Next Generation Media Access Control (NGMA) techniques have been designed to support diverse applications with heterogeneous priorities. In industrial cyber-physical systems (CPS), the number of connected devices and systems is expected to grow significantly, demanding dependable and prompt network services. In this work, we present a novel scheme, Dynamic Fragmentation-MAC (DyFrag-MAC) that offers dynamic, differentiated channel access to the traffic of various priorities. DyFrag-MAC works on fragmenting the data of normal priority in order to support early delivery of urgent priority data. In prior work, urgent priority data either had to wait for the complete transmission of lower-priority packets or relied on multi-channel protocols to gain access. We compared the proposed fragmentation scheme with FROG-MAC and industrial Deterministic and Synchronous Multi-channel Extension (i-DSME). FROG-MAC fragmented the lower priority packets, but did not adjust the fragment size dynamically, whereas i-DSME utilized multiple channels and adaptive contention mechanisms; both protocols lack the ability to preempt ongoing lower-priority transmissions. Hence, the performance evaluation in terms of average delay and throughput reveals better performance of DyFRAG-MAC for the heterogeneous traffic.
Efficient management of heterogeneous traffic with varying priorities is critical in Wireless Body Area Networks (WBANs). The priority mechanisms embedded in Media Access Control (MAC) schemes largely govern the performance of WBAN in terms of reliability, delay and energy efficiency. Minimizing the delay between packet generation and reception is critical for enhancing WBAN performance and associated health outcomes; however, delay optimization must be tailored to each traffic priority. In this work, we proposed a novel priority-based MAC protocol, Adaptive and Dynamic Polling MAC for Prioritized Traffic (ADP2-MAC), designed to support heterogeneous traffic in WBANs. The protocol utilizes a probabilistic approach to dynamically determine channel polling/listening intervals. ADP2-MAC not only identifies traffic arrival patterns to determine optimal polling intervals but also interrupts the transmission of lower-priority data when urgent packets are expected. The performance of ADP2-MAC has been compared with the MAC protocol for Variable Data Rates (MVDR) which supports heterogeneous traffic by assigning different data rates based on traffic priority. ADP2-MAC outperforms MVDR due to its use of probabilistic polling intervals and an interruption mechanism designed to efficiently handle urgent-priority data.
