An efficient UWB radio architecture for busy signal MAC protocols

Large wireless ad hoc and sensor networks impose tight constraints on cost and power dissipation, so nodes usually adopt a single transceiver approach. Since a single transceiver cannot assess the status of existing transmissions, it wastes valuable time and energy on handshaking packets and corrupted packets. To avoid such overhead, we propose a single transceiver approach based on ultra wideband (UWB) and a companion medium access control (MAC) layer based on busy tone multiple access (BTMA). BTMA reduces the time and energy spent on collisions as compared to handshaking protocols. It is well suited for ad hoc and sensor networks since it permits random distributed medium access with no central point of failure. The single transceiver leverages the inherently low duty cycle of impulse-based UWB (I-UWB) to assess the status of a packet during its transmission. This paper describes the I-UWB system architecture, and simulations show that it effectively detects a busy signal without affecting data transmission.