Soft Real-Time Chains for Multi-Hop Wireless Ad-Hoc Networks

Prioritized MAC protocols are needed to support soft real-time communication in wireless networks. In this paper, we introduce real-time chain, a new prioritized MAC protocol to support soft real-time data flows in multi-hop wireless ad-hoc networks. By avoiding packet collisions and limiting the effect of priority inversions, real-time chain is able to provide soft real-time and bandwidth guarantees. Furthermore, the use of multiple channels enables high spatial reuse and transmission rates. Finally, our approach can be integrated with a slightly modified version of the IEEE 802.15.4 standard. The protocol has been fully implemented on Crossbow MICAz hardware and its performance has been validated with a large set of both indoor and outdoor experiments