Narrow Results

The definition and relative theories of disjoint paths with QoS constraints were summarized, the model of disjoint optimal paths with QoS constraints problem was illustrated. current disjoint paths algorithm were analyzed, at last the direction for future study and problem existed of disjoint paths algorithm with QoS constraints were put forward.

Considering the limited energy and transmission range of sensor nodes in sensor networks, a tree-based energy-efficient routing algorithm is discussed. According to maximum residual energy of nodes, a tree whose root is the sink node was set up in the covered field in which nodes with maximum residual energy less than ɛ are leaves. And a reliable routing algorithm is used when there have nodes death in the transmitting process. To optimize the algorithm, we use the β-constraint, which puts a soft limit on the maximum number of children a node can have in a tree. It can achieve lower latency and more energy-efficient, and the lifetime of the network is prolonged.

The QoS routing is a hot issue in research, among which the QoS multi-constraint routing is a difficult problem. Pointing out a weak point in the H_MCOP algorithm, the author successfully applies geometric series and binary search algorithm to it, and gets a heuristic routing algorithm of the QoS multi-constrained routing. And the author makes simulation based on NS2, the results of which indicate that this algorithm can find a low cost path and the calculation costs to find the path is low too.