A MAC protocol to manage communications in localization systems based on IEEE802.15.4

Abstract

This paper presents an upper MAC protocol based on a centralized master multi-slave architecture which is used to coordinate communications among the different type of nodes required for an indoor localization system (ILS) based on IEEE 802.15.4. This protocol works for the non-beacon enabled mode of the referred standard and is used to avoid additive delays in the localization communications. The protocol is based on the flexible time-triggered paradigm and includes adaptations to dephase the transmissions of nodes and to enable an easy computation of the correspondent offsets. It is shown that the protocol is well adapted for four requirements of localization systems: bursts of periodic frames with a fixed period, coexistence of short and long frames, efficient bandwidth utilization with reduced usage from control frames and mobile nodes with reduced processing power. This protocol enables to improve the temporal localization granularity of 500 different nodes from around 100 to around 7 seconds.