LoRaWAN vs. 6TiSCH: Which one scales better?

Abstract

Internet of Things (IoT) has been a hot topic in both academia and industry for the last few years. There are many possible applications, in fields as smart cities, home automation, smart buildings, agriculture, automated metering, logistic, industrial automation, among others. Such a wide range of applications resulted in various technological solutions in order to enable Machine-to-Machine (M2M) communications, in which we highlight those for wide area networks. In that sense, two widely used sub-GHz protocols for Low Power Wide Area (LPWA) communications are: Long Range (LoRa), using the upper layers defined by Long Range Wide Area Network (LoRaWAN); and IEEE 802.15.4g, using the upper layers defined by IPv6 over the Time-Slotted Channel Hopping (TSCH) mode of IEEE 802.15.4e (6TiSCH). While LoRaWAN is a well-known and widespread protocol, 6TiSCH offers IPv6 connectivity to LPWA networks and is used in important standards such as Wireless Smart Ubiquitous Network (Wi-SUN). This paper aims at determining how well each protocol scales, analyzing different aspects such as packet loss, delay, and the maximum number of nodes per square area. In order to achieve such results, computer simulations are performed using open-source simulators. The obtained results demonstrate that the best scalability depends on which scenarios are considered. For scenarios with multiple gateways requiring low latency or low packet transmission rates, LoRaWAN demonstrates better results. However, in scenarios with high packet transmission rates and where the latency is not a major concern, 6TiSCH is more appropriate. Moreover, even in the best case, the latency associated with the LoRaWAN technology may be considerably smaller than associated with 6TiSCH. Such novelty results are obtained in a fair and realistic way and, noting that both technologies could be used to build LPWA networks, it can help system designers to decide between the two technologies.