To transmit a certain number of data packets from one node to another, the node needs to spend a certain amount of energy. Likewise, there will be some energy consumed when the node receives the data packets from other nodes. The amount of energy consumed by transmitting the data is a function of the distance to the intended destination as well as the size of the data flow. For the reception, the energy is modeled as a function of the data flow. The energy functions for both transmission and reception for link i−j are given as follows