부산대학교 도서관

In this article, we consider the mobility of an end device (ED) in low-power wide-area networks (LPWANs) and we focus on the continuity of the ED session with the application server when this ED is moving from the coverage of one operator to that of another one. One of the methods to achieve the continuity of the session after roaming is the use of an IPv6-based scheme. As LPWAN is characterized by a fixed message rate and very small bandwidth as well as asymmetric communication, an efficient header compression scheme is required. Recently, the Internet Engineering Task Force LPWAN working group has proposed a static context header compression (SCHC) to compress IPv6 into LPWAN through a rule-based mechanism. In this article, we first extend the SCHC scheme to support session continuity and the new scheme is called mobile SCHC (MSCHC). MSCHC consists of several contexts, instead of the static context for SCHC and we also improve the use of the memory by dividing the rules into layers. Then, we investigate the mobility of the ED to show how the continuity of the session can be achieved while transmitting and receiving data when the ED is roaming between different operators. The proposed solution is based on the use of light mobile IPv6 messages compressed with MSCHC. Finally, the proposed mechanism is implemented in the popular LoRaWAN technology, evaluated and compared with the existing solutions provided by the LoRaWAN v1.1 standard.