Patent ID: 8583978
Filing Date: 2013-11-12
Classification: H04L

Abstract:
1. A method of distributing a multicast message in a Low power and Lossy Networks (LLN), the method comprising: receiving, at an intermediate node in a multicast network, a multicast message from a parent node of the intermediate node, wherein the multicast network is a directed acyclic graph and the parent node is located closer to a root node of the directed acyclic graph than the intermediate node; transmitting the multicast message to child nodes of the intermediate node in the multicast network, wherein the child nodes are located further from the root node of the directed acyclic graph than the intermediate node; storing the multicast message in a cache at the intermediate node; receiving, at the intermediate node in the multicast network, an acknowledgement message from each acknowledging child node within an acknowledging subset of less than all of the child nodes of the intermediate node, wherein the acknowledgement message indicates that the acknowledging child node successfully received the multicast message; accessing information indicating a population of the child nodes to which the multicast message transmission was directed; comparing the acknowledging subset of the child nodes revealed by the acknowledgement messages with the population of the child nodes to which the multicast message transmission was directed; identifying, based on results of the comparison between the acknowledging subset of the child nodes revealed by the acknowledgement messages with the population of the child nodes to which the multicast message transmission was directed, a non-acknowledging subset of less than all of the child nodes; and retransmitting, from the cache at the intermediate node, the multicast message to the non-acknowledging subset of the child nodes.