Optimal Relay Placement for Indoor Sensor Networks

To many sensor networks, the robust operation dependson deploying relays to ensure wireless coverage. This paperconsiders the crucial problem of optimal relay placement for wirelesssensor networks in indoor environments. The placement of relaysis essential for ensuring communication quality and data collection.A number of existing algorithms have been proposed forensuring full sensing coverage and network connectivity. These algorithmscan hardly be applied to indoor environments because ofthe complexity of indoor environments, in which a radio signal canbe dramatically degraded by obstacles like walls. We firstly theoreticallyprove that the indoor relay placement problem is NP-hard.We then predict radio coverage of a given relay deployment in indoorenvironments, and then propose a efficient greedy algorithmfor computing the relay deployment locations for required coveragequality. This algorithm is proved to provide a factor approximationto the theoretical optimum, where and n is the number of all grid points. Experimental results demonstrate the proposed algorithm achieves betterperformance than two other algorithms. To our knowledge, ourwork is the very first that study the optimal relay placement problemfor sensor networks in complex indoor environments.