Fast join and synchronization schema in the IEEE 802.15.4e MAC

The Time Slotted Channel Hopping (TSCH) Medium Access Control (MAC) has been introduced in the recent IEEE 802.15.4e amendment to improve energy efficiency and reliability of short range wireless communications in industrial applications. However the joining phase can take very long time due to the operation of TSCH and beside being a problem in the deployment phase it may become a relevant source of energy consumption. To overcome this issue the present contribution investigates the problem of acquiring the first synchronization in a TSCH network from several points of view: (i) two novel mechanisms are proposed and implemented in real motes to speed up joining operations; (ii) for each of them, the average joining time is analytically modeled with closed form expressions as a function of node density, communication reliability, and beacon transmission frequency; (iii) the effectiveness of these novel algorithms and the accuracy of their models are experimentally validated in different scenarios.