JPH0753322Y2 - Signal transmission control device in cordless telephone - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a signal transmission control device in a low power cordless telephone.

[Prior Art] Conventionally, in a low-power cordless telephone composed of a set of a master unit and a slave unit that are paired with each other, when calling from the outside through a central line, the master unit synchronizes with a call signal interval,
Both handsets are designed to ring. In this case, the sets are connected by a control channel that transmits a signal of a prescribed format, and then data is transmitted and received by a call channel that transmits a signal of an arbitrary format.

[Problems to be solved by the invention] However, when data is exchanged by ordinary signal transmission in a communication channel as described above, since the transmission format of this signal generally uses a long code composed of many bits, If the interval between call signals from the outside is short (PBX, etc.) or the distance between the master unit and the slave unit is large, it will not be possible to perform data transfer in synchronization with the signal without correct identification. In this case, in some cases, the cordless handset does not emit the ringing tone in synchronization with the ringing signal, and the ringing may become impossible.

The present invention solves the above-mentioned problem. In a call channel, by continuously sending out a short dedicated code, both the master unit and the slave unit can properly output the ringing tone in synchronization with an external ringing signal. An object of the present invention is to provide a signal transmission control device in a cordless telephone capable of ringing.

[Means for Solving the Problems] In order to achieve the above object, the present invention transmits and receives predetermined data by transmitting signals through a control channel and a communication channel between a pair of a master unit and a slave unit that are paired with each other. In such a cordless telephone, the signal transmission control device uses a code signal composed of bit synchronization and frame synchronization as a ringer control signal during an incoming call at the time of signal transmission on a communication channel.

[Operation] With the above configuration, after the signal transmission in the predetermined format on the control channel, a short code signal composed of bit synchronization and frame synchronization is repeatedly transmitted as a ringer control signal during an incoming call at the time of signal transmission on the communication channel. As a result, even if the distance between the sets is long, the data can be accurately extracted, and the ringer can be sounded in synchronization with the call signal from the outside.

[Embodiment] An embodiment of the signal transmission control device in the cordless telephone of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of this cordless telephone.

The machine is composed of a set of a connection device (master unit or base side) 2 and a cordless telephone (slave unit or hand side) 3 that are paired with each other and connected to a central office line 1. A multi-channel access (MCA) method in which a control channel (C ch) and multiple call channels (S ch) are allocated between the sets, and one free channel is selected to start a call when the call of any set is started Has been adopted. In addition, base unit 2
Is a transmitter and receiver that sends and receives control signals and call signals to and from the slave unit, a synthesizer that specifies a transmission / reception channel, and a vacancy that determines whether the received call channel is empty based on the reception output of the receiver. It is composed of a judgment circuit and a control circuit for controlling the whole including MCA processing.

2 (a) to (d) show the frame formation (format) of the transmission signal currently used in the cordless telephone, (a) is the transmission format of the control channel, and (b) to (d) are the communication channels. Shows the transmission format of. FIG. 2 (e) shows the format of the ring ON / OFF code during an incoming call on the communication channel according to the present invention.
According to the present invention, as shown in this format, a short dedicated code signal consisting of 40-bit bit synchronization and 16-bit frame synchronization is used as a ringer control signal during an incoming call at the time of signal transmission on a communication channel.

The frame synchronization signal upstream (slave to master) data is ringer ON, and downstream (slave to slave) data is ringer.
It is used as an OFF signal.

By continuously sending and receiving such short dedicated codes, it becomes easy to judge the signal transmission even when there is a distance between the sets, and both the master unit and the slave unit synchronize with the call from the outside. It becomes easy to operate. Therefore, even if error detection of data is not performed, it is resistant to noise and operates accurately.

[Advantages of the Invention] As described above, according to the present invention, in a cordless telephone, a short ring consisting of bit synchronization and frame synchronization is used as a ringer control signal during an incoming call at the time of signal transmission by a communication channel after signal transmission by a control channel. Since the repetition of the code signal is used, the data signal can be transmitted in synchronization with the signal even when the distance between the sets is long and the interval of the call signal from the outside is short, and the child signal is transmitted. The ringer of the base unit and the base unit can be sounded in synchronization with the call signal, which is solved by the fact that the call cannot be made, and it is resistant to noise and the operation accuracy is good.

[Brief description of drawings]

FIG. 1 is a block diagram of a cordless telephone according to an embodiment of the present invention, and FIGS. 2 (a) to 2 (d) are frame diagrams of transmission signals used in current cordless telephones.
FIG. 2 (e) is a frame configuration diagram of a transmission signal in a communication channel according to the present invention. 2 ... Connection device (base unit), 3 ... Cordless telephone (slave unit).

Claims (1)

[Scope of utility model registration request] 1. A cordless telephone set which transmits and receives predetermined data by transmitting a signal through a control channel and a communication channel between a set consisting of a master unit and a slave unit which are paired with each other. A signal transmission control device in a cordless telephone, wherein a code signal composed of bit synchronization and frame synchronization is used as a ringer control signal during a call.