# Design and Implementation of a Passive Optical Network for a Small Town +
## 4 Results
An example of an aerial optical cable connection between buildings is presented in Figure 5.
* The connecting subscriber cable is installed with a suspension element on the pole and on the house, according to the suspension requirements, and the maximum distance between the support points should not exceed 20 m.
* After removing the carrier element from the cable, an SC/APC field-mount connector is installed on site, which provides an optical connection to the ONU subscriber unit;
* Connection cables connect to free optical ports of the PLC splitters located in the connection sleeves or to fibers coming from adjacent sleeves with splitters. Once the connections to the subscribers have been successfully run, the next step in the PON construction is to install the optical connectors. This process meets the specific requirements for managing, accessing, and maintaining the cable reserve in order to ensure the reliability and maintainability of the network. When installing optical connectors, the following features are observed:  
* Installation of fiber optic connectors is completed on an existing pole with a metal band and plate from the connector kit. * The plank is placed parallel to the roadway, if possible, on the side of the pedestrian strip 20 cm below the point of suspension of the optical cable. * There are two reserves of cable for aerial installation, including one to use when the socket can be disassembled from the ladder and the fibers are to be welded in a workspace next to the ladder (400 cm) and one to install inside the socket (150 cm). * The configuration and placement of the cable is carried out according to the geometric requirements specified in Figure 6, and it is not allowed to leave a spare cable longer than 5 m on each side. * The permissible reserve for future installation of the socket without interruption of the cable must be up to 13 m, measured from the point of suspension of the cable. A detail of fiber exit from manhole to low voltage pole for a PON (CC590), located in Southwestern region, Blagoevgrad, Bulgaria, can be seen in Figure 6. It illustrates the route of the aerial cable, the splitters in the distribution cabinet, the HDPE pipes, the socket sleeves in shafts, the grounding system, and the cable tensioning assembly. This construction approach is used by various telecommunications service providers in the region. Such aerial PON installations significantly reduce construction costs and are suitable for fiber optic connectivity in areas with low construction. After the main elements of the PON have been installed, such as the terminal poles, distribution cabinets, and connection sockets, the next important step in the construction of the network is the connection of the individual subscribers by connection cables. This is a process that is associated with precise planning and execution in order to guarantee optical continuity, minimal signal losses, and resistance to external influences [20; 21; 22]. Optical modules with two fibers are included in the patch cables and, when connected to the carrier element, the optical module is separated by an additional 86 cm, equal to the reserve of the distribution cable plus the reserve necessary for the installation of the SC/APC connector and the formation of the reserve within the socket. The reserve is formed around that of the distribution cable, ensuring a quality connection to the subscriber. The optical connector is installed on the ground surface and then inserted into the socket along with the reserve left. In the next step, the connector installed on the subscriber branch is connected. This stage is important for ensuring a quality and reliable connection. After connecting the subscriber cables to the splitters in the sockets, it is important to consider the architectural structure of the distribution PON network, which affects the choice of cable infrastructure. Figure 7 shows how the standard G-PON reach can be extended by introducing a remote extender between the OLT (central office) and the customers (ONTs).