Telephone system, telephone control apparatus, and base unit of cordless telephone apparatus

Abstract

To provide a telephone system in which a communication band between a master unit and a slave unit of a used cordless telephone device is not oppressed even when an incoming call occurs, and the slave unit does not wastefully consume power.SOLUTION: When receiving the provision of the simultaneous incoming call notice from the master set 1, the master set CS1 informs the user about the occurrence of the incoming call through a display section 47 and a ringer. Upon the receipt of an incoming call reply operation from a user through an operation section 49, a tentative reply section 411 generates a tentative reply and provides it to a master unit 1, and a link connection request section 412 generates a link connection request and provides it to a slave unit PS1 wirelessly connected to its own unit. When mutual radio communication becomes possible with the slave unit PS1 to which the link connection request is provided through the link connection request part 412, an incoming call response part 413 forms an incoming call response and provides it to the main device 1.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a telephone system configured by connecting a cordless telephone device, in which a base unit and a handset are wirelessly connected, to a telephone control device such as a main unit or a SIP (Session Initiation Protocol) server, a telephone control device used in the telephone system, and a base unit of the cordless telephone device. [Background technology]

[0002] In recent years, business phone systems (button telephone systems) have been configured by connecting cordless telephone devices to telephone control devices such as main units and SIP servers. A cordless telephone device functions as a single telephone device by wirelessly connecting a base unit and a handset. In a telephone system configured using cordless telephone devices, it is necessary to minimize the influence of other nearby telephone systems and ensure proper communication through the cordless telephone devices housed in the telephone control device. For this reason, Patent Document 1, described below, discloses an invention relating to a telephone system in which, in response to instructions from the main unit, the base unit receives surrounding signals, measures information about the signals, and notifies the main unit of this information, and the main unit controls the timing of signal transmission from the base unit to the handset. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-119655 Summary of the Invention [Problem to be solved by the invention]

[0004] In telephone systems using cordless telephone devices, the effects of other nearby telephone systems are not the only problem. When multiple cordless telephone devices are connected to a main unit, there are problems such as a congestion of the communication bandwidth between the base unit and the handset when a call is received, and an increase in the power consumption of the handset when a call is received. For example, the DECT (Digital Enhanced Cordless Telecommunication) standard is sometimes used as a communication method between the base unit and the handset that make up a cordless telephone system.

[0005] As disclosed in detail in Patent Document 1, the DECT standard specifies that the communication method for the downlink from the master unit to the slave unit is a time division duplex method using time division multiplexing, and that the communication method for the uplink from the slave unit to the master unit is a time division multiple access method. The DECT standard also specifies that the frequency band to be used is the "1.9 GHz band," and that the number of channels is a maximum of five.

[0006] In the DECT standard, one channel of coded data is divided into frames of 10 milliseconds (ms), and each frame is divided into 24 time slots as shown in Fig. 9 of Patent Document 1. In the following, time slots will be simply referred to as slots. Twelve slots S0 to S11 in the first half frame period of one frame are used for downlink from the parent device to the child devices, and 12 slots S12 to S23 in the second half frame period are used for uplink from the child devices to the parent device.

[0007] In DECT-compliant cordless telephone devices used in business phone systems, unless the power is off, each cordless telephone device uses one of the 12 slots in standby (idle) mode to transmit various control information, including synchronization signals, from the base unit to the handset. This slot (control signal slot) is called a dummy bearer. While multiple handsets are typically connectable to a base unit, control information is transmitted to each handset using one slot (dummy bearer) in standby mode, whether only one handset is connected to the base unit or multiple handsets are connected. In this case, no information is transmitted from the handset to the base unit.

[0008] Suppose that an incoming call is received from this standby state, and the telephone control device notifies the base unit of the incoming call. In this case, the base unit uses a dummy bearer to notify each handset of a link connection request (data session connection request), and the handset searches for an available slot and contacts the base unit to attempt to acquire a slot to use for communication. The link connection request is a request to create an environment in which the base unit and handset can communicate with each other, and is not intended to notify the base unit of the incoming call. Then, once a slot for mutual communication between the base unit and handset has been acquired in response to the link connection request, the base unit releases the dummy bearer and notifies the base unit of the incoming call using the acquired downlink slot. At the same time, the base unit also identifies an uplink slot so that it can receive information from the handset.

[0009] In this way, the pair of downlink slots and uplink slots acquired for mutual communication between the parent device and the child device are called a traffic bearer. Various control information, including synchronization signals, is transmitted through the traffic bearer, and after a call line is connected to the other party, voice information is also transmitted. Because various control information and the like are transmitted through the traffic bearer, the process of identifying (acquiring) the traffic bearer and releasing the dummy bearer is called merging the dummy bearer into the traffic bearer.

[0010] Therefore, when a call is received at a telephone control device in a business phone system, the telephone control device simultaneously notifies the base units of the subordinate cordless telephone devices of the call. In this case, each base unit simultaneously sends a link connection request to each handset, and the handset units simultaneously search for an available slot and contact the base unit to attempt to acquire a slot for communication. As mentioned above, there are only 12 slots for both uplink and downlink. Therefore, if each cordless telephone device simultaneously attempts to acquire a traffic bearer, they may compete for the slot, constricting the communication bandwidth and preventing a rapid link connection (acquisition of a traffic bearer) between the base unit and the handset. Furthermore, the handset units of the cordless telephone devices are battery-powered. Therefore, if each handset were to search for an available slot and contact the base unit to acquire a slot for communication in response to a link connection request every time a call was received, the power consumption of all the handset units of the cordless telephone devices would increase, resulting in a shortened battery life.

[0011] In view of the above, the object of the present invention is to prevent the wireless communication bandwidth between the base unit and the handset from being constricted and the handset from wasting power when an incoming call occurs in a telephone system formed using a plurality of cordless telephone devices in which the base unit and the handset are wirelessly connected. [Means for solving the problem]

[0012] In order to solve the above problem, the telephone system of the invention described in claim 1 comprises: A telephone system in which a plurality of base units of cordless telephone devices, each of which comprises a base unit and a handset connected by wireless communication, are connected to a telephone control device connected to a wide area network, the base units being connected to the telephone control device, The telephone control device a simultaneous incoming call notification means for starting to provide simultaneous incoming call notifications to the plurality of base units connected to the device when an incoming call occurs on a telephone line accommodated in the device; a simultaneous incoming call canceling means for canceling the simultaneous incoming call notifications to base units other than the one base unit that is the sender of the provisional response when a provisional response arrives from one of the plurality of base units; a communication line connection means for connecting a communication line between the base unit that has transmitted the provisional response and a telephone terminal that is a call originator when an incoming call response arrives from the base unit that has transmitted the provisional response, thereby enabling a call between the telephone terminal that is a call originator and the handset that is wirelessly connected to the base unit; Equipped with Each of the plurality of base units an incoming call notification means for notifying a user of an incoming call occurrence when the simultaneous incoming call notification is provided from the telephone control device; a receiving means for receiving an incoming call response operation from a user; a provisional response means for forming the provisional response and providing it to the telephone control device when the incoming call response operation is accepted through the accepting means; a link connection requesting means for generating a link connection request when the receiving means receives the call response operation and providing the link connection request to the handset that is wirelessly connected to the handset; an incoming call response means for forming the incoming call response and providing it to the telephone control device when wireless communication becomes possible between the handset that has provided the link connection request through the link connection request means; The present invention is characterized by comprising:

[0013] According to the telephone system of the invention described in claim 1, in the telephone control device, when an incoming call occurs on the telephone line accommodated in the device, the simultaneous incoming call notification means starts providing simultaneous incoming call notifications to multiple base units connected to the device. When a provisional response arrives from one of the multiple base units, the simultaneous incoming call cancellation means cancels the simultaneous incoming call notifications to base units other than the one base unit that sent the provisional response. When an incoming call response arrives from the one base unit that sent the provisional response, the communication line connection means connects a communication line between the one base unit that sent the provisional response and the calling telephone terminal, enabling a call between the calling telephone terminal and a handset wirelessly connected to the one base unit.

[0014] In each of the plurality of base units, when a simultaneous incoming call notification is provided from the telephone control device, the incoming call notification means notifies the user of the occurrence of an incoming call. In this case, when an incoming call response operation from the user is received through the reception means, the provisional response means forms a provisional response and provides it to the telephone control device, and the link connection request means forms a link connection request and provides it to the handset that is wirelessly connected to the base unit. When wireless communication with the handset that provided the link connection request through the link connection request means becomes possible, the incoming call response means forms an incoming call response and provides it to the telephone control device.

[0015] As a result, after the simultaneous call notification, all other calls to the base units other than the base unit that was answered by the user are canceled, and the base unit that was answered sends a link connection request to the handset, thereby creating a state in which only the cordless telephone unit that has the answered base unit functions, allowing the cordless telephone unit that has the answered base unit to answer the call. [Effects of the Invention]

[0016] According to this invention, after a simultaneous call notification is sent, all other calls to the base unit other than the base unit that was answered are canceled, and only the cordless telephone device that has the answered base unit functions. As a result, when an incoming call occurs, no cordless telephone device other than the cordless telephone device that has the answered base unit functions, which prevents congestion on the communication bandwidth between the base unit and the handset and prevents the handset from wasting power. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a diagram illustrating an example of the configuration of a business phone system according to an embodiment; [Figure 2] 2 is a block diagram illustrating an example of the configuration of a main unit used in the business phone system according to the embodiment. FIG. [Figure 3] 1 is a block diagram illustrating an example of the configuration of a base unit of a cordless telephone device used in a business phone system according to an embodiment of the present invention. [Figure 4] 1 is a block diagram illustrating an example of the configuration of a handset of a cordless telephone device used in a business phone system according to an embodiment of the present invention. [Figure 5] FIG. 2 is a sequence diagram for explaining the operation of the business phone system according to the embodiment. [Figure 6] 4 is a flowchart for explaining processing performed by the main unit 1 of the business phone system according to the embodiment. [Figure 7] 10 is a flowchart for explaining processing performed by a base unit CS1 of the business phone system according to the embodiment. [Figure 8] 8 is a flowchart continuing from FIG. 7. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, with reference to the drawings, an embodiment of a telephone system according to the present invention and the devices used in the telephone system, namely, a telephone control device and a base unit for a cordless telephone device, will be described. In the embodiment described below, the telephone system according to the present invention will be described as being applied to a so-called business phone system formed, for example, in a company office. Furthermore, the main unit used in the business phone system is an embodiment of the telephone control device according to the present invention, and the base unit for a cordless telephone device used in the business phone system is an embodiment of the base unit for a cordless telephone device according to the present invention.

[0019] [Business phone system configuration example] Figure 1 is a diagram illustrating an example of the configuration of a business phone system according to this embodiment. For simplicity's sake, this embodiment will be described using an example in which a business phone system is configured by connecting three cordless telephone devices 21, 22, and 23 to a main unit 1, as shown in Figure 1. However, the present invention is not limited to this example, and it is of course possible to connect even more cordless telephone devices to the main unit 1 and configure a larger-scale business phone system.

[0020] Each of the cordless telephone devices 21, 22, and 23 comprises a cell station CS1, CS2, or CS3 as a base unit and a personal station PS1, PS2, or PS3 as a handset. Hereinafter, the cell stations CS1, CS2, and CS3 will be referred to as base units CS1, CS2, and CS3, and the personal stations PS1, PS2, and PS3 will be referred to as handset units PS1, PS2, and PS3. Each of the base units CS1, CS2, and CS3 and each of the handset units PS1, PS2, and PS3 are wirelessly connected.

[0021] It is also possible to wirelessly connect multiple handset units to each of the base units CS1, CS2, and CS3. However, for simplicity, this embodiment will be described assuming that one handset unit is connected to one base unit. Also, although not shown, the extension telephone units connected to the main unit 1 can be not only cordless telephone units 21, 22, and 23, but also digital key telephone terminals, as in a normal business phone system.

[0022] In this embodiment, wireless connections between base units CS1, CS2, and CS3 of cordless telephone devices 21, 22, and 23 and respective handset units PS1, PS2, and PS3 are made by the TDMA / TDD method using the DECT standard (method) for digital cordless telephones. Main unit 1 can accommodate one or more telephone lines L1 to Lm (m is an integer of 2 or greater). Base units CS1, CS2, and CS3 of cordless telephone devices 21, 22, and 23 are connected to main unit 1. In the example of FIG. 1, base units CS1, CS2, and CS3 are connected to main unit 1 by wire, but wireless connection is also possible.

[0023] The main unit 1 performs call control and circuit switching control for the multiple cordless telephone devices 21, 22, and 23, as well as other business phone control functions, and also has the function of supplying a reference synchronization signal SYNC to each of the multiple cordless telephone devices 21, 22, and 23. In this example, the reference synchronization signal SYNC is a signal with a period of 130 milliseconds (ms).

[0024] Each of base units CS1, CS2, and CS3 of cordless telephone devices 21, 22, and 23 synchronizes with reference synchronization signal SYNC from main unit 1 to generate a frame synchronization signal as a synchronization signal with a period of one frame (10 milliseconds (ms)), which is the unit communication period of a DECT-standard digital cordless telephone, and performs TDMA / TDD wireless communication using the DECT standard with handset units PS1, PS2, and PS3 based on the generated frame synchronization signal. Therefore, all of multiple cordless telephone devices 21, 22, and 23 operate in synchronization with reference synchronization signal SYNC from main unit 1.

[0025] 1, each of cordless telephone devices 21, 22, and 23 is a telephone terminal that is connected to main unit 1 and forms part of a business phone system. For this reason, call control signals such as incoming call notifications and outgoing call requests, as well as other control signals, are sent and received between main unit 1. Note that other control signals include, for example, control signals for controlling the LCDs (Liquid Crystal Displays) and LEDs (Light Emitting Diodes) of cordless telephone devices 21, 22, and 23 to notify the user of the operating status of other cordless telephone devices connected to main unit 1.

[0026] Typically, each of the base units CS1, CS2, and CS3 is installed at a predetermined location in an office. As a result, as shown in Fig. 1, the base unit CS1 can communicate with the slave units PS1 and the like within a wireless communication area Ar1, and the base unit CS2 can communicate with the slave units PS2 and the like within a wireless communication area Ar2. Furthermore, the base unit CS3 can communicate with the slave units PS3 and the like within a wireless communication area Ar3.

[0027] In this way, each of the base units CS1, CS2, and CS3 and each of the slave units PS1, PS2, and PS3 form wireless communication areas Ar1, Ar2, and Ar3, respectively, where wireless communication is possible, based on their respective communication functions. The wireless communication areas Ar1, Ar2, and Ar3 are set up so that they overlap slightly. This allows the slave units PS1, PS2, and PS3 to switch between the base units CS1, CS2, and CS3 with which they communicate, allowing them to communicate while moving within the wireless communication areas Ar1, Ar2, and Ar3.

[0028] In this embodiment, the base units CS1, CS2, and CS3 of the cordless telephone devices 21, 22, and 23 are provided with user interfaces such as a ringer, LCD, LED, and operation unit, and also realize the function of connecting the main unit 1 and the handset units PS1, PS2, and PS3. The handset units PS1, PS2, and PS3 of the cordless telephone devices 21, 22, and 23 are not provided with user interfaces such as a ringer, LCD, LED, and operation unit, but function as so-called handsets (transmitters and receivers) equipped with a receiver and a transmitter.

[0029] Of course, the above-described configurations of the cordless telephone devices 21, 22, and 23 are merely examples. In some cases, the base unit only functions to connect the main unit and the handset, and the handset is equipped with a user interface such as a ringer, LCD, LED, and operation unit. Therefore, even in this embodiment, the handset PS1, PS2, and PS3 may also be equipped with a user interface such as a ringer, LCD, LED, and operation unit. However, in this embodiment, as will be described later, before the base unit and the handset are able to communicate with each other (a traffic bearer state), it is necessary to notify the user of an incoming call through the base units CS1, CS2, and CS3 and accept a response operation from the user. Therefore, in this embodiment, the base units CS1, CS2, and CS3 are equipped with a user interface such as a ringer, LCD, LED, and operation unit.

[0030] As mentioned above, in a conventional business phone system configured using cordless telephone devices, when there is an incoming call (an external call) on a telephone line accommodated by the main unit, the main unit notifies all subordinate cordless telephone devices of the incoming call (providing simultaneous incoming call notification). However, in cordless telephone devices, as mentioned above, normally, rather than immediately performing an incoming call notification process such as emitting a ring tone, each base unit sends a link connection request to its subordinate handset units via a dummy bearer.

[0031] In response, each handset searches for a slot to use and contacts the base unit to attempt to acquire a slot to use for communication. Once a slot for mutual communication between the base unit and handset has been acquired, the base unit releases the dummy bearer, outputs a display notifying the occurrence of an incoming call, and activates a ringer. At the same time, the base unit also identifies an uplink slot so that it can receive information from the handset. The base unit also notifies the handset of the incoming call using the acquired downlink slot, and if the handset is equipped with a ringer, the handset may also notify the handset of the incoming call.

[0032] In this way, in the case of a business phone system using cordless telephone devices, a traffic bearer consisting of a downlink slot and an uplink slot is acquired, and an incoming call notification is made after the handset is ready for communication. However, in this case, the process of acquiring the traffic bearer is performed in all cordless telephone devices. Therefore, when there are a large number of cordless telephone devices, there is a possibility that slots will be competed for, which will constrict the communication bandwidth and make it impossible to respond to incoming calls promptly. Furthermore, the process of acquiring the traffic bearer is performed even in cordless telephone devices that are not used to respond, which increases the power consumption of the handset.

[0033] Therefore, in the business phone system of this embodiment, when there is an incoming call on the telephone line accommodated by main unit 1, main unit 1 provides a simultaneous incoming call notification to subordinate cordless telephone units 21, 22, and 23, as in the conventional case. However, base units CS1, CS2, and CS3 of cordless telephone units 21, 22, and 23 do not immediately send link connection requests to handsets PS1, PS2, and PS3. After receiving the simultaneous incoming call notification, base units CS1, CS2, and CS3 notify the user of the occurrence of the incoming call by, for example, emitting a ringtone for a certain period of time (for example, 5 to 10 seconds), and wait for the user to respond to the call.

[0034] In this case, let us assume that a user performs an operation to answer an incoming call (incoming call answering operation) on, for example, base unit CS1 among base units CS1, CS2, and CS3. In this embodiment, base unit CS1 sends a provisional response to main unit 1 and sends a link connection request to handset PS1. Upon receiving the provisional response from base unit CS1, main unit 1 cancels the simultaneous incoming call notification to base units CS2 and CS3 other than base unit CS1, but continues the simultaneous incoming call notification to base unit CS1. If handset PS1 is functioning and a traffic bearer is acquired, base unit CS1 returns an incoming call response to main unit 1 and connects a call line between the originating outside telephone and handset PS1 via base unit CS1, enabling the call.

[0035] In this way, in the business phone system of this embodiment, when an incoming call occurs on a telephone line accommodated by the main unit 1, traffic bearer acquisition processing is not performed in all of the cordless telephone units 21, 22, and 23 under the control of the main unit 1. This prevents the communication bandwidth between the base unit and the handset from being constricted when an incoming call is received, enables the call line to be quickly connected, and enables the call to be started quickly, while also realizing power savings in the handset units not being used for incoming calls.

[0036] A specific example of the configuration of the main unit 1, base units CS1, CS2, CS3 of the cordless telephone units 21, 22, 23, and handsets PS1, PS2, PS3 that constitute the business phone system of this embodiment that realizes the above functions will be described below.

[0037] [Configuration example of main unit 1] Fig. 2 is a block diagram illustrating an example of the configuration of main unit 1 used in the business phone system of the embodiment. As shown in Fig. 2, main unit 1 is configured to include line I / F (Interface) 11 to which telephone lines L1 to Lm are connected, control unit 12 equipped with a computer for controlling main unit 1 as a whole, line LSI (Large Scale Integration) unit 13, and reference oscillator 14.

[0038] Under the control of the control unit 12, the line I / F 11 supplies voice signals (received voice signals) from the lines L1 to Lm to the line LSI unit 13, and supplies control signals such as call control signals from the lines to the control unit 12. Also, under the control of the control unit 12, the line I / F 11 transmits voice signals (transmitted voice signals) from the line LSI unit 13 to the other party via the lines L1 to Lm, and also transmits control signals such as call control signals from the control unit 12 to the other party via the lines L1 to Lm.

[0039] The line LSI unit 13 includes n extension processing circuits 131, 132, ..., 13n corresponding to n extension telephone devices, and a timing signal generating unit 130. The subscript n basically means an integer of 1 or more. However, since the extension processing circuits 131 and 132 already exist in FIG. 2, the letter n in FIG. 2 means an integer of 3 or more.

[0040] The timing signal generator 130 generates a transmission clock signal CK and a multiplexing / division timing signal TM from a reference clock signal from a high-precision reference oscillator 14 using a quartz crystal resonator, and supplies these to n extension processing circuits 131 to 13n. The n extension processing circuits 131 to 13n have the same configuration, and each includes an audio signal processor 31, a control signal processor 32, a synchronization signal processor 33, and a multiplexing / division processor 34.

[0041] The audio signal processing unit 31 is connected to the line I / F 11 and also to the multiplexing / division processing unit 34, and is a processing circuit for processing the received audio signal from the line I / F 11 and the transmitted audio signal from the multiplexing / division processing unit 34. A transmission clock signal CK is supplied to the audio signal processing unit 31 from the timing signal generating unit 130.

[0042] The control signal processing unit 32 is connected to the control signal input / output terminal of the control unit 12 and also to the multiplexing / division processing unit 34, and is a processing circuit for control signals such as call control signals when making and receiving calls, and when terminating a call. In other words, the control signal processing unit 32 is a processing circuit for both control signals from the main unit 1 to the cordless telephone device and control signals from the cordless telephone device to the main unit 1. The transmission clock signal CK from the timing signal generating unit 130 is also supplied to the control signal processing unit 32.

[0043] The synchronization signal processing unit 33 is connected to the synchronization signal output terminal of the control unit 12 and also to the multiplexing / division processing unit 34, and is a processing circuit for the reference synchronization signal SYNC having a predetermined synchronization signal pattern from the control unit 12. Similarly, the transmission clock signal CK from the timing signal generating unit 130 is also supplied to this synchronization signal processing unit 33.

[0044] The multiplexing / division processing unit 34 is connected to the audio signal processing unit 31, the control signal processing unit 32, and the synchronization signal processing unit 33, and is also connected to each of the base units CS1 to CSn of the cordless telephone devices 21 to 2n. The multiplexing / division processing unit 34 performs processing based on the timing signal TM from the timing signal generating unit 130. The multiplexing / division processing unit 34 multiplexes (time division multiplexes) the audio signal from the audio signal processing unit 31, the control signal from the control signal processing unit 32, and the reference synchronization signal SYNC from the synchronization signal processing unit 33 to generate a multiplexed signal. The multiplexing / division processing unit 34 supplies the generated multiplexed signal to each of the base units CS1 to CSn.

[0045] Furthermore, the multiplexing / division processing unit 34 divides (separates) the multiplexed signal from each of the master units CS1 to CSn into an audio signal and a control signal based on the timing signal TM from the timing signal generating unit 130. The multiplexing / division processing unit 34 supplies the divided (separated) audio signal to the audio signal processing unit 31, and supplies the divided (separated) control signal to the control signal processing unit 32.

[0046] 2, the control unit 12 of the main unit 1 in this embodiment includes a connected base unit storage unit 121, a simultaneous incoming call notification unit 122, a simultaneous incoming call cancellation unit (referred to as a simultaneous incoming call CAN unit in FIG. 2) 123, and a call line connection unit 124. The connected base unit storage unit 121 functions as a so-called address management unit, and stores and holds the correspondence between terminal identification information such as the extension numbers and MAC addresses of the cordless telephone devices 21, 22, and 23 connected to the main unit 1 and each of the extension processing circuits 131 to 13n. The connected base unit storage unit 121 can also distinguishably manage base units that have notified an incoming call and base units that have sent a provisional response, which will be described later.

[0047] When an incoming call occurs on the telephone line accommodated by the device, the simultaneous incoming call notification unit 122 forms an incoming call notification (simultaneous incoming call notification) and simultaneously provides it to the base units CS1, CS2, and CS3 of the subordinate cordless telephone devices. After providing the simultaneous incoming call notification to the base units CS1, CS2, and CS3, if a provisional response is sent from one of the base units, the simultaneous incoming call cancellation unit 123 performs processing to cancel the simultaneous incoming call notification to base units other than the base unit that sent the provisional response. Therefore, the simultaneous incoming call notification to the base unit that sent the provisional response continues.

[0048] When a subordinate cordless telephone device answers an incoming call, the telephone line connection unit 124 connects a communication line between the other party's outside telephone and the base unit that answered. Also, when a call is made from a subordinate cordless telephone device and the other party answers, the telephone line connection unit 124 connects a communication line between the base unit of the calling cordless telephone device and the other party's outside telephone. This makes it possible to make a call using the handset of the cordless telephone device.

[0049] In this way, main unit 1 has the function of providing simultaneous incoming call notifications to base units CS1, CS2, and CS3 of subordinate cordless telephone devices. In this case, for example, if there is a provisional response from base unit CS1, it has the function of canceling the incoming call notifications to base units CS2 and CS3 while continuing the simultaneous incoming call notification to base unit CS1. After this, if there is an incoming call response from base unit CS1 that made the provisional response, it has the function of canceling the simultaneous incoming call notification to base unit CS1, connecting a communication line between the calling outside telephone and base unit CS1, and enabling the call through handset PS1 wirelessly connected to base unit CS1.

[0050] [Configuration example of cordless telephone devices 21, 22, and 23] Next, an example of the configuration of cordless telephone devices 21, 22, and 23 of this embodiment, which are composed of a base unit and a handset, will be described. Note that since base units CS1, CS2, and CS3 of cordless telephone devices 21, 22, and 23 each have the same configuration, the configuration will be specifically described below using base unit CS1 as an example. Similarly, since handset units PS1, PS2, and PS3 of cordless telephone devices 21, 22, and 23 each have the same configuration, the configuration will be specifically described below using handset PS1 as an example.

[0051] <Configuration example of parent unit> 3 is a block diagram illustrating an example of the configuration of base unit CS1 of cordless telephone device 21 used in the business phone system of this embodiment. As shown in FIG. 3, base unit CS1 is configured to include a control circuit 41 for controlling the entire base unit CS1, a line LSI unit 42, a synchronization signal generating circuit 43, a wireless communication circuit 44, and oscillators 45 and 46. Control circuit 41 is configured with a computer mounted thereon and realizes functions such as call control in base unit CS1. Control circuit 41 also includes a provisional response unit 411, a link connection request unit 412, and an incoming call response unit 413, and is connected to a display unit 47, a ringer 48, and an operation unit 49. Details of control circuit 41 will be described later.

[0052] The line LSI unit 42 is a circuit for exchanging audio signals, control signals, and synchronization signals with the main unit 1. The line LSI unit 42 comprises a division / multiplexing processing unit 421, a control signal processing unit 422, an audio signal processing unit 423, a synchronization signal detection unit 424, and a PLL (Phase Locked Loop) unit 425. The PLL unit 425 is supplied with an oscillation signal of a reference frequency from an oscillator 45, and is also supplied with a multiplexed signal from the main unit 1. In this example, the frequency of the oscillation signal of the oscillator 45 is set to, for example, 2048 MHz (0.488 nanoseconds (ns)).

[0053] The PLL unit 425 extracts the clock signal CK component from the timing signal generation unit of the main unit 1 by so-called self-clocking from the multiplexed signal from the main unit 1. The PLL unit 425 compares the phase of the extracted clock signal CK component with that of the oscillation signal from the oscillator 45, and based on the comparison result, generates a system clock signal SCK for the main unit CS1 that is synchronized with the clock signal CK component from the oscillation signal of the oscillator 45. The PLL unit 425 supplies the generated system clock signal SCK to the division / multiplexing processing unit 421, the control signal processing unit 422, the audio signal processing unit 423, and the synchronization signal detection unit 424 as a clock signal for signal processing, and also supplies it to the synchronization signal generation circuit 43.

[0054] The division / multiplexing processing unit 421 is connected to the main unit 1, and is also connected to the control signal processing unit 422, the audio signal processing unit 423, and the synchronization signal detection unit 424. The division / multiplexing processing unit 421 divides (separates) the multiplexed signal from the main unit 1 into a control signal, an audio signal, and a reference synchronization signal SYNC. The control signal, the audio signal, and the reference synchronization signal SYNC divided (separated) by the division / multiplexing processing unit 421 are supplied to the control signal processing unit 422, the audio signal to the audio signal processing unit 423, and the synchronization signal detection unit 424, respectively.

[0055] Furthermore, the division / multiplexing processing unit 421 multiplexes the control signal from the control signal processing unit 422 and the audio signal from the audio signal processing unit 423 to generate a multiplexed signal, and supplies the generated multiplexed signal to the main unit 1. 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 division / multiplexing processing unit 421. The control signal processing unit 422 is a processing circuit for control signals such as call control signals when making and receiving calls, and when ending a call (both control signals from the main unit 1 to the cordless telephone device 21 and control signals from the cordless telephone device 21 to the main unit 1).

[0056] The audio signal processing unit 423 is connected to the wireless communication circuit 44 and the division / multiplexing processing unit 421, and is a processing circuit for processing the transmitted audio signal received from the handset PS1 via the wireless communication circuit 44 and the received audio signal from the division / multiplexing processing unit 421. The synchronization signal detection unit 424 receives the reference synchronization signal SYNC from the division / multiplexing processing unit 421 and detects a predetermined synchronization signal pattern contained in the reference synchronization signal SYNC. As a result, the synchronization signal detection unit 424 generates a reference synchronization pulse PS that is synchronized with the reference synchronization signal SYNC and has the same period (130 ms) as the reference synchronization signal SYNC as the signal at the time of detection. The synchronization signal detection unit 424 supplies the generated reference synchronization pulse PS to the synchronization signal generation circuit 43.

[0057] The synchronization signal generating circuit 43 comprises a counter 431 and a synchronization signal generating unit 432. A reference synchronization pulse PS having a period of 130 ms is supplied to a preset terminal PRE of the counter 431 from the synchronization signal detecting unit 424 of the line LSI unit 42, and a system clock signal SCK is supplied as a count input from the PLL unit 425. An output count value CNT of the counter 431 is supplied to the synchronization signal generating unit 432. The synchronization signal generating unit 432 generates a synchronization signal FL having a frame period (10 ms) of the DECT standard from the output count value CNT of the counter 431. The synchronization signal generating circuit 43 supplies the frame synchronization signal FL generated by the synchronization signal generating unit 432 to the wireless communication circuit 44.

[0058] The wireless communication circuit 44 is configured to include a control unit 441, a TDMA modulation / demodulation unit 442, and a wireless communication unit (denoted as "RF" in FIG. 4) 443. The wireless communication unit 443 is a circuit unit for performing wireless communication with the slave PS1. The control unit 441 is connected to the TDMA modulation / demodulation unit 442 and the wireless communication unit 443, and is also connected to the control circuit 41. The control unit 441 also has the function of supplying the TDMA modulation / demodulation unit 442 with a control signal based on a control signal obtained from the control circuit 41, and supplying information obtained from the TDMA modulation / demodulation unit 442 to the control circuit 41.

[0059] 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 modulates the control signal from the control unit 441 and the audio signal from the audio signal processing unit 423 in order to transmit them to the slave unit PS1. The signals modulated by this TDMA modulation / demodulation unit 442 are transmitted to the slave unit PS1 via the wireless communication unit 443. The TDMA modulation / demodulation unit 442 also demodulates the audio signal and control signal from the signal received from the slave unit PS1 by the wireless communication unit 443, supplies the demodulated audio signal to the audio signal processing unit 423, and supplies the demodulated control signal to the control unit 441.

[0060] The TDMA modulation / demodulation unit 442 includes a PLL unit 4421 for clock generation. The PLL unit 4421 is supplied with an oscillation signal from the oscillator 46 and a 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 that of the oscillation signal from the oscillator 46, and generates a timing signal and a clock signal synchronized with the frame synchronization signal FL from the oscillation signal of the oscillator 46 based on the comparison result. 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 PS1 in a period corresponding to an allocatable downlink slot, and processes a reception signal from the slave unit PS1 using an uplink slot.

[0061] As described above, when the base unit CS1 is connected to the main unit 1 and in standby mode, it starts synchronization processing for communication with the handset PS1 and constantly transmits synchronization signals and control information to the handset PS1 via a dummy bearer to maintain a state in which communication is possible. As described above, when the base unit CS1 is notified of an incoming call, it forms a link connection request as a normal process and sends it to the handset PS1 via the dummy bearer. Upon receiving the link connection request, the handset PS1 searches for an available slot, identifies a slot (traffic bearer) to be used for communication, and notifies the base unit CS1 of this. The base unit CS1 acquires the identified slot and uses it to establish a connection between the base unit CS1 and the handset PS1, thereby establishing a state in which communication can be performed.

[0062] In this embodiment, base unit CS1 cooperates with main unit 1 to perform processing for responding to an incoming call by itself in response to an instruction from the user, before performing the normal processing for an incoming call described above. That is, it is assumed that a simultaneous incoming call notification from main unit 1 is received through division / multiplexing processing unit 421 and control signal processing unit 422 of line LSI unit 42 and supplied to control circuit 41. In this case, control circuit 41 does not immediately send a link connection request to handset PS1, but instead displays the occurrence of an incoming call on display unit 47 for a certain period of time (for example, 5 to 10 seconds), and rings ringer 48 to notify the user of the occurrence of the incoming call.

[0063] During the fixed period during which the user is notified of the occurrence of the incoming call, the control circuit 41 accepts an incoming call response operation (provisional response operation) from the user via the operation unit 49. The incoming call response operation includes an operation of pressing the response button provided on the operation unit 49 of the base unit CS1, an operation of picking up the handset PS1 placed on the base unit CS1 so as to maintain the on-hook state, and an operation of setting the handset PS1 to an off-hook state. Of course, it may also be any other operation that the control circuit 41 can recognize as an incoming call response operation.

[0064] When the control circuit 41 receives an incoming call response operation from the user, the provisional response unit 411 first functions to form a provisional response and provides it to the main unit 1 through the control signal processing unit 422 and the division / multiplexing processing unit 421 of the line LSI unit 42. As a result, as described above, in this example, the main unit 1 cancels simultaneous incoming call notifications to base units CS2 and CS3 other than base unit CS1, which is the sender of the provisional response.

[0065] Furthermore, the link connection request unit 412 of the control circuit 41 generates a link connection request and transmits it to the slave PS1 via the control unit 441, the TDMA modulation / demodulation unit 442, and the wireless communication unit 443 of the wireless communication circuit 44. As a result, as described above, the slave PS1 performs a search process for an available slot, identifies a slot to be used for communication, and notifies the master CS1 of the slot. The notification is received via the wireless communication unit 443, the TDMA modulation / demodulation unit 442, and the control unit 441 of the wireless communication circuit 44 of the master CS1. The control unit 441 of the master CS1 obtains the identified slot in response to the notification and uses it to connect the master CS1 and the slave PS1, thereby enabling communication. The control unit 441 notifies the control circuit 41 of the result.

[0066] In this case, the incoming call response unit 413 in the control circuit 41 functions to form a normal incoming call response and transmits it to the main unit 1 via the control signal processing unit 422 and division / multiplexing processing unit 421 of the line LSI unit 42. This causes the main unit 1 to function as described above, and a call line is connected between the originating outside telephone and the base unit CS1. In this case, a traffic bearer has been selected between the base unit CS1 and the handset PS1, and wireless communication is already possible, so that a call can be made using the originating outside telephone and the handset PS1 wirelessly connected to the base unit CS1.

[0067] The provisional response formed by provisional response unit 411 and the normal incoming call response formed by incoming call response unit 413 are formed in the main unit 1 in a manner that allows them to be distinguished from each other. For example, in the case of a provisional response, predetermined flag information is turned on, and in the case of a normal incoming call response, the predetermined flag information is turned off. Alternatively, the provisional response and the normal incoming call response may have different response types (type information included in each response information). In addition, various methods can be used in the main unit 1 to distinguish between a provisional response and a normal incoming call response, such as by using different formats for the provisional response and the normal incoming call response. In this embodiment, for example, the response type included in the provisional response and the response type included in the normal incoming call response are made different, and the main unit 1 can distinguish between a provisional response and a normal incoming call response by checking the response type.

[0068] 3 is explained using the base unit CS1 as an example, but the same function can be realized in base units CS2 and CS3 by providing a similar configuration. That is, when a call is received, the cordless telephone units 21, 22, and 23 under the control of the main unit 1 are notified of the call simultaneously, and the user is notified of the occurrence of the call via the base units CS1, CS2, and CS3. Then, only the base unit that accepts the call response operation from the user provides a provisional response to the main unit 1 and a link connection request to the handset.

[0069] Therefore, as described above, the main unit 1 cancels the simultaneous incoming call notification to base units that have not accepted an incoming call response operation (provisional response operation) from the user. This prevents cordless telephone devices from competing for slots, thereby suppressing the congestion of the wireless communication bandwidth between the base unit and handset when a call comes in. Furthermore, a base unit that has not accepted an incoming call response operation (provisional response operation) from the user does not issue a link connection request to the handset, so the handset does not operate to prepare the call environment. This therefore reduces the power consumption of the handset corresponding to the base unit that has not accepted an incoming call response operation.

[0070] <Example of handset configuration> FIG. 4 is a block diagram showing an example of the configuration of the slave PS1. As shown in FIG. 4, the slave PS1 is configured with a wireless communication circuit 51, a control circuit 52, a codec circuit 53, an oscillator 54, a microphone 55, and a speaker 56. The control circuit 52 is configured as a microprocessor including a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), non-volatile memory, etc., and realizes the function of controlling each part of the slave PS1. The microphone 55 constitutes a transmitter, and the speaker 56 constitutes a receiver. The wireless communication circuit 51 is configured with a control unit 511, a TDMA modulation / demodulation unit 512, and a wireless communication unit (denoted as "RF" in FIG. 5) 513. The wireless communication unit 513 is a circuit unit for performing wireless communication with the master CS1.

[0071] Control unit 511 is connected to TDMA modulation / demodulation unit 512 and wireless communication unit 513, and is also connected to control circuit 52. Control unit 511 controls the overall operation of wireless communication circuit 51, and supplies a control signal to TDMA modulation / demodulation unit 512 based on a control signal obtained from control circuit 52.

[0072] 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 modulates the control signal from the control unit 511 and the audio signal from the codec circuit 53 in order to transmit them to the base unit CS1. The signal modulated by the TDMA modulation / demodulation unit 512 is transmitted to the base unit CS1 via the wireless communication unit 513. The TDMA modulation / demodulation unit 512 also demodulates the audio signal and control signal from the signal received from the base unit CS1 by the wireless communication unit 513, supplies the demodulated audio signal to the codec circuit 53, and supplies the demodulated control signal to the control unit 511.

[0073] TDMA modulation / demodulation unit 512 includes PLL unit 5121 for clock generation. PLL unit 5121 is supplied with an oscillation signal from oscillator 54 and a demodulated signal of the received signal from wireless communication unit 513. PLL unit 5121 generates a clock signal synchronized with the clock component of the demodulated signal of the received signal from the oscillation signal from oscillator 54. The clock signal from PLL unit 5121 is used as a clock signal for processing in TDMA modulation / demodulation unit 512.

[0074] The codec circuit 53 decodes the voice signal demodulated by the TDMA modulation / demodulation unit 512, converts it into an analog voice signal, and supplies the analog voice signal to the speaker 56 to emit it as a received voice. The codec circuit 53 also encodes the analog voice signal picked up by the microphone 55 and supplies it to the TDMA modulation / demodulation unit 512. When a call is made from the handset PS1, the control circuit 52 transmits a call control signal at the time of making a call to the base unit CS1 via the wireless communication circuit 51, and when a call control signal at the time of receiving an incoming call from the base unit CS1 is received, the control circuit 52 performs processing such as emitting a ring tone from the speaker 56.

[0075] The control unit 511 of the wireless communication circuit 51 controls the TDMA modulation / demodulation unit 512 in response to a control signal from the base unit CS1 corresponding to the wireless communication circuit 51, searches for and identifies slots to be used for communication in the downlink and uplink, and performs reception / transmission processing. For example, when a simultaneous incoming call occurs and a simultaneous incoming call notification is sent from the main unit 1 to the handset PS1 via the base unit CS1, the handset PS1 searches for an available slot and acquires an available slot to use for the call. Then, the handset PS1 cooperates with the base unit CS1 to use the acquired available slot as a traffic bearer to make the call.

[0076] As described above, during standby, the handset PS1 is capable of receiving synchronization signals and control signals from the base unit through one predetermined slot (dummy bearer) in the downlink. When an incoming or outgoing call occurs, as described above, the dummy bearer is merged with the traffic bearer, and the slots to be used for communication in the downlink and uplink are identified to carry out the call. As described above, the handset PS1 of the cordless telephone device used in the telephone system of this embodiment is configured in the same way as a handset of a conventional cordless telephone device, and no special configuration changes are required to realize the present invention.

[0077] The above explanation is about the base unit CS1 and handset PS1 of the cordless telephone device 21, but as mentioned above, the base units CS2 and CS3 and handset PS1 and PS2 of the other cordless telephone devices 22 and 23 have the same configuration and function in the same way.

[0078] [Explanation of the operation of the business phone system according to the embodiment] Figure 5 is a sequence diagram for explaining the operation of the business phone system according to the embodiment. Figure 5 shows an example in which an incoming call is received from an outside telephone on the telephone line accommodated in the main unit 1, and the base unit CS1 and handset PS1 of the cordless telephone device 21 function to carry out the call. A specific description will be given below.

[0079] As shown in the upper left corner of Figure 5, an outside telephone connected to a wide-area telephone network initiates a call operation (step S51) with a telephone line connected to the main unit 1 as the destination, and a call notification including the telephone number assigned to the destination telephone line is sent to the main unit 1 (step S52). Upon receiving the call notification, the main unit 1, as described above, activates the simultaneous incoming call notification unit 122 of the control unit 12 to provide simultaneous incoming call notifications to the base units CS1, CS2, and CS3 of the cordless telephone units 21, 22, and 23 under its control (step S53). Under the control of the control circuit 41, each of the base units CS1, CS2, and CS3 to which the simultaneous incoming call notification has been provided displays an incoming call on the display unit 47 and sounds the ringer 48, thereby calling the respective users (notifying them of the incoming call) (steps S54, S55, and S56).

[0080] Let us assume that the user of cordless telephone device 21, noticing the incoming call through the incoming call display and ringing, performs a response operation on operation unit 49 of base unit CS1 (step S57). In this case, control circuit 41 of base unit CS1 functions to execute a provisional incoming call response process (step S58). Specifically, in the provisional incoming call response process, provisional response unit 411 of control circuit 41 of base unit CS1 functions to form a prerequisite response and transmit this to main unit 1 (step S59). Furthermore, link connection request unit 412 of control circuit 41 of base unit CS1 functions to form a link connection request and transmit this to handset PS1 located under its own unit (step S60).

[0081] In the main unit 1 to which the provisional response has been provided from the base unit CS1, the simultaneous incoming call cancellation unit 123 functions to perform simultaneous incoming call cancellation processing (step S61). Specifically, the simultaneous incoming call cancellation processing is processing for canceling simultaneous incoming call notifications to base units CS2 and CS3 other than the base unit CS1 that sent the provisional response (step S62). Therefore, the provision of simultaneous incoming call notifications to the base unit CS1 that sent the provisional response is continued (step S63). Furthermore, in the slave unit PS1 to which the link connection request has been provided from the base unit CS1, link connection processing is executed in cooperation with the base unit CS1 (step S64). In step S64, as described above, the slave unit PS1 searches for an available slot, acquires a traffic bearer in cooperation with the base unit CS1, and prepares an environment in which mutual communication is possible.

[0082] When a traffic bearer is acquired between the base unit CS1 and the handset PS1, and the base unit CS1 and the handset PS1 are able to communicate with each other (the link is connected), the control circuit 41 of the base unit CS1 executes an incoming call response process (step S65). In this incoming call response process, the incoming call response unit 413 functions to form an incoming call response and performs processing to provide this to the main unit 1 (step S66). Having received the incoming call response from the base unit CS1, the main unit 1 executes a response process (step S67). In this response process, the communication line connection unit 124 of the control unit 12 of the main unit 1 functions to return a response (response message) to the calling outside telephone set indicating that the incoming call will be responded to (step S68).

[0083] As a result, a call line is established between the originating outside telephone and the handset PS1 via the base unit CS1 of the cordless telephone device 21 (step S69), enabling communication. As explained with reference to the sequence diagram of FIG. 5, after the simultaneous incoming call notification in step S53, link connection processing is performed only between the base unit CS1 that accepted the incoming call response operation in step S57 and the corresponding handset PS1. In this way, link connection processing is not performed between the base unit CS2 and the handset PS2, which received the simultaneous incoming call notification, or between the base unit CS3 and the handset PS3, so that the wireless communication bandwidth between the base unit and the handset is not constrained. Furthermore, since link connection processing is not performed between the base unit CS2 and the handset PS2, which received the simultaneous incoming call notification, or between the base unit CS3 and the handset PS3, unauthorized power consumption is not performed between the handset PS2 and the handset PS3, preventing an increase in power consumption.

[0084] [Summary of processing on Main Unit 1 and Parent Unit CS1] Next, the processing performed in each of the main unit 1 and base unit CS1 used in the business phone system of this embodiment will be summarized with reference to flowcharts.

[0085] <Processing of Main Unit 1> FIG. 6 is a flowchart illustrating the processing performed by main unit 1 of the business phone system according to the embodiment, specifically the processing performed when a call is made to a telephone line accommodated by main unit 1 (when an incoming call occurs). The processing of the flowchart shown in FIG. 6 is processing executed by control unit 12 of main unit 1. Control unit 12 receives an outgoing call notification, which has a telephone line accommodated in main unit 1 as the destination, via telephone lines L1 to Lm (step S101), and determines whether or not the outgoing call notification has been received (step S102). If it is determined in the determination processing of step S102 that the outgoing call notification has not been received, the processing from step S101 is repeated, and the arrival of an outgoing call notification, which has a telephone line accommodated in main unit 1 as the destination, is waited for.

[0086] Assume that in the determination process of step S102, it is determined that an outgoing call notification has been received with the telephone line accommodated in the device as the destination. In this case, under the control of the control unit 12, the simultaneous incoming call notification unit 122 functions to transmit (provide) simultaneous incoming call notifications to the base units CS1, CS2, and CS3 of the cordless telephone devices 21, 22, and 23 connected to the device (step S103). Thereafter, the control unit 12 receives responses from the base units CS1, CS2, and CS3 that have notified the device of the incoming call (step S104), and determines whether or not the responses have been received (step S105). If in the determination process of step S105 it is determined that responses have not been received from the base units CS1, CS2, and CS3, the control unit 12 repeats the process from step S104 and waits for responses from the base units CS1, CS2, and CS3.

[0087] If it is determined in the determination process of step S105 that responses have been received from base units CS1, CS2, and CS3, the control unit 12 determines whether the received response is a provisional response (step S106). If it is determined in the determination process of step S106 that the received response is a provisional response, the simultaneous incoming call cancellation unit 123 functions under the control of the control unit 12 to cancel simultaneous incoming call notifications to base units other than the base unit that is the sender of the provisional response (step S107). Thereafter, the control unit 12 repeats the process from step S104 to receive responses from base units that are providing simultaneous incoming call notifications.

[0088] Also, assume that the determination process in step S106 determines that the received response is not a provisional response. In this case, the received response is a normal incoming call response indicating that the incoming call will be answered, so under the control of the control unit 12, the communication line connection unit 124 functions and executes an incoming call response process (step S108). The incoming call response process in step S108 sends a reply to the calling outside telephone indicating that the incoming call will be answered, and connects a communication line between the calling outside telephone and the base unit that responded to the incoming call. As a result, a communication line is connected between the calling outside telephone and the handset that is wirelessly connected to the base unit that responded to the incoming call, and communication is enabled.

[0089] Thereafter, it is determined whether the call has ended based on whether a notification that the telephone line has been disconnected has arrived from either the outside telephone or the base unit that answered the call (step S109). If it is determined that the call has not ended, the process of step S109 is repeated to wait for the call to end. If it is determined in the determination process of step S109 that the call has ended, the connected communication line is released (step S110), and the process from step S101 is repeated.

[0090] In this way, when main unit 1 receives a call notification with the telephone line it accommodates as the destination, it starts providing simultaneous call notification to base units CS1, CS2, and CS3 of subordinate cordless telephone units 21, 22, and 23. After this, when a provisional response is sent from base unit 1, it cancels simultaneous call notification to base units other than the source of the provisional response. This allows only the simultaneous call notification to the base unit that provided the provisional response to be used, and allows the call to be answered using only the cordless telephone unit that has that base unit.

[0091] <Processing of parent unit CS1> 7 and 8 are flowcharts for explaining the processing performed by the base unit CS1 of the business phone system according to the embodiment, and for explaining the processing when handling simultaneous incoming call notifications. The processing in the flowcharts shown in Fig. 7 and Fig. 8 is executed mainly by the control circuit 41 of the base unit CS1.

[0092] The control circuit 41 of the base unit CS1 receives an incoming call notification (a simultaneous incoming call notification) sent simultaneously from the main unit 1 (step S201), and determines whether or not the simultaneous incoming call notification has been received (step S202). If it is determined in the determination process of step S202 that the simultaneous incoming call notification has not been received, the process from step S201 is repeated and the control circuit 41 waits for the arrival of the simultaneous incoming call notification from the main unit 1. If it is determined in the determination process of step S202 that the simultaneous incoming call notification from the main unit 1 has been received, the control circuit 41 displays on the display unit 47 that an incoming call has occurred and rings the ringer 48 to notify the user of the cordless telephone unit 21 of the occurrence of the incoming call.

[0093] Thereafter, control circuit 41 of base unit CS1 accepts an incoming call response operation (provisional response operation) from the user through operation unit 49 (step S204), and determines whether the provisional response operation has been accepted (step S205). If it is determined in the determination process of step S205 that the provisional response operation has been accepted, provisional response unit 411 in control circuit 41 functions to form a provisional response and transmit this to main unit 1 (step S206). As a result, main unit 1 cancels the simultaneous incoming call notification of base units other than the base unit that sent the provisional response, as described above.

[0094] Furthermore, in the control circuit 41 of the base unit CS1, the link connection request unit 412 functions to form a link connection request and transmit it to the subordinate handset PS1 via the dummy bearer, thereby establishing a link with the handset PS1 and enabling mutual communication (step S207). When the link with the handset PS1 is established in the control circuit 41 of the base unit CS1, the call response unit 413 functions to form a normal call response and transmits it to the main unit 1 (step S208). As a result, as described above, the main unit 1 functions to connect a communication line between the calling outside telephone and the base unit CS1 that sent the normal call response. Therefore, the base unit CS1 also connects a communication line in response to this (step S209), enabling communication using the handset PS1.

[0095] Thereafter, the control circuit 41 determines whether the call has ended due to an on-hook operation of the handset PS1 or an off-hook operation of the outside telephone of the calling party (step S210). If it is determined in the determination process of step S210 that the call has not ended, the process of step S210 is repeated, and the control circuit 41 waits for the call to end and the call to be ended. If it is determined in the determination process of step S210 that the call has ended, the control circuit 41 releases the call line, returns the connection state with the handset PS1 to a so-called standby state in which the handset PS1 is connected via a dummy bearer (step S211), and repeats the process from step S201.

[0096] On the other hand, suppose that in the determination process of step S205, it is determined that a provisional response operation from the user has not been accepted in step S204. In this case, the process proceeds to the process of Fig. 8, and it is determined whether a certain time (e.g., 5 to 10 seconds) has elapsed since the call (notification of an incoming call) was started in step S203, and whether the time has expired (step S212). If it is determined in the determination process of step S212 that the time has expired, the call process started in step S203 is terminated (step S213), and normal incoming call processing is executed (step S213).

[0097] As described above, normal call reception processing involves sending a link connection request to the handset PS1 via a dummy bearer, obtaining a traffic bearer in cooperation with the handset PS1, establishing a link connection state that allows mutual communication with the handset PS1, and notifying the user of the incoming call. After this, if an answering operation is performed, a call line is connected to the calling outside telephone, enabling communication, and the call line is released when the call is ended.

[0098] Similar processing is performed for the other cordless telephone devices 22, 23, and when the other cordless telephone devices 22, 23 answer the call, the notification of the incoming call ends and the traffic bearer is released. This puts the base station CS1 into a standby state where control information and the like is provided to the handset PS1 via the dummy bearer. After the normal incoming call processing performed in step S214, the processing from step S201 in Fig. 7 is repeated.

[0099] If it is determined in step S212 that the time has not expired, the main unit 1 receives a simultaneous incoming call notification from the main unit 1 (step S215), and then determines whether a simultaneous incoming call notification has arrived (step S216). The processes in steps S215 and S216 correspond to the process of checking whether a provisional response operation has been performed on another cordless telephone device. This is because, if a provisional response operation has been performed on another cordless telephone device, the main unit 1 cancels the simultaneous incoming call notification to base units other than the sender of the provisional response, as described above.

[0100] If it is determined in the determination process of step S216 that the simultaneous incoming call notification has not been received, it means that a response operation has already been performed on another cordless telephone device, so the call process started in step S203 is terminated (step S217). After this, the process from step S201 in Fig. 7 is repeated. Also, if it is determined in the determination process of step S216 that a simultaneous incoming call notification has been received, the process from step S204 in Fig. 7 is repeated to accept a response operation for a provisional response.

[0101] In this way, when base unit CS1 receives the simultaneous incoming call notification, it notifies the user of the incoming call and accepts a provisional response operation, and if the provisional response operation is accepted, it provides a provisional response to main unit 1. This makes it possible to respond to the incoming call only through the unit that sent the provisional response, and once a traffic bearer is acquired with handset PS1 and the link is connected, it can provide a normal incoming call response to main unit 1. This connects a call line to the outside telephone of the calling party, and the call can be made using subordinate handset PS1.

[0102] [Effects of the embodiment] According to the telephone system of the above-described embodiment, in a telephone system formed using a plurality of cordless telephone devices 21, 22, and 23 in which a base unit and a handset are wirelessly connected, even when an incoming call occurs, the wireless communication bandwidth between the base unit and the handset is not constrained. Furthermore, when an incoming call occurs, the cordless telephone devices 21, 22, and 23 are always configured not to perform the process of establishing a link between the base unit and the handset, thereby preventing the handset from wasting power.

[0103] [Variations] In the above embodiment, the case where cordless telephone devices 21, 22, and 23 are connected to main unit 1 has been described as an example, but the present invention is not limited to this. Two or more cordless telephone devices may be connected to main unit 1, but the effect of the present invention will be greater if more cordless telephone devices are connected to main unit 1.

[0104] In the above-described embodiment, the fixed period of time during which provisional response operations are accepted after the simultaneous incoming call notification is set to an appropriate period of, for example, 5 to 10 seconds, but this is not limited to this. The fixed period can be set to various time intervals, and can also be set by the user depending on the operating environment.

[0105] In the above-described embodiment, the cordless telephone devices used to build the business phone system are described as employing the DECT system, but this is not limited to this. For example, the present invention can also be applied to cases where a telephone system is built using cordless telephone devices employing the PHS (Personal Handy-phone System) system or the SXGP (Shared eXtended Global Platform) system.

[0106] In the above embodiment, when an incoming call occurs on the telephone line accommodated in the main unit 1, the processing in the main unit 1 and the base unit 1 is different from the conventional processing. In the above-described embodiment, "an incoming call occurs on a telephone line accommodated in the main unit 1" means that the telephone line accommodated in the main unit (telephone control device) of the called party is identified by a telephone number. That is, it is assumed that a telephone number is assigned to the telephone line accommodated in the main unit 1. However, in recent years, the called party's telephone line may be identified by identification information other than a telephone number, such as a URL (Uniform Resource Locator) or an email address. For this reason, in this specification, etc., "an incoming call occurs on a telephone line accommodated in the main unit 1" intends that the identification information for identifying the telephone line may be any information, not limited to a telephone number.

[0107] [others] As can be seen from the above description of the embodiment, the functions of the respective means in the claims are realized by the respective units of the devices described below in the embodiment. That is, the functions of the simultaneous incoming call notification unit, simultaneous incoming call cancellation unit, and call line connection unit in the claimed telephone control device are realized by the simultaneous incoming call notification unit 122, simultaneous incoming call cancellation unit 123, and call line connection unit 124 of the control unit 12 of the main unit 1 in the embodiment. Also, the storage functions of the incoming call notification unit, reception unit, provisional response unit, link connection request unit, and incoming call response unit of the claimed base unit are realized by the display unit 47, ringer 48, operation unit 49, provisional response unit 411, link connection request unit 412, and incoming call response unit 413 of the base unit CS1 in the embodiment. [Explanation of symbols]

[0108] 1...Main unit, 11...Line I / F, 12...Control circuit, 121...Connection base unit memory unit, 122...Mass incoming call notification unit, 123...Mass incoming call cancellation unit, 124...Telephone line connection unit, 13...Line LSI unit, 14...Reference transmitting device, 21, 22, 23...Cordless telephone device, CS1, CS2, CS3...Base unit, PS1, PS2, PS3...Handset, 41...Control circuit, 411...Provisional response unit, 412...Link connection request unit, 413...Incoming call response unit, 42 ...Line LSI unit, 43...Synchronization signal generating circuit, 44...Wireless communication circuit, 441...Control unit, 442...TDMA modulation / demodulation unit, 443...Wireless communication unit, 47...Display unit, 48...Ringer, 49...Operation unit, 51...Wireless communication circuit, 511...Control unit, 512...TDMA modulation / demodulation unit, 5121...PLL unit, 513...Wireless communication unit, 52...Control circuit, 53...Codec circuit, 54...Transmitter, 55...Transmitter (microphone), 56...Receiver (speaker)

Claims

1. A telephone system in which a plurality of base units of cordless telephone devices, each of which comprises a base unit and a handset connected by wireless communication, are connected to a telephone control device connected to a wide area network, the base units being connected to the telephone control device, The telephone control device a simultaneous incoming call notification means for starting to provide simultaneous incoming call notifications to the plurality of base units connected to the device when an incoming call occurs on a telephone line accommodated in the device; a simultaneous incoming call canceling means for canceling the simultaneous incoming call notifications to base units other than the one base unit that is the sender of the provisional response when a provisional response arrives from one of the plurality of base units; a communication line connection means for connecting a communication line between the base unit that has transmitted the provisional response and a telephone terminal that is a call originator when an incoming call response arrives from the base unit that has transmitted the provisional response, thereby enabling a call between the telephone terminal that is a call originator and the handset that is wirelessly connected to the base unit; Equipped with Each of the plurality of base units an incoming call notification means for notifying a user of an incoming call occurrence when the simultaneous incoming call notification is provided from the telephone control device; a receiving means for receiving an incoming call response operation from a user; a provisional response means for forming the provisional response and providing it to the telephone control device when the incoming call response operation is accepted through the accepting means; a link connection requesting means for generating a link connection request when the receiving means has received the call response operation and providing the link connection request to the handset that is wirelessly connected to the handset; an incoming call response means for forming the incoming call response and providing it to the telephone control device when wireless communication becomes possible between the handset that has provided the link connection request through the link connection request means; A telephone system comprising:

2. A telephone control device of a telephone system configured by connecting a plurality of base units of cordless telephone devices, each of which is composed of a base unit and a handset connected by wireless communication to a telephone control device connected to a wide area network, Each of the plurality of base units comprises: an incoming call notification means for notifying a user of the occurrence of an incoming call when a simultaneous incoming call notification is received from the telephone control unit; a receiving means for receiving an incoming call response operation from the user; a provisional response means for forming a provisional response when the incoming call response operation is received through the receiving means and providing the provisional response to the telephone control unit; a link connection request means for forming a link connection request when the incoming call response operation is received through the receiving means and providing the link connection request to the handset that is wirelessly connected to the base unit; and an incoming call response means for forming an incoming call response when wireless communication becomes possible between the base unit and the handset that provided the link connection request through the link connection request means and providing the link connection request to the telephone control unit, a simultaneous incoming call notification means for starting to provide the simultaneous incoming call notification to the plurality of base units connected to the device when an incoming call occurs on a telephone line accommodated in the device; a simultaneous incoming call canceling means for canceling the simultaneous incoming call notifications to base units other than the one base unit that is the sender of the provisional response when the provisional response arrives from one of the plurality of base units; a communication line connection means for connecting a communication line between the base unit that is the sender of the provisional response and a telephone terminal that is a call originator when the call response arrives from the base unit that is the sender of the provisional response, thereby enabling a call between the telephone terminal that is the call originator and the handset that is wirelessly connected to the base unit; A telephone control device comprising:

3. A telephone system in which a plurality of cordless telephone device base units, each of which comprises a base unit and a handset connected by wireless communication, are connected to a telephone control device connected to a wide area network, the base unit comprising: The telephone control device comprises: a simultaneous incoming call notification means for starting to provide simultaneous incoming call notifications to a plurality of base units connected to the device when an incoming call occurs on a telephone line accommodated in the device; a simultaneous incoming call cancellation means for canceling the simultaneous incoming call notifications to base units other than the one base unit that is the sender of the provisional response when a provisional response arrives from one of the plurality of base units; and a call line connection means for connecting a call line between the base unit that is the sender of the provisional response and a call originating telephone terminal when an incoming call response arrives from the base unit that is the sender of the provisional response, thereby enabling a call between the call originating telephone terminal and the handset wirelessly connected to the base unit, an incoming call notification means for notifying a user of an incoming call occurrence when the simultaneous incoming call notification is provided from the telephone control device; a receiving means for receiving an incoming call response operation from a user; a provisional response means for forming the provisional response and providing it to the telephone control device when the incoming call response operation is accepted through the accepting means; a link connection requesting means for generating a link connection request when the receiving means has received the call response operation and providing the link connection request to the handset that is wirelessly connected to the handset; an incoming call response means for forming the incoming call response and providing it to the telephone control device when wireless communication becomes possible between the handset that has provided the link connection request through the link connection request means; A base unit of a cordless telephone device comprising:

Images