  We consider a conflict-free minimum latency data aggregation problem that
occurs in different wireless networks. Given a network that is presented as an
undirected graph with one selected vertex (a sink), the goal is to find a
spanning aggregation tree rooted in the sink and to define a conflict-free
aggregation minimum length schedule along the arcs of the tree directed to the
sink. Herewith, at the same time slot, each element of the network can either
send or receive at most one message. Only one message should be sent by each
network element during the whole aggregation session, and the conflicts caused
by signal interference should be excluded. This problem is NP-hard and remains
NP-hard even in the case when the aggregation tree is given. Therefore, the
development of efficient approximate algorithms is very essential for this
problem. In this paper, we present new heuristic algorithms based on the
genetic local search and the variable neighborhood search metaheuristics. We
conducted an extensive simulation that demonstrates the superiority of our
algorithms compared with the best of the previous approaches.
