing a direction on each network link such that the resulting graph is a destination oriented DAG. Whenever a node loses routes to the destination, it(More)
Link reversal algorithms provide a simple mechanism for routing in mobile ad hoc networks. These algorithms maintain routes to any particular destination in the network, even when the network topology changes frequently. In link reversal, a node reverses its incident links whenever it loses routes to the destination. Link reversal algorithms have been(More)
We study atomic routing games on networks in which players choose a path with the objective of minimizing the maximum congestion along the edges of their path. The social cost is the global maximum congestion over all edges in the network. We show that the price of stability is 1. The price of anarchy, PoA, is determined by topological properties of the(More)
Fair cake-cutting is the division of a cake or resource among N users so that each user is content. Users may value a given piece of cake differently, and information about how a user values different parts of the cake can only be obtained by requesting users to “cut” pieces of the cake into specified ratios. One of the most interesting open questions is to(More)
Counting networks are a class of distributed data structures that support highly concurrent implementations of shared Fetch&Increment counters. Applications of these counters include shared pools and stacks, load balancing, and software barriers [4, 12, 13, 18]. A limitation of counting networks is that the resulting shared counters can be incremented, but(More)
We study the problem of maintaining sketches of recent elements of a data stream. Motivated by applications involving network data, we consider streams that are <i>asynchronous</i>, in which the observed order of data is not the same as the time order in which the data was generated. The notion of recent elements of a stream is modeled by the <i>sliding(More)
We consider the problem of maintaining aggregates over recent elements of a massive data stream. Motivated by applications involving network data, we consider asynchronous data streams, where the observed order of data may be different from the order in which the data was generated. The set of recent elements is modeled as a sliding timestamp window of the(More)
Direct routing is the special case ofbufferless routing whereN packets, once injected into the network, must be delivered to their destinations without collisions. We give a general treatment of three facets of direct routing: 1. Algorithms. We present a polynomial-timegreedy direct algorithm which is worst-case optimal. We improve the bound of the greedy(More)