JP2000078661A - Radio communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication system where a sufficient standby time is secured without increasing power consumption in the case that a slave station makes intermittent reception in the radio communication system where a master station and the slave station use a control channel to send/receive control information. SOLUTION: When timing for starting reception comes during intermittent reception of a slave station for radio communication, a reception operation is started to a control channel (step S1), and when no carrier is detected (step S2; NO), no reception is conducted (step S3), and when any carrier is detected (step S2; YES), whether data are addressed to its own station or to other station is discriminated (steps S4, S5). When it is discriminated that the data are addressed to its own station, communication with the master station is started (step S5), and when no discrimination is made, similar processing is repeated till the reception consecutive time elapses (step S7) and when the reception consecutive time elapses, the reception is cancelled (step S3).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication system in which a master station and one or more slave stations are wirelessly connected, such as an analog cordless telephone system, and a predetermined control channel is provided between the master station and the slave stations. , And belongs to the technical field of a wireless communication system that establishes a wireless connection by transmitting and receiving control information.

[0002]

2. Description of the Related Art In recent years, in an analog cordless telephone system widely used, an unused communication channel is selected from a number of communication channels to perform communication between a master station and a slave station. In the communication channel, an FM-modulated voice signal is transmitted and received in a full-duplex system. At this time,
In order to establish a wireless connection in the call channel, using a predetermined control channel, after transmitting and receiving various control information including information of the call channel between the master station and the slave station,
The transition to one communication channel starts normal communication.

[0003] Incidentally, the slave station is generally configured to connect a rechargeable battery to supply power. Therefore, in order to reduce power consumption when waiting for a call from the master station, the control channel is intermittently received at predetermined time intervals, carrier detection is performed, and then the presence or absence of call data addressed to the own station is determined. . At this time, in order to reliably receive the call data, when a carrier is detected, a sufficient time is required to continue the reception state for about 2 to 3 seconds and determine the call data.

[0004]

However, when the above-mentioned intermittent reception is performed, the carrier received during standby is not always the call data addressed to the own station. For example, the control information may be control information addressed to another slave station in the cordless telephone system to which the own station belongs, or a control channel used in a different cordless telephone system is often detected. Since the cordless telephone guarantees a radio range of 100 m, many cordless telephone systems are used in a specific area in many cases, and this tendency is remarkable especially in an apartment house and its vicinity. .

[0005] Therefore, when the control at the time of intermittent reception is performed as described above, carriers including call data and the like not addressed to the own station are frequently detected, and each time the reception state is continued for a certain period of time, The problem is that the standby time is shortened because extra power required for reception is consumed.

In view of the above, the present invention has been made in view of such a problem. In a wireless communication system including a master station and a slave station, when the intermittent reception of the slave station is performed using the control channel, the consumption is reduced. It is an object of the present invention to provide a wireless communication system capable of sufficiently securing a standby time without increasing power.

[0007]

According to a first aspect of the present invention, there is provided a radio communication system comprising a master station and a slave station, wherein the master station and the slave station have a predetermined control channel. A wireless communication system for transmitting and receiving control information in frame units via a wireless communication system and establishing a wireless connection in accordance with the control information, wherein the master station transmits control information including data designated by the slave station. When control information including response data to the control information is not received from the slave station indicated by the designated data until a predetermined retransmission time elapses from the transmission timing of the control information, the control information is transmitted by the control information transmitting unit. Control information retransmitting means for retransmitting the control information, wherein the slave station performs intermittent reception operation control for performing an intermittent reception operation on the control channel at a preset time interval. A stage, a carrier detecting means for detecting a carrier in the control channel during the intermittent receiving operation, when the carrier in the control channel is detected by the carrier detection means, said retransmission time 1
A reception continuation unit that continues the reception operation until a reception continuation time that is the sum of the time length of the frame elapses, and whether the control information including the designated data of the own station is received by the reception operation by the reception continuation unit. And control means for transmitting control information including response data to the master station when control information including designated data of the own station is detected by the detection means. .

According to the present invention, the slave station performs an intermittent reception operation at a preset time interval during standby and performs carrier detection on the control channel. At this time, the master station transmits control information including designated data of the slave station in frame units.
Then, the slave station detects the carrier and continues the reception operation for the reception duration time. On the other hand, if the master station does not receive the response data from the specified slave station by the elapse of the predetermined retransmission time,
Retransmit the transmitted control information to the slave station. At this time, since the reception continuation time of the slave station is set to the sum of the retransmission time and the time length of one frame, the retransmitted control information can be reliably received. Further, when the slave station detects the designated data of the own station from the received control information, the slave station transmits the control information including the response data to the master station, so that the master station and the slave station can promptly shift to communication using the communication channel. As described above, the reception duration of the slave station is set to the minimum time required to receive the control information retransmitted from the master station, so that power consumption during intermittent reception can be suppressed.

A wireless communication system according to a second aspect of the present invention is the wireless communication system according to the first aspect, wherein a reception continuation operation is performed when a detection result of the detection unit is obtained during reception by the reception continuation unit. And a reception continuation canceling means for canceling the operation.

According to the present invention, when the slave station detects a carrier at the time of intermittent reception and enters the reception continuation state, it is detected that the control information includes the specified data of the own station or the specified If no data is detected, the reception continuation operation is stopped. Therefore, it is sufficient to continue the reception operation up to the reception continuation time only when it is unknown whether or not the data includes the designated data of the own station, and the time for performing unnecessary reception is reduced, and the power consumption at the time of intermittent reception is further reduced. Can be.

A wireless communication system according to a third aspect is the wireless communication system according to the first or second aspect, wherein the wireless communication system has a maximum of N (N is an integer of 2 or more) slave stations. Registration is possible and the retransmission time is 1
It is characterized by being set to 2N times the time length of the frame.

According to the present invention, the maximum number of slave stations that can be registered in the wireless communication system is N, and the retransmission time is set to N frames for transmitting control information to N slave stations, It was set to 2N frames, which is the sum of N frames for receiving response data from the station. Therefore, the retransmission time when transmitting and receiving frame data by the half-duplex method can be minimized, and the reception duration time can be shortened accordingly.

A wireless communication system according to a fourth aspect of the present invention comprises a master station and a plurality of slave stations, and the slave stations can register at most N (N is an integer of 2 or more). A station is a wireless communication system that transmits and receives control information in a frame unit via a predetermined control channel and establishes a wireless connection according to the control information, wherein the master station is an actual When the number of slave stations registered in the slave station is M (M is an integer equal to or less than N), a slave station registration number transmitting means for transmitting data indicating M, and transmitting control information including designation data of the slave station. Control information transmitting means, and control information including response data to the control information from a slave station indicated by the designated data until a retransmission time set in association with the M elapses from the transmission timing of the control information. Is not received, Control information retransmitting means for retransmitting the control information transmitted by the control information transmitting means, wherein the slave station receives and stores the data indicating the M transmitted by the slave station registration number transmitting means. Slave station registration number storage means, intermittent reception operation control means for performing intermittent reception operation on the control channel at a preset time interval, and carrier detection means for detecting a carrier in the control channel during the intermittent reception operation, When the carrier in the control channel is detected by the carrier detection means, the data indicating the M is read from the slave station registration number storage means, and the retransmission time set in association with the M and one frame are read. The reception continuation means for continuing the reception operation until the reception continuation time which is the sum elapses, and the reception operation by the reception continuation means, the designation of own station Detecting means for detecting whether or not control information including data is received, and control information including response data to the master station when control information including designated data of the own station is detected by the detecting means. And a response means for transmitting.

According to the present invention, the actual registration number M is transmitted in advance from the number N of child stations that can be registered from the parent station, and the child station that has received the information stores M. Then, the slave station performs an intermittent reception operation at a preset time interval during standby, and performs carrier detection on the control channel. At this time,
The master station transmits control information including designated data of the slave station in frame units. Then, the slave station detects the carrier and continues the reception operation for the reception duration time. On the other hand, if the master station does not receive the response data from the specified slave station until the retransmission time set corresponding to M elapses, the master station retransmits the transmitted control information to the slave station. At this time, the slave station reads the data indicating M and sets the reception duration to the sum of the retransmission time set for M and the time length of one frame, so that the retransmitted control information can be reliably received. it can. Further, when the slave station detects the designated data of the own station from the received control information, the slave station transmits the control information including the response data to the master station, so that the master station and the slave station can promptly shift to communication using the communication channel. As described above, the reception duration time of the slave station is set to the minimum time required to receive the control information retransmitted from the master station, and can be changed to an appropriate time corresponding to M.
Power consumption during intermittent reception can be suppressed while flexibly corresponding to the system configuration.

According to a fifth aspect of the present invention, in the wireless communication system according to the fourth aspect, the reception continuation operation is performed when a detection result of the detection means is obtained during reception by the reception continuation means. And a reception continuation canceling means for canceling the operation.

According to the present invention, when the slave station detects a carrier at the time of intermittent reception and enters a reception continuation state, the reception continuation operation is stopped when it is determined whether or not control information of the slave station is included. I did it. Therefore, it is sufficient to continue reception only when it is unknown whether or not control information of the own station is included, so that the time for performing unnecessary reception is reduced, and power consumption during intermittent reception can be further suppressed.

According to a sixth aspect of the present invention, in the wireless communication system according to the fourth or fifth aspect, the retransmission time is set to 2M times the time length of the one frame. I do.

According to the present invention, when the number of slave stations actually registered in the wireless communication system is M, the retransmission time is set to an M frame for transmitting control information to the M slave stations, and 2M frames, which is the sum of M frames for receiving response data from slave stations. Therefore, it is possible to minimize the retransmission time and the reception duration time when transmitting and receiving the frame data by the half-duplex method while flexibly corresponding to the system configuration.

A wireless communication system according to a seventh aspect is the wireless communication system according to any one of the first to sixth aspects, wherein the wireless communication system is a cordless telephone system connected to a telephone line. It is characterized by.

According to the present invention, in a cordless telephone system, control information is transmitted and received between a master station and a slave station using a control channel, and the slave station performs the above-described control when performing intermittent reception during standby. To do. Therefore,
A cordless telephone slave station can reduce power consumption during standby and can increase standby time.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. Here, the present invention is applied to an analog cordless telephone system that includes a master station and a plurality of slave stations and uses a 250 MHz / 380 MHz band to transmit and receive control information via a control channel and transmit and receive voice signals via a communication channel. An embodiment in which is applied will be described.

FIG. 1 is a block diagram showing a system configuration of a cordless telephone system according to this embodiment. Figure 1
As shown in FIG. 1, the cordless telephone system according to the present embodiment includes a master station 1 connected to a telephone line and four slave stations 2, 3, 4, and 5 wirelessly connected to the master station 1. Have been. Although the number of slave stations may be further increased, a case where four slave stations are included will be described for simplicity.

In FIG. 1, when the wireless connection is established between the master station 1 and the slave stations 2 to 5, the transmission frequency of the master station 1 and the reception frequency of the slave stations 2 to 5 use the 380 MHz band. And the reception frequency of the master station 1 are in the 250 MHz band. And in each frequency band,
A total of 89 wireless channels are reserved. Most of the radio channels are allocated as speech channels, but some predetermined radio channels are used as control channels. The master station 1 and the slave stations 2 to 5 first establish a wireless connection using the control channel, and perform subsequent wireless communication using the one communication channel confirmed to be an empty channel.

For example, when the slave station 2 is engaged in a telephone call via the master station 1, a predetermined communication channel in the 250 MHz band is FM-modulated by a voice input signal from the slave station 2 through a microphone or the like. The data is transmitted to the master station 1, and after being received by the master station 1, it is demodulated and transmitted to the telephone line. On the other hand, the audio signal arriving at the master station 1 from the telephone line causes
A predetermined communication channel in the Hz band is FM-modulated and transmitted to the slave station 2. After being received by the slave station 2, it is demodulated and output as sound from a receiver or the like. As described above, the audio signal is transmitted and received between the master station 1 and the slave station 2 using the full-duplex method using two frequencies.

On the other hand, before starting the call, the slave stations 2 to 5
Intermittently receives a predetermined control channel of the 380 MHz band, and waits for call data transmitted from the master station 1. In this way, the slave stations 2 to 5 perform the intermittent reception operation, thereby minimizing the power consumption during standby. In the control channel, various control information other than the call data is transmitted and received between the master station 1 and the slave stations 2 to 5 as frame data. In this frame data, the time length of one frame is constant. Then, after performing MSK modulation on the control channel at a modulation speed of about 1200 to 2400 bps based on the frame data, transmission and reception are performed between the master station 1 and the slave stations 2 to 5 by a half-duplex method.

FIG. 2 is a diagram showing a data structure of frame data transmitted and received between the master station 1 and the slave stations 2 to 5 in this embodiment. As shown in FIG. 2, the frame data includes ID, BCH code, slave station number, transmission data, BCH
The code includes a code, and a required number of bits are allocated to each. A bit synchronization (not shown) is provided at the head,
It generally includes a predetermined pattern for frame synchronization.

In the frame data shown in FIG. 2, the ID is assigned as a unique number to each cordless telephone system. Thus, even when a plurality of cordless telephone systems exist within the radio wave reach range, the master station 1 and the slave stations 2 to 5 analyze the ID, and the received frame data is transmitted to the cordless telephone system to which the own station belongs. It is possible to correctly recognize that the message is transmitted within the device.

The slave station number is a number assigned to identify a slave station included in the cordless telephone system.
Regardless of the number of actually registered slave stations, it is necessary to allocate a sufficient number of bits to distinguish the maximum number of slave stations that can be registered. This slave station number indicates the destination slave station in the frame data transmitted from the master station 1 to the slave stations 2 to 5, but in the frame data transmitted from the slave stations 2 to 5 to the master station 1, It means the originating slave station.

The transmission data is data to be actually transmitted, and includes types such as a command for transmitting a predetermined instruction and a status indicating various states. For example, there are call data transmitted from the master station 1 to the slave stations 2 to 5 and response data transmitted from the slave stations 2 to 5 to the master station 1. Note that a code indicating the type of the transmission data may be provided at the beginning of the transmission data.

The BCH code following the ID and the BCH code following the transmission data are added to correct errors caused by radio noise or the like when reading the frame data. Error correction is performed separately for the ID part and the other part. The stronger the number of bits allocated to the BCH code, the more powerful error correction can be performed. However, an appropriate number of bits is allocated in consideration of the overall bit allocation.

In the frame data configured as described above, bits are appropriately allocated to each element as described above, and it is general that the total number of bits of the frame data is set to a constant value. By doing so, the modulation speed becomes 1
Since it is constant at 200 bps or 2400 bps, the time length of one frame can be kept constant, and the timing design for data transmission / reception can be simplified.

Using the frame data shown in FIG. 2, calling data and the like are transmitted from the master station 1 to the slave stations 2 to 5 using the control channel. The stations 2 to 5 transmit the frame data including the response data to the master station 1 after confirming that the call data is addressed to the own station. On the other hand, when the response data is not returned, the master station 1 retransmits the frame data at a timing when a predetermined retransmission time has elapsed from the timing at which the frame data was first transmitted. The details of the setting of the retransmission time will be described later.

Next, an intermittent reception operation performed by the slave station 2 during standby and a process of transmitting and receiving frame data in the standby state in the present embodiment will be described with reference to FIGS. Since the same applies to the case of the slave stations 3 to 5, the case of the slave station 2 will be described as a representative.

FIG. 3 is a timing chart when frame data is not transmitted from master station 1 when slave station 2 is performing intermittent reception. As shown in FIG.
From the receiving off state to the receiving on state intermittently at regular time intervals T, and perform the receiving operation on the control channel. Specifically, the power supply to the wireless system is started, the reception frequency is stabilized on a predetermined control channel, and carrier detection is performed. When it is confirmed that no carrier is detected on the control channel, the supply of power to the wireless system is stopped again. As shown in FIG. 3, it can be seen that it takes Ton time to perform this series of operations.

In the example of FIG. 3, since the frame data is not transmitted from the master station 1 and the control channel is always in a carrier-less state, a pattern in which the reception is always ON only for every Ton at the time interval T is repeated. Here, in general, the longer the time interval T of the intermittent reception, or the shorter the time Ton during which the reception is turned on, the shorter the power consumption can be suppressed. However, if T is set too long, there is a problem that the response to the call data is delayed, and Ton depends on the characteristics of the wireless circuit, and therefore, there are limitations.

FIG. 4 is a timing chart when frame data is transmitted from the master station 1 when the slave station 2 is performing intermittent reception. As shown in FIG. 4, when the reception is turned on for the first time, since the frame data is not yet transmitted from the master station 1, the slave station 2 sets the T as described above.
Reception is turned on only during on. Then, at a timing t1 before the reception is turned on for the second time after the elapse of the time interval T, the master station 1 starts transmitting frame data to the slave station 2. This frame data includes, for example, call data to be transmitted to the slave station 2 when there is an incoming call to the telephone line. In the frame data, one frame has a fixed time length Tf.

In a time zone in which no frame data is transmitted / received, the transmission state of the master station 1 is not clear as shown by a chain line in the figure. That is, there is a case where call data or the like is transmitted to the other slave stations 3 to 5. However, since the upper limit of the continuous occupation time of the control channel is about 4 seconds, the transmission state cannot be maintained for a very long time.

After the timing t1, the slave station 2 turns on the reception, detects the carrier for the control channel used by the master station 1 at the timing t2 after the power-on and the delay time for stabilizing the reception frequency. Is done. In this case, the slave station 2 checks whether or not frame data addressed to the own station has been received. Therefore, the slave station 2 does not shift to the reception-off state, but continues the reception-on state for a certain reception duration from the timing t2. In the present embodiment, the reception continuation time is defined as a retransmission time Tr described later and a time length Tf of one frame.
And the sum is set.

In the example shown in FIG. 4, the reception and analysis of the frame data by the slave station 2 are started after timing t2. On the other hand, at the timing t2, since the master station 1 is already transmitting frame data, the slave station 2 receives frame data in a state where the vicinity of the head is missing. In this case, the slave station 2 cannot normally analyze the frame data.

On the other hand, since the master station 1 does not receive the frame data to be transmitted from the slave station 2 as response data to the transmitted frame data, the master station 1 starts retransmission of the frame data after a predetermined retransmission time Tr has elapsed from the timing t2. I do. The retransmission time Tr is set to an appropriate value in consideration of the specifications of the cordless telephone system, etc.
A specific method for determining the position will be described later.

After the retransmission of the frame data is started, 1
At timing t3 after the time length Tf of the frame, the master station 1
Retransmission of the frame data is completed. Here, t3
= T1 + Tr + Tf, and since the timing t1 is before the timing t2, it can be seen that the reception duration Tr + Tf of the slave station 2 has not yet ended at the timing t3. Therefore, the slave station 2 can receive the entire retransmitted frame data, and can normally analyze the frame data and identify the call data addressed to the own station.

In FIG. 4, the slave station 2 receives the reception time T
During the period of r + Tf, the reception-on state is shown. However, if it is possible to identify the calling data addressed to the own station within the reception continuation time, the intermittent reception is stopped at that time. Then, the communication may be shifted to communication with the master station 1 using the communication channel. If it is determined that the control information is not addressed to the own station but is addressed to other slave stations 3 to 5 or various control information in another cordless telephone system, the reception continuation state may be stopped at that time.

FIG. 5 is a flowchart showing a frame data reception process performed by the slave station 2 during intermittent reception. Since the same processing is performed in the case of the slave stations 3 to 5, the case of the slave station 2 will be described as a representative.

In FIG. 5, it is assumed that the slave station 2 is currently in a standby state and is performing an intermittent reception operation. Then, as described above, when the timing to turn on the reception at every time interval T arrives, in step S1, the slave station 2 starts the reception operation for the predetermined control channel.

In step S2, carrier detection for the control channel is performed. That is, it is determined whether or not a reception wave of a frequency corresponding to the control channel exists based on a reception level or the like in the reception circuit. As a result, if no carrier is detected (step S2; NO), the process proceeds to step S3, and if a carrier is detected (step S2; YES), the process proceeds to step S4.

In step S3, since it is confirmed that no carrier exists in the control channel, the receiving operation for the control channel is stopped. In this case, the above-mentioned time Ton is required from the start of reception in step S1 to the stop of reception in step S3.

On the other hand, in step S4, the frame data is received on the currently received control channel,
Then, it is determined from the slave station number whether or not the frame data is addressed to the own station. As a result, if it is determined that the frame data is addressed to the own station (step S4; YES), the process proceeds to step S5. If it is not determined that the frame data is addressed to the own station (step S4; NO), the process proceeds to step S5. S6
Move on to Note that the determination of “NO” in step S4 includes a case where it is unknown whether or not the frame data is addressed to the own station.

In step S5, the operation shifts to a communication operation in the communication channel by transmitting response data to the master station 1 or the like. It should be noted that information on idle channels and the like are also transmitted from the master station 1 to the slave station 2.

On the other hand, in step S6, the frame data is received on the currently received control channel,
From the slave station number, it is determined whether or not the frame data is addressed to another station. As a result, if it is determined that the frame data is addressed to another station (step S6; YES), it is no longer necessary to continue the receiving operation, so the process proceeds to step S3, where it is determined that the frame data is addressed to another station. If not (step S6; NO), the process proceeds to step S7. Note that the determination of “NO” in step S6 includes a case where it is unknown whether or not the frame data is addressed to another station.

In step S7, it is determined whether or not the above-described reception duration Tr + Tf has elapsed since the carrier was detected. As a result, when it is determined that the reception duration Tr + Tf has elapsed (step S7; YES), the process proceeds to step S3 to stop the reception operation. On the other hand, if it is determined that the reception duration time Tr + Tf has not yet elapsed (step S7; NO), the process returns to step S2 and repeats the processing of steps S2 to S7.

The slave station 2 performs the above processing, and when a carrier is detected in the control channel, the master station 1
The frame data can be received regardless of the transmission timing of the frame data. That is, even when the frame data transmitted first from the master station 1 cannot be received, the reception operation of the slave station 2 is continued so that the frame data retransmitted after the elapse of the retransmission time can be reliably received. When frame data not addressed to the own station is received, the continuation of the receiving operation is stopped, so that useless receiving is not performed.

Next, a specific method of setting the retransmission time Tr in the master station 1 will be described with reference to FIG. In the present embodiment, since the reception continuation time of the slave stations 2 to 5 is Tr + Tf, the shorter the retransmission time Tr, the more advantageous in reducing the power consumption of the slave stations 2 to 5. Therefore, in FIG. 6, a description will be given of a condition for setting a retransmission time Tr as short as possible with a timing chart when four slave stations 2 to 5 are registered.

In FIG. 6, it is assumed that the master station 1 transmits frame data including call data to all the slave stations 2 to 5. Also, it is assumed that the slave stations 2 to 5 that have received the call data transmit frame data including response data to the master station 1. Since the transmission and reception of frame data on the control channel between the master station 1 and the slave stations 2 to 5 are performed by the half-duplex system as described above, each frame data transmitted and received between the master station 1 and the slave stations 2 to 5 is transmitted. It is necessary to appropriately consider the timing of

As shown in FIG. 6, frames 1 to 8 are continuously and sequentially allocated as frame data transmitted and received between the master station 1 and the slave stations 2 to 5. These can be divided into odd frames for transmitting call data from the master station 1 to the slave stations 2 to 5, and even frames for transmitting response data from the slave stations 2 to 5 to the master station 1. In this embodiment, the time length Tf of one frame includes, as a margin, the time required for starting up the radio circuit and stabilizing the radio frequency in addition to the data transmission time of the actual frame data. And

First, the master station 1 transmits calling data to the slave station 2 in the frame 1. Similarly, the call data is transmitted to the slave station 3 by the frame 3, to the slave station 4 by the frame 5, and to the slave station 5 by the frame 7.

On the other hand, even when the call data is received by the slave stations 2 to 5, the response data is not transmitted until the response data is transmitted.
Since a certain processing time is required, for example, the slave station 2 cannot immediately transmit the response data to the master station 1 in the frame 2. Therefore, the slave station 2 transmits the response data by the frame 4 sandwiching two frames. Similarly, the slave station 3 transmits the response data by the frame 6, and the slave station 4 transmits the response data by the frame 8. Further, the slave station 5 transmits the response data in the frame 2 of the next cycle.

When the master station 1 does not receive the response data in the even-numbered frames from the slave stations 2 to 5, in the next cycle, the master station 1 uses the odd-numbered frames in the same order.
5 is retransmitted. Therefore, for example, the response data for the slave station 2 is transmitted in the frame 1 and then retransmitted in the next cycle of the frame 1, and this cycle becomes the retransmission time Tr as it is. The call data is retransmitted to the slave stations 2 to 5 after the same retransmission time Tr has elapsed.

The above-mentioned cycle is eight times the time length Tr of one frame because eight frames are continuous. As a result, the retransmission time Tr and the time length Tr of one frame are obtained.
It can be understood that the relationship of (1) satisfies the relationship of Tr = 8Tf. In this case, the reception duration time of the slave stations 2 to 5 is Tr + Tf.
= 9Tf.

Although the above description has been made on the premise that the number of child stations that can be registered is four, the same applies to a case where N child stations can be generally registered. In this case, the retransmission time Tr satisfies the relationship Tr = 2N × Tf.
In this case, the reception continuation time of the slave stations 2 to 5 is (2N +
1) It becomes Tf.

By the way, the setting of the retransmission time Tr described above depends on the number N of slave stations that can be registered in the cordless telephone system.
Will depend on However, in an actual cordless telephone system, not all N substations that can be registered are necessarily registered, and only M (N> N) substations may be registered and used. In this case, for example, in the frame of FIG. 6, a portion corresponding to an unregistered slave station becomes an empty frame, and data transmission / reception is not performed.

However, the retransmission time Tr and the reception continuation time Tr + Tf can be shortened by expanding and contracting the repetition period of each frame instead of providing an empty frame for a slave station that is not actually registered. Can be done. For this purpose, since the actual registration number M of the slave stations can be recognized only by the master station 1, it is necessary to notify this to the slave stations 2 to 5 and variably set the retransmission time in association with M. . Further, the slave stations 2 to 5 need to store the registered number M notified from the master station 1 and variably set the reception duration in association with M.

More specifically, the master station transmits frame data including the registered number M of slave stations to the slave stations 2 to 5 at an appropriate timing. In the slave stations 2 to 5 receiving this, M is stored in a nonvolatile memory means such as a flash memory. Then, the retransmission time Tr after the master station 1 transmits the frame data to the slave stations 2 to 5 is adjusted to M, for example, 2M
X Set to Tf. On the other hand, the slave stations 2 to 5 set the reception duration Tr + Tf corresponding to M read from the memory means to, for example, (2M +
1) Tf is set, and judgment is made based on this value.

As described above, the retransmission time Tr and the reception continuation time Tr + Tf are variably set in conformity with the actual registered number M of slave stations, so that the actual registered number M is smaller than the slave station registerable number N. Further, it is possible to further reduce the transmission and reception of the frame data and further reduce the power consumption at the time of the intermittent reception of the slave station.

In the above-described embodiment, a case has been described in which frame data reception processing during intermittent reception is mainly performed by the slave station 2. However, the same applies to other slave stations. The master station may perform intermittent reception similarly to the slave station, and perform the above-described frame data reception processing. In this case, the processing is useful in that the power consumption can be reduced even in the master station.

In the above embodiment, the case where the present invention is applied to an analog cordless telephone system has been described. However, the present invention is not limited to this, and control information is transmitted between a master station and a slave station using a control channel. The present invention can be widely applied to a wireless communication system in which transmission / reception is performed by a half-duplex method and a slave station performs intermittent reception at a fixed time interval.

[0066]

According to the first aspect of the present invention, when the slave station performs the intermittent reception operation while waiting, the reception continuation time at the time of carrier detection is determined by the retransmission time of the master station and the time length of one frame. Because the sum is set, the total reception time of the slave station can be shortened while reliably transmitting and receiving control information.
A wireless communication system capable of suppressing power consumption during intermittent reception can be provided.

According to the second aspect of the present invention, when the slave station enters the reception continuation state during the intermittent reception, if it is determined whether or not the control information includes the designated data of the own station, the reception is performed. Since the continuous operation is stopped, it is possible to provide a wireless communication system in which the time for performing unnecessary reception can be shortened, and the power consumption during intermittent reception can be further suppressed.

According to the third aspect of the present invention, in a wireless communication system capable of registering a maximum of N slave stations, the retransmission time is set to 2N frames, so that frame data is transmitted and received by a half-duplex method. In this case, it is possible to provide a wireless communication system capable of setting the retransmission time and the reception duration time to the minimum.

According to the fourth aspect of the present invention, the actual number of registered slave stations is transmitted to the slave station, stored in a similar manner to the slave station, and the retransmission time is set in association with M. Accordingly, it is possible to provide a wireless communication system in which the reception duration is appropriately varied in accordance with this, and which can flexibly cope with the system configuration and suppress the power consumption at the time of intermittent reception.

According to the fifth aspect of the present invention, when the slave station enters the reception continuation state during the intermittent reception, if it is determined whether or not the control information includes the designated data of the own station, the reception is performed. Since the continuous operation is stopped, it is possible to provide a wireless communication system in which the time for performing unnecessary reception can be shortened, and the power consumption during intermittent reception can be further suppressed.

According to the sixth aspect of the present invention, M
In a wireless communication system in which child stations are registered,
Since the retransmission time is set to 2M frames, a wireless communication system capable of minimizing and setting the retransmission time and the reception duration when transmitting and receiving frame data by the half-duplex method while flexibly responding to the system configuration is provided. it can.

According to the seventh aspect of the present invention, since the above-described control is performed in the cordless telephone system, the slave station of the cordless telephone can reduce the power consumption during standby, and can increase the standby time. A cordless telephone system having a highly convenient slave station that can take advantage of the above features can be provided.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a cordless telephone system according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a data structure of frame data according to the embodiment of the present invention.

FIG. 3 is a timing chart of a reception operation when frame data is not transmitted from a master station to a slave station performing intermittent reception.

FIG. 4 is a timing chart of a reception operation when frame data is transmitted from a master station to a slave station performing intermittent reception.

FIG. 5 is a flowchart illustrating a process of receiving frame data during an intermittent operation performed by a slave station.

FIG. 6 is a timing chart illustrating a method of setting a retransmission time in a master station when four slave stations are provided.

[Explanation of symbols]

 1 ... master station 2, 3, 4, 5 ... slave station

Claims (7)

[Claims] 1. A wireless communication system comprising a master station and a slave station, wherein the master station and the slave station transmit and receive control information in a frame unit via a predetermined control channel, and establish a wireless connection according to the control information. In the system, the master station is a control information transmitting unit that transmits control information including the specified data of the slave station, and is indicated by the specified data until a predetermined retransmission time elapses from a transmission timing of the control information. Control information retransmitting means for retransmitting the control information transmitted by the control information transmitting means when control information including response data to the control information is not received from the slave station to be controlled, wherein the slave station is set in advance. Intermittent reception operation control means for performing an intermittent reception operation on the control channel at a predetermined time interval; and a key for detecting a carrier in the control channel during the intermittent reception operation. Carrier detection means, and when a carrier in the control channel is detected by the carrier detection means, a reception continuation that continues a reception operation until a reception continuation time that is a sum of the retransmission time and a time length of one frame elapses. Means, detection means for detecting whether or not control information including designated data of the own station has been received by the reception operation by the reception continuation means, and control information including designated data of the own station detected by the detection means And a response unit for transmitting control information including response data to the master station in a case where the communication is performed. 2. During reception by said reception continuation means,
The wireless communication system according to claim 1, further comprising a reception continuation stop unit that stops the reception continuation operation when the detection result of the detection unit is obtained. 3. The wireless communication system may include a maximum of N (N
3. The wireless communication system according to claim 1, wherein a slave station whose number is an integer of 2 or more) can be registered, and the retransmission time is set to 2N times a time length of the one frame. 4. . 4. A mobile station comprising a master station and a plurality of slave stations, wherein the slave stations can register at most N (N is an integer of 2 or more), and the master station and the slave stations use predetermined control channels. A wireless communication system that transmits and receives control information in frame units via the control information and establishes a wireless connection in accordance with the control information, wherein the master station is a slave station that is actually registered among the registrable N stations. When the number is M (where M is an integer equal to or less than N), a slave station registration number transmitting means for transmitting data indicating M; a control information transmitting means for transmitting control information including designated data of the slave station; When control information including response data to the control information from the slave station indicated by the designated data is not received from a transmission timing of the information until a retransmission time set in association with the M elapses, the control information transmission is performed. Sent by means Control information retransmitting means for retransmitting the control information, wherein the slave station receives the data indicating the M transmitted by the slave station registration number transmitting means, and stores the slave station registration number storage means. An intermittent reception operation control unit that performs an intermittent reception operation on the control channel at a preset time interval; a carrier detection unit that detects a carrier in the control channel during the intermittent reception operation; When a carrier in the channel is detected, the data indicating the M is read from the slave station registration number storage means, and the reception continuation time which is the sum of the retransmission time and one frame set in association with the M is read. A receiving continuation unit that continues a receiving operation until a lapse of time; and a receiving operation by the receiving continuing unit receives control information including designated data of the own station. Detecting means for detecting whether or not control information including designated data of the own station is detected by the detecting means, and response means for transmitting control information including response data to the master station. A wireless communication system characterized by the following. 5. While the reception is continued by the reception continuation means,
The wireless communication system according to claim 4, further comprising a reception continuation stop unit that stops the reception continuation operation when the detection result of the detection unit is obtained. 6. The wireless communication system according to claim 4, wherein the retransmission time is set to 2M times the time length of the one frame. 7. The wireless communication system according to claim 1, wherein the wireless communication system is a cordless telephone system connected to a telephone line.