JP2018164130A - Telephone system, subordinate device of telephone system, and host device of telephone system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately perform notification of whether synchronization between a host device and a subordinate device such as a cordless telephone device connected to the hoste device is performed.SOLUTION: A reference synchronization signal SYNC generated in a hub device 2 is supplied to a master unit of a cordless telephone device, and a frame synchronization signal FL used in the master unit is generated by using the reference synchronization signal SYNC in the master unit. This frame synchronization signal FL is fed back to the hub device 2, the reference synchronization signal SYNC and the frame synchronization signal FL are compared with each other in comparison units 26(1) to 26(n) to detect synchronization shift, and notification of the detection result is performed through LED units 28(1) to 28(n).SELECTED DRAWING: Figure 4

Description

  The present invention relates to a telephone system including a digital cordless telephone apparatus to which a TDMA (Time Division Multiple Access) / TDD (Time Division Duplex) system is applied, and the telephone system according to the present invention. It relates to the apparatus and method used.

  In recent years, a business phone system (button telephone system) configured by connecting a cordless telephone device in which a parent device and a child device are wirelessly connected as a lower device to a higher device such as a so-called main device has been provided. It has become to. In many cases, a communication system conforming to the DECT (Digital Enhanced Cordless Telecommunication) standard is used between the parent device and the child device constituting the cordless telephone device.

  In the DECT standard, the downlink communication method from the parent device to the child device is a time division duplex method using a time division multiplexing method, and the uplink communication method from the child device to the parent device is a time division method. It is defined that it is a time division duplex method using a multiple access method. Further, in the DECT standard, the frequency band to be used is “1.9 GHz band” different from the “2.4 GHz band” in the case of the conventional cordless telephone apparatus, and the maximum number of channels is 5 channels. Is stipulated.

  In the DECT standard, one frame in one channel of encoded data is 10 milliseconds (ms) and is divided into 24 time slots as shown in FIG. In the following, a time slot is simply referred to as a slot. The 12 slots S0 to S11 in the first half frame period of one frame are used for the downlink from the master unit to the slave units, and the 12 slots S12 to S23 in the second half frame period are used as the slave units. Used for uplink from the main unit to the base unit.

  In the case of a telephone system in which a plurality of DECT standard cordless telephone apparatuses are connected to a host apparatus, as described above, each cordless telephone is set so as not to overlap each slot of one frame. Used by the device. For this reason, the cordless telephone devices must be synchronized. In particular, when a large number of cordless telephone devices are connected to a host device such as a business phone, the number of cordless telephone devices that can be used will be less than the cordless telephone devices that can actually be used if they are not synchronized. there is a possibility.

  In other words, even if the slot to be used is determined between the cordless telephone devices so that they do not overlap, if the synchronization is not correct, the situation where the slot is used redundantly between different cordless telephone devices occurs. To do. In this case, a cordless telephone device that cannot make a normal call may occur. Therefore, in the cordless telephone device of the DECT standard used in the business phone system, as disclosed in Patent Document 1 described later, synchronization is performed between the cordless telephone devices based on a synchronization signal from a higher-level device such as the main device. I try to take it.

JP2015-177238

  Even when the technique described in Patent Literature 1 is used, there is a possibility that synchronization between the cordless telephone apparatuses may be lost due to various factors. For example, consider a case where a host device and a cordless telephone device are connected by a LAN (Local Area Network). For example, if the synchronization signal line of the LAN cable that connects the host device and the cordless telephone device is broken, if a LAN cable that is longer than the specified length is used, a nonstandard LAN cable is used. In some cases, synchronization between the higher-level device and the cordless telephone device is lost. In this case, the synchronization between the cordless telephone devices that are synchronized by using the synchronization signal from the host device is not matched.

  Also, if there are many relay devices such as hub devices between the main device and cordless phone device, even if the main device sends a synchronization signal to all cordless phone devices at the same timing, the cordless phone device There is a concern that there will be a shift when it arrives. In addition, there is a concern that the synchronization between the cordless telephone devices may be shifted due to the influence of the accuracy of an oscillator for generating a system clock in each cordless telephone device.

  Due to such factors, when the synchronization between cordless telephone devices is not matched, as described above, the slot cannot be used effectively, and the number of cordless telephone devices that can be used simultaneously may be less than expected. There is. However, on the user side, even if the number of cordless telephone devices connected simultaneously is reduced due to synchronization loss, whether synchronization loss has occurred, jamming radio waves have occurred, or congestion has occurred. I do not know the cause. In order to identify the cause, it is necessary to analyze the radio wave using an analyzer or the like, but it takes time and effort.

  In view of the above, the above-described problem is solved, and the first invention appropriately determines whether or not synchronization is established between a host device and a lower device such as a cordless telephone device connected thereto. It aims at making it possible to notify to. A second object of the present invention is to enable synchronization to be autonomously performed when synchronization is not established between a host device and a lower device such as a cordless telephone device connected thereto.

In order to solve the above problem, a telephone system according to a first invention provides:
A plurality of lower-level devices such as a cordless telephone device composed of a parent device and a child device and a hub device to which the cordless telephone device is connected are connected to the upper device, and between the parent device and the child device. The unit communication period is divided into a plurality of slots, and at least one slot is used in each of communication from the parent device to the child device and communication from the child device to the parent device, and TDMA (Time Division Multiple Access) is used. Connection) / TDD (Time Division Duplex) system for performing a wireless communication,
The host device is
First synchronization signal generation means for generating a first synchronization signal to be supplied to each of the lower-level devices;
First sending means for sending the first synchronizing signal generated by the first synchronizing signal generating means to each of the lower-level devices;
First receiving means for receiving a second synchronization signal generated based on the first synchronization signal from each of the lower-level devices;
The second synchronization signal received from each of the lower order devices received through the first receiving means is compared with the first synchronization signal from the first synchronization signal generating means to detect a synchronization error. Comparing means to
Informing means for informing the comparison result in the comparing means for each of the lower devices connected to the own device,
Each of the subordinate devices
Second accepting means for accepting the first synchronization signal from the host device;
Based on the first synchronization signal received through the second reception means, second synchronization signal generation means for generating the second synchronization signal used in the own device;
And a second sending means for sending the second synchronizing signal generated by the second synchronizing signal generating means to the host device.

  According to the telephone system of the first aspect of the invention, the first synchronization signal generated by the higher-level device is provided to the lower-level device, and the first synchronization signal is used in the lower-level device and used by the lower-level device. A second synchronization signal is generated. The second synchronization signal generated by this lower-level device is fed back to the higher-level device, and the comparison means compares the first synchronization signal with the second synchronization signal to detect the presence or absence of synchronization deviation. Then, in the higher-level device, the notification means notifies the presence / absence of synchronization deviation for each lower-level device connected to the higher-level device. Thereby, it is possible to clearly notify the user of the devices in which the synchronization error has occurred.

In order to solve the above problems, the telephone system of the second invention is:
A plurality of lower-level devices such as a cordless telephone device composed of a parent device and a child device and a hub device to which the cordless telephone device is connected are connected to the upper device, and between the parent device and the child device. The unit communication period is divided into a plurality of slots, and at least one slot is used in each of communication from the parent device to the child device and communication from the child device to the parent device, and TDMA (Time Division Multiple Access) is used. Connection) / TDD (Time Division Duplex) system for performing a wireless communication,
The host device is
First synchronization signal generation means for generating a first synchronization signal to be supplied to each of the lower-level devices;
First sending means for sending the first synchronizing signal generated by the first synchronizing signal generating means to each of the lower-level devices;
First receiving means for receiving a second synchronization signal generated based on the first synchronization signal from each of the lower-level devices;
The second synchronization signal received from each of the lower order devices received through the first receiving means is compared with the first synchronization signal from the first synchronization signal generating means to detect a synchronization error. Comparing means to
When the comparison result of the comparison means indicates the occurrence of synchronization deviation, based on the comparison result, the first synchronization signal generated by the first synchronization signal generator supplied to the synchronization deviation occurrence source Correcting means for correcting a signal and supplying the signal to the generation source of the synchronization deviation through the first sending means,
Each of the subordinate devices
Second accepting means for accepting the first synchronization signal from the host device;
Based on the first synchronization signal received through the second reception means, second synchronization signal generation means for generating the second synchronization signal used in the own device;
And a second sending means for sending the second synchronizing signal generated by the second synchronizing signal generating means to the host device.

  According to the telephone system of the second aspect of the invention, the first synchronization signal generated by the higher-level device is provided to the lower-level device, and the first synchronization signal is used by the lower-level device and used by the lower-level device. A second synchronization signal is generated. The second synchronization signal generated by this lower-level device is fed back to the higher-level device, and the comparison means detects the synchronization deviation by comparing the first synchronization signal and the second synchronization signal. Then, when a synchronization deviation occurs, based on the comparison result of the comparison means, the correction means generates a second synchronization signal that causes the synchronization deviation, that is, the synchronization apparatus. The first synchronization signal supplied to the generation source of the deviation is corrected and supplied to the generation source of the synchronization deviation. As a result, the synchronization error can be resolved autonomously (automatically) by the host device.

  According to the first invention of this application, it is possible to appropriately notify whether or not synchronization is achieved between the host device and the lower devices such as a plurality of cordless telephone devices. Further, according to the second invention of this application, synchronization can be autonomously performed when synchronization is not established between the host device and the lower devices such as a plurality of cordless telephone devices.

It is a block diagram which shows the example of a whole structure of the telephone system of embodiment. It is a block diagram for demonstrating the structural example of a main apparatus. It is a figure for demonstrating the structural example of the management information (database) formed in the address management DB of a main apparatus. It is a block diagram for demonstrating the structural example of a hub apparatus. It is a block diagram for demonstrating the structural example of a main | base station. It is a block diagram for demonstrating the structural example of a subunit | mobile_unit. It is a figure for demonstrating the example of the alerting | reporting aspect of the synchronization shift by LED. It is a block diagram for demonstrating the hub apparatus of another example. It is a figure for demonstrating the example of the alerting | reporting aspect of the synchronization shift by LED. It is a block diagram for demonstrating the hub apparatus of another example. It is a block diagram for demonstrating the hub apparatus of another example. It is a figure for demonstrating the frame structure of a DECT specification.

  Hereinafter, an embodiment of a system, a cordless telephone device, and a hub device according to the present invention will be described with reference to the drawings. In the embodiment described below, for example, when the present invention is applied to a business phone system (button phone system) formed by connecting a plurality of telephone devices to a so-called main device in a company office or the like Will be described as an example.

[Telephone system configuration example]
FIG. 1 is a block diagram showing an example of the overall configuration of the telephone system of this embodiment. In the telephone system of this example, a plurality of cordless telephone devices 31, 32,..., 3n (n is an integer of 3 or more; below) as extension telephone devices via the hub device 2 with respect to the main device 1. The same) is connected. When viewed from the main device 1, the hub device 2 and the cordless telephone devices 31, 32, ..., 3n are subordinate devices. Further, when viewed from the cordless telephone devices 31, 32,..., 3n, the main device 1 and the hub device 2 are all higher-level devices. When viewed from the hub device 2, the main device 1 is a higher-level device, and the cordless telephone devices 31, 32,..., 3n are lower-level devices.

  Each of the cordless telephone devices 31 to 3n is one to which the cordless telephone device of the present invention is applied. Each of the cordless telephone devices 31 to 3n includes a base set BS1, BS2,..., BSn as a parent device and a handset HS1, HS2,. Each of base units BS1 to BSn and each of slave units HS1 to HSn are wirelessly connected. In this embodiment, the wireless connection between each of the parent devices BS1 to BSn of the cordless telephone devices 31 to 3n and each of the child devices HS1 to HSn conforms to the DECT standard (method) of the above-described digital cordless phone. This is performed by the TDMA / TDD method used.

  A plurality of slave units can be wirelessly connected to each of the master units BS1 to BSn. However, in this example, one slave unit is connected to one master unit. It is set as the structure. Although not shown, the extension telephone apparatus connected to the main apparatus 1 is not limited to the cordless telephone apparatuses 31, 32,..., 3n, and is connected to a digital button telephone terminal in the same manner as a normal business phone. It is also possible to do.

  As will be described later, the main apparatus 1 has a SIP (Session Initiation Protocol) server function and is described as a telephone line connected to an IP (Internet Protocol) network and a conventional public switched telephone network (hereinafter simply referred to as a telephone network). .) Can be accommodated. The parent devices BS1 to BSn of the cordless telephone devices 31 to 3n are connected to the main device 1 via the hub device 2. The main device 1 performs call control and circuit switching control for the plurality of cordless telephone devices 31 to 3n and other business phone control.

  The hub device 2 is one to which the hub device according to the present invention is applied. The hub device 2 is one of the relay devices of the communication network, and has a plurality of connection ports. The hub device 2 does not transmit the received data to all the devices connected to each connection port, and is related to confirming the destination. It has a function to transmit only to the device. The hub device 2 has a function of generating a reference synchronization signal SYNC (first synchronization signal) and supplying the reference synchronization signal SYNC to each of a plurality of lower-level devices such as the cordless telephone devices 31 to 3n connected to the connection port of the own device. I have. In this example, the reference synchronization signal SYNC is a signal having a period of 130 milliseconds (ms).

  Each of the base units BS1 to BSn of the cordless telephone apparatuses 31 to 3n is synchronized with the reference synchronization signal SYNC from the hub apparatus 2, and one frame (10 milliseconds (ms), which is a unit communication period of a DECT standard digital cordless telephone. )), A frame synchronization signal (second synchronization signal) as a synchronization signal is generated, and TDMA / TDD wireless communication using the DECT standard is performed based on the generated frame synchronization signal. Execute with HSn. Accordingly, all of the plurality of cordless telephone apparatuses 31 to 3n are operated in synchronization with the reference synchronization signal SYNC from the main apparatus 1 if there is no problem.

  Each of base units BS1 to BSn generates frame synchronization signal FL based on reference synchronization signal SYNC. In this embodiment, each of the parent devices BS1 to BSn is connected to the slave devices HS1 to HSn based on the generated frame synchronization signal in every other slot of a plurality of slots in one frame period. It is assumed that control is performed so that wireless communication is performed using one of these. In this embodiment, each of the slave units HS1 to HSn performs wireless communication with the master unit BS1 to BSn using one of every other slot in a plurality of slots in one frame period. Assumed to be performed.

  In the telephone system of this embodiment, each of the parent devices BS1 to BSn connected to the hub device 2 generates the frame synchronization signal FL generated based on the reference synchronization signal SYNC from the hub device 2 in its own device. Feedback is provided to the hub device 2. Then, the hub device 2 compares the reference synchronization signal SYNC generated by itself and the frame synchronization signal FL from each of the parent devices BS1 to BSn, determines the presence / absence of synchronization deviation, and notifies the determination result. To be able to. Hereinafter, a configuration example of each device constituting the telephone system of this embodiment will be described.

  In this embodiment, each of the cordless telephone apparatuses 31 to 3n is an IP telephone, and is connected to a host apparatus such as the main apparatus 1 having the SIP server function via a LAN. An IP telephone is a telephone service provided using IP (Internet Protocol), a packet communication protocol used on the Internet. An IP telephone corresponding to an IP telephone converts voice into digital data, divides it into units called packets, and sends a voice signal to the other party of the call via the LAN or IP network (Internet). Enable voice calls with.

[Configuration Example of Main Device 1]
FIG. 2 is a block diagram for explaining a configuration example of the main apparatus 1. As shown in FIG. 2, the main apparatus 1 includes a connection port 101 to the IP network, an IP network interface (hereinafter abbreviated as IP network I / F) 102, and a packet disassembly / generation unit 103. Yes. The main apparatus 1 includes a telephone network interface (hereinafter abbreviated as a telephone network I / F) 104, a connection port 105 to the telephone network, and an address management database (hereinafter abbreviated as an address management DB) 106. And. Further, the main apparatus 1 includes a LAN interface (hereinafter abbreviated as “LAN I / F”) 107, a LAN connection port 108, and a control unit 110.

  The control unit 110 controls each unit of the main apparatus 1 of this embodiment, and as shown in FIG. 2, a CPU (Central Processing Unit) 111, a ROM (Read Only Memory) 112, a RAM (Random Access Memory). ) 113 is a computer device unit configured to be connected through the system bus 114. Although not shown, for example, a nonvolatile memory such as an EEPROM (Electrically Erasable and Programmable ROM) or a flash memory is provided, and data to be retained even when the power is turned off, for example, various setting parameters and functions are improved. It is possible to store and hold new programs provided for the purpose.

  The connection port 101 constitutes a connection end to the IP network. The IP network I / F 102 receives a packet supplied through the IP network, converts it into a packet in a format that can be processed by itself, and supplies the packet to the control unit 110. The IP network I / F 102 converts a packet to be transmitted supplied through the control unit 110 into a packet in a transmission format, and transmits the packet to the IP network.

  The connection port 105 constitutes a connection end to the telephone network. The telephone network I / F 104 receives data supplied through the telephone network, converts it into data in a format that can be processed by itself, and supplies the data to the control unit 110. Further, the telephone network I / F 104 converts data to be transmitted supplied through the control unit 110 into data in a transmission format, and transmits the data to the telephone network.

  The connection port 108 constitutes a connection end to the LAN. The LAN I / F 107 receives a packet supplied through the LAN, converts it into a packet in a format that can be processed by the own device, and supplies the packet to the control unit 110. The LAN I / F 107 converts a packet to be transmitted supplied through the control unit 110 into a packet in a format for transmission, and transmits this to the LAN.

  The packet decomposition / generation unit 103 performs packet decomposition and generation. The packet decomposition / generation unit 103 mainly includes a terminal device connected to the telephone network and an IP telephone terminal such as the cordless telephone devices 31 to 3n subordinate to the main device 1. When a call is made between the two, a packet of data to be transmitted and received is decomposed and generated. Specifically, a packet to be transmitted to a terminal device connected to the telephone network from the cordless telephone devices 31 to 3n connected to the main device 1 via the hub device 2 is transmitted through the connection port 108 and the LAN I / F 107. It is supplied to the control unit 110. The packet is supplied from the control unit 110 to the packet decomposing / generating unit 103, where the packet is decomposed, and then transmitted to the telephone network through the telephone network I / F 104 and the connection port 105, and transmitted to the intended destination. The

  Data from the terminal device connected to the telephone network to the cordless telephone devices 31 to 3n connected to the main device 1 via the hub device 2 is transferred to the control unit 110 through the connection port 105 and the telephone network I / F 104. To be supplied. The data is supplied from the control unit 110 to the packet decomposing / generating unit 103, where the data is converted into a packet of a predetermined format, and then sent to the LAN through the LAN I / F 107 and the connection port 108 to be the target cordless telephone apparatus. 31 to 3n.

  Packets are transmitted and received between an external terminal device connected to the IP network and the cordless telephone devices 31 to 3n connected to the main device 1 via the hub device 2. For this reason, the packet decomposition / generation unit 103 does not perform packet decomposition or generation, and the IP network I / F 102 and the LAN I / F 107 prepare and transmit the data format as it is. Similarly, packets are also transmitted and received between the cordless telephone apparatuses 31 to 3n connected to the main apparatus 1 via the hub apparatus 2, so that the packet decomposition / generation unit 103 performs packet decomposition and generation. Rather, packets are transmitted and received through the LAN I / F 107.

  The address management DB 106 stores and holds address information about a terminal device that is connected to an IP network or a LAN and may be called through the main device 1 in order to realize a registrar server function. Specifically, the control unit 110 of the main device 1 receives registration requests (register requests) from various terminal devices connected thereto through the IP network I / F 102 and the LAN I / F 107. In this case, the control unit 110 extracts address information such as a URI (Uniform Resource Identifier) and an IP address included in the received request. Then, the control unit 110 registers the extracted address information in the address management DB 106 or updates the registration information in the address management DB 106 using the extracted address information.

  In this way, the information registered and managed in the address management DB 106 is referred to, and the communication destination requested from the cordless telephone devices 31 to 3n connected to the own machine through the LAN is surely specified. And the main apparatus 1 implement | achieves the function as a proxy server which transfers the information (packet data) which should be transmitted to the specified other party. The information registered and managed in the address management DB 106 is also used for discrimination of incoming calls to the cordless telephone devices 31 to 3n connected to the own machine through the LAN.

  FIG. 3 is a diagram for describing a configuration example of management information (database) formed in the address management DB 106. The address management DB 106 of the main apparatus 1 stores address information about the cordless telephone apparatuses 31 to 3n connected to the main apparatus 1 through the LAN, in addition to the address information of other IP telephone systems connected to the IP network. Also manage.

  Basically, the management information formed in the address management DB 106 of the main device 1 is a URI (SIP URI) transmitted from a terminal device connected to the IP network and an IP address as described above. In the address management DB 106 of the main apparatus 1 according to this embodiment, as shown in FIG. 3, for the cordless telephone apparatuses 31 to 3n connected to the main apparatus 1 via LAN, in addition to the URI and IP address, the MAC ( Media Access Control) Manages addresses and extension numbers.

  Then, it is assumed that main device 1 accepts a call request (call request) to an external terminal device connected to the IP network from cordless telephone devices 31 to 3n of the telephone system of this embodiment. In this case, the control unit 110 of the main device 1 identifies a target destination terminal device based on the management information of its own address management DB 106, and transfers a message to the identified terminal device. . Further, it is assumed that the main apparatus 1 accepts an incoming call request (external line incoming call) to a cordless telephone apparatus connected to the LAN through the IP network or the telephone network. In this case, the control unit 110 of the main apparatus 1 receives the transmitted message and sends it out to the own system.

  As described above, the main device 1 of this embodiment includes the packet decomposition / generation unit 103 and the address management DB 106, and relays messages between terminal devices connected to various networks to which the main device 1 is connected. be able to. Therefore, the main device 1 of this embodiment can perform connection between external lines and internal lines, connection between internal lines, and can notify the subordinate cordless telephone apparatus and the like of the use status of communication lines. .

  In addition, the control unit 110 can grasp a communication line in use or an empty communication line through the IP network I / F 102, the telephone network I / F 104, and the LAN I / F 107 so that the circuit can be appropriately exchanged. ing. In addition, the control unit 110 provides control information for controlling the turning on and off of the LEDs and the like to be supplied to the cordless telephone devices 31 to 3n connected through the LAN according to the grasped usage state of the communication line. Form. The control information is transmitted to the LAN through the LAN I / F 107 and the connection port 108, and is transmitted to the cordless telephone devices 31 to 3n through the hub device 2.

[Configuration of Hub Device 2]
FIG. 4 is a block diagram for explaining a configuration example of the hub device 2. As illustrated in FIG. 4, the hub device 2 includes a LAN I / F 21, a switching control unit 22, and a plurality of LAN I / Fs 23 (1) to 23 (n). Note that the letter n used as a subscript like LANI / F23 (n) means an integer of 1 or more. For example, in FIG. 4, there are LANI / F23 (1) and 23 (2). Therefore, the subscript n in FIG. 4 is an integer of 3 or more. Subscript n is used in the same manner.

  The LAN I / F 21 is an interface for transmitting / receiving data to / from a host device higher than the own device. The switching control unit 22 realizes a function of confirming a transmission destination of received data and transmitting the received data only to a target transmission destination. The switching control unit 22 manages the MAC address and IP address of the connected device for each connection port in a memory (not shown), and appropriately manages which device is connected to which connection port.

  Each of the plurality of LAN I / Fs 23 (1) to 23 (n) is an interface for transmitting / receiving data to / from a device lower than the own device. Each of the lower LAN I / Fs 23 (1) to 23 (n) includes at least a data line used for transmission of packet data Dt in which voice signals, call control signals, and the like are packetized, and a reference synchronization signal. A reference synchronization signal line used for transmission of SYNC and a frame synchronization signal line used for transmission of frame synchronization signal FL are provided, and these connections are made possible.

  In FIG. 4, the connection port on the LAN I / F 21 side and the connection ports on the LAN I / F 23 (1) to 23 (n) side are not shown, but by connecting a LAN cable to the connection port. The plurality of signal lines can be simultaneously connected to the LAN I / F 21 and the LAN I / Fs 23 (1) to 23 (n).

  The hub device 2 includes an oscillator 24 that oscillates a reference signal, and a synchronization signal generation circuit that generates a 130 ms reference synchronization signal SYNC based on the reference signal from the oscillator 24. Further, the hub device 2 corresponds to the LAN I / Fs 23 (1) to 23 (n), the comparison units 26 (1) to 26 (n), and the LED (Light Emitting Diode) drivers 27 (1) to 27 ( n) LED units 28 (1) to 28 (n) having at least two colors of LEDs are provided. Each of the LED units 28 (1) to 28 (n) of this embodiment includes, for example, a green LED whose emission color is green and a red LED whose emission color is red.

  Each of the comparison units 26 (1) to 26 (n) receives the reference synchronization signal SYNC from the synchronization signal generation circuit 25 and the corresponding cordless telephone devices 31 to 3n received through the corresponding LAN I / Fs 23 (1) to 23 (n). The frame synchronization signal is supplied from a lower level device. Then, each of the comparison units 26 (1) to 26 (n) compares the phases of both signals, detects whether or not a synchronization shift has occurred, and determines the detection result as a corresponding LED driver 27 (1). ) To 27 (n).

  Each of the comparison units 26 (1) to 26 (n) of this embodiment detects that no synchronization deviation has occurred if the phase difference is within the reference range, and the phase difference is outside the reference range. It is detected that a synchronization error has occurred. In this embodiment, the reference synchronization signal SYNC is a signal having a period of 130 ms, and the frame synchronization signal FL is a signal having a period of 10 ms. For this reason, for comparison, the phase difference between, for example, the rising edge of the reference synchronization signal SYNC and the rising edge of the latest (immediately adjacent) frame synchronization signal FL is obtained. That is, it is detected how much the frame synchronization signal FL is advanced or delayed with respect to the reference synchronization signal SYNC.

  As another method, for example, the phase comparison may be performed at the timing of every 13 periods from the rising edge of the frame synchronization signal FL immediately before the rising edge of the reference synchronization signal SYNC. In each of the comparison units 26 (1) to 26 (n), the reference synchronization signal SYNC is divided by a factor of 13, and the phase difference between the divided signal and the frame synchronization signal FL is calculated. You may make it ask.

  Each of the LED drivers 27 (1) to 27 (n) supplies a drive signal to the green LED when the detection results from the corresponding comparison units 26 (1) to 26 (n) are not out of synchronization. The drive signal is not supplied to the red LED. Thereby, when there is no synchronization shift, only the green LED can emit light. On the contrary, when the detection results from the corresponding comparison units 26 (1) to 26 (n) are out of synchronization, each of the LED drivers 27 (1) to 27 (n) A drive signal is supplied, and a drive signal is not supplied to the green LED. Thereby, when there is a synchronization shift, only the red LED can emit light.

  Note that if there is a LAN I / F 23 (1) to 23 (n) that is not connected to a device, the frame synchronization signal FL from the connected device is not supplied to the LAN I / F. In the corresponding comparison units 26 (1) to 26 (n), comparison processing is not performed. For this reason, LED of corresponding LED part 28 (1) -28 (n) does not light-emit.

  In this way, the hub device 2 compares the reference synchronization signal SYNC generated by itself with the frame synchronization signal FL from the parent devices BS1 to BSn of the cordless telephone devices 31 to 3n described later, and the occurrence of the synchronization deviation occurs. Presence / absence can be notified by the light emission color of the LED.

[Configuration Example of Base Unit BS1 of Cordless Telephone Device 31]
Next, a configuration example of the base units BS1 to BSn of the cordless telephone devices 31 to 3n will be described. In this embodiment, the base units BS1 to BSn of the cordless telephone apparatuses 31 to 3n are configured similarly. Therefore, in the following, a configuration example of the base unit BS1 of the cordless telephone apparatus 31 will be described as a configuration example of the base units BS1 to BSn.

  FIG. 5 is a block diagram for explaining a configuration example of base unit BS1. As shown in FIG. 5, the base unit BS1 includes a control circuit 41 for controlling the entire base unit BS1, a line LSI unit 42, a synchronization signal generation circuit 43, a radio communication circuit 44, and oscillators 45 and 46. And a LAN I / F 47.

  The LAN I / F 47 is an interface for transmitting / receiving a signal to / from a host device higher than the own device. The LAN I / F 47 is used to transmit at least a data line used for transmission of packet data Dt such as a voice signal and a call control signal, a reference synchronization signal line used for transmission of a reference synchronization signal SYNC, and a frame synchronization signal FL. A frame synchronization signal line is provided to enable these connections. In FIG. 5, the connection port to which the LAN I / F 47 is connected is not shown.

  The control circuit 41 includes a computer device. The control circuit 41 has a function of performing control such as call control in the base unit BS1. The line LSI unit 42 is a circuit for exchanging audio signals and control signals with the main apparatus 1, and includes a packet decomposition / generation unit 421, a control signal processing unit 422, an audio signal processing unit 423, A PLL (Phase locked Loop) unit 424 is included.

  The PLL unit 424 is supplied with the oscillation signal having the reference frequency from the oscillator 45 and the reference synchronization signal SYNC from the main device 1. In this example, the frequency of the oscillation signal of the oscillator 45 is, for example, 2048 MHz (0.488 nanoseconds (ns)). The PLL unit 424 performs phase comparison between the reference synchronization signal SYNC from the main device 1 and the oscillation signal from the oscillator 45, and based on the comparison result, the PLL unit 424 synchronizes with the reference synchronization signal SYNC from the oscillation signal of the oscillator 45. A system clock signal SCK of the machine BS1 is generated.

  Then, the PLL unit 424 supplies the generated system clock signal SCK as a signal processing clock signal to each of the packet decomposition / generation unit 421, the control signal processing unit 422, and the audio signal processing unit 423, and a synchronization signal generation circuit 43.

  The packet disassembly / generation unit 421 is connected to a data line for transmitting packet data Dt in which voice signals and control signals from the hub device 2 are packetized, and is connected to the control signal processing unit 422 and the voice signal processing unit 423. Is done. Then, the packet decomposition / generation unit 421 decomposes the packet data Dt from the main device 1, extracts the control signal and the audio signal, the control signal is sent to the control signal processing unit 422, and the audio signal is sent to the audio signal processing unit. 423, respectively. The packet decomposition / generation unit 421 packetizes the control signal from the control signal processing unit 422 and the audio signal from the audio signal processing unit 423 to generate packet data, and the generated packet data is converted into the main device 1. To supply.

  The control signal processing unit 422 is connected to the control signal input / output terminal of the control circuit 41, and is also connected to the packet decomposition / generation unit 421. And the like (a control signal from the main device 1 to the cordless telephone device 31 and a control signal from the cordless telephone device 31 to the main device 1).

  The audio signal processing unit 423 is connected to the wireless communication circuit 44 and is also connected to the packet decomposition / generation unit 421, and the transmission voice signal and packet decomposition / generation received from the slave unit HS 1 from the wireless communication circuit 44. 4 is a processing circuit for a received voice signal from the unit 421.

  The synchronization signal generation circuit 43 includes a counter 431 and a synchronization signal generation unit 432. The counter 431 is supplied with the reference synchronization signal SYNC having a period of 130 ms from the hub device 2 to the preset terminal and the system clock signal SCK from the PLL unit 424 as a count input. Then, the output count value CNT of the counter 431 is supplied to the synchronization signal generator 432.

  The synchronization signal generation unit 432 generates a frame synchronization signal FL having a DECT standard frame period (10 ms) from the output count value CNT of the counter 431. The synchronization signal generation circuit 43 supplies the frame synchronization signal FL generated by the synchronization signal generation unit 432 to the wireless communication circuit 44. At the same time, the frame synchronization signal FL is fed back to the hub device 2 through the frame synchronization signal line of the LAN I / F 47.

  Next, the wireless communication circuit 44 will be described. In this embodiment, the wireless communication circuit 44 uses a general-purpose wireless communication LSI for a parent device for performing DECT standard wireless communication. The wireless communication circuit 44 includes a control unit 441, a TDMA modulation / demodulation unit 442, and a wireless communication unit 443. The wireless communication unit 443 is a circuit unit for performing wireless communication with the child device HS1.

  The control unit 441 is connected to the TDMA modulation / demodulation unit 442 and the wireless communication unit 443 and also connected to the control circuit 41. The control unit 441 controls the overall operation of the wireless communication circuit 44 and supplies a control signal based on the control signal obtained from the control circuit 41 to the TDMA modulation / demodulation unit 442.

  The TDMA modulation / demodulation unit 442 is connected to the control unit 441 and the audio signal processing unit 423 of the line LSI unit 42 and is also connected to the wireless communication unit 443, and from the control signal from the control unit 441 and the audio signal processing unit 423. Is modulated in order to transmit the audio signal to the slave unit HS1. The signal modulated by the TDMA modulation / demodulation unit 442 is transmitted to the slave unit HS1 through the wireless communication unit 443.

  The TDMA modulation / demodulation unit 442 demodulates the audio signal and the control signal from the received signal from the slave unit HS1 received by the wireless communication unit 443, and supplies the demodulated audio signal to the audio signal processing unit 423 for demodulation. The control signal is supplied to the control unit 441.

  The TDMA modulation / demodulation unit 442 includes a PLL unit 4421 for generating a clock. The PLL unit 4421 is supplied with the oscillation signal from the oscillator 46 and the frame synchronization signal FL from the synchronization signal generation circuit 43.

  The PLL unit 4421 compares the phase of the frame synchronization signal FL from the synchronization signal generation circuit 43 with the oscillation signal from the oscillator 46, and synchronizes the frame synchronization signal FL from the oscillation signal of the oscillator 46 based on the comparison result. A timing signal and a clock signal are generated.

  The TDMA modulation / demodulation unit 442 uses the timing signal and the clock signal synchronized with the frame synchronization signal FL to generate a transmission signal to the slave unit HS1 in a period corresponding to one of the slots in the downlink that can be allocated and used. At the same time, the received signal from the slave unit HS1 is processed using one of the slots in the uplink.

  Master unit BS1 is connected to hub device 2, starts synchronization processing for communication with slave unit HS1, and always sends a transmission signal to slave unit HS1. Then, the control unit 441 of the radio communication circuit 44 of the base unit BS1 sends the transmission signal generated by the TDMA modulation / demodulation unit 442 to the slave unit HS1 through the radio communication unit 443 using one slot set in the own unit. When a response is returned from the slave unit HS1, the slot used for transmitting the transmission signal is used for the downlink, and the slot that received the response from the slave unit HS1 is used for the uplink to establish synchronization. , Control to perform transmission / reception. That is, wireless communication is performed between the parent device BS1 and the child device HS1 using the specified slot.

[Configuration example of handset HS1 of cordless telephone device 31]
Next, a configuration example of the cordless handsets HS1 to HSn of the cordless telephone devices 31 to 3n will be described. In this embodiment, the cordless handsets HS1 to HSn of the cordless telephone devices 31 to 3n are configured similarly. Therefore, in the following, a configuration example of the slave unit HS1 of the cordless telephone apparatus 31 will be described as a configuration example of the slave units HS1 to HSn.

[Example of slave unit configuration]
FIG. 6 is a block diagram for explaining a configuration example of the slave unit HS1. As shown in FIG. 6, the slave unit HS1 includes a wireless communication circuit 51, a control circuit 52, a codec circuit 53, an oscillator 54, a microphone 55, and a speaker 56. The microphone 55 constitutes a transmitter, and the speaker 56 constitutes a receiver.

  The wireless communication circuit 51 uses a general-purpose wireless communication LSI for handset for performing DECT standard wireless communication. The wireless communication circuit 51 includes a control unit 511, a TDMA modulation / demodulation unit 512, and a wireless communication unit 513. The wireless communication unit 513 is a circuit unit for performing wireless communication with the parent device BS1.

  The control unit 511 is connected to the TDMA modulation / demodulation unit 512 and the wireless communication unit 513 and is also connected to the control circuit 52. The control unit 511 controls the overall operation of the wireless communication circuit 51 and supplies a control signal based on the control signal obtained from the control circuit 52 to the TDMA modulation / demodulation unit 512.

  The TDMA modulation / demodulation unit 512 is connected to the control unit 511 and the wireless communication unit 513 and is also connected to the codec circuit 53, and transmits the control signal from the control unit 511 and the audio signal from the codec circuit 53 to the base unit BS1. To do modulation. The signal modulated by TDMA modulation / demodulation unit 512 is transmitted to base unit BS1 through radio communication unit 513.

  The TDMA modulation / demodulation unit 512 demodulates the audio signal and the control signal from the received signal from the base unit BS1 received by the wireless communication unit 513, supplies the demodulated audio signal to the codec circuit 53, and demodulates the control signal. Is supplied to the control unit 511.

  The TDMA modulation / demodulation unit 512 includes a PLL unit 5121 for clock generation. The PLL unit 5121 is supplied with the oscillation signal from the oscillator 54 and the demodulated signal of the reception signal from the wireless communication unit 513. The PLL unit 5121 receives the oscillation signal from the oscillator 54. A clock signal synchronized with the clock component of the demodulated signal is generated. The clock signal from the PLL unit 5121 is used as a processing clock signal in the TDMA modulation / demodulation unit 512.

  The codec circuit 53 decodes the audio signal demodulated by the TDMA modulation / demodulation unit 512, converts the audio signal into an analog audio signal, supplies the analog audio signal to the speaker 56, and emits the received audio as received audio. The codec circuit 53 encodes the analog audio signal collected by the microphone 55 and supplies the encoded analog audio signal to the TDMA modulation / demodulation unit 512.

  The control circuit 52 transmits a call control signal at the time of calling from the child device HS1 to the parent device BS1 through the wireless communication circuit 51, and also performs call control at the time of incoming from the parent device BS1. When a signal is received, processing such as emitting a ringtone from the speaker 56 is performed.

[Informing about synchronization performed by hub device 2 and base units BS1 to BSn in cooperation]
In the telephone system of this embodiment configured by each device having the above-described configuration, the hub apparatus 2 and the parent devices BS1 to BSn of the cordless telephone apparatuses 31 to 3n cooperate to cause a synchronization error. It is possible to report between existing devices. This is equivalent to notifying whether or not the cordless telephone devices connected to the hub device 2 are synchronized.

  That is, as described above, the hub device 2 and the parent devices BS1 to BSn are connected by a LAN cable including at least a data line, a reference synchronization signal line, and a frame synchronization signal line. The data line bi-directionally transmits packet data (main data) Dt formed by packetizing voice signals and control signals. The reference synchronization signal line transmits the reference synchronization signal SYNC generated by the hub device 2 from the hub device 2 to each of the parent devices BS1 to BSn. The frame synchronization signal line transmits the frame synchronization signal generated using the reference synchronization signal SYNC from the hub device 2 to the hub device 2 from each of the parent devices BS1 to BSn in each of the parent devices BS1 to BSn.

  As described with reference to FIG. 4, the hub device 2 includes comparison units 26 (1) to 26 (n) corresponding to the LAN I / Fs 23 (1) to 23 (n). Comparison units 26 (1) to 26 (n) compare the reference synchronization signal SYNC with the frame synchronization signal FL from the corresponding base unit BS1 to BSn, and determine whether or not there is a synchronization shift determined by the result of this comparison. , The light is emitted from the LEDs 28 (1) to 28 (n).

  FIG. 7 is a diagram for explaining an example of a notification mode of synchronization deviation by LEDs. In FIG. 7, connection ports PT (1) to PT (n) constitute the connection end of the LAN cable and are connected to corresponding LAN I / Fs 23 (1) to 23 (n). The LAN cable LC (1) that connects the base unit BS1 and the connection port PT (1) of the hub device 2 is normal. The LAN cable LC (2) that connects the base unit BS2 and the connection port PT (2) of the hub device 2 is normal. However, in the LAN cable LC (n) that connects the base unit BSn and the connection port PT (n) of the hub device 2, the reference synchronization signal line that transmits the reference synchronization signal SYNC is disconnected inside the LAN cable LC (n). Assume that the synchronization signal SYNC cannot be transmitted from the hub device 2 to the base unit BSn.

  In this case, the base units BS1 and BS2 appropriately generate the frame synchronization signal FL based on the reference synchronization signal SYNC from the hub device 2 and feed it back to the hub device 2. However, since the base unit BSn is not supplied with the reference synchronization signal SYNC from the hub device 2, a frame synchronization signal FL that is not synchronized with the reference synchronization signal SYNC is formed and transmitted to the hub device 2.

  In this case, in the comparison unit 26 (1) corresponding to the connection port PT (1) to which the LAN cable LC (1) from the base unit BS1 is connected, the reference sync signal SYNC and the frame sync signal FL from the base unit BS1 It can be determined that the synchronization is correct. In this case, based on the determination result of the comparison unit 26 (1), the LED driver 27 (1) supplies a drive current to the green LED of the LED unit 28 (1) and does not supply a drive current to the red LED. As a result, the green LED of the LED section 28 (1) is turned on and the red LED is turned off, and the reference synchronization signal SYNC and the frame synchronization signal formed by the base unit BS1 are synchronized. Informed. That is, it is notified that the synchronization between the hub device 2 and the base unit BS1 is in agreement.

  Similarly, in the comparison unit 26 (1) corresponding to the connection port PT (2) to which the LAN cable LC (2) from the base unit BS2 is connected, the reference synchronization signal SYNC and the frame synchronization signal FL from the base unit BS2 It can be determined that the synchronization is correct. In this case, based on the determination result of the comparison unit 26 (2), the LED driver 27 (2) supplies a drive current to the green LED of the LED unit 28 (2) and does not supply a drive current to the red LED. As a result, the green LED of the LED unit 28 (2) is turned on and the red LED is turned off, and it is notified that the reference synchronization signal SYNC and the frame synchronization signal formed by the base unit BS2 are synchronized. The That is, it is notified that the synchronization between the hub device 2 and the base unit BS2 is in agreement.

  On the other hand, in the comparison unit 26 (n) corresponding to the connection port PT (n) to which the LAN cable LC (n) from the parent device BSn is connected, the reference synchronization signal SYNC and the frame synchronization signal from the parent device BS2 are used. When compared with FL, it can be determined that synchronization is not achieved. This is because the reference synchronization signal SYNC from the hub device 2 is not supplied to the base unit BSn. In this case, based on the determination result of the comparison unit 26 (n), the LED driver 27 (n) does not supply a drive current to the green LED of the LED unit 28 (2n), but supplies a drive current to the red LED. . As a result, the green LED of the LED unit 28 (2) is turned off and the red LED is turned on, and the reference synchronization signal SYNC formed by the hub device 2 and the frame synchronization signal FL formed by the base unit BS2 It is informed that a synchronization error occurs. That is, it is notified that the synchronization between the hub device 2 and the parent device BSn is out of synchronization.

  In the state shown in FIG. 7, since the reference synchronization signal SYNC generated by the hub device 2 and the frame synchronization signal FL generated by each of the parent devices BS1 and BS2 are synchronized, It can be understood that the synchronization with the base unit BS2 is correct. Then, base unit BSn can grasp that synchronization with master units BS1 and BS2 that are synchronized is not synchronized (synchronization has occurred).

  In this case, the synchronization shift can be eliminated by replacing the LAN cable LC (n) connecting the hub device 2 and the base unit BSn with a normal one. In addition, since a LAN cable longer than specified or a nonstandard LAN cable is used, the reference synchronization signal SYNC and the frame synchronization signal FL may cause a synchronization error. Even in such a case, the synchronization error can be eliminated by simply changing the LAN cable used for connection to an appropriate one. Thus, since the location where the synchronization deviation occurs can be accurately identified, it is possible to realize the early elimination of the synchronization deviation by taking an appropriate response to the location.

[Another example of hub device (1)]
By the way, when the area where the business phone system is built is wide or spreads over a plurality of floors, there may be a case where a sufficient number of cordless telephone devices cannot be connected to the main device 1 with only one hub device 2. In such a case, it is conceivable to connect another hub device as a lower device to the hub device 2. However, in the case of the hub apparatus 2 described with reference to FIG. 4, since a path for transmitting the reference synchronization signal SYNC to the host apparatus is not provided, the occurrence of synchronization deviation between the hub apparatuses cannot be detected.

  Accordingly, the hub device 2A of another example of the hub device described below receives the reference synchronization signal SYNC (upper) from the higher-level device and synchronizes with the reference synchronization signal SYNC (lower-order) by itself. ) Can be generated. Further, the hub device 2A can transmit the reference synchronization signal SYNC (lower level) generated in the own device to the higher level device.

  FIG. 8 is a block diagram for explaining the hub device 2A. In the hub device 2A shown in FIG. 8, the same reference numerals are given to the same components as those of the hub device 2 described with reference to FIG. 4, and a detailed description thereof will be omitted because it is duplicated. As can be seen by comparing the hub device 2A in FIG. 8 with the hub device 2 in FIG. 4, the configuration of the LAN I / F 21A and the synchronization signal generation circuit 25A on the host device side is the same as that of the hub device 2 shown in FIG. Is different.

  That is, the LAN I / F 21A of the hub apparatus 2A transmits the data line, the reference synchronization signal upper line for transmitting the reference synchronization signal SYNC (upper) from the upper apparatus, and the reference synchronization signal SYNC (lower) from the own apparatus. And a reference sync signal lower line. The synchronization signal generation circuit 25A receives the reference synchronization signal SYNC (upper) and the reference signal from the oscillator 24 from the host device received through the LAN I / F 21A, and receives the reference synchronization signal SYNC (upper) from the host device. A reference synchronization signal SYNC having a period of 130 ms that is synchronized with is generated and output.

  The reference synchronization signal SYNC output from the synchronization signal generation circuit 25A is similar to the case of the hub device 2 described with reference to FIG. 4, and the LAN I / Fs 23 (1) to 23 (n) on the lower device side and the LAN cable Through a reference signal line, it is provided to lower-level devices such as cordless telephone devices 31 to 3n. Further, as shown in FIG. 8, the reference synchronization signal SYNC output from the synchronization signal generation circuit 25A is sent to the hub device 2 positioned higher through the LAN I / F 21A on the host device side and the reference synchronization signal lower line of the LAN cable. Alternatively, it is provided to another hub device 2A. In other words, in this example, the hub device 2 and other hub devices 2A exist above the hub device 2A.

  The hub device 2 (FIG. 4) and the other hub device 2 </ b> A (FIG. 8) located at the upper level correspond to the LAN I / Fs 23 (1) to 23 (n) to which the lower level devices are connected. 1) to 26 (n) are provided. The comparison units 26 (1) to 26 (n) are supplied with the reference synchronization signal SYNC generated by the synchronization signal generation circuits 25 and 25A of the own device, and the frame synchronization signal FL or the reference synchronization from the lower apparatus. A signal SYNC (lower order) is supplied to perform phase comparison.

  That is, when the subordinate devices connected to the LAN I / Fs 23 (1) to 23 (n) are the parent devices BS1 to BSn of the cordless telephone devices 31 to 3n, the comparison units 26 (1) to 26 (n) Is supplied with a frame synchronization signal FL generated by the base units BS1 to BSn. On the other hand, when the subordinate device connected to the LAN I / Fs 23 (1) to 23 (n) is the hub device 2A, the comparison unit 26 (1) to 26 (n) generates the data in the hub device 2A. The reference synchronization signal SYNC (lower order) is supplied.

  Each of the comparison units 26 (1) to 26 (n) normally performs phase comparison between a reference synchronization signal having a period of 130 ms and a frame synchronization signal having a period of 10 ms. Therefore, as described above, for comparison, the phase difference between, for example, the rising edge of the reference synchronization signal SYNC and the rising edge of the latest frame synchronization signal FL is obtained. However, when the hub device 2A exists at the lower level, each of the comparison units 26 (1) to 26 (n) transmits a frame synchronization signal having a 10 ms period and a 130 ms reference synchronization signal SYNC (lower level) from the lower level device. One of them is supplied.

  However, if the reference synchronization signal SYNC is divided by 13, the frame synchronization signal FL can be formed, and if the frame synchronization signal FL is multiplied by 13, the reference synchronization signal SYNC can be formed. That is, the reference synchronization signal SYNC and the frame synchronization signal FL are in a frequency division / multiplication relationship, and the synchronization is inherently correct even if the periods are different.

  there. Each of the comparison units 26 (1) to 26 (n) has the reference synchronization signal SYNC (lower order) from the hub apparatus 2A even if the signal from the lower order apparatus is the frame synchronization signal FL from the base unit BS1 to BSn. However, in comparison, for example, by detecting a phase difference between, for example, the rising edge of the reference synchronization signal SYNC and the rising edge of the latest frame synchronization signal FL, it is possible to detect the synchronization shift. Accordingly, if the phase difference is within the predetermined range, no synchronization deviation has occurred, and if the phase difference is outside the predetermined range, it can be detected that the synchronization deviation has occurred.

  As described above, when the hub device 2A (lower device) is connected to the hub device 2 (higher device), the reference synchronization signal SYNC generated by the hub device 2A is transmitted from the hub device 2. It is generated using the reference synchronization signal SYNC (upper order). For this reason, normally, the synchronization of the reference synchronization signal SYNC (higher level) of the hub device 2 that is the higher level device and the reference synchronization signal SYNC (lower level) of the hub device 2A that is the lower level device should match.

  However, if the reference synchronization signal SYNC (upper) from the hub device 2 as the upper device is not properly provided to the hub device 2A as the lower device due to disconnection of the upper line of the reference synchronization signal of the LAN cable, both A synchronization error occurs during Even in this case, by using the hub device 2A as a lower device, in the hub device 2 which is a higher device, the comparison units 26 (1) to 26 (n) and the LED drivers 27 (1) to 27 (n) The function of the LED units 28 (1) to 28 (n) can also detect and report a synchronization shift between the own device (hub device 2) and the hub device 2A as a lower device.

[Notification regarding synchronization when the hub device 2A exists below the hub device 2]
FIG. 9 is a diagram for explaining an example of a synchronization deviation notification mode by the LED in the telephone system in which the hub device 2A exists below the hub device 2. As shown in FIG. 9, the hub device 2 is connected to the main device 1, and the base devices BS1, BS2,... Of the cordless telephone device and the hub device 2A (1) are connected as subordinate devices of the hub device 2. Has been. The hub device 2A (1) is connected to the parent device BS11, BS12,... And the hub device 2A (2). Base units BS21 to BS2n are connected to hub device 2A (2).

  Each of base units BS1, BS2,..., Base units BS11, BS12,..., And base units BS21 to BS2n has the configuration shown in FIG. Each of the hub devices 2A (1) and 2A (2) has the configuration shown in FIG. Further, in each of the hub device 2 and the hub devices 2A (1) and 2A (2), the connection ports PT (1) to PT (n) constitute the connection end of the LAN cable, and the corresponding LAN I / F23 (1) to 23 (n) are connected. In FIG. 9, illustration of LAN I / Fs 23 (1) to 23 (n) and the like is omitted.

  Then, as shown in FIG. 9, a disconnection occurs in the reference synchronization signal upper line of the LAN cable LCA connecting the hub device 2 and the hub device 2A (1), and the reference synchronization signal SYNC from the hub device 2 is generated. It is assumed that (higher level) is not supplied to the hub device 2A (1). Similarly, a disconnection occurs in the reference synchronization signal line of the LAN cable LCB connecting between the hub device 2A (2) and the base unit BS22, and the reference synchronization signal SYNC from the hub device 2A (1) is the parent. Assume that the machine BS22 is not supplied. All other connections shall be made appropriately.

  In this case, in the LED unit 28 (n) of the hub device 2 located immediately below the main device 1, the green LED is turned off and the red LED is turned on by the functions of the comparison unit 26 (n) and the LED driver 27 (n). It will be in the state. Thereby, it is notified that a synchronization error has occurred between the hub device 2 and the hub device 2A (1). Further, the LED unit 28 (2) of the hub device 2A (2) positioned at the lowest position in the hub device depends on the functions of the comparison unit 26 (2) and the LED driver 27 (2) of the hub device 2A (2). The green LED is turned off and the red LED is turned on. Thereby, it is notified that a synchronization error has occurred between the hub device 2A (2) and the base unit BS22. Since the other LED units are all in the state in which the green LED is lit and the red LED is turned off, no synchronization deviation occurs between the devices connected through the corresponding connection ports. .

  However, in practice, since a synchronization error occurs between the hub device 2 and the hub device 2A (1), the parent devices BS1, BS2,... Connected to the hub device 2 and the hub device 2A (1). .., BS21, BS22,... Connected to the hub device 2A (2) is out of synchronization. However, instead of notifying the device in which the synchronization error has occurred, it is possible to notify which device the synchronization error has occurred. Therefore, synchronization between the devices such as changing the LAN cable to an appropriate one is possible. By taking appropriate measures to eliminate the deviation, the entire telephone system can be synchronized.

  Therefore, even when a large-scale business phone system is configured using the hub device 2 or the plurality of hub devices 2A, the light emission states of the LED units 28 (1) to 28 (n) in the hub devices 2 and 2A are maintained. Based on this, it is possible to reliably identify the devices that are out of synchronization. Then, it is possible to promptly take appropriate measures such as replacement of the LAN cable so that all the telephone terminals accommodated in the main device 1 such as a cordless telephone device can be used appropriately.

[Another example of hub device (2)]
By the way, there is a case where the cause of the synchronization error is not the LAN cable connecting the devices. For example, in the base units BS1 to BSn and the hub devices 2 and 2A, the accuracy of an oscillator that generates a reference signal for generating a system clock is bad, or the oscillator includes an error due to a change in ambient temperature. As a result, a synchronization error may occur. In this case, the synchronization deviation cannot be eliminated by changing the LAN cable.

  Therefore, the hub apparatus 2B, which is another example of the hub apparatus described below, can provide the reference synchronization signal SYNC provided to the lower apparatus to the lower apparatus after correcting the reference synchronization signal SYNC according to the detected amount of synchronization deviation. It is a thing.

  FIG. 10 is a block diagram for explaining the hub device 2B. In the hub apparatus 2B shown in FIG. 10, the same reference numerals are given to the parts configured in the same manner as the hub apparatus 2 described with reference to FIG. 4, and detailed descriptions thereof will be omitted because they are duplicated. As can be seen by comparing the hub device 2B of FIG. 10 and the hub device 2 of FIG. 4, a correction unit is provided between each of the LAN I / Fs 23 (1) to 23 (n) and the synchronization signal generation circuit 25. The difference is that 29 (1) to 29 (n) are provided. Further, each of the comparison units 26A (1) to 26A (n) provided corresponding to each of the LAN I / Fs 23 (1) to 23 (n) corresponds to notification information corresponding to the detected synchronization deviation. A difference is that the correction units 29 (1) to 29 (n) are supplied.

  That is, each of the comparison units 26A (1) to 26A (n) has the same function as the comparison units 26 (1) to 26 (n) of the hub device 2 shown in FIG. Each of the comparison units 26A (1) to 26A (n) receives the reference synchronization signal SYNC from the synchronization signal generation circuit 25 and the corresponding LAN I / Fs 23 (1) to 23 (n) and cordless telephone devices 31 to 3n. The frame synchronization signal is supplied from a lower level device. Then, each of the comparison units 26A (1) to 26A (n) compares the phases of both signals, detects whether or not synchronization has occurred, and determines the detection result as the corresponding LED driver 27 (1 ) To 27 (n).

  Further, each of the comparison units 26A (1) to 26A (n) notifies the corresponding correction units 29 (1) to 29 (n) of the notification information indicating the detected shift amount of both synchronization signals. For example, when the frame synchronization signal FL from the lower-level device is delayed with respect to the reference synchronization signal SYNC, notification information indicating “+ (plus) deviation amount” is formed, and the corresponding correction unit 29 ( 1) to 29 (n) are notified. In addition, when the frame synchronization signal FL from the lower apparatus is advanced with respect to the reference synchronization signal SYNC, notification information that is “− (minus) deviation amount” is formed, and the corresponding correction unit 29 ( 1) to 29 (n) are notified.

  In this case, the “+ shift amount” corresponds to the “delay amount” of the frame synchronization signal FL with respect to the reference synchronization signal SNC. The “−shift amount” corresponds to the “advance amount” of the frame synchronization signal FL with respect to the reference synchronization signal SNC. Each of these “+ deviation amount” and “−deviation amount” is time information such as 1 ms unit, 1/10 ms unit, and 1/100 ms unit. In addition, “+ deviation amount” and “−deviation amount” may be expressed by the number of system clocks.

  Each of the correction units 29 (1) to 29 (n) is configured to update the reference synchronization signal SYNC from the synchronization signal generation circuit 25 based on the notification information indicating the amount of deviation from the comparison units 26 (1) to 26 (n). Correct the period. When the notification information from the comparison units 26 (1) to 26 (n) is “+ shift amount”, the frame synchronization signal is delayed by “+ shift amount” with respect to the reference synchronization signal SYNC. Become. In this case, the correction units 29 (1) to 29 (n) correct the reference synchronization signal SYNC so that the period of the reference synchronization signal SYNC is shortened (early) by the “deviation amount”. In this case, since the period of the original reference synchronization signal SYNC is 130 ms, correction is made to shorten it to, for example, 129 ms, 128 ms, etc. according to the amount of deviation.

  Conversely, when the notification information from the comparison units 26 (1) to 26 (n) is “−shift amount”, the frame synchronization signal FL is advanced by “−shift amount” with respect to the reference synchronization signal SYNC. It will be out. In this case, the correction units 29 (1) to 29 (n) correct the period of the reference synchronization signal SYNC to be longer (slower) by the “shift amount”. Since the period of the original reference synchronization signal SYNC is 130 ms, correction is made to make it longer, for example, 131 ms, 132 ms, etc. according to the amount of deviation.

  It should be noted that the correction unit is not 1 ms unit but can be performed with higher accuracy as described above, such as 1/10 ms unit or 1/100 ms unit. On the contrary, it is possible to make a larger correction such as 2 ms unit or 3 ms unit.

  Each of the correction units 29 (1) to 29 (n) provides the corrected reference synchronization signal SYNC to the lower-level devices such as the cordless telephone devices 31 to 3n through the LAN I / Fs 23 (1) to 23 (n). To do. As a result, the lower-level devices such as the cordless telephone devices 31 to 3n generate the frame synchronization signal FL based on the corrected reference synchronization signal SYNC from the hub device 2B, so that the cycle of the frame synchronization signal FL is adjusted. The synchronization of the reference synchronization signal SYNC generated by the synchronization signal generation circuit 25 of the hub device 2B and the frame synchronization signal generated by the lower devices such as the parent devices BS1 to BSn of the cordless telephone devices 31 to 3 can be synchronized. .

  When the comparators 26A (1) to 26A (n) do not detect synchronization deviation, the notification information indicating the amount of synchronization deviation is 0 (zero) or within a predetermined range that does not require correction. Thus, correction by the correction units 29 (1) to 29 (n) is not performed. Therefore, in this case, the reference synchronization signal from the synchronization signal generation circuit 25 is provided as it is to the lower apparatus through the correction units 29 (1) to 29 (n) and the LAN I / Fs 23 (1) to 23 (n).

  In this way, the function of the hub device 2B allows synchronization between the hub device 2B and a lower level device such as a cordless telephone device connected to the hub device 2B without bothering the user (user). The hub device 2B can be adjusted autonomously.

[Another example of hub device (3)]
FIG. 11 is a block diagram for explaining another example of the hub device 2C. A hub device 2C shown in FIG. 11 has the functions of the hub device 2A shown in FIG. 8 and the hub device 2B shown in FIG. Accordingly, in the hub device 2C shown in FIG. 11, the same reference numerals are given to the parts configured in the same manner as the hub device 2A shown in FIG. 8 and the hub device 2B shown in FIG. Since it overlaps, it abbreviate | omits.

  Then, by using the hub device 2C shown in FIG. 11, both the synchronization deviation between the reference synchronization signal SYNC and the frame synchronization signal and the synchronization deviation between the reference synchronization signal (upper) and the reference synchronization signal (lower) are detected. Notification can be made and synchronization between the two synchronization signals can be automatically performed.

[Effect of the embodiment]
In the case of using the hub device 2 of the above-described embodiment, a synchronization shift is generated between the reference synchronization signal generated by the host device and the frame synchronization signal generated by the parent device of the cordless telephone device which is the lower device. It is possible to report between the generated devices (locations). As a result, it is possible to quickly take an appropriate response for eliminating the synchronization error for the location.

  Further, when the hub device 2A is used, a synchronization deviation occurs between a reference synchronization signal generated by, for example, the hub device 2 that is a higher-level device and a reference synchronization signal generated by the hub device 2A that is a lower-level device. If this is the case, this can be notified. As a result, it is possible to quickly take an appropriate response for eliminating the synchronization error for the location.

  Further, when the hub device 2B of the above-described embodiment is used, it is generated between the reference synchronization signal generated by the host device and the frame synchronization signal generated by the parent device of the cordless telephone device which is the lower device. It is possible to automatically correct the synchronization error and synchronize. In addition, it is possible to notify between devices (locations) causing a synchronization error.

  When the hub device 2B according to the above-described embodiment is used, a reference synchronization signal generated by, for example, the hub device 2 that is a higher-level device and a reference synchronization signal generated by the hub device 2C that is a lower-level device. It is possible to automatically correct the synchronization deviation occurring between the two and synchronize. In addition, it is possible to notify between devices (locations) causing a synchronization error.

[Modification]
When the hub devices 2B and 2C of the above-described embodiment are used, there is a place where the synchronization error is not resolved after the occurrence of the synchronization error is first identified and the LAN cable is replaced. In this case, it is possible to autonomously eliminate the synchronization error. Specifically, when the hub devices 2B and 2C are used, first, the correction units 29 (1) to 29 (n) do not perform correction, and the reference synchronization signals from the synchronization signal generation circuits 25 and 25A are used as they are. / F23 (1) to 23 (n) to be supplied to the subordinate apparatus.

  For example, the correction units 29 (1) to 29 (n) are configured not to function the correction function unless a predetermined enable signal for causing them to function is supplied. Alternatively, until the predetermined control signal is supplied to the comparison units 26 (1) to 26 (n), the comparison units 26 (1) to 26 (n) send notification signals corresponding to the synchronization shift to the correction unit 29 (1). ˜29 (n) should not be supplied.

  In the former case, the hub devices 2B and 2C are provided with an instruction operation unit and an enable signal generation unit for receiving an instruction operation for instructing supply of the enable signal to the correction units 29 (1) to 29 (n). In the latter case, the hub devices 2B and 2C are provided with an instruction operation unit for receiving an instruction operation for instructing supply of predetermined control signals to the comparison units 26 (1) to 26 (n) and a generation unit for the control signals. .

  First, the synchronization unit 26A (1) to 26A (n), the LED drivers 27 (1) to 27 (n), and the LED units 28 (1) to 28 (n) function to cause a synchronization error. Identify the devices between them and take appropriate measures such as replacing the LAN cable with an appropriate one. In this way, all external factors for synchronization loss are eliminated.

  Thereafter, correction processing by the correction units 29 (1) to 29 (n) is performed by a user's instruction operation. In this way, it is possible to appropriately correct only the synchronization shift that has occurred due to internal factors such as inaccuracy of the oscillator of the lower-level device, and to eliminate the synchronization shift. Therefore, an excessive burden is not applied to the correction units 29 (1) to 20 (n).

  In the above-described embodiment, the hub apparatus 2, the hub apparatus 2A, the hub apparatus 2B, and the hub apparatus 2C are always provided below the main apparatus 1. However, the present invention is not limited to this. For example, in the case of a relatively small business phone system, a business phone system may be configured by directly connecting a cordless telephone device to the main device. For this reason, the function of the hub device 2 described with reference to FIG. 4 and the function of the hub device 2B described with reference to FIG. Thereby, it is possible to specify between the devices in which the synchronization deviation occurs by the LED unit of the main apparatus, or to automatically correct the synchronization deviation.

  In the above-described embodiment, the audio signal and the control signal are packetized and provided as packet data, and the reference synchronization signal and the frame synchronization signal are transmitted by using an unused line of the LAN cable as a dedicated transmission line. I did it. However, it is not limited to this. For example, a reference synchronization signal or a frame synchronization signal can be multiplexed with packet data and transmitted.

  In this case, the multiplexing / demultiplexing unit is provided in the previous stage (synchronization signal generation circuit 25, comparison unit 26, and switching control unit 22 side) of the LAN I / Fs 23 (1) to 23 (n) of the hub device 2 or the like. Provide. Then, the signal multiplexed by the multiplexing / demultiplexing unit is transmitted through the LAN I / F 23 (1) to 23 (n), the packet data separated here is supplied to the switching control unit 22, and the frame synchronization signal is transmitted. What is necessary is just to supply to a comparison part.

  On the other hand, a multiplexing / separating unit is provided in the preceding stage (on the packet decomposition / generation unit 421 and PLL unit 424 side) of the LAN I / F 47 of the base units BS1 to BSn. Here, the packet data from the packet disassembly / generation unit 421 and the frame synchronization signal from the synchronization signal generation circuit 43 are multiplexed and transmitted to the host device through the LAN I / F 47. Also, the multiplexed signal received through the LAN I / F 47 is separated by the multiplexing / separating unit, and the separated packet data is supplied to the packet decomposing / generating unit 421, or the reference synchronization signal SYNC is supplied to the PLL unit 424. You can do it.

  In the hub devices 2, 2A, 2B, and 2C according to the above-described embodiments, the two-color LEDs of the green LED and the red LED are used. However, the present invention is not limited to this. For example, if only a red LED is used and a synchronization error has occurred, the red LED is turned on or blinked. If a synchronization error has not occurred, the red LED is turned off to cause a synchronization error. You may make it alert | report the presence or absence of generation | occurrence | production of. Further, the emission color of the LED used is not limited to green and red, and various colors can be used.

  Further, in the hub devices 2, 2A, 2B, and 2C according to the above-described embodiments, the presence or absence of the occurrence of synchronization deviation is notified through the LED units 28 (1) to 28 (n). However, the present invention is not limited to this. . The hub devices 2, 2A, 2B, and 2C may be provided with an LCD (Liquid Crystal Display) and an LCD controller, and the presence / absence of occurrence of a synchronization shift may be notified through the LCD.

[Others]
The function of the first synchronization signal generation means of the host device in the claims is realized by the synchronization signal generation circuit 25 of the hub device 2 of the embodiment, and the first sending means and the first reception of the host device in the claims The functions of the means are realized mainly by the LAN I / Fs 23 (1) to 23 (n) of the hub device 2 of the embodiment. Further, the function of the comparison means of the higher-level device in the claims is realized by the comparison units 26 (1) to 26 (n) of the hub devices 2, 2A, 2B, and 2C of the embodiment, and the notification of the higher-level device in the claims is made. The function of the means is realized mainly by the LED units 28 (1) to 28 (n) of the hub devices 2, 2A, 2B, and 2C of the embodiment.

  The functions of the second receiving means and the second sending means of the subordinate device in the claims are realized by the LAN I / F 47 such as the base unit BS1 of the embodiment, and the second synchronization signal of the subordinate device in the claim The function of the generation means is realized by the synchronization signal generation circuit 43 such as the base unit BS1 of the embodiment.

  Further, the correction unit 29 (1) to 29 (n) of the hub devices 2B and 2C of the embodiment realizes the function of the correction means of the host device of the embodiment. Further, the functions of the third sending means and the third receiving means of the host device in the claims are realized mainly by the LAN I / F 21A of the hub devices 2B and 2C of the embodiment.

DESCRIPTION OF SYMBOLS 1 ... Main apparatus, 101 ... Connection port to IP network, 102 ... IP network I / F, 103 ... Packet disassembly / generation part, 104 ... Telephone network I / F, 105 ... Connection port to telephone network, 106 ... Address Management DB, 107 ... LAN I / F, 108 ... LAN connection port, 110 ... control unit, 2, 2A, 2B, 2C ... hub device, 21, 21A ... LAN I / F, 22 ... switch control unit, 23 (1)- 23 (n) ... LAN I / F, 24 ... oscillator, 25, 25A ... synchronization signal generation circuit, 26 (1) to 26 (n) ... comparison unit, 26A (1) -26A (n) ... comparison unit, 27 ( 1) -27 (n) ... LED driver, 28 (1) -28 (n) ... LED unit, 29 (1) -29 (n) ... correction unit, 31-3n ... cordless telephone device, BS1-BSn ... parent Machine 41... Control circuit 42 line LSI unit 42 ... Packet decomposition / generation unit, 422 ... Control signal processing unit, 423 ... Audio signal processing unit, 424 ... PLL unit, 43 ... Synchronization signal generation circuit, 431 ... Counter, 432 ... Synchronization signal generation unit, 44 ... Wireless communication circuit, 441 ... Control unit, 442 ... TDMA modulation / demodulation unit, 4421 ... PLL unit, 443 ... Wireless communication unit, 45 ... Oscillator, 46 ... Oscillator, HS1 to HSn ... Slave unit, 47 ... LAN I / F

Claims (6)

A plurality of lower-level devices such as a cordless telephone device composed of a parent device and a child device and a hub device to which the cordless telephone device is connected are connected to the upper device, and between the parent device and the child device. The unit communication period is divided into a plurality of slots, and at least one slot is used in each of communication from the parent device to the child device and communication from the child device to the parent device, and TDMA (Time Division Multiple Access) is used. Connection) / TDD (Time Division Duplex) system for performing a wireless communication,
The host device is
First synchronization signal generation means for generating a first synchronization signal to be supplied to each of the lower-level devices;
First sending means for sending the first synchronizing signal generated by the first synchronizing signal generating means to each of the lower-level devices;
First receiving means for receiving a second synchronization signal generated based on the first synchronization signal from each of the lower-level devices;
The second synchronization signal received from each of the lower order devices received through the first receiving means is compared with the first synchronization signal from the first synchronization signal generating means to detect a synchronization error. Comparing means to
Informing means for informing the comparison result in the comparing means for each of the lower devices connected to the own device,
Each of the subordinate devices
Second accepting means for accepting the first synchronization signal from the host device;
Based on the first synchronization signal received through the second reception means, second synchronization signal generation means for generating the second synchronization signal used in the own device;
A telephone system comprising: a second sending means for sending the second synchronizing signal generated by the second synchronizing signal generating means to the host device. A plurality of lower-level devices such as a cordless telephone device composed of a parent device and a child device and a hub device to which the cordless telephone device is connected are connected to the upper device, and between the parent device and the child device. The unit communication period is divided into a plurality of slots, and at least one slot is used in each of communication from the parent device to the child device and communication from the child device to the parent device, and TDMA (Time Division Multiple Access) is used. Connection) / TDD (Time Division Duplex) system for performing a wireless communication,
The host device is
First synchronization signal generation means for generating a first synchronization signal to be supplied to each of the lower-level devices;
First sending means for sending the first synchronizing signal generated by the first synchronizing signal generating means to each of the lower-level devices;
First receiving means for receiving a second synchronization signal generated based on the first synchronization signal from each of the lower-level devices;
The second synchronization signal received from each of the lower order devices received through the first receiving means is compared with the first synchronization signal from the first synchronization signal generating means to detect a synchronization error. Comparing means to
When the comparison result of the comparison means indicates the occurrence of synchronization deviation, based on the comparison result, the first synchronization signal generated by the first synchronization signal generator supplied to the synchronization deviation occurrence source Correcting means for correcting a signal and supplying the signal to the generation source of the synchronization deviation through the first sending means,
Each of the subordinate devices
Second accepting means for accepting the first synchronization signal from the host device;
Based on the first synchronization signal received through the second reception means, second synchronization signal generation means for generating the second synchronization signal used in the own device;
A telephone system comprising: a second sending means for sending the second synchronizing signal generated by the second synchronizing signal generating means to the host device. A plurality of lower-level devices such as a cordless telephone device composed of a parent device and a child device and a hub device to which the cordless telephone device is connected are connected to the upper device, and between the parent device and the child device. The unit communication period is divided into a plurality of slots, and at least one slot is used in each of communication from the parent device to the child device and communication from the child device to the parent device, and TDMA (Time Division Multiple Access) is used. Connection) / TDD (Time Division Duplex) type telephone system subordinate device for performing wireless communication,
The higher-level device includes a first synchronization signal generation unit that generates a first synchronization signal to be supplied to each of the lower-level devices, and the first synchronization signal generated by the first synchronization signal generation unit. First sending means for sending to each of the lower devices, first receiving means for receiving a second synchronization signal generated based on the first synchronization signal from each of the lower devices, and the first A comparison for detecting a synchronization shift by comparing the second synchronization signal received from each of the lower-order devices with the first synchronization signal received from the first synchronization signal generation unit, received through one reception unit. Means, and based on the comparison result of the comparison means, it is possible to report the deviation between the first synchronization signal and the second synchronization signal, or to correct the deviation,
The subordinate device is:
Second accepting means for accepting the first synchronization signal from the host device;
Based on the first synchronization signal received through the second reception means, second synchronization signal generation means for generating the second synchronization signal used in the own device;
A subordinate apparatus of a telephone system, comprising: a second sending means for sending the second synchronizing signal generated by the second synchronizing signal generating means to the higher order apparatus. A plurality of lower-level devices such as a cordless telephone device composed of a parent device and a child device and a hub device to which the cordless telephone device is connected are connected, and a plurality of unit communication periods are set between the parent device and the child device. In each of the communication from the parent device to the child device and the communication from the child device to the parent device, TDMA (Time Division Multiple Access) / TDD (Time Division Multiple Access) is used by using at least one slot. (Division Duplex) A high-order device of a telephone system that performs wireless communication of a method,
The lower-level device uses the second synchronization unit that receives the first synchronization signal from the higher-level device and the first synchronization signal received through the second reception unit. Second synchronization signal generation means for generating a second synchronization signal; and second transmission means for transmitting the second synchronization signal generated by the second synchronization signal generation means to the host device. It is prepared
First synchronization signal generation means for generating a first synchronization signal to be supplied to each of the lower-level devices;
First sending means for sending the first synchronizing signal generated by the first synchronizing signal generating means to each of the lower-level devices;
First receiving means for receiving a second synchronization signal generated based on the first synchronization signal from each of the lower-level devices;
The second synchronization signal received from each of the lower order devices received through the first receiving means is compared with the first synchronization signal from the first synchronization signal generating means to detect a synchronization error. Comparing means to
A higher-level device of a telephone system, comprising: a notification unit that notifies a comparison result of the comparison unit for each lower-level device connected to the own device. A plurality of lower-level devices such as a cordless telephone device composed of a parent device and a child device and a hub device to which the cordless telephone device is connected are connected, and a plurality of unit communication periods are set between the parent device and the child device. In each of the communication from the parent device to the child device and the communication from the child device to the parent device, TDMA (Time Division Multiple Access) / TDD (Time Division Multiple Access) is used by using at least one slot. (Division Duplex) A high-order device of a telephone system that performs wireless communication of a method,
The lower-level device uses the second synchronization unit that receives the first synchronization signal from the higher-level device and the first synchronization signal received through the second reception unit. Second synchronization signal generation means for generating a second synchronization signal; and second transmission means for transmitting the second synchronization signal generated by the second synchronization signal generation means to the host device. It is prepared
First synchronization signal generation means for generating a first synchronization signal to be supplied to each of the lower-level devices;
First sending means for sending the first synchronizing signal generated by the first synchronizing signal generating means to each of the lower-level devices;
First receiving means for receiving a second synchronization signal generated based on the first synchronization signal from each of the lower-level devices;
The second synchronization signal received from each of the lower order devices received through the first receiving means is compared with the first synchronization signal from the first synchronization signal generating means to detect a synchronization error. Comparing means to
When the comparison result of the comparison means indicates the occurrence of synchronization deviation, based on the comparison result, the first synchronization signal generated by the first synchronization signal generator supplied to the synchronization deviation occurrence source A high-order apparatus of a telephone system, comprising: correction means for correcting a signal and supplying the signal to the generation source of synchronization loss through the first sending means. A higher-level device of the telephone system according to claim 4 or 5,
Third accepting means for accepting a synchronization signal from another host device above the own device;
A third sending means for sending the first synchronizing signal generated by the synchronizing signal generating means to the other host device;
The higher-level apparatus of the telephone system, wherein the first synchronization signal generation means generates the first synchronization signal based on the synchronization signal received through the third reception means.

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