Dariusz R. Kowalski

Broadcasting in undirected ad hoc radio networks

We consider distributed broadcasting in radio networks, modeled as undirected graphs, whose nodes have no information on the topology of the network, nor even on their immediate neighborhood. For randomized broadcasting, we give an algorithm working in expected time <i>O</i>(<i>D</i> log(<i>n/D</i>) + log² <i>n</i>) in <i>n</i>-node radio networks of diameter <i>D</i>, which is optimal, as it matches the lower bounds of Alon et al. [1] and Kushilevitz and Mansour [14]. Our algorithm improves the best previously known randomized broadcasting algorithm of Bar-Yehuda, Goldreich and Itai [3], running in expected time <i>O</i>(<i>D</i> log <i>n</i> + log² <i>n</i>). For deterministic broadcasting, we show the lower bound Ω(<i>n</i>(log <i>n</i>)/(log (<i>n</i>/<i>D</i>)))) on broadcasting time in <i>n</i>-node radio networks of diameter <i>D</i>. This implies previously known lower bounds of Bar-Yehuda, Goldreich and Itai [3] and Bruschi and Del Pinto [5], and is sharper than any of them in many cases. We also give an algorithm working in time <i>O</i>(<i>n</i> log <i>n</i>), thus shrinking -- for the first time -- the gap between the upper and the lower bound on deterministic broadcasting time to a logarithmic factor.

Optimal deterministic broadcasting in known topology radio networks

We consider deterministic broadcasting in radio networks whose nodes have full topological information about the network. The aim is to design a polynomial algorithm, which, given a graph G with source s, produces a fast broadcast scheme in the radio network represented by G. The problem of finding a fastest broadcast scheme for a given graph is NP-hard, hence it is only possible to get an approximation algorithm. We give a deterministic polynomial algorithm which produces a broadcast scheme of length

On selection problem in radio networks

\mathcal{O}(D + \log ^2 n)

Deterministic broadcasting time in radio networks of unknown topology

, for every n-node graph of diameter D, thus improving a result of Gąsieniec et al. (PODC 2005) [17] and solving a problem stated there. Unless the inclusion NP

Interference-Resilient Information Exchange

\subseteq

Faster Deterministic Broadcasting in Ad Hoc Radio Networks

BPTIME(