Patent ID: 8270313
Filing Date: 2012-09-18
Classification: H04L,H04W

Abstract:
1. A method for determining a rank of a node i in a multi-hop wireless network, wherein the network includes a gateway node, client nodes, and relay nodes, wherein a node p(i) is a default parent of the node i having a rank R(p(i), and wherein the network uses a directed acyclic graph (DAG) topology, comprising steps of: transmitting at least one data packet from the node i to the node p(i) over a wireless link; counting a number of successful transmissions of most recent transmissions of data packets; determining an expected transmission time (ETX) for the wireless link based on the number of successful transmissions in the most recent transmissions; and assigning a rank R(i) to the node i as R(p(i))·ETX(i, p(i))+A, wherein ETX(i, p(i)) is the ETX of the wireless link, and A is a constant, wherein the transmitting is to the default parent p(i) of the node (i) and the counting, determining, and assigning steps are performed by a gateway node in the multi-hop wireless network and the rank avoids cycles in the DAG representing the network.