A method for communication in a wireless sensor network of an industrial control system. The network includes a plurality of device nodes and at least one gateway. The method includes aggregating in at least one wireless device data originating from at least two data packets. The method includes receiving at a first node at least one first data packet for a first destination address and aggregating data from the at least one data packet with data from at least one second data packet, intended for the same first destination address, forming an aggregated data packet and sending the aggregated data packet to another node or to said gateway. In other aspects of the invention a method, system and a computer program for carrying out the method are described.