## 3 Criteria and Dataset Specification  
Each of the shortlisted technologies in Section 2 has numerous characteristics and technical criteria that may need to be considered when selecting a communication solution for the substation. Due to this, ML was employed to help in the selection of criteria that are important in deciding or selecting the best communication technology for the substations. The ML process needs a dataset to train on in order to make the right selection. This dataset must be comprehensive and cover all of the criteria for the communication technologies suitable for implementation at the electrical distribution substation. The identified criteria were frequency, data rate, distance, bandwidth, line of sight (LoS), scalability, interference, topology, and terrain factor (city, plains, coastal, forestry, and mountains). The overall flow of this research is summarized in Figure 1. The information below is the justification of the selected criteria:  
1. Frequency is defined as the rate of radio signals measured in Hertz (Hz) to transmit and receive communication signals. Each technology has its own operating frequency spectrum, which can be classified into two categories: (1) licensed: assigned solely to operators for independent use; and (2) unlicensed: assigned to each citizen for non-exclusive use subject to regulatory limits such as transmission power restrictions. 2. Bandwidth is defined as the range that carries a signal within a band of frequencies. For example, a system that operates on frequencies between 150 MHz and 200 MHz operates with a bandwidth of 50 MHz. 3. Data rate is defined as the amount of data transmitted over a network in a certain period of time, commonly expressed in megabit per second (Mbps). 4. Distance refers to the coverage offered by a communication technology. Some wireless technologies, such as SATCOM, LoRa, and private LTE, are known to offer long-distance coverage, whereas others offer short-distance coverage (Zigbee, WiFi). Shorter coverage usually leads to higher deployment of a particular technology in the selected areas. 5. Terrain factor divides the land into several categories as follows: 1. City: The city area is known to contain the highest user density, with buildings and existing wireless communication technologies. It is one of the factors affecting the reliability of communication technologies, especially in terms of the line-of-sight (LoS) interference. 2. Coastal: The coastal area is defined as the interface or transition area between land and sea, including large inland lakes. Because of its large area and low population density, it is assumed to contain no LoS interference. 3. Plains: The plains are defined as a broad area of relatively flat land. The assumption is that they contain lower user density compared to the city and less or almost no LoS interference due to the wide area and lower vegetation. 4. Forestry: A forest is defined as an area with more than 0.5 hectares of land, trees taller than 5 m, and a canopy cover of more than 10%, or trees capable of reaching these thresholds in situ. It does not include land that is predominantly used for agricultural or urban land use. The assumption is that it contains the lowest user density. However, the high density of forest affects the communication technology's reliability, especially for wireless technology. 5. Mountains: A mountain is a land that is raised above the surrounding landscape. It is usually in the form of a peak with a well-defined summit. The assumption is that mountainous areas contain low density of users and trees. However, due to the topography, it requires higher cost and longer time for cable installation. 6. Scalability is defined in this research as the ability of the communication technology to be scaled, measured in terms of percentage. It is dependent on the topology and data rate that each technology can offer, in which the more devices are added to a network, the longer the communication delay on the network.