Using Location Information for Scheduling in 802.15.3 MAC

Abstract

In recent years, UWB has received much attention as a suitable Physical Layer (PHY) for Wireless Personal Area networks (WPANS). UWB allows for low cost, low power, high bandwidth, short reach communication well suited for personal operating spaces. One of the key features offered by UWB is very accurate ranging between a transmitter/receiver pair. The IEEE 802.15.3 is a MAC protocol that has been proposed for WPANs. In this MAC, a combination of CSMA/CA and TDMA is used to achieve channel scheduling. The TDMA component ensures only one transmitter/receiver pair within a piconet is active at any given time thereby ensuring an exclusion region that covers the whole piconet. In this paper, we propose a less stringent scheduling mechanism that allows for concurrent communication between UWB transmitter/receiver pairs within a piconet. Exclusion is necessary only when the communicating entities are close enough such that interference between them would adversely affect successful reception of data at the receivers. The Piconet Coordinator (PNC) uses the ranging information provided by UWB to accurately position transmitters and receivers. The PNC schedules parallel transmissions between distinct transmit/receive pairs as long as they do not interfere. We present the results of our simulations of our proposed modifications and show that the network throughput can be significantly increased with very little change to the 802.15.3 MAC.