| 摘要 |
<p>A telephone call device and a method thereof can lower a telephone call rate, even though a caller and a receiver use any kind of terminal. When a phone call is made from an extension to a central office line, a conventional method is employed. In case the phone call is made from the extension to a portable terminal or vice versa, the phone call is performed through a special exchange for a wireless communication network, without passing a conventional local telephone network. As a result, the telephone call rate is lowered, and the wireless communication companies also save the cost, thereby increasing the subscribers.</p> |
