Optimal on-body relay placement for energy efficient in vivo communications

This paper investigates energy efficient in vivo communication with multi-source nodes. In such a network, the in vivo sensor nodes transmit their sensing information to an on-body destination node. Due to the associated high path loss with implant devices, on-body relay nodes can be used to convey the information bits from the in vivo source nodes to the on-body destination node in an energy efficient manner. In this context, the paper objective is to select the optimal on-body relay locations that result in the minimum per bit average energy consumption for the in vivo networks using the minimum number of on-body relay nodes. The problem is formulated as an integer program that can be efficiently solved using commercial optimization solvers. Numerical results demonstrate the significant improvement in energy consumption and quality-of-service (QoS) support, when on-body relays are optimally located.