1. Field of the Invention
The present invention relates to terminal regulation management devices, and more particularly, to a terminal regulation management device for regulating incoming/outgoing calls of radio terminals.
2. Description of the Related Art
W-CDMA (Wideband-Code Division Multiple Access) is a communication scheme using a wider frequency band than the existing CDMA and has the advantages of faster data transfer rate and higher communication quality.
In W-CDMA network systems, if the communication traffic of a certain base station increases because of an event (e.g., a fireworks festival, concert, sport event or the like), call congestion or communication degradation possibly occurs, making communications unavailable. For example, if the number of channels simultaneously transmitted and received by a base station increases, the level of interference power interfering with the individual radio communication channels in the frequency band rises, making it impossible to maintain the communication quality.
Thus, before the communication quality becomes uncontrollable, incoming/outgoing calls of mobile units existing in the radio communication area are regulated. When the incoming/outgoing call regulation is initiated, the base station sends the mobile units the information that the incoming/outgoing calls are being regulated, and the incoming/outgoing calls of the mobile units are rejected by the base station.
Usually, the incoming/outgoing call regulation is applied equally to all mobile units, but there has been proposed a technique of preferentially connecting previously registered mobile units during congestion (see, e.g., Japanese Unexamined Patent Publication No. 05-316039). A technique is also known in which those mobile units of which the count of outgoing calls to an identical number per unit time is large are preferentially connected (see, e.g., Japanese Unexamined Patent Publication No. 2004-23648). Further, the outgoing call regulation explained below is actually performed. Individual mobile units are automatically grouped at the time of purchase, and during congestion, the number of groups whose outgoing calls are permitted is restricted in accordance with the degree of congestion and the regulated groups are changed at fixed intervals of time (see, e.g., “Material for the investigation commission on the use of information communication systems in times of disaster” (online), Tohoku Bureau of Telecommunications, Ministry of Internal Affairs and Communications (searched on May 10, 2006, Internet URL: http://www.ttb.go.jp/saigai/houkoku/index.html)).
However, the technique disclosed in Japanese Unexamined Patent Publication No. 05-316039 is associated with the problem that when an event such as a fireworks festival is held, even those users whose zone of daily life is near the site of the event are subject to the incoming/outgoing call regulation unless they register their mobile units in advance.
With the technique disclosed in Japanese Unexamined Patent Publication No. 2004-23648, the mobile units of users whose daily life zone differs from the area where they are requesting outgoing call are preferentially treated in accordance with the outgoing call count per unit time, whereas the mobile units of users who live in that area are subject to the incoming/outgoing call regulation.
According to the technique described in the “Material for the investigation commission on the use of information communication systems in times of disaster” (online) by Tohoku Bureau of Telecommunications, Ministry of Internal Affairs and Communications, the incoming/outgoing call regulation is enforced equally on the basis of the groups into which the individual mobile units are placed at the time of contract, without regard to the frequency of use in the daily life zone. A problem therefore arises in that communication is not necessarily secured for the mobile units of those users whose daily life zone overlaps with the call regulation area.