Seamless roaming and guaranteed communication using a synchronized single-hop multi-gateway 802.15.4e TSCH network

TL;DR

This paper presents a novel multi-gateway IEEE 802.15.4e TSCH network architecture that enables seamless mobility and communication for industrial wireless sensor networks through synchronization mechanisms.

Contribution

It introduces the Virtual Grand Master concept and schedule synchronization to support mobile nodes in a multi-gateway TSCH network.

Findings

Seamless roaming achieved with synchronized BBRs.

Mobile nodes maintain communication without desynchronization.

Fast handover supported through schedule synchronization.

Abstract

Industrial wireless sensor networks (WSNs) are being used to improve the efficiency, productivity and safety of industrial processes. An open standard that is commonly used in such cases is IEEE 802.15.4e. Its TSCH mode employs a time synchronized based MAC scheme together with channel hopping to alleviate the impact of channel fading. Until now, most of the industrial WSNs have been designed to only support static nodes and are not able to deal with mobility. In this paper, we show how a single-hop, multi-gateway IEEE 802.15.4e TSCH network architecture can tackle the mobility problem. We introduce the Virtual Grand Master (VGM) concept that moves the synchronization point from separated Backbone Border Routers (BBRs) towards the backbone network. With time synchronization of all BBRs, mobile nodes can roam from one BBR to another without time desynchronization. In addition to time synchronization, we introduce a mechanism to synchronize the schedules between BBRs to support fast handover of mobile nodes.