| 摘要 |
The present invention provides a cordless telephone having the ability to operate when power fails to the base unit. In a first embodiment, the handset includes a switch and a telephone line interface to connect a speaker and microphone directly to the public switched telephone network (PSTN) bypassing the base unit and allowing corded telephone operability of the handset of the cordless telephone. In a second embodiment the handset provides power to the base unit in the event of an AC power failure to the base unit. In this corded mode, the battery of the handset provides auxiliary power to the base unit. To further reduce power consumption and increase operation time of the battery in the handset, the RF transceivers of the base unit and handset can be unpowered by the provided direct serial connection between serial interfaces of the base unit and handset. In both embodiments, the cordless telephone operates in conventional fashion when in a wireless mode. <IMAGE> |
