Energy Efficient Data Recovery from Corrupted LoRa Frames

Abstract

High frame-corruption is widely observed in Long Range Wide Area Networks (LoRaWAN) due to the coexistence with other networks in ISM bands and an Aloha-like MAC layer. LoRa's Forward Error Correction (FEC) mechanism is often insufficient to retrieve corrupted data. In fact, reallife measurements show that at least one-fourth of received transmissions are corrupted. When more frames are dropped, LoRa nodes usually switch over to higher spreading factors (SF), thus increasing transmission times and increasing the required energy. This paper introduces ReDCoS, a novel coding technique at the application layer that improves recovery of corrupted LoRa frames, thus reducing the overall transmission time and energy invested by LoRa nodes by several-fold. ReDCoS utilizes lightweight coding techniques to pre-encode the transmitted data. Therefore, the inbuilt Cyclic Redundancy Check (CRC) that follows is computed based on an already encoded data. At the receiver, we use both the CRC and the coded data to recover data from a corrupted frame beyond the built-in Error Correcting Code (ECC). We compare the performance of ReDCoS to (i) the standard FEC of vanilla-LoRaWAN, and to (ii) Reed Solomon (RS) coding applied as ECC to the data of LoRaWAN. The results indicated a 54x and 13.5x improvement of decoding ratio, respectively, when 20 data symbols were sent. Furthermore, we evaluated ReDCoS on-field using LoRa SX1261 transceivers showing that it outperformed RS-coding by factor of at least 2x (and up to 6x) in terms of the decoding ratio while consuming 38.5% less energy per correctly received transmission.

Divide and Code: Efficient and Real-time Data Recovery from Corrupted LoRa Frames

“…Throughout our experiments we reported an FDR of 0. In contrast, ReDCoS reports an FDR of 0.13% for 𝑘 = 10 and 𝑡 = 8 and 0.11% for 𝑘 = 20 and 𝑡 = 4 [11], i.e., more than 0.1% of decoded payloads of ReDCoS are falsely decoded. Finding the Optimum Point.…”

“…However, the vast majority of their frames, i.e., 95%, were transmitted on SF12. Although the above would necessitate the adoption of erasure coding mechanisms, Rahmadhani et al [10], and Yazdani et al [11] showed considerable amounts of received frames ending up corrupted. Specifically, they reported frame corruption of 32% and 50% in SF8, using multiple GWs and single-GW, respectively.…”

“…4 We provide a probabilistic analysis of successful decoding in DC (see § IV). 5 Through simulations and real-world experiments using our testbed of LoRa-modules, we compare DC not only to the built-in errorcorrecting scheme of LoRaWAN but also to Reed Solomon codes and the recent scheme ReDCoS [11]. Furthermore, we dictate the ratio among data bytes and error-correcting bytes that optimizes consumption and decoding ratio (see § V).…”

Communication Technologies for Interoperable Smart Microgrids in Urban Energy Community: A Broad Review of the State of the Art, Challenges, and Research Perspectives

“…To ensure security, an “advanced encryption standard” is used. The spreading factor, bandwidth, and coding rate are the key physical layer parameters that influence LoRa’s coverage and power consumption, which are described in the following [ 110 , 111 ].…”

LoRa Communication Quality Optimization on Agriculture Based on the PHY Anti-Frame Loss Mechanism

“…In addition, we believe that both data recovery and improved reception rates are parallel and effective means of improving communication stability. Yazdani et al [11] proposed a method to recover LoRa data efficiently, which helped to improve data integrity, but the recoverability of the data was unstable, and receiving the data as completely as possible in complex environments is a prerequisite for recovering the data.…”