Utilization of RSSI on Visitor's Cellphones in Calculating Distance to Wifi Transmitter in the Reading Room of the State Polytechnic of Malang Library

The pandemic period caused by the coronavirus disease causes restrictions on the number of users in a room to minimize the spread, for example, libraries. The library is a room area that can cause virus transmission when crowds of visitors. A system is needed to provide information regarding the number of library visitors. Utilizing a network (wifi transmitter) available in the library can provide information on the number of visitors based on the number of network users in a room. Utilization of the network (wifi transmitter) can be in the form of a positioning system by utilizing the wifi signal beam received by the user in RSSI (Received Signal Strength Indicator). To calculate the estimated user position, a trilateration method is used based on the placement of three wifi transmitters. The library visitor positioning system consists of users as wifi transmitter users and admins. At the X-coordinate, the measuring point with a low deviation of the measurement value is indicated by points C and E with a value of 0.1. The large deviation of the measurement value is indicated by the P point of 4.5. At the Y coordinate, point O has a low deviation value of 1.25, and the largest deviation value is at point M of 5.6. The accuracy of the X coordinate shows a value of 97.647% and at the Y coordinate of 96.57%. Both coordinates have good accuracy for the points used as position measurements.