In addition, we also measured the transfer delay time and the overhead generated by increasing the number of concurrent connections. We compared the overhead generated by an increasing number of concurrent users. Figure 6 shows the results. As the concurrent number of users increase, the overhead of the polling method increases, while the overhead of WebSocket system was barely noticeable. In the polling method, starting from the client’s request, the forward delay time, the time of 60 ms consuming, and the time while waiting re-request, even if the response occurs after the response time from the server, all become overhead. However, using the WebSocket system, connections that occur after the first connection, resulted in the connection being maintained, with no additional latency. Figure 7 is a graph comparing the response times of the system using the polling and WebSocket methods. The x-axis represents the number of requests, and the y-axis represents the response time (ms).