رئیس دانشکده مهندسی برق و کامپیوتر مجله مهندسی برق دانشگاه تبریز 2008-7799 51 1 2021 04 21 T2AS: Topology/Traffic Aware Scheduling to Optimize the End-to-end Delay in IEEE802.154e-TSCH Networks T2AS: Topology/Traffic Aware Scheduling to Optimize the End-to-end Delay in IEEE802.154e-TSCH Networks 129 137 13330 FA E. Mozaffari Ahrar Computer Department, Faculty of Engineering, Bu-Ali Sina University, Hamedan, Iran. M. Nassiri Computer Department, Faculty of Engineering, Bu-Ali Sina University, Hamedan, Iran. Journal Article 2020 01 07 <span lang="EN-AU">The Time Synchronized Channel Hopping (TSCH) mode of IEEE 802.15.4e has been widely used as an access method for the industrial Internet of Things (IoT). It permits to overcome the performance limits of 802.15.4 standard in such networks. It provides bounded latency and increased network capacity while mitigating the effects of interference and multipath fading. In this paper, we tackle two critical concerns of industrial networks, namely end-to-end reliability and delay by proposing two centralized scheduling mechanisms; First, the Height-based Scheduling (HS) that computes the schedule only based on the network topology. Second, T²AS, which takes into account both traffic demand and network topology to calculate the schedule. The later mechanism uses a composite weighting function that allows scheduling links with more load and longer distance from the root in earlier timeslots. This prioritizes the flows with more traffic to be scheduled earlier. Both algorithms provide subsequential scheduling for multi-hop scenarios. Simulation results, obtained from the OpenWSN emulator, particularly confirm the efficiency of T²AS in terms of reliability and end-to-end latency. More precisely, it guarantees a reliability of more than 99% for all network sizes. Furthermore, T²AS provides a noticeable bounded delay by delivering data packets within a single slotframe.</span> <span lang="EN-AU">The Time Synchronized Channel Hopping (TSCH) mode of IEEE 802.15.4e has been widely used as an access method for the industrial Internet of Things (IoT). It permits to overcome the performance limits of 802.15.4 standard in such networks. It provides bounded latency and increased network capacity while mitigating the effects of interference and multipath fading. In this paper, we tackle two critical concerns of industrial networks, namely end-to-end reliability and delay by proposing two centralized scheduling mechanisms; First, the Height-based Scheduling (HS) that computes the schedule only based on the network topology. Second, T²AS, which takes into account both traffic demand and network topology to calculate the schedule. The later mechanism uses a composite weighting function that allows scheduling links with more load and longer distance from the root in earlier timeslots. This prioritizes the flows with more traffic to be scheduled earlier. Both algorithms provide subsequential scheduling for multi-hop scenarios. Simulation results, obtained from the OpenWSN emulator, particularly confirm the efficiency of T²AS in terms of reliability and end-to-end latency. More precisely, it guarantees a reliability of more than 99% for all network sizes. Furthermore, T²AS provides a noticeable bounded delay by delivering data packets within a single slotframe.</span> https://tjee.tabrizu.ac.ir/article_13330_1a3d53889d53934aa8f49bb94fd7e36a.pdf