How far is the distance between a BBK and a PHILPS cordless phone?
The data signals and control logic signals of the cordless telephone are physically on the same carrier frequency. Therefore, the digital signal needs to be compressed in time domain before transmitting. After receiving, the time domain expansion is carried out. Considering the nonideal nature of wireless channels, channel coding is required before data is transmitted. The CDCT method is adopted in the design of error detection and error correction after retransmission. Different channels are coded with different redundancy. Mainly uses two kinds of error: R-CRC encoding (16bitCRC) code and X-CRC (4bitCRC) code. The R-CRC code is mainly used in the A domain and B domain (control signal) error detection and retransmission request (data signal) channel encoding. The X-CRC code is mainly used for error encoding B domain of non error transmission.
Cordless telephone is essentially a combination of full duplex radio and cable system and the logic control circuit, it can through radio waves in the medium of space electric field effectively within the implementation of the auxiliary machine and the plane between the "wireless" link. Most fully simulated cordless telephone set. Simply speaking, cordless telephone telephone body and the handle is separated into the host (machine tools) and auxiliary machine (machine) the two part, the host is connected with the user's phone line telephone network, auxiliary machine maintain communication via a radio channel with the host, not by the traditional telephone handle word limit rope.
In general, BBK and PHILPS cordless phones, the machine has a distance of about 10 meters.
