An Efficient Anycast Mechanism for 802.15.4-TSCH to Improve QoS in IIoT

Abstract

The Industrial Internet of Things (IIoT) has emerged as a technology that automates industrial processes. In IIoT networks, data are collected from various nodes and sent to a base station for managerial purposes. However, in the industrial environment, network reliability and delay are significant challenges due to the high likelihood of packet loss in radio networks. Anycast is a link layer mechanism that increases reliability and reduces delay by allowing multiple receivers to be connected to a sender, and a single packet is simultaneously sent to all receivers. The receivers decode the packet based on their priorities, and transmission succeeds if at least one receiver can decode the packet. Moreover, mechanisms exist to limit the number of duplicates. This paper proposes a novel centralized anycast aware scheduling algorithm (AASA), which implements anycast based on the 802.15.4e-time-slotted channel hopping (TSCH) standard and in the stack of the 6TiSCH protocol. The goal of AASA is to improve IIoT networks more reliable and reduce end-to-end delay. To do this, upon a link failure, AASA chooses an alternative link and the packet is sent without any delay via that link through the same time slot. We implemented AASA in 6TiSCH simulator and carried out different scenarios to investigate its efficiency under various conditions. Results from simulations show that AASA effectively increases reliability by reducing repetitive packet transmissions and, thus, decreasing the delay in packet delivery.