# Energy-Efficient LoRa Routing for Smart Grids
## 2 Literature Review  
Much research has been conducted recently on taking advantage of the fast transfer rate and low latency offered by modern communication technologies. Smart grids (SGs), on the other hand, are widely installed by utility companies because their advanced metring infrastructure (AMI) provides various benefits, including cost savings for metre reading and service team deployment. AMIs can also be installed and give coverage anywhere there is an energy consumer, even in rural areas. It is also critical to use an adequate wireless communication device to meet the demands of SG operation. Communication technologies such as Bluetooth, ZigBee, and WiFi are well-developed for IoT applications, but they are limited to a specific range and waste much power. Thus, they are not suitable  
Figure 2: Flow diagram of the different phases of the proposed system. for transmitting data in the SG or in other wide-area applications [21]. The protocol for precision agriculture (PA) systems utilises both WiFi and LoRa wireless technologies, where the CH node is the bridge that allows communication between them. A tree topology of multiple hops has been introduced, which enables reaching further distances while reducing data transmission from one node to another [22]. To meet the needs of the SG to save power and send data over long distances, a new infrastructure for wireless communication called the low-power wide-area network (LPWAN) is being built. LPWANs [23] assist with the transmission distance-energy efficiency trade-offs. Currently, LoRa is one of the most-popular LPWAN technologies, and the performance of the LoRa modules can be improved by customising the parameters, including the bandwidth, transmission power, code rate, and spreading factor (SF) [24; 25]. Integrated home automation systems that utilise multiple communication technologies such as LoRaWAN, server-based LoRa gateways, and Bluetooth connectivity to control different types of appliances were proposed by [26]. IoT-based AMI daily reporting and billing in a residential grid using LoRa technology were designed by [27]. A new two-hop implementation of the LoRa WAN LEACH protocol (LLP) was proposed by [28] using the LEACH algorithm to optimise the throughput and power dissipation. Table 1 compares some of the energy-efficient routing protocols used for SG communication in WSNs. In homogeneous sensor networks, LEACH [36] is a self-organising, flexible clustering approach using randomisation to distribute the energy load uniformly throughout the network. In LEACH, grouped nodes can be clustered, with one node serving as the local base station (BS) or cluster head (CH). Sensors choose to be local cluster heads with a certain probability at any given time. The cluster head communicates its status to other nodes in the network. LEACH alternates the function of the CH among all nodes to evenly share the energy load. Even if the network is capable of adjusting and reducing the protocol's performance, a poor clustering design will still affect its operation if the CHs are not optimally selected for the frequent rounds. Therefore, the most-challenging aspect of dynamic clustering is CH selection [37]. Every time a CH is re-selected, the priority for CH selection causes dynamic clusters to be formed, which increases the energy overheads. \begin{table}
\begin{tabular}{p{14.2 pt} p{142.3 pt} p{142.3 pt} p{142.3 pt}} \hline \hline
**Reference** & **Protocol** & **Description** & **Limitations** \\ \hline
[29] & Improved-adaptive-ranking-based energy-efficient opportunistic routing protocol (I-AREOR) & An energy-balanced clustering protocol to apply the green IoT to smart cities & Limited to the energy efficiency problem in WSNs; does not consider factors such as the latency, throughput, and reliability of data transmission \\
[30] & Path operator calculus centrality (SPOCC) & Analysis of the E.C.