| 20090239465 | DOORPHONE SYSTEM - A doorphone system includes a relay station. A doorphone master station and a relay station are wirelessly connected, and the relay station and the cordless extension master station are wirelessly connected. A wireless communication link between the doorphone master station and the cordless extension master station is established via the relay station. Namely, all of the wireless communication between the doorphone master station and the cordless extension master station is executed via the relay station. The above doorphone system can effectively enlarge the communicatable range between the doorphone master station and the cordless extension master station. By using a cordless phone instead of the relay station, a system formed by combining the doorphone system and the cordless phone can be easily formed. | 09-24-2009 |
