# Analysis of AMI Communication Methods in Various Field Environments
## 4 Area Types of Field Environments  
In this section, in order to analyze the AMI communication performances and construct communication models for various field environments, we select 18 sites for experimental measurements and classify these sites into five areas according to their characteristics as follows:  
* Overhead Residential Area
* Overhead Commercial Area
* Overhead Rural Area
* Overhead Factory Area
* Underground Area  
In Figures 14-18, the NDIS maps and their aerial images of the 18 sites with 48 MPs are illustrated according to their areas, respectively. Here, the first four areas belong to the overhead power line  
Figure 12: LOS experiments of Wi-SUN and ZigBee modems. (**a**) Experiments of a range from 5 m to 200 m (Wi-SUN and ZigBee), where the attenuation rate (AR) values start from \(-20.0\). (**b**) Experiments of a range from 100 m to 1000 m (Wi-SUN), where the AR value is \(-31.0\). Figure 13: Packet error rate (PER) test of the Wi-SUN modems. (**a**) Receiver sensitivity experiments. The sensitivities are \(<\)\(-107\) dBm at PER \(<\) 10%. (**b**) PER test of the LOS experiment of Figure 12b. system and the last area 'Underground Area' is concerned with the underground power line system. Properties of the 18 sites are also summarized in Table 1. In these tables, the distance implies the wire distance to each MP and thus has meaning for the PLC connection. Overhead Residential Area consists of 20 to 30 customers within a radius of about 100 m from the corresponding transformer. On the other hand, the Overhead Rural Area has few houses in a wide range. As mentioned in Table 1, Overhead Commercial, Rural, and Factory Areas suffer from various noises generated due to neon signs, solar power plants, and motors. For the underground power line case of Figure 18, Site 5-1 is a residential area and Site 5-2 is an area where residential and commercial facilities are mixed as summarized in Table 1. As observed in Figure 18c, Site 5-3 is an apartment complex, which consists of eight buildings with a maximum of 20 stories and a minimum of 8 stories, and has a total of 984 households (Apartments, which receive the medium voltage of 22.9 kV, directly construct and manage their power systems, which are  
Figure 16: NDIS maps for the Overhead Rural Area. (**a**) Site 3-1. (**b**) Site 3-2. (**c**) Site 3-3. Figure 17: NDIS maps for the Overhead Factory Area. (**a**) Site 4-1. (**b**) Site 4-2. (**c**) Site 4-3. Figure 18: NDIS maps for Underground Area. (**a**) Site 5-1. (**b**) Site 5-2. (**c**) Site 5-3.  
composed of transformers, switch gears, and meters. Hence, these apartments are not covered by KEPCO's NDIS.). In this case, the communication measurements are conducted from the first basement distribution panel of an apartment building of 18 stories to the 1 st, 8 th, and 17 th floors. It is known that the PLC communication performance is not good for the underground power line case. For the wireless communication case, the performance is also not good because several smart meters are usually mounted inside metal housings of different floors. This mount prevents transmit electromagnetic signals. As shown in Figure 19a, the NDIS map can graphically provide the positions of distribution lines and power facilities, such as transformers, meters, and utility poles. In the NDIS map of Figure 19a, the blue circles mean the utility poles and the green lines between the blue circles represent the low-voltage distribution lines. The green and arrowed lines that extend from the blue circles represent the lines that supply electrical energies to the customers. The circle and three inverted triangles inside the red dotted box indicate the utility pole with three single-phase transformers installed. On the NDIS map, MP means the location of the smart meter of the customer to be measured, and can be identified by using the pole number connected to the customer.