Energy Consumption and Performance of IEEE 802.15.4e TSCH and DSME

International audienceThe recent IEEE 802.15.4e standard has introduced two interesting modes of operation: Time Slotted Channel Hopping (TSCH) and Deterministic and Synchronous Multi-channel Extension (DSME). Both provide a mix of time and frequency division to improve the performance of the previously available synchronized MAC mode (beacon-enabled 802.15.4). In this paper, we compare the performance of DSME and TSCH with respect to the energy consumption, throughput, and delay through an analysis of their respective ways of operation. We use an energy consumption model coming from our previous experience on the design of recent energy harvesting motes for the GreenNet platform. Our results show that DSME performs slightly better in terms of the energy consumption spent in data transfers. Both protocols exhibit similar delays for a given duty cycle, nevertheless, TSCH obtains shorter delay and higher throughput for low duty cycles. For higher duty cycles, TSCH results in lower throughput—for applications that send little data, the fixed slot configuration of TSCH results in wasted bandwidth. DSME can allocate shorter slots, which is beneficial for applications that transmit short packets

Stripe: a Distributed Scheduling Protocol for 802.15.4e TSCH Networks

Les rapports de recherche du LIG - ISSN: 2105-0422The 802.15.4e Time Slotted Channel Hopping (TSCH) mode defines how nodes operate according to a common shared schedule that determines which device may transmit frames on a given channel and during a given timeslot. By taking advantage of channel diversity, TSCH increases reliability and cell allocation to two nodes for a given transmission results in reduced collision probability. As the standard does not specify how to construct the common schedule, there is a need for finding adequate scheduling algorithms. In this paper, we propose Stripe, a distributed scheduling protocol that allocates timeslots in temporal alignments having the property that multi hop forwarding of packets benefits from the minimal delay. Stripe ensures short delays both for upward and downward traffic. The protocol comprises two phases: the relocation phase that reconfigures the random pre-allocated cells in a schedule fitting convergecast traffic and a reinforcement phase that schedules additional cells to support the traffic generated and relayed by each node towards the sink. We evaluate Stripe with an enhanced 6TiSCH simulator and compare its performance with Orchestra [1]. The results from extensive simulations show that Stripe presents fast convergence, short delays, and improved packet delivery ratio