A Novel Topology Control with Reconfigurable Radio for Sustainable Wireless Ad Hoc Networks

Existing topology controls enable wireless nodes to control parameters, such as adjusting the transmission power or switching operating modes between a sleep mode and an active mode, to achieve energy savings and prolong network lifetime. However, the topology controls assume that the operating frequency is fixed or can be changed in a narrow range of frequencies, thus the communication distance is not radically changed because of the radio propagation characteristic. Our thesis is that "by introducing a new control dimension, frequency control, with an advanced radio technology, reconfigurable radio, where the transmission range can be dramatically changed by the operating frequency selection over a wide frequency range, wireless ad hoc networks can extend their network lifetime from the topology controls". The paper presents distributed topology control algorithms, reconfigurable radio topology control (RTC) and reconfigurable radio dynamic topology control (RDTC), which construct a minimum hop routing tree using multiple frequency bands. The proposed topology control algorithms based on reconfigurable radio are implemented using USRP nodes as a proof of concept. Large scale simulation results show that the proposed topology controls can extend the network lifetime compared with the existing approaches.