© 1998 by British Computer Society
The Complexity of Interval Routing on Random Graphs
1 Dipartimento di Matematica Pura ed Applicata, University of L'Aquila, via Vetoio loc. Coppito, I-67100 l'Aquila, Italy Email: flammini{at}univaq.it, 2 Department of Computer Science, Utrecht University, Padualaan 14, 3584 CH Utrecht, The Netherlands, 3 Dipartimento di Informatica e Sistemistica, University of Rome La Sapienza, via Salaria 113, I-00198 Rome, Italy
Several methods exist for routing messages in a network without using complete routing tables (compact routing). In k-interval routing schemes (k-IRS), links carry up to k intervals each. A message is routed over a certain link if its destination belongs to one of the intervals of the link. We present some results for the necessary value of k in order to achieve shortest-path routing. Even though low values of k suffice for very structured networks, we show that for general graphs interval routing cannot significantly reduce the space requirements for shortest-path routing. In particular we show that for suitably large n, there are suitable values of p such that for randomly chosen graphs G
Gn, p the following holds, with high probability: if G admits an optimal k-IRS, then
[equation: see PDF]
. The result is obtained by means of a novel matrix representation for the shortest paths in a network.
Received October 3, 1996. revised January 21, 1998.