JP2009147773A - Intercom system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intercom system capable of improving communication quality in the entire system by monitoring the communication error situation between an intercom master unit and a repeater. <P>SOLUTION: The intercom system has an intercom slave unit, the intercom master unit, the repeater, and a cordless slave unit, and establishes a radio communication link between the intercom master unit and the cordless slave unit via the repeater. Concretely, the intercom system discriminates a communication error of a radio signal transmitted to the repeater to measure the communication error rate between the intercom master unit and the repeater, and then the number of times for transmitting a radio signal to the cordless slave unit is set based on the communication error rate, thereby: effectively reducing the occurrence of the communication error in the radio signal transmitted to the cordless slave unit from the repeater; and improving the communication quality of the entire intercom system in broadcast. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a door phone system.

  Conventionally, a doorphone slave unit has been installed at the entrance, and a doorphone master unit has been installed in the house, and two-way audio transmission and reception between the doorphone slave unit and the doorphone master unit has been performed to respond to visitors. There is a known door phone system that can be used. For example, Patent Document 1 discloses that even when an external line communication or an internal line communication of a cordless telephone and a door phone call occur simultaneously, occurrence of a busy state due to a shortage of radio resources is reduced, and each call can be notified. A door phone system is described. In this technique, a radio signal is transmitted in packets. Further, Patent Document 2 describes a door phone system that allows an operator to recognize visitor information even when a notification operation of visitor information indicating a visit of the visitor is impossible. ing. In addition, techniques related to the present invention are described in Patent Documents 3 and 4.

JP 2007-13539 A Japanese Patent Laid-Open No. 2004-241985 JP 2004-304551 A JP 2006-101326 A

  However, in the techniques described in Patent Documents 1 to 4 described above, it is not possible to perform a recovery process for a communication error in a broadcast transmission operation from the intercom master unit to the cordless slave unit when the cordless slave unit is called. In addition, the communication quality of the entire system may be deteriorated. This is due to the fact that one-way broadcast transmission is performed without establishing a wireless communication link between the doorphone master unit and the cordless slave unit when the cordless slave unit is called.

  Examples of the problem to be solved by the present invention are as described above. An object of the present invention is to provide a door phone system capable of improving communication quality in the entire system by monitoring a communication error situation between the door phone master unit and the repeater.

  According to the first aspect of the present invention, a door phone slave unit, a door phone master unit wired to the door phone slave unit, a repeater wirelessly connected to the door phone master unit, and a cordless wirelessly connected to the repeater A door phone system that establishes a wireless communication link between the doorphone parent device and the cordless child device via the repeater, and is transmitted from the doorphone parent device to the repeater A communication error determining unit that determines a communication error in a signal, and a communication error rate in wireless communication between the doorphone master unit and the repeater is measured based on the communication error determined by the communication error determining unit. Based on the communication error rate measured by the communication error rate measuring means at the time of calling the communication error rate measuring means and the cordless slave unit And a transmission number setting means for setting the number of times of transmitting the radio signal to the cordless handset from the repeater.

  In one embodiment of the present invention, a door phone slave unit, a door phone master unit wired to the door phone slave unit, a repeater wirelessly connected to the door phone master unit, and a cordless wirelessly connected to the repeater A door phone system that establishes a wireless communication link between the doorphone parent device and the cordless child device via the repeater, and is transmitted from the doorphone parent device to the repeater A communication error determining unit that determines a communication error in a signal, and a communication error rate in wireless communication between the doorphone master unit and the repeater is measured based on the communication error determined by the communication error determining unit. Based on the communication error rate measuring means and the communication error rate measured by the communication error rate measuring means at the time of calling the cordless slave unit , And a transmission number setting means for setting the number of times of transmitting the radio signal to the cordless handset from the repeater.

  The above door phone system is preferably used to interact with a visitor by bidirectionally transmitting and receiving voice between the door phone slave unit and the door phone master unit. Specifically, the door phone system includes a door phone slave unit, a door phone master unit wired to the door phone slave unit, a repeater wirelessly connected to the door phone master unit, and a cordless slave unit wirelessly connected to the repeater. And establishing a wireless communication link between the doorphone master unit and the cordless slave unit via the repeater. In this case, the communication error determining unit determines a communication error in a radio signal transmitted from the doorphone master unit to the repeater, and the communication error rate measuring unit determines whether the doorphone master unit and the repeater are based on the communication error. Measure the communication error rate in wireless communication between. Then, the transmission number setting means sets the number of times the wireless signal is transmitted from the repeater to the cordless child device based on the communication error rate. In other words, the above door phone system monitors the communication error status (corresponding to the surrounding radio wave status) between the door phone master unit and the repeater at any time, and as a result, the cordless slave unit calls the repeater from the repeater. Switch the broadcast transmission operation to the cordless slave unit. As a result, it is possible to effectively reduce the occurrence of communication errors in the radio signal transmitted from the repeater to the cordless slave unit, and to improve the communication quality of the entire door system during broadcast communication. .

  In one aspect of the door phone system, the transmission number setting means sets the number of times of transmitting the wireless signal to 2 or more when the communication error rate is greater than a predetermined value, and the communication error rate is If it is less than or equal to the predetermined value, the number of times the wireless signal is transmitted can be set to one.

  In another aspect of the door phone system, the repeater transmits to the door phone master unit a retransmission of a radio signal determined as a communication error by the communication error determining unit when the cordless slave unit is called. The wireless signal is transmitted to the cordless slave unit according to the number of times set by the transmission number setting unit when a wireless signal determined by the communication error determination unit is received and received by the communication error determination unit. Send. As a result, communication between the doorphone master unit and the repeater can be made error-free when the cordless slave unit is called.

  Preferably, in the above door phone system, the wireless signal is generated by compressing image data captured by the camera of the door phone slave unit and dividing the image data after the image compression into a plurality of packets. Corresponds to packet data. Further, the communication error determination means determines the communication error based on an error detection code in the packet data. Further, the communication error determining means determines the communication error for each one of the packet data, and the repeater determines that for each one of the packet data when the communication error is determined by the communication error determining means. The re-transmission request is sent to the doorphone master unit.

  In another aspect of the door phone system, wireless communication is performed by a frequency hopping method among the door phone master unit, the repeater, and the cordless slave unit. As a result, since the frequency used for transmission is changed for each transmission, when the communication error rate is relatively high, the frequency used for the radio signal can be reduced by transmitting the radio signal multiple times. Therefore, it is possible to appropriately suppress the occurrence of communication errors in the cordless slave unit.

  Preferably, the communication error rate measuring means measures the communication error rate when calling the cordless child device.

  Preferably, the communication error rate measuring means measures the communication error rate by using a time during which a wireless communication link for interacting with a visitor is not established.

  In a preferred embodiment, the communication error rate measuring means is provided in the repeater.

  In a preferred embodiment, the communication error rate measuring means is provided in the doorphone master unit.

  In another aspect of the door phone system, the door phone master device includes a first wireless unit that performs wireless communication with the repeater, and the cordless slave device includes a third wireless device that performs wireless communication with the repeater. A wireless unit, and the repeater includes a line control unit that functions as a base unit for each of the first wireless unit and the third wireless unit, and the first wireless unit and the third wireless unit A second wireless unit that performs wireless communication with each unit. In this case, in the door phone system, the repeater functions as a wireless master unit, and the door phone master unit and the cordless slave unit function as a wireless slave unit to form a wireless communication link.

  In another aspect of the door phone system, the repeater includes a telephone line interface circuit for operating as a cordless telephone. In this aspect, the repeater is configured as a cordless telephone. Specifically, in the above door phone system, the cordless telephone functions as a wireless master unit, and the door phone master unit and the cordless slave unit function as a wireless slave unit to form a wireless communication link. This makes it possible to easily construct a system that combines a door phone system and a cordless telephone. In addition, in the case of a cordless telephone cordless handset, the cordless telephone cordless handset can function as a cordless cordless handset.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[System configuration]
First, a door phone system according to an embodiment of the present invention will be described. FIG. 1 is a schematic diagram illustrating a system configuration of a door phone system 101 according to an embodiment.

  The door phone system 101 mainly includes a door phone slave unit 1, a door phone master unit 2, a repeater 3, and cordless slave units 4a to 4d. Below, when using each of cordless cordless handset 4a-4d without distinguishing, it will only describe with "cordless cordless handset 4". Basically, the door phone system 101 is a system capable of responding to a visitor by bidirectionally transmitting and receiving voice between the door phone slave unit 1 and the door phone master unit 2 or the cordless slave unit 4. . Specifically, the door phone system 101 is configured as a television door phone system capable of communicating not only audio signals but also video signals captured by the camera of the door phone slave unit 1.

  The doorphone slave unit 1 is installed outside the house (such as a doorway), and the doorphone master unit 2 is installed in the house (such as a living room). The doorphone slave unit 1 and the doorphone master unit 2 are wiredly connected by a two-wire signal line L, and communicate with each other through the signal line L. Moreover, the intercom base unit 2 and the repeater 3 are wirelessly connected, and the repeater 3 and the cordless slave unit 4 are wirelessly connected. Specifically, in the door phone system 101, the repeater 3 functions as a wireless master device, the door phone master device 2 and the cordless slave device 4 function as wireless slave devices, and a wireless communication link is formed. That is, a wireless communication link is established between the intercom master unit 2 and the cordless slave unit 4 via the repeater 3. As a result, all wireless communication between the doorphone master unit 2 and the cordless slave unit 4 is performed via the repeater 3.

  The repeater 3 is configured to be able to charge the cordless slave unit 4a. That is, the repeater 3 includes a charging unit (not shown) having a function of charging the cordless slave unit 4a. For example, the repeater 3 is configured as a charging stand on which the cordless child device 4a can be placed. Furthermore, the repeater 3 is configured such that the wireless communication function can be switched on / off by a switch or the like. On the other hand, the cordless cordless handsets 4b, 4c, and 4d are placed on charging bases 5b, 5c, and 5d that can be charged respectively. Although FIG. 1 shows the door phone system 101 configured using four cordless slave units 4a to 4d, the door phone system may be configured using only one cordless slave unit 4. You may comprise a door phone system using the cordless cordless handset 4 of two or more.

  Here, the wireless communication link in the door phone system 101 will be briefly described. Basically, when the call button of the door phone slave unit 1 is pressed, a wireless communication link is established between the door phone master unit 2 and the repeater 3 to perform two-way communication. In this case, a wireless communication link is not established between the repeater 3 and the cordless handset 4, and one-way broadcast transmission from the repeater 3 to the cordless handset 4 is performed. Thereafter, when the call button of the cordless handset 4 is pressed, a wireless communication link is established between the repeater 3 and the cordless handset 4 and two-way communication is performed. Specifically, two-way communication is performed between one of the cordless slave devices 4a to 4d (that is, the cordless slave device whose call button is pressed) and the repeater 3.

[Configuration in each component]
FIG. 2 is a block diagram illustrating the overall configuration of the door phone system 101 according to the present embodiment. As described above, the door phone system 101 includes the door phone slave unit 1, the door phone master unit 2, the repeater 3, and the cordless slave unit 4. In FIG. 2, for convenience of explanation, one cordless slave unit 4 is shown as a representative. Actually, the door phone system 101 includes one or more cordless slave units 4.

  The intercom handset 1 mainly includes a microphone 11, a speaker 12, a call button 13, a multiplexing circuit 14, and a camera 15. The microphone 11 collects the voice of the visitor, and the speaker 12 outputs the voice of the user (which means a person at home). The call button 13 is pressed when a visitor calls. The camera 15 is configured to include an image sensor such as a CCD, and images a visitor. The camera 15 is activated when the call button 13 is pressed. The multiplexing circuit 14 processes an audio signal, an image signal, a signal corresponding to the operation of the call button 13, and the like, and inputs / outputs signals to / from the intercom base unit 2 via the signal line L. Specifically, when the visitor presses the call button 13, the multiplexing circuit 14 transmits a signal corresponding to the press of the call button 13 (hereinafter also referred to as “call signal”) to the intercom base unit 2. The multiplex circuit 14 receives a signal corresponding to the voice of the visitor collected by the microphone 11, transmits this signal to the doorphone master unit 2, and a signal corresponding to the user's voice from the doorphone master unit 2. And outputs this signal to the speaker 12. Further, the multiplexing circuit 14 transmits the image data captured by the camera 15 to the doorphone master unit 2.

  Next, the intercom base unit 2 mainly includes a multiplexing circuit 21, a video signal processing unit 22, a display panel 23, an A / D conversion unit 24a, an image storage unit 24b, an image compression processing unit 24c, A packet data buffer 24d, a wireless unit 25, a control unit 26, an audio signal processing unit 27, a microphone 27a, a speaker 27b, an operation unit 28, and an antenna 29 are provided. The multiplexing circuit 21 is controlled by the control unit 26 and inputs / outputs signals between the video signal processing unit 22 and the audio signal processing unit 27. The video signal processing unit 22 demodulates the image data captured by the camera 15 of the door phone slave unit 1, and the display panel 23 is configured by a liquid crystal or the like, and displays the image data demodulated by the video signal processing unit 22. The A / D conversion unit 24a performs A / D conversion on the image data from the video signal processing unit 22, and the image storage unit 24b stores the image data in a memory (frame memory). Specifically, the image storage unit 24b stores image data (corresponding to a still image) captured at an appropriate timing. Then, the image compression processing unit 24c performs processing for compressing the image data stored in the image storage unit 24b according to the JPEG format or the like, and further divides the compressed image data into N packets in the packet data buffer 24d. The packet data created in this way is stored.

  The audio signal processing unit 27 modulates / demodulates the audio signal, and the microphone 27a collects the user's voice. The speaker 27b outputs the voice of the visitor and generates a ringing tone when a calling signal is received from the door phone slave unit 1. The operation unit 28 includes various buttons (not shown), and is operated when the user makes a call with the doorphone parent device 2 or when the user ends the call with the doorphone parent device 2. The control unit 26 receives a signal from the operation unit 28 and controls the multiplexing circuit 21, the video signal processing unit 22, the audio signal processing unit 27, the wireless unit 25, and the like.

  The wireless unit 25 is configured to be able to wirelessly communicate with the repeater 3 via the antenna 29. Specifically, the wireless unit 25 functions as a slave unit with respect to the wireless unit 32 in the repeater 3 (that is, the wireless unit 32 serves as a master unit) and performs wireless communication. Specifically, the radio unit 25 transmits a call signal to the repeater 3 via the antenna 29 when a call signal from the door phone slave unit 1 is received, thereby establishing a wireless communication link with the repeater 3. Establish. At this time, the wireless unit 25 transmits packet data stored in the packet data buffer 24d to the repeater 3. Thus, the radio unit 25 corresponds to the first radio unit.

  In the present embodiment, the control unit 26 performs the following processing. When a request for retransmission of packet data is received from the repeater 3 via the wireless unit 25, such as when the cordless handset 4 is called from the repeater 3, the control unit 26 sends the packet to the repeater 3. Processing is performed so that the data is retransmitted. Then, when there is a request for transmission of the next packet data from the repeater 3, the control unit 26 performs processing so that the next packet data is transmitted. In this way, the control unit 26 performs processing so that all N pieces of packet data corresponding to one image are transmitted to the repeater 3.

  Next, the repeater 3 includes an antenna 31, a radio unit 32, a packet data buffer 33, a control unit 34, and a communication error rate measurement unit 35. The packet data buffer 33 stores packet data received via the wireless unit 32, and the control unit 34 controls the wireless unit 32, the communication error rate measuring unit 35, and the like. The communication error rate measuring unit 35 measures the communication error rate between the doorphone master unit 2 and the repeater 3 based on the communication error in the packet data transmitted from the doorphone master unit 2 to the repeater 3. Specifically, the communication error rate measuring unit 35 acquires a ratio of the number of packets in which a communication error has occurred with respect to the total number of packets received by the repeater 3 as a communication error rate. For example, the communication error rate measuring unit 35 measures the communication error rate when the cordless slave device 4 is called. Thus, the communication error rate measuring unit 35 corresponds to a communication error rate measuring unit.

  The wireless unit 32 is configured to be able to wirelessly communicate with the wireless unit 25 in the intercom base unit 2 and the wireless unit 42 in the cordless handset 4 by line control. Specifically, the wireless unit 32 has a built-in line control unit (not shown) and functions as a master unit for the wireless units 25 and 42 (that is, the wireless units 25 and 42 as slave units) Perform wireless communication. As a result, wireless communication can be performed between the intercom master unit 2 and the cordless slave unit 4 via the repeater 3. The wireless unit 32 establishes a wireless communication link with the cordless slave unit 4 by transmitting the call signal to the cordless slave unit 4 via the antenna 31 when receiving the call signal from the door phone master unit 2. To do. More specifically, the wireless unit 32 receives packet data and the like from the wireless unit 25 of the intercom base unit 2 and transmits packet data and the like stored in the packet data buffer 33 to the cordless handset 4. For example, the wireless unit 32 broadcasts packet data to the cordless handset 4 when the cordless handset 4 is called (broadcast). When the door phone system 101 includes a plurality of cordless slave units 4, the wireless unit 32 broadcasts packet data to all cordless slave units 4. Thus, the radio unit 32 corresponds to a second radio unit.

  In the present embodiment, the control unit 34 performs the following processing. The control unit 34 determines a communication error in the packet data transmitted from the intercom base unit 2 to the repeater 3, and performs processing to request the intercom base unit 2 to retransmit the packet data determined to be a communication error. Do. Further, the control unit 34 sets the number of times packet data is transmitted from the repeater 3 to the cordless handset 4 based on the communication error rate measured by the communication error rate measuring unit 35. Then, when the packet data determined to have no communication error is received, the control unit 34 broadcasts the packet data to the cordless slave unit 4 at the number of transmissions thus set. To process. For example, the control unit 34 performs a process of transmitting packet data twice when the communication error rate is larger than a predetermined value, and transmitting packet data only once when the communication error rate is equal to or lower than the predetermined value. . The control unit 34 determines a communication error for each piece of packet data, and makes a retransmission request for each piece of packet data. Thus, the control unit 34 in the repeater 3 operates as a communication error determination unit and a transmission count setting unit.

  Next, the cordless handset 4 includes an antenna 41, a wireless unit 42, a control unit 43, a packet data buffer 44a, an image expansion processing unit 44b, an image storage unit 44c, a display panel drive circuit 45, a display A panel 46, an audio signal processing unit 47, a microphone 47a, a speaker 47b, a call button 48a, and an end button 48b are provided. The packet data buffer 44a stores the packet data received via the wireless unit 42, and the image decompression processing unit 44b receives the JPEG format etc. when all the N pieces of packet data (corresponding to the compressed image data) are received. The image storage unit 44c stores the expanded image data in a memory (frame memory). The display panel drive circuit 45 drives the display panel 46 to display the image data stored in the image storage unit 44 c on the display panel 46. The display panel 46 is a display device configured using liquid crystal or the like.

  The audio signal processing unit 47 modulates / demodulates the audio signal. The microphone 47a collects a user's voice, and the speaker 47b outputs a visitor's voice and generates a ringing tone when a call signal from the repeater 3 is received. The call button 48a is pressed when the user makes a call using the cordless handset 4, and the call end button 48b is pressed when the user ends the call using the cordless handset 4. The control unit 43 receives signals from the call button 48a and the call end button 48b and controls the audio signal processing unit 47, the wireless unit 42, and the like.

  The wireless unit 42 is configured to be able to wirelessly communicate with the repeater 3 via the antenna 41. Specifically, the wireless unit 42 functions as a slave unit with respect to the wireless unit 32 in the repeater 3 (that is, the wireless unit 32 serves as a master unit) and performs wireless communication. Specifically, the wireless unit 42 receives a call signal from the repeater 3 and establishes a wireless communication link with the repeater 3 when the call button 48a is pressed. As a result, a wireless communication link is established among the door phone master unit 2, the repeater 3, and the cordless slave unit 4. That is, a voice link is formed among the doorphone slave unit 1, the doorphone master unit 2, the repeater 3, and the cordless slave unit 4. Thereby, a visitor and a user can have a conversation between the doorphone cordless handset 1 and the cordless cordless handset 4. Thus, the wireless unit 42 corresponds to a third wireless unit.

  Here, with reference to FIG. 3, the radio | wireless communication system between the door phone main | base station 2, the repeater 3, and the cordless subunit | mobile_unit 4 is demonstrated. In this embodiment, a frequency hopping method (FHSS: Frequency Hopping Spread Spectrum) is used as a wireless communication method among the intercom master unit 2, the repeater 3, and the cordless slave unit 4. In FIG. 3, time is shown on the horizontal axis and frequency is shown on the vertical axis. As shown in the figure, in the frequency hopping method, the frequency set when transmitting and receiving a radio signal is changed every predetermined time. In other words, the frequency used at the time of transmission is changed for each packet data. In this example, the frequency is changed in the order of f0 → f7 → f4 → f1 → f5 → f2 → f6 → f3. The frequency to be changed and the order of changing the frequency are determined in advance.

  A hatching area A1 in FIG. 3 represents the frequency of radio waves used by a wireless LAN, a microwave oven, or the like. Such a radio wave can become an interference wave in the wireless communication between the door phone base unit 2, the repeater 3, and the cordless handset 4. Specifically, since the frequency f4 is located in the hatching area A1, it is considered that the radio signal when the frequency f4 is used is likely to cause a communication error.

  Next, an example of the state of the transmission slot and the reception slot when the repeater 3 performs wireless communication will be described with reference to FIG. FIG. 4 shows a time division multiplex slot composed of a transmission slot and a reception slot. Specifically, the transmission slot is composed of a slot SL1 and a slot SL2, and the reception slot is composed of a slot SL3 and a slot SL4. The slot SL1 is used for transmitting packet data from the repeater 3 to the intercom master unit 2, and the slot SL2 is used for broadcasting packet data from the repeater 3 to the cordless slave unit 4. On the other hand, the slot SL3 is used for the repeater 3 to receive packet data from the intercom base unit 2, and the slot SL4 is unused.

  Next, an example of the packet data structure will be described with reference to FIG. As shown in the figure, the packet data includes data D1 corresponding to the image serial number, data D2 corresponding to the packet number, image data D3, and error detection code D4. The image serial number corresponds to the serial number in the image captured by the intercom base unit 2, and the packet number corresponds to the serial number in the packet data divided into N pieces. The image data D3 corresponds to data obtained by dividing image-compressed image data into N packets. That is, the image data D3 corresponds to a payload. Further, the error detection code D4 corresponds to a checksum, CRC (Cyclic Redundancy Check), or the like. The error detection code D4 is embedded in the packet data by the intercom base unit 2. And the repeater 3 discriminate | determines the communication error in packet data based on the error detection code D4.

[Processing performed by each component]
Below, the process which the door phone main | base station 2, the repeater 3, and the cordless cordless handset 4 perform is demonstrated.

  In this embodiment, the repeater 3 sets the number of times packet data is transmitted to the cordless handset 4 based on the communication error rate measured by the communication error rate measuring unit 35 when the cordless handset 4 is called. To do. Specifically, the repeater 3 transmits packet data twice or more when the communication error rate is greater than a predetermined value, and transmits packet data only once when the communication error rate is equal to or less than a predetermined value. The broadcast transmission operation is switched so that That is, in this embodiment, the communication error status (corresponding to the surrounding radio wave status) between the intercom master unit 2 and the repeater 3 is monitored as needed, and the relay is performed when the cordless slave unit 4 is called based on the result. The broadcast transmission operation from the device 3 to the cordless handset 4 is switched. Further, in the present embodiment, when the cordless handset 4 is called, the repeater 3 performs processing so as to request the intercom base unit 2 to retransmit the packet data determined to be a communication error. As a result of the processing, when packet data having no communication error is received from the intercom base unit 2, processing is performed so that the packet data is transmitted to the cordless handset 4.

  The above communication is performed for the following reason. When the cordless handset 4 is called, a wireless communication link is not established between the repeater 3 and the cordless handset 4, and one-way broadcast transmission from the repeater 3 to the cordless handset 4 is performed. Therefore, even if a communication error occurs in the packet data transmitted from the repeater 3 to the cordless handset 4, basically error recovery cannot be performed. In other words, since bidirectional communication is not performed between the repeater 3 and the cordless slave unit 4 when the cordless slave unit 4 is called, the cordless slave unit 4 retransmits packet data having a communication error to the repeater unit 3. (In other words, the repeater 3 cannot receive a re-transmission request from the cordless handset 4), and error recovery cannot be performed. Therefore, the communication quality in the whole door phone system may be deteriorated.

  Therefore, in the present embodiment, the communication status between the intercom base unit 2 and the repeater 3 is monitored as needed, and based on the result, the cordless handset 4 is called from the repeater 3 to the cordless handset 4 when the cordless handset 4 is called. Switch the broadcast transmission operation to the optimum one. Basically, since the cordless handset 4 tends to be arranged near the repeater 3, the communication status (corresponding to the communication error rate) between the doorphone master unit 2 and the repeater 3 is the doorphone parent. It can be considered that the communication state between the machine 2 and the cordless handset 4 is represented as a representative. Therefore, by switching the broadcast transmission operation according to the communication error rate, it is possible to effectively reduce the occurrence of communication errors in the packet data transmitted from the repeater 3 to the cordless slave unit 4. Specifically, when wireless communication is performed using the frequency hopping method, the frequency used for transmission is changed for each packet transmission, so packet data is transmitted multiple times when the communication error rate is relatively high. By doing so, it is possible to appropriately suppress the frequency used for the packet data from overlapping with the frequency of the interference wave (see FIG. 3), and effectively reduce the occurrence of communication errors in the cordless slave unit 4. It becomes possible to do. As described above, according to the present embodiment, it is possible to improve the communication quality of the entire door system 101 at the time of broadcast communication.

  Here, with reference to FIG. 6 thru | or FIG. 9, the process which the door phone main | base station 2, the repeater 3, and the cordless subunit | mobile_unit 4 perform is demonstrated concretely.

  FIG. 6 is a flowchart showing the overall processing performed by each of the door phone master unit 2, the repeater 3, and the cordless slave unit 4. Specifically, FIG. 6 roughly shows a process from establishing a wireless communication link among the doorphone master unit 2, the repeater 3, and the cordless slave unit 4 to disconnecting the wireless communication link. Moreover, the process of step S101-S105 is performed by the intercom base unit 2, the process of step S106-S112 is performed by the repeater 3, and the process of step S113-S118 is performed by the cordless cordless handset 4.

  First, the process performed by the doorphone master unit 2 will be described. In step S101, door phone master unit 2 determines whether or not the call button 13 of door phone slave unit 1 has been pressed by a visitor. That is, it is determined whether or not a call signal is received from the door phone slave unit 1. If the call button 13 has been pressed (step S101; Yes), the process proceeds to step S102. If the call button 13 has not been pressed (step S101; No), the process returns to step S101.

  In step S102, the intercom master unit 2 executes a process for calling the repeater 3. Specifically, the doorphone master unit 2 receives the call signal from the doorphone slave unit 1 because the call button 13 is pressed (step S101; Yes), and transmits the call signal to the repeater 3. To do. Then, the process proceeds to step S103. In step S <b> 103, the intercom master unit 2 establishes a wireless communication link with the repeater 3. Specifically, the radio communication link is established by the intercom master unit 2 and the repeater 3 communicating with each other under the control of the line control unit in the repeater 3. Then, the process proceeds to step S104.

  In step S104, intercom base unit 2 executes packet data transmission processing to be described later. Then, the process proceeds to step S105. In step S <b> 105, door phone base unit 2 disconnects the wireless communication link with repeater 3. Specifically, when the user presses the end button 48b of the cordless handset 4 and the wireless communication link between the repeater 3 and the cordless handset 4 is disconnected, the intercom base unit 2 Disconnect the wireless communication link. In this case, the intercom master unit 2 and the repeater 3 communicate with each other under the control of the line control unit of the repeater 3, thereby disconnecting the wireless communication link. Thereafter, the intercom base unit 2 transitions to a standby state. When the above process ends, the process exits the flow.

  Next, processing performed by the repeater 3 will be described. In step S106, the repeater 3 determines whether or not there is a call from the intercom master unit 2. That is, it is determined whether or not a call signal from the doorphone master unit 2 has been received. The intercom base unit 2 transmits a calling signal to the repeater 3 in the process of step S102 described above. If there is a call from the intercom base unit 2 (step S106; Yes), the process proceeds to step S107. If there is no call (step S106; No), the process returns to step S106.

  In step S <b> 107, since there is a call from the intercom base unit 2, the repeater 3 establishes a wireless communication link with the intercom base unit 2. Specifically, the intercom master unit 2 and the repeater 3 communicate with each other under the control of the line control unit of the repeater 3 to establish a wireless communication link. Then, the process proceeds to step S108. In step S108, the repeater 3 executes a process for calling the cordless child device 4. Specifically, the repeater 3 transmits a call signal to the cordless child device 4. Then, the process proceeds to step S109.

  In step S109, the repeater 3 executes packet data transmission / reception processing described later. Then, the process proceeds to step S110. In step S110, the repeater 3 establishes a wireless communication link with the cordless child device 4. Specifically, when the user presses the call button 48 a in the cordless handset 4, the repeater 3 establishes a wireless communication link with the cordless handset 4. In this case, the wireless communication link is established when the repeater 3 and the cordless handset 4 communicate with each other under the control of the line control unit of the repeater 3. Then, the process proceeds to step S111.

  In step S111, the repeater 3 disconnects the wireless communication link with the cordless child device 4. Specifically, when the user presses the end button 48 b in the cordless handset 4, the repeater 3 releases the wireless communication link with the cordless handset 4. In this case, the wireless communication link is disconnected by the repeater 3 and the cordless slave unit 4 communicating with each other under the control of the line control unit of the repeater 3. Then, the process proceeds to step S112. In step S112, the repeater 3 disconnects the wireless communication link with the doorphone master unit 2. Also in this case, the wireless communication link is disconnected when the repeater 3 and the intercom base unit 2 communicate with each other under the control of the line control unit of the repeater 3. As a result, the wireless communication link is disconnected among the door phone master unit 2, the repeater 3, and the cordless slave unit 4. Thereafter, the repeater 3 transitions to a standby state. When the above process ends, the process exits the flow.

  Next, a process performed by the cordless handset 4 will be described. In step S113, the cordless handset 4 determines whether or not there is a call from the repeater 3. That is, it is determined whether or not the calling signal from the repeater 3 has been received. The repeater 3 transmits a call signal to the cordless child device 4 in the process of step S108 described above. If there is a call from the repeater 3 (step S113; Yes), the process proceeds to step S114. If there is no call (step S113; No), the process returns to step S113.

  In step S114, the cordless handset 4 executes packet data reception processing described later. Then, the process proceeds to step S115. In step S115, the cordless handset 4 determines whether or not the user has pressed the call button 48a in the cordless handset 4. If the call button 48a has been pressed (step S115; Yes), the process proceeds to step S116. If the call button 48a has not been pressed (step S115; No), the process returns to step S114.

  In step S116, since the call button 48a is pressed, the cordless handset 4 establishes a wireless communication link with the repeater 3. Specifically, the cordless handset 4 and the repeater 3 communicate with each other under the control of the line control unit of the repeater 3 to establish a wireless communication link. In this case, a call start request signal is transmitted from the cordless handset 4 to the intercom base unit 2 via the repeater 3. As a result, a wireless communication link is established among the doorphone master unit 2, the repeater 3, and the cordless slave unit 4. That is, a voice link is formed among the doorphone slave unit 1, the doorphone master unit 2, the repeater 3, and the cordless slave unit 4. When the above process ends, the process proceeds to step S117.

  In step S117, the cordless handset 4 determines whether or not the user has pressed the call end button 48b. When the end button 48b is pressed (step S117; Yes), the process proceeds to step S118. When the end button 48b is not pressed (step S117; No), the process returns to step S117.

  In step S118, because the end button 48b has been pressed, the cordless handset 4 disconnects the wireless communication link with the repeater 3. In this case, the wireless communication link is disconnected by the cordless handset 4 and the repeater 3 communicating with each other under the control of the line control unit of the repeater 3. Thereafter, the cordless handset 4 changes to a standby state. When the above process ends, the process exits the flow.

  FIG. 7 is a flowchart showing the packet data transmission process in step S104 described above. This packet data transmission process is executed by the intercom base unit 2 and is mainly performed for transmitting packet data to the repeater 3.

  First, in step S201, the door phone master unit 2 captures image data captured by the camera 15 of the door phone slave unit 1 at an appropriate timing to obtain a still image. Then, the process proceeds to step S202. In step S202, the intercom base unit 2 performs a process of compressing the image (captured image) captured in step S201. For example, an image compression process is performed using a JPEG format or the like. Then, the process proceeds to step S203.

  In step S203, the intercom base unit 2 generates packet data by dividing the image data (compressed image data) compressed in step S202 into N packets. Then, intercom base unit 2 stores the created packet data in packet data buffer 24d. When the above process ends, the process proceeds to step S204. In step S204, door phone base unit 2 initializes packet number counter PN corresponding to the number of packet data to be transmitted to repeater 3 (PN = 0). Then, the process proceeds to step S205.

  In step S205, intercom base unit 2 transmits the packet data indicated by packet number counter PN to repeater 3. Specifically, door phone base unit 2 transmits packet data in accordance with a frequency hopping method. In this case, the intercom base unit 2 transmits one packet data at a predetermined time interval (time slot). Note that the frequency used for transmission is changed for each packet transmission. When the above process ends, the process proceeds to step S206.

  In step S <b> 206, intercom base unit 2 determines whether a packet data retransmission request is received from repeater 3. If there is a retransmission request (step S206; Yes), the process returns to step S205. In this case, the intercom base unit 2 performs again the process of transmitting the packet data requested to be retransmitted from the repeater 3 (step S205). On the other hand, when there is no retransmission request (step S206; No), the process proceeds to step S207.

  In step S207, intercom base unit 2 increments packet number counter PN. That is, “1” is added to the packet number counter PN. Then, the process proceeds to step S208. In step S <b> 208, door phone base unit 2 determines whether or not a transmission request for the next packet data is received from repeater 3. If there is a request for transmission of the next packet data (step S208; Yes), the process proceeds to step S209. On the other hand, when there is no next packet data transmission request (step S208; No), the process returns to step S208. That is, it waits until there is a request for transmission of the next packet data.

  In step S209, intercom base unit 2 determines whether or not transmission of all N pieces of packet data has been completed based on packet number counter PN. If transmission of all packet data has been completed (step S209; Yes), the process proceeds to step S210. On the other hand, when transmission of all packet data has not been completed (step S209; No), the process returns to step S205. In this case, door phone base unit 2 repeats the processing of steps S205 to S209 until transmission of all packet data is completed.

  In step S210, the intercom base unit 2 determines whether or not the wireless communication link with the repeater 3 is to be disconnected. Specifically, it is determined whether or not the user presses the end button 48b of the cordless handset 4 and the wireless communication link between the repeater 3 and the cordless handset 4 is disconnected. When the wireless communication link is disconnected (step S210; Yes), the process exits the flow. When the wireless communication link is not disconnected (step S210; No), the process returns to step S201. That is, the intercom base unit 2 continues to transmit packet data to the repeater 3 until the wireless communication link is disconnected.

  FIG. 8 is a flowchart showing the packet data transmission / reception process in step S109 described above. This packet data transmission / reception process is executed by the repeater 3 and is mainly performed for receiving packet data from the intercom master unit 2 and for transmitting packet data to the cordless slave unit 4. The processing is executed when the cordless handset 4 is called.

  First, in step S301, the repeater 3 transits to a packet data reception standby state. Then, the process proceeds to step S302. In step S <b> 302, the repeater 3 performs a process for initializing the communication error rate measuring unit 35. Specifically, an error counter ErrCnt corresponding to the number of packets in which a communication error has occurred is set to “0”, and a packet number counter PktCnt corresponding to the total number of packets received by the repeater 3 is set to “0”. The communication error rate corresponds to “error counter ErrCnt / packet number counter PktCnt”. When the above process ends, the process proceeds to step S303.

  In step S303, the repeater 3 determines whether or not packet data is received from the intercom base unit 2. If packet data has been received (step S303; Yes), the process proceeds to step S304. If packet data has not been received (step S303; No), the process returns to step S303. In step S304, the repeater 3 increments the packet number counter PktCnt because the packet data is received from the intercom base unit 2. That is, “1” is added to the packet number counter PktCnt. Then, the process proceeds to step S305.

  In step S305, the repeater 3 determines whether the received packet data (received packet data) is normal. That is, the repeater 3 determines a communication error for each packet data. Specifically, the repeater 3 determines a communication error based on the error detection code D4 embedded in the packet data. For example, the repeater 3 itself generates an error detection code based on the image data D3 in the packet data, and determines a communication error depending on whether or not this matches the error detection code D4 embedded in the packet data. If the packet data is normal (step S305; Yes), the process proceeds to step S307.

  On the other hand, if the packet data is not normal (step S305; No), that is, if it is determined that there is a communication error, the process proceeds to step S306. In step S306, the repeater 3 increments the error counter ErrCnt and requests the intercom base unit 2 to retransmit the packet data. That is, it requests retransmission of the same packet data as the packet data determined to be a communication error. Then, the process returns to step S303. By performing the processing of steps S303 to S306 in this way, error recovery can be performed appropriately when a communication error occurs, and communication between the intercom master unit 2 and the repeater 3 can be made error-free. Become.

  In step S307, the repeater 3 stores the packet data determined to be normal in the packet data buffer 33. Then, the process proceeds to step S308. In step S308, the repeater 3 broadcasts one packet data to the cordless handset 4. Specifically, the repeater 3 broadcasts packet data according to a frequency hopping method. In this case, the repeater 3 transmits one packet data at a predetermined time interval (time slot). Note that the frequency used for broadcast transmission is changed for each packet transmission. When the above process ends, the process proceeds to step S309.

  In step S309, the repeater 3 determines whether or not the communication error rate is greater than a predetermined value. Here, the repeater 3 performs processing for switching the broadcast transmission operation to the cordless handset 4 (specifically, processing for switching the number of times packet data is transmitted to the cordless handset 4). In this case, the repeater 3 obtains a communication error rate by calculating “error counter ErrCnt / packet number counter PktCnt”, and makes a determination. The predetermined value used for determination is set in advance.

  If the communication error rate is greater than the predetermined value (step S309; Yes), the process proceeds to step S310. In this case, since the communication error rate is relatively large, it is considered that a communication error is likely to occur. Therefore, the repeater 3 broadcasts the packet data to the cordless handset 4 again (step S310). That is, the same packet data as the packet data transmitted in step S308 is transmitted again. In this case, the repeater 3 transmits the same packet data to the cordless child device 4 twice. Then, the process proceeds to step S311. On the other hand, when the communication error rate is equal to or lower than the predetermined value (step S309; No), the process proceeds to step S311. In this case, since the communication error rate is relatively small, it cannot be considered that the communication error is likely to occur. Therefore, the repeater 3 does not broadcast the packet data to the cordless child device 4 again. In other words, the repeater 3 broadcasts packet data to the cordless handset 4 only once.

  In step S311, the repeater 3 requests the intercom base unit 2 to transmit the next packet data. Then, the process proceeds to step S312. In step S312, the repeater 3 determines whether to establish a wireless communication link with the cordless handset 4. Specifically, it is determined whether or not the user presses the call button 48a of the cordless handset 4 and a wireless communication link with the cordless handset 4 is to be established. If the wireless communication link is established (step S312; Yes), the process exits the flow. If the wireless communication link is not established (step S312; No), the process returns to step S303. That is, the repeater 3 repeats the processes of steps S303 to S312 until the wireless communication link with the cordless slave unit 4 is established.

  In the process shown in FIG. 8, when the communication error rate is larger than the predetermined value, the packet data is transmitted twice to the cordless handset 4 (see step S310 and the like). You may send more than once. Further, even when the communication error rate is equal to or lower than a predetermined value, the packet data may be transmitted to the cordless handset 4 twice or more. Furthermore, as described above, it is not limited to switching between two types of transmission times (one time and two times) by determining whether or not the communication error rate is larger than a predetermined value. Three or more types of transmissions may be switched by making a determination on the communication error rate using two or more determination values, or the number of transmissions may be continuously changed according to the communication error rate.

  FIG. 9 is a flowchart showing the packet data reception process in step S114 described above. This packet data reception process is executed by the cordless handset 4 and is mainly performed for receiving packet data from the repeater 3 and displaying an image based on the packet data received from the repeater 3. . The packet data reception process is executed when the cordless handset 4 is called. That is, this process is repeatedly executed until the user presses the call button 48a of the cordless handset 4 (see step S115 in FIG. 6).

  First, in step S401, the cordless handset 4 transitions to a packet data reception standby state. Furthermore, the cordless handset 4 initializes the packet data buffer 44a. Then, the process proceeds to step S402. In step S402, the cordless handset 4 determines whether or not packet data is received from the repeater 3. If packet data has been received (step S402; Yes), the process proceeds to step S403. If packet data has not been received (step S402; No), the process returns to step S402.

  In step S403, the cordless handset 4 determines whether the received packet data (received packet data) is normal. That is, the cordless handset 4 determines a communication error in the packet data. Specifically, the cordless handset 4 determines a communication error based on the error detection code D4 embedded in the packet data. If the packet data is normal (step S403; Yes), the process proceeds to step S404. In this case, the cordless handset 4 stores the received packet data in the packet data buffer 44a (step S404). Then, the process proceeds to step S405. On the other hand, if the packet data is not normal (step S403; No), that is, if it is determined that a communication error has occurred, the process returns to step S402. In this case, the cordless handset 4 does not store the received packet data in the packet data buffer 44a. That is, the cordless handset 4 stores only normal packet data in the packet data buffer 44a.

  In step S405, the cordless handset 4 determines whether all N pieces of packet data have been prepared. If all the N pieces of packet data are available (step S405; Yes), the process proceeds to step S406. On the other hand, when all the N pieces of packet data are not complete (step S405; No), the process returns to step S402. In this case, the processes in steps S402 to S405 are repeated until all N pieces of packet data are obtained.

  In step S406, the cordless handset 4 performs a process of decompressing the N pieces of packet data (corresponding to the compressed image data) stored in the packet data buffer 44a. For example, an image expansion process is performed using a JPEG format or the like. Then, the process proceeds to step S407. In step S407, the cordless handset 4 displays the image expanded in step S406 on the display panel 46. Specifically, an image is displayed on the display panel 46 by controlling the display panel drive circuit 45. When the above process ends, the process exits the flow.

  As described above, the door phone system according to the present embodiment is connected to the door phone slave unit, the door phone master unit wired to the door phone slave unit, the repeater wirelessly connected to the door phone master unit, and the repeater. A wireless communication link between the doorphone master unit and the cordless slave unit via the repeater. Then, the communication error determining means determines a communication error in a radio signal transmitted from the doorphone master unit to the repeater, and the communication error rate measuring means is based on the communication error between the doorphone master unit and the repeater. The communication error rate in the wireless communication is measured, and the transmission number setting means sets the number of times the wireless signal is transmitted from the repeater to the cordless slave unit based on the communication error rate. Thereby, it becomes possible to improve the communication quality in the whole door system at the time of calling the cordless child device (at the time of broadcast communication).

[Modification]
In the above description, an example in which the repeater 3 measures the communication error rate in the wireless communication between the door phone master unit 2 and the repeater 3 has been described. In other words, an example in which the repeater 3 includes the communication error rate measuring unit 35. However, the present invention is not limited to this. In another example, the doorphone master unit 2 can measure a communication error rate in wireless communication between the doorphone master unit 2 and the repeater 3. In other words, the communication error rate measuring unit can be provided in the door phone base unit 2. In this case, intercom base unit 2 requests retransmission of packet data received from repeater 3 (this request indicates that a communication error has occurred in packet data transmitted to repeater 3). In the above example, the communication error rate is obtained after the wireless communication link between the intercom master unit 2 and the repeater 3 is established, and the number of packet data transmissions is set. However, the present invention is not limited to this. That is, it is not limited to obtaining the communication error rate by setting the error counter ErrCnt and the packet number counter PktCnt to “0” (see step S302) after establishing the wireless communication link between the intercom base unit 2 and the repeater 3. In another example, the number of transmissions of packet data to the cordless handset 4 is set in consideration of the communication error rate at the time of establishing the wireless communication link so far, that is, in consideration of the past history of the communication error rate. can do. That is, it is not necessary to reset the communication error rate each time a wireless communication link is established and to newly obtain the communication error rate.

  Furthermore, although the example which measures a communication error rate at the time of calling of the cordless subunit | mobile_unit 4 was shown above, it is not limited to this. In another example, the communication error rate can be measured by using a time during which a wireless communication link for interacting with a visitor is not established. In other words, the communication error rate is automatically set by establishing the wireless communication link between the doorphone master unit 2 and the repeater 3 and performing the wireless communication when the wireless communication link for interacting with the visitor is not established. May be measured automatically.

  Next, FIG. 10 is a schematic diagram showing a system configuration of a door phone system 102 according to a first modification. Door phone system 102 mainly includes door phone slave unit 1, door phone master unit 2, repeater 3a, and three cordless slave units 4b, 4c, and 4d. In addition, the same code | symbol is attached | subjected to the component same as the door phone system 101 (refer FIG. 1) mentioned above, and the description is abbreviate | omitted.

  In the door phone system 101 described above, the repeater 3 is configured to be able to charge the cordless slave unit 4, but in the door phone system 102 according to the first modification, the repeater 3a is configured to be able to charge the cordless slave unit 4. It has not been. That is, in the first modification, the repeater 3a does not have a function as a charging stand for the cordless slave unit. In the door phone system 102, the door phone master unit 2 and the repeater 3a are wirelessly connected, and the repeater 3a and the cordless slave units 4b to 4d are connected wirelessly. Specifically, in the door phone system 102, the repeater 3a functions as a wireless master device, and the door phone master device 2 and the cordless slave devices 4b to 4d function as wireless slave devices, thereby forming a wireless communication link. .

  Next, FIG. 11 is a schematic diagram showing a system configuration 103 according to the second modification. The door phone system 103 mainly includes a door phone slave unit 1, a door phone master unit 2, a cordless telephone master unit 6, and a cordless telephone slave unit 7. In addition, the same code | symbol is attached | subjected to the component same as the door phone system 101 (refer FIG. 1) mentioned above, and the description is abbreviate | omitted.

  The door phone system 103 according to the second modified example is constructed using a cordless telephone master unit 6 instead of the repeater 3 and a cordless telephone slave unit 7 instead of the cordless slave unit 4. This is different from the door phone system 101 described above. In other words, the door phone system 103 according to the second modification is configured by a cordless telephone base unit 6 having the same function as the repeater 3 described above (specifically, a function as a wireless base unit). Yes. That is, the door phone system 103 has two functions: a door phone call function for talking with a visitor and a telephone call function for making a phone call via a telephone line.

  Specifically, the cordless telephone base unit 6 includes a handset unit 63 having a microphone and a receiver for a user to actually carry out a conversation, and a telephone line interface circuit (not shown), and makes a telephone call via the telephone line. It is configured to be possible. The cordless telephone master unit 6 and the doorphone master unit 2 are wirelessly connected, and the cordless telephone master unit 6 and the cordless telephone slave unit 7 are wirelessly connected. Specifically, in the door phone system 103, the cordless telephone base unit 6 functions as a wireless base unit, the door phone base unit 2 and the cordless telephone handset 7 function as wireless base units, and a wireless communication link is formed. Yes. That is, a wireless communication link is established between the doorphone master unit 2 and the cordless phone slave unit 7 via the cordless phone master unit 6. As a result, all the wireless communication between the doorphone master unit 2 and the cordless phone slave unit 7 is performed via the cordless phone master unit 6. Thus, in the door phone system 103 according to the second modification, the cordless telephone base unit 6 functions as a relay that relays wireless communication between the door phone base unit 2 and the cordless telephone handset 7 in the door phone system 103. Further, the door phone system 103 is implemented by implementing the communication protocol of the wireless unit 25 and the cordless telephone cordless handset 7 built in the door phone master unit 2 in accordance with the communication protocol of the existing cordless telephone (compatible). The system is built.

  According to the door phone system 103 according to the second modified example described above, the door phone master unit 2 is caused to function as a wireless slave unit, and the cordless telephone master unit 6 is functioned as a wireless master unit to establish a wireless communication link. Therefore, it is possible to easily construct a system that combines a door phone system and a cordless telephone.

  In the above, an example in which the door phone system 103 is configured using the cordless telephone master unit 6 instead of the repeater 3 is shown, but in another example, the door phone system 101 (see FIG. 1) having the repeater 3 is used. On the other hand, a new door phone system can be constructed by adding the cordless telephone master unit 6. In this case, the wireless communication function in the repeater 3 is turned off (invalidated) (thereby, the repeater 3 functions only as a charging stand for the cordless slave unit 4a), the doorphone master unit 2, A new system can be constructed by re-registering the parent-child relationship between the cordless slave unit 4 and the cordless telephone master unit 6. That is, a new wireless communication link is constructed with the cordless telephone master unit 6 as a wireless master unit and the doorphone master unit 2 and the cordless slave unit 4 as wireless slave units. In still another example, a new system can be constructed by adding the cordless telephone master unit 6 to the door phone system 102 (see FIG. 10). Further, a new system can be constructed by adding not only the cordless telephone master unit 6 but also the cordless telephone slave unit 7 to the door phone system 101 or the door phone system 102.

  Furthermore, the present invention can be applied to a room (baby) monitor system, a security (surveillance) camera system, and a system having a recorder in these systems. In addition, the present invention can also be applied to information broadcast display devices (such as wirelessly connected message boards).

It is the schematic which shows the system configuration | structure of the door phone system which concerns on a present Example. It is a block diagram which shows the whole structure of a door phone system. It is a figure for demonstrating the radio | wireless communication system between a door phone main | base station, a repeater, and a cordless cordless handset. It is a figure for demonstrating the state of the transmission slot at the time of a relay device performing radio | wireless communication, and a receiving slot. It is a figure for demonstrating the example of a packet data structure. It is a flowchart which shows the whole process which each of an intercom master unit, a repeater, and a cordless cordless handset performs. It is a flowchart which shows the packet data transmission process performed by the door phone main unit. It is a flowchart which shows the packet data transmission / reception process performed by the repeater. It is a flowchart which shows the packet data reception process performed by a cordless cordless handset. It is the schematic which shows the system configuration | structure of the door phone system which concerns on a 1st modification. It is the schematic which shows the system configuration | structure of the door phone system which concerns on a 2nd modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Doorphone cordless handset 2 Doorphone master phone 3, 3a Repeater 4, 4a, 4b, 4c, 4d Cordless cordless handset 5b, 5c, 5d Charging stand 6 Cordless phone master phone 7 Cordless phone cordless handset 101, 102, 103 Door phone system

Claims (13)

A relay comprising: a doorphone slave unit; a doorphone master unit wired to the doorphone slave unit; a repeater wirelessly connected to the doorphone master unit; and a cordless slave unit wirelessly connected to the repeater. A doorphone system for establishing a wireless communication link between the doorphone master unit and the cordless slave unit via a device,
A communication error determining means for determining a communication error in a radio signal transmitted from the doorphone master to the repeater;
Based on the communication error determined by the communication error determining means, a communication error rate measuring means for measuring a communication error rate in wireless communication between the doorphone master unit and the repeater;
The number of transmissions for setting the number of times the wireless signal is transmitted from the repeater to the cordless slave unit based on the communication error rate measured by the communication error rate measuring unit when the cordless slave unit is called A door phone system comprising: setting means.   The transmission count setting means sets the number of times of transmitting the radio signal to 2 or more when the communication error rate is greater than a predetermined value, and when the communication error rate is equal to or less than the predetermined value, The door phone system according to claim 1, wherein the number of times of transmitting the radio signal is set to one.   The repeater requests the intercom master unit to retransmit a radio signal determined to be a communication error by the communication error determination unit when calling the cordless slave unit, and communicates by the communication error determination unit. The wireless signal is transmitted to the cordless child device according to the number of times set by the transmission number setting means when a wireless signal determined not to have an error is received. The door phone system according to 2.   The wireless signal corresponds to packet data created by compressing image data captured by the camera of the door phone slave unit and dividing the image data after the image compression into a plurality of packets. The door phone system according to any one of claims 1 to 3.   The doorphone system according to claim 4, wherein the communication error determination unit determines the communication error based on an error detection code in the packet data. The communication error determining means determines the communication error for each of the packet data,
6. The repeater makes a re-transmission request to the intercom master unit for each packet data when the communication error is determined by the communication error determination means. Door phone system as described in.   The doorphone system according to any one of claims 1 to 6, wherein wireless communication is performed by a frequency hopping method among the doorphone master unit, the repeater, and the cordless slave unit.   The door phone system according to any one of claims 1 to 7, wherein the communication error rate measuring unit measures the communication error rate when calling the cordless child device.   8. The communication error rate measuring means measures the communication error rate by using a time during which a wireless communication link for responding to a visitor is not established. The door phone system according to one item.   The door phone system according to any one of claims 1 to 9, wherein the communication error rate measuring means is provided in the repeater.   The doorphone system according to any one of claims 1 to 9, wherein the communication error rate measuring means is provided in the doorphone master unit. The doorphone master unit includes a first wireless unit that performs wireless communication with the repeater,
The cordless handset includes a third wireless unit that performs wireless communication with the repeater,
The repeater includes a line control unit that functions as a master unit for each of the first radio unit and the third radio unit, and performs radio communication with the first radio unit and the third radio unit, respectively. The door phone system according to any one of claims 1 to 11, further comprising a second wireless unit that performs the following.   The doorphone system according to any one of claims 1 to 12, wherein the repeater includes a telephone line interface circuit for operating as a cordless telephone.

Images