@inproceedings{
    FKKO03,
    editor = "Richa, Andrea and Welch, Jennifer",
    author = "Flor{\'e}en, Patrik and Kaski, Petteri and Kohonen, Jukka and Orponen, Pekka",
    publisher = "Association for Computing Machinery",
    title = "Multicast time maximization in energy constrained wireless networks",
    url = "http://doi.acm.org/10.1145/941079.941087",
    booktitle = "Proceedings of the 2003 Joint Workshop on Foundations of Mobile Computing (DIALM-POMC'03, San Diego CA, September 2003)",
    address = "New York NY",
    abstract = "We consider the problem of maximizing the lifetime of a given multicast connection in a wireless network of energy-constrained (e.g.\ battery-operated) nodes, by choosing ideal transmission power levels for the nodes relaying the connection. We distinguish between two basic operating modes: In a {\em static} assignment, the power levels of the nodes are set at the beginning and remain unchanged until the nodes are depleted of energy. In a {\em dynamic} assignment, the powers can be adjusted during operation. We show that lifetime-maximizing static power assignments can be found in polynomial time, whereas for dynamic assignments, a quantized-time version of the problem is NP-hard. We then study the approximability of the quantized dynamic case and conclude that no polynomial time approximation scheme (PTAS) exists for the problem unless P=NP. Finally, by considering two approximation heuristics for the dynamic case, we show experimentally that the lifetime of a dynamically maintained multicast connection can be made several times longer than what can be achieved by the best possible static assignment.",
    note = "",
    flags = "copy",
    year = "2003",
    keywords = "ad hoc networks, wireless communications, multicast, network lifetime, energy-aware computation",
    pages = "50--58"
}