| 摘要 |
A communication device including an RF transmitter mounted in conjunction with an IR transmitter allowing data to be transmitted by RF as well as by IR. Such a device may be a portable badge worn by moving personnel to transmit IR and RF signals to one of a plurality of second devices each being a fixed reader having an IR and RF receiver, and typically being mounted in a respective enclosed space, such as a room. In use, IR transmissions from the portable device are detected by the IR receiver of the reader in the same room and thus provide an immediate identification of the room (or enclosed space) wherein the portable device is located. On the other hand, if the IR transmitter in the portable device is concealed or for any other reason is not within line-of-sight of the reader in its immediate proximity, then the RF signal transmitted by the RF transmitter in the portable device is detected by the RF receiver in the reader, thereby allowing tracking of the portable device in either eventuality. |
