BIT INDEX EXPLICIT REPLICATION (BIER) FOR EFFICIENT ROUTING THROUGH A DESTINATION ORIENTED DIRECTED ACYCLIC GRAPH (DODAG) IN RESOURCE CONSTRAINED LOW-POWER AND LOSSY NETWORKS (LLNS)

摘要

In one embodiment, a first node in a network receives one or more bitmaps from one or more child nodes of the first node according to a directed acyclic graph (DAG) as used by RPL, the IPv6 Routing Protocol for Low-power and lossy networks (LLNs). Each of the one or more child nodes is associated with a corresponding unique bit position in the one or more bitmaps. The first node stores, in a forwarding table, the one or more bitmaps received from the one or more child nodes of the first node. The first node receives a message that includes a destination bitmap that identifies one or more destinations of the message via one or more set bits at bit positions associated with the one or more child nodes. The first node forwards the message towards the identified one or more destinations based on the destination bitmap and the one or more bitmaps stored in the forwarding table of the first node. Aggregating node bitmaps by OR operation with the bitmaps of their children allows to spare resources in nodes of LLNs; forwarding to the destination can be easily performed via AND operation on bitmaps. Deciding unicast or broadcast forwarding based on the density of interested children saves energy by optimally avoiding awaking of nodes.