Summary form only given. Topology control of wireless sensor networks (WSNs) is a key design challenge in terms of extending the lifetime of the network. The paper presents a fault tolerant topology control by adding necessary redundant nodes to the network's simple communication backbone, which results a higher vertex connectivity degree. It provides not only fault tolerance for unreliable node failure, but also support for upper level protocols. The paper also identifies several factors and synchronization methods which may affect the redundant node selection. A simulation study shows the improvement of network lifetime with a desired vertex connectivity degree.