eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Leibniz International Proceedings in Informatics
1868-8969
2019-09-06
78:1
78:20
10.4230/LIPIcs.ESA.2019.78
article
Multicommodity Multicast, Wireless and Fast
Ravi, R.
1
Rudenko, Oleksandr
2
Tepper School of Business, Carnegie Mellon University, Pittsburgh, PA, USA
Carnegie Mellon University, Pittsburgh, PA, USA
We study rumor spreading in graphs, specifically multicommodity multicast problem under the wireless model: given source-destination pairs in the graph, one needs to find the fastest schedule to transfer information from each source to the corresponding destination. Under the wireless model, nodes can transmit to any subset of their neighbors in synchronous time steps, as long as they either transmit or receive from at most one transmitter during the same time step. We improve approximation ratio for this problem from O~(n^(2/3)) to O~(n^((1/2) + epsilon)) on n-node graphs. We also design an algorithm that satisfies p given demand pairs in O(OPT + p) steps, where OPT is the length of an optimal schedule, by reducing it to the well-studied packet routing problem. In the case where underlying graph is an n-node tree, we improve the previously best-known approximation ratio of O((log n)/(log log n)) to 3. One consequence of our proof is a simple constructive rule for optimal broadcasting in a tree under a widely studied telephone model.
https://drops.dagstuhl.de/storage/00lipics/lipics-vol144-esa2019/LIPIcs.ESA.2019.78/LIPIcs.ESA.2019.78.pdf
Rumor
scheduling
broadcast
multicommodity
multicast
optimization algorithms
approximation
packet routing