Feasibility study of IEEE 802.15.4e DSME utilizing IR-UWB and S-Aloha

In this paper, we analyze the effects of guaranteed time slots (GTSs) to the performance of IEEE 802.15.4 slotted Aloha (S-Aloha) medium access control (MAC) protocol utilizing impulse radio ultrawideband (IR-UWB) technology. IEEE 802.15.4e, amendment to IEEE 802.15.4 standard, defines an optional MAC scheme termed as deterministic and synchronous multi-channel extension (DSME). One of the key features of DSME is that it enables the MAC to operate in fully scheduled mode utilizing DSME-GTS slots for communications. The feasibility of DSME-GTSs is analytically derived in terms of throughput and it is verified by simulations performed in Opnet. Furthermore, the impact of DSME-GTSs for packet delivery ratio and delay is simulated in wireless hospital room scenario and the results are compared to contention-based operation of IEEE 802.15.4 MAC. The results show that significantly higher throughput and packet delivery ratio is achieved when IEEE 802.15.4 MAC operates in fully scheduled mode. In addition, fully scheduled mode guarantees upper bound for end-to-end data packet delay, and therefore it is the preferable mode for transmitting vital biomedical information.