JP3270810B2 - Digital cordless telephone system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital cordless telephone system composed of an arbitrary number of slave units and a plurality of master units that can wait for the slave units.

[0002]

2. Description of the Related Art A slave unit of a digital cordless telephone waits in synchronization with a logical control channel transmitted by a base unit, and thereafter enters the control of the base unit transmitting the logical control channel.
Depending on the usage status of the master unit, there may be cases where calling from the slave unit and incoming call to the slave unit cannot be performed. In order to cope with this situation, the base unit recognizes the usage status of the wired or wireless audio path managed by the base unit, and determines whether a new slave unit other than the slave unit currently connected to the base unit can be newly connected. Means for determining whether
Means for notifying the use status of the master unit on the logical control channel, and means for recognizing the notification unit to the slave unit and notifying the user whether or not the master unit currently waiting is available. There is a method of providing.

[0003] In addition, the contents of the above-mentioned notification means to the slave unit,
When it is recognized that the waiting master unit is unusable, the synchronization with the logical control channel transmitted by the master unit is discarded, and the synchronization with the logical control channel transmitted by another master unit or the same master unit is performed. There is a method of providing a means.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in order to solve these problems, and allocates at least one of a predetermined number of continuous radio communication slots to a logical control channel for establishing a radio link. Allocating another slot to a service channel used for transmitting user data such as voice data, and repeating the predetermined number of continuous wireless communication slots to perform wireless communication with the slave unit. The slave unit that waits in synchronization with the logical control channel transmitted by the master unit and the usage status of another slot used for transmitting the user data, the usage status of a wired voice path, or the occurrence status of various failures are monitored. Control means for determining whether a wireless link can be newly established with the slave unit based on the monitoring result. In the wireless telephone system, when the control unit determines that a new wireless link cannot be established with the slave unit, the transmission is performed at a transmission timing of a wireless communication slot allocated to the logical control channel while maintaining the service channel. Means for starting the transmission at the transmission timing of the wireless communication slot to which the logical control channel is assigned when it is determined that the logical control channel is possible. Provides a digital cordless telephone system capable of stopping standby for an unusable base unit and, if there is an available base unit, waiting in synchronization with a logical control channel transmitted by the base unit. .

[0005] Even if the user is informed to the slave unit by the above-mentioned notification information that the parent unit waiting is unusable, it does not make sense if the user does not notice it. The user has no means of knowing whether there is a usable master unit other than the waiting master unit.

[0006] In addition, when the slave unit recognizes that the standby master unit is unusable from the content of the notification information,
When the synchronization with the logical control channel transmitted by the master unit is discarded and control means for synchronizing with the logical control channel transmitted by the other master unit or the same master unit is provided, the logical unit in which the slave unit newly establishes the synchronization. There is no guarantee that the master sending the control channel will be available.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems in the prior art, the present invention determines whether or not a digital cordless parent device (including a PBX) can be newly connected to a child device. Control means for performing the control, and when connection is impossible, transmission of the logical control channel is stopped.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a digital cordless telephone comprising an arbitrary number of slave units and a plurality of master units capable of waiting for the slave units. In particular, PBX is a product suitable for the present invention. Not specified. This digital cordless base unit uses a wired or wireless audio path (in PHS, a wireless audio path is a TDMA / TD
D is a service channel on D, and a home parent device can usually manage three channels of services). However, if a device such as another child device is blocked or a failure is detected, the currently connected child device is detected. When the use of the handset other than the handset becomes impossible and the call from the other handset or the call to the other handset cannot be performed any more, the service channel for call or data transfer ( SCH: Ser defined in the item of RCR STD28 1st edition, Chapter 4, Section 2, 4 "Channel types"
In the "Vice Channel", the item "Base station (C
S) and the mobile station (PS) are defined as a generic term for the channels used in the communication phase), and the logical control channel (RCR STD28 1st edition, Chapter 4, Section 2, “Channel types” L defined in the item
CCH: Logical Control Channel
el, in the same item, the logical control channel is “base station (C
S) and the mobile station (PS) are defined as a generic term for the channels used in the link channel establishment phase.) Further, there is provided a control means for starting transmission of the logical control channel when a call from another child device or an incoming call to another child device becomes possible while the logical control channel is stopped.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a PHS showing one embodiment of the present invention.
(Personal Handy-phone Sys
FIG. 4 is a block diagram showing a master device of the present invention (tem). FIG. 2 is a schematic diagram of a communication frame showing the concept on the time axis of the channel slot of the TDMA / TDD system used by the PHS. Four slots a to d shown above the solid line are used for communication from the master unit to the slave unit. The channel (the transmission slot of the parent device) and the four slots e to h shown below the solid line represent channels (reception slots of the parent device) used for communication from the child device to the parent device. Slots a and e are used for the logical control channel LCCH, and slots b and f, c, g, d, and h are sequentially paired as a set of independent bidirectional service channels TCH3, TCH1, TCH2, and TCH3.
Used as

In the master unit shown in FIG. 1, a main control unit 1 (a baseband processor for managing the entire master unit) has a radio control unit 2 (TD).
A channel control is instructed to a baseband processor that manages frames on the MA / TDD, and transmission and reception of the logical control channel LCCH and the service channels TCH1 to TCH1 to 3 are repeated at the timing shown in FIG. In the present embodiment, the main control unit 1 detects the usage status of the TCHs 1 to 3 or the usage status of the wired audio path, and further, the occurrence of various failures, and the TCH 1 to 3 and the wired audio path are all in use. If there is any failure or some failure has occurred, it is determined that a new slave unit cannot be connected, and the wireless control unit 2 is instructed to stop transmission of the logical control channel LCCH. The radio control unit 2 instructed to do this is the logical control channel LCCH
The high-frequency switch 4 is switched from the isolator 5 side to the ground side at the transmission slot timing described above, the output of the power amplifier 3 is cut off, and the transmission of the logical control channel LCCH is stopped. However, at the transmission timing of the service channels TCH1 to TCH3, the high-frequency switch 4 is returned to the isolator 5 side, and the communication of the three user data using the service channels TCH1 to TCH3 is continuously maintained.

When the logical control channel LCCH is stopped, the main control unit 1 causes a failure due to termination of a slave unit using the service channel TCH on the wired voice path or the TDMA / TDD or recovery from failure. When it is determined that another slave unit can be newly used by the cancellation of the above, the wireless control unit 2 is instructed to restart the transmission of the logical control channel LCCH. In response to this, the radio control unit 2 fixes the high-frequency switch 4 to the isolator 5 side and restarts transmission of the logical control channel LCCH.

The timing charts of FIGS. 3 and 4 show that the repetition of the TDMA / TDD slot shown in FIG.
LOT TIMING is represented on the time axis, and the slots in use among the slots are shown by being painted out.
Also TCH1 POWER, TCH2 POWER, T
CH3 POWER is a management signal used by the main control unit 1 to indicate the use status of TCH1, TCH2, and TCH3. The signal is high when the target TCH is in use and low when it is not in use. Also,
CCH POWER is an administrative signal used by the main controller 1 for indicating the transmission status of the logical control channel LCCH.
Low when all of CH1, TCH2 and TCH3 are in use, h when any of TCH is unused
It becomes igh. Furthermore, TX POWER indicates the transmission output of the wireless telephone.

In FIG. 3, only TCH2 is in use before point A, but TCH3 is in use after point A and TCH1 is in use after point B. Therefore,
At the point C, since all of the THC is in use, the main control unit 1 Set POWER to low. CCH
When POWER is low, the radio control unit 2 switches the high-frequency switch 4 to the ground side at the slot timing of the logical control channel LCCH transmission to stop the transmission of the logical control channel LCCH.

In FIG. 4, before point D, all TCHs
In use, the main control unit 1 POWER is low
In response to this, the radio control unit 2 receives the
High frequency switch at the timing of channel LCCH transmission
4 to the ground side to transmit the logical control channel LCCH.
I have stopped shining. After point D, TCH2 is unused
The main control unit 1 returns to CCH at point E. POWER
As a result, the radio control unit 2 receiving this signal performs logical control.
High frequency at slot timing of channel LCCH transmission
Logical control by returning switch 4 to isolator 5 side
The transmission of the control channel LCCH is restarted. In addition, from point F
In the descending, since all TCHs are in use, the main control unit 1
CCH at point G Set POWER to low and again
The received radio control unit 2 transmits the logical control channel LCCH.
Switch high frequency switch 4 to ground at slot timing
The transmission of the replacement logical control channel LCCH is stopped.

[0015]

According to the present invention, standby for an unusable master unit is stopped without providing a new control means in the slave unit, and if there is an available master unit, the slave unit is synchronized with the logical control channel transmitted by the master unit. You can wait.

The slave unit does not wait for the unusable master unit, and the slave unit is often provided with means for indicating to the user on a liquid crystal display or the like that synchronization with the master unit has been performed. , It is now possible to determine whether or not a call can be made from the child device and an incoming call can be received from the parent device to the child device, and the operation of the child device can be easily understood.

Since there is no logical control channel of the base unit which is short but cannot be used when viewed from the child unit, it is possible to wait for the base unit which is available at a relatively long distance but can be used as a whole. The use efficiency of the parent machine can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a PHS master according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a communication frame showing a concept on a time axis of a TDMA / TDD channel slot used by a PHS.

FIG. 3 is a timing chart showing an embodiment of the present invention.

FIG. 4 is a timing chart showing an embodiment of the present invention.

[Description of Signs] 1: Main control unit 2: Radio control unit 3: Power amplifier 4: High frequency switch 5: Isolator 6a to 6c: ADPCM codec 7: Exchange ANT: Antenna modem: π / 4 shift QPSK modem

Claims (1)

(57) [Claims] At least one of a predetermined number of continuous wireless communication slots is assigned to a logical control channel for establishing a wireless link, and another slot is assigned to a service channel used for transmitting user data such as voice data. A base unit of a digital cordless telephone that performs wireless communication with a slave unit by allocating and repeating the predetermined number of continuous wireless communication slots, and the logical control channel transmitted by the base unit.
Monitor the slave unit that waits in synchronization with the network and the usage status of other slots used for transmitting the user data, the usage status of a wired voice path, or the occurrence status of various failures, and newly based on the monitoring result. in <br/> digital cordless telephone system composed of a determined control unit whether it is possible to establish a radio link with the handset, the control means impossible to establish a radio link with the new handset When it is determined that the transmission is stopped at the transmission timing of the radio communication slot allocated to the logical control channel while the service channel is continued, and when it is determined that the transmission is possible, the transmission of the radio communication slot allocated to the logical control channel is performed. Means for starting the transmission at a timing,
The slave unit is a logical control channel transmitted by the waiting master unit.
If the console stops, wait for the unusable base unit to wait.
Stops, and if there is a usable parent machine, the theory that the parent machine sends it
That can be synchronized with the physical control channel
Digital cordless telephone system according to claim.