Reliability Improvement of LoRa with ARQ and Relay Node

Abstract

In our modern world, many Internet of Things (IoT) technologies are being researched and developed. IoT devices are currently being used in many fields. IoT devices use Wi-Fi and Bluetooth, however, communication distance is short and battery consumption is high. In areas such as smart cities and smart farms, IoT technology is needed to support a wide coverage with low power consumption. Low Power Wide Area (LPWA), which is a transmission used in IoT supporting a wide area with low power consumption, has evolved. LPWA includes Long Range (LoRa), Narrowband (NB-IoT), and Sigfox. LoRa offers many benefits as it communicates the longest distances, is cheap and consumes less battery. LoRa is used in many countries and covers a range of hundreds of square kilometers (km2) with a single gateway. However, if there are many obstacles to smart cities and smart farms, it causes communication problems. This paper proposes two (2) solutions to this problem: the relay method which is a multi-hop method and the Automatic Repeat Request (ARQ) system that detects packet loss in real-time and requests retransmission for LoRa. In this study, the actual performance of LoRa in the problematic environment was measured and the proposed method was applied. It was confirmed that the transmission rate of LoRa dropped when there were many obstacles such as trees. To use LoRa in a smart farm with a lot of space, multi-hop was observed to be better. An ARQ system is needed to compensate for the unexpected drop in the forward rate due to the increase in IoT devices. This research focused on reliability, however, additional network methods and automatic repeat request (ARQ) systems considering battery time should be researched in symmetry. This study covers the interdisciplinary field of computer science and wireless low power communication engineering. We have analyzed the LoRa/LoRaWAN technology in an experimental approach, which has been somewhat less studied than cellular network or WiFi technology. In addition, we presented and improved the performance evaluation results in consideration of various local and climatic environments.

LoRaWAN Mesh Networks: A Review and Classification of Multihop Communication

“…The work proposed in [36] uses an Automatic Repeat Request (ARQ) mechanism and relay nodes to improve reliability on LoRa networks. The relay nodes chose the best parent to transmit the data based on collected RSSI.…”

“…Table 3 summarizes the classification of the devices, presenting the nomenclature, characteristics, and the most important details of each one. [17] Router-Device Single Yes Yes Choi et al [36] Relay-Device Single Yes Yes Dias and Grilo [24] Router-Device Single No Yes Diop and Pham [33] Relay-Device Single Yes Yes Duong and Kim [22] Relay-Device Single Yes Yes Dwijaksara et al [30] Router-Gateway Multi No Yes…”

“…Relay-Device ( Figure 6a) -Smart Building -Industrial -Improve connection -Access to power supply Aslam et al [37] Choi et al [36] Diop and Pham [33] Duong and Kim [22] Sisinni et al [32] Tanjung et al [35] Weiwei Zhou and Wang [34] Relay-Gateway (Figure 6b) -Smart Farm -Connect remote areas -Concentrate data traffic Aslam et al [37] Sisinni et al [31] Relay-Device Relay-Gateway ( Figure 6c) -Smart City -Improve coverage area -Concentrate data traffic -Battery powered devices None Table 5. Cont.…”

“…Many authors have proposed multihop solutions for LoRaWAN [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ], where some devices act as relays to other devices. The forwarding mechanism is a crucial choice for a multihop LoRaWAN, as it may affect the performance of the network, in terms of throughput, reliability, latency, and energy consumption.…”

Development of Self-generated and LPWA-based Crop Growth Environment Monitoring and Bigdata Analysis System

“…Due to these problems, smart farms for field crops require self-power supply and LPWA(Low-Power Wide-Area) wireless communication technology. LPWA communication technology is a network technology designed for low-power, long-distance communication and is mainly used to transmit small amounts of data such as sensor data and monitoring information at low power [5][6][7][8]. LPWA communication encompasses several protocols and technologies.…”