New Busytone Solutions to Medium Access Control inWireless Mesh, Ad Hoc, and Sensor Networks

Busytone was proposed three decades ago and has been the most famous solution to the hidden terminal problem. However, no busytone-based protocols have ever been deployed in practice. Most previous papers attributed this fact to its dual transceiver requirement, and some also pointed out the overhead and inefficiency problem due to the additional energy and bandwidth consumed by busytone. However, the actual issue that prevents busytone from being used for decades is the receiver busytone self-interference (RBTSI) problem. In short, the busytone signals transmitted by a receiver considerably interfere with its own data signal reception even if they are transmitted/received in different frequencies, since the busytone signal strength is significantly higher than the received data signal strength at the receiver location, and filters are not perfect. In this paper, we propose the detached busytone approach that transmits busytone signals before the associated data signals. This is the first busytone solution that can get around the aforementioned RBTSI issue. It is also the first continuous busytone solution that can support single transceiver per node. We also proposed the shortened busytone technique, which is the first solution that can address the dialogue-induced idleness problem. Both the proposed DBT approach and shortened busytone technique can be applied to various previous busytone-based protocols such as DBTMA and PCMA.