Time Synchronization with Channel Hopping Scheme for LoRa Networks

Abstract

Low-Power Wide Area Networks (LPWAN) for resilient Internet of Things (IoT) ecosystems come with unprecedented cost for the minimal load of communication. Long Range (LoRa) Wide Area Network (LoRaWAN) is a LPWAN which has a long range, low bit rate and acts as a connectivity enabler. However, making an efficient collaborative service of clock synchronization is challenging. In this paper we tackle two problems of effective robustness in LoRa network. First, current research typically focuses on the benefits of LoRa but ignores the requirement of reliability, which may invalidate the expected benefits. To tackle this problem, we introduce a novel time synchronization scheme for radically reducing usage of existing Aloha type protocol that handles energy consumption and service quality. Second, we look into the security space of LoRa network, i.e. channel selection scheme for the given spectrum. Attacks like selective jamming are possible in LoRa network because the entire spectrum space is not used, and utilization of few channels are comparatively higher. To tackle this problem, we present a channel hopping scheme that integrates cryptographic channel selection with the time notion for the current communication. We evaluate time synchronization and the channel hopping scheme for a real-world deployed peer to peer (P2P) model using commodity hardware. This paper concludes by suggesting the strategic research possibilities on top of this platform.