In this paper, a routing protocol for k-anycast communication based upon the anycast tree scheme is proposed for wireless sensor networks. Multiple-metrics are utilized for instructing the route discovery. A source initiates to create a spanning tree reaching any one sink with source node as the root. Subsequently, we introduce three schemes for k-anycast: a packet is transmitted to exact k sinks, at least k sinks, and at most k sinks, where, a packet can be transmitted to k or more than k sinks benefiting from broadcast technique without wasting the source energy for replicating it. 
Routing protocol for k-anycast communication in rechargeable wireless sensor networks