A call admission control maximizing the number of general calls from nondisaster area considering the priority calls When a disaster occurs, the demands for telephone calls increase because of safety confirmation and emergency requests. The increases cause network congestion. Recently, trunk reservation control 1 has been proposed to solve this problem. In this control, there are two types of calls: emergency calls for fire departments or police and general calls 2. However, general calls in the disaster include different information such as confirming the safety, confirming the situation of the disaster, requesting supplies, etc 3. In this paper, we propose call admission control (CAC) for disaster. In our system, all calls are classified into three types of calls: emergency calls, disaster general calls, and nondisaster general calls. Moreover, our proposed CAC is performed using two threshold values. Our objective is to maximize the number of nondisaster general calls while keeping call blocking probabilities both emergency calls and disaster general calls. In order to derive our optimal threshold, we model our proposed CAC by using queueing theory. Moreover, we show effectiveness by numerical calculation. Keywords: call admission control, queueing theory, call blocking probability, disaster situation.

Designing a Safety Confirmation System that Utilizes Human Behavior in Disaster Situations. This paper introduces a use case to discuss how to design services for disaster situations as well as to elucidate the development and evaluation of our safety confirmation system, which utilizes human behavior in disaster situation. The success of the safety confirmation system based on information sharing among evacuation centers depends on the intercenter movement of humans. In order to know whether the safety confirmation service would work effectively or not after a massive disaster, we conducted a survey that examined how many evacuation centers were visited after the East Japan Earthquake and the periods over which the evacuees visited the centers. As a result, we confirmed that many evacuees were still visiting centers 72 h after the earthquake, making our technology effective in responding to a disaster.