JP4134394B2 - Wireless communication system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention uses, for example, an analog cordless telephone system, multi-channel access technology, and a master station and one or more slave stations transmit and receive control data through a control channel, and one call from a plurality of call channels. The present invention belongs to the technical field of wireless communication systems that perform wireless communication by allocating channels.
[0002]
[Prior art]
  In recent years, in an analog cordless telephone system that has been widely used, multi-channel access technology is used to determine an empty channel from among a large number of call channels, and an unused call channel is selected to select a master station and a slave station. A wireless connection is established between them, and wireless communication is performed. In this call channel, FM-modulated audio signals are transmitted and received, and various data such as MSK-modulated dial information are transmitted and received.
[0003]
  On the other hand, since the reception frequency band is different between the master station and the slave station, it is necessary to determine the above-described free channel prior to establishment of the wireless connection in both the master station and the slave station. In other words, if it is determined by the master station that a predetermined call channel in the 250 MHz band to be received by the master station is an empty channel, the slave station specifies the empty channel as a slave station, and then the slave station supports the 380 MHz band to be received. After confirming whether or not the call channel to be used is an empty channel, the wireless connection is finally performed using this call channel. At this time, if a plurality of empty channels are searched in advance on the master station side and stored as candidates for empty channels to be designated as slave stations, the determination of empty channels is repeated many times during wireless connection. This eliminates the need to perform wireless connection efficiently.
[0004]
[Problems to be solved by the invention]
  However, the transmission / reception between the master station and the slave station at the time of establishing the above-described wireless connection is performed using the control channel, whereas the determination of the empty channel needs to be performed by switching the reception frequency to the call channel. In order to stabilize the reception frequency in the radio circuit, it takes a time of about several tens of ms. When the control channel and the communication channel are shifted many times in both the master station and the slave station, the total time is considerably long. It will take.
[0005]
  In addition to this, considering that the reception frequency bands and installation positions of the master station and the slave station are different, the call channel determined as an empty channel in the master station is also determined as an empty channel in the slave station as well. Not exclusively. As a result, it may occur that a longer time is required until a call channel that is determined as an empty channel is found in both the master station and the slave station.
[0006]
  As described above, the conventional cordless telephone has a problem that it is difficult to establish a wireless connection between the master station and the slave station within a short time. The present invention has been made in view of such problems. When establishing a wireless connection between a master station and a slave station, the present invention shifts to a call channel, which is an empty channel, and starts wireless communication in a short time. An object of the present invention is to provide a wireless communication system that can perform the above-described operation.
[0007]
[Means for Solving the Problems]
  In order to solve the above-described problem, a wireless communication system according to claim 1 is provided with a master station and one or a plurality of slave stations, and the master station and the slave stations are transmitted and received by a predetermined control channel. A wireless communication system that performs wireless communication using one call channel set out of a plurality of call channels according to data, wherein the master station determines whether there is an empty channel from the plurality of call channels And a free channel notification for transmitting free channel notification data indicating a free channel based on a determination result of the free channel determination unit to the receivable slave station by the control channel. Data transmission means;When the reception ON notification data as the reception status notification data from the slave station is received, the empty channel notification data is transmitted, and when the reception ON notification data from the slave station is not received, the empty channel designation data is transmitted. The free channel designation for designating a free channel based on the determination result of the free master channel determining unit as a communication channel to be connected to the slave station when establishing a wireless connection with the data transmitting unit for transmitting the mobile station Empty channel designation data transmission means for transmitting data to the slave station via the control channel;And the slave station determines whether or not the call channel corresponding to the idle channel notification data is an idle channel after receiving the idle channel notification data from the master station. And empty channel confirmation data transmitting means for transmitting, to the master station, empty channel confirmation data indicating the determination result of the slave station empty channel determining means by the control channel,When the slave station has received the idle channel designation data from the master station, it has been confirmed by the slave station idle channel determination means that the call channel corresponding to the idle channel designation data is already an idle channel. Transmits empty channel confirmation data indicating the confirmation result to the parent station by the empty channel confirmation data transmission means, establishes a wireless connection using the communication channel with the parent station,Transmission / reception of the idle channel notification data and the idle channel confirmation data between the master station and the slave station is repeatedly performed at a predetermined timing.BeIt is characterized by that.
[0008]
  According to the present invention, the master station determines whether or not there is a free channel from a plurality of call channels in a timely manner, and based on the determination result, free channel notification data is received from the receivable slave station. Transmit on the control channel. The slave station that has received the message determines whether or not the corresponding call channel is an empty channel, and transmits empty channel confirmation data indicating the determination result to the parent station on the control channel. These transmission / reception processes are repeated at an appropriate timing while waiting for a slave station, for example.. YoThus, since a call channel that is determined to be an empty channel in both the master station and the slave station at a specific time can be recognized in common between the master station and the slave station, a wireless connection will be established thereafter. In this case, wireless communication can be started in a short time.Also, when the master station and the slave station establish a wireless connection, the master station transmits the idle channel designation data to the slave station based on the determination result of the idle channel, and the slave station that has received this transmits the idle channel designation data, When it is confirmed in advance that the corresponding call channel is an empty channel, the empty channel confirmation data is transmitted to the master station without checking the empty channel again, and then between the master station and the slave station. A wireless connection using this call channel is established. Therefore, when establishing a wireless connection, it is not necessary for both the master station and the slave station to determine an empty channel. When the slave station receives empty channel designation data from the master station, the slave station confirms an empty channel from the slave station. After the data is transmitted, the slave station can shift to the call channel, and the result of the processing previously performed between the master station and the slave station can be effectively utilized to quickly shift to the call operation.
[0009]
  Claim2The wireless communication system according to claim1In the wireless communication system described above, the idle channel notification data and the idle channel confirmation data are transmitted and received between the master station and the slave station only when the slave station is being charged.
[0010]
  According to the present invention, transmission / reception for notification and confirmation of an empty channel as described above is not performed between a slave station that is not being charged and the master station, and the transmission / reception is performed only for a slave station that is being charged. I made it. Therefore, without any increase in power consumption of the slave station, if there is even one slave station that is being charged, a wireless connection between the master station and the slave station can be established in a short time.
[0011]
  Claim3The wireless communication system according to claim 1.Or 2In the wireless communication system according to claim 1, the slave station repeatedly receives reception status notification data via the control channel at a predetermined timing to notify the master station that the idle channel notification data can be received. The information processing apparatus further includes data transmission means, and the master station transmits the idle channel notification data by the idle channel notification data transmission means when receiving the reception status notification data from the slave station.
[0012]
  According to the present invention, the slave station repeatedly transmits the reception state notification data to the master station at a predetermined timing using the control channel to inform the master station that the idle channel data can be received. Is received and sent and received for notification and confirmation of the empty channel as described above. Therefore, necessary free channel information can be acquired when appropriate conditions for recognizing a free channel such as a charging state and an intermittent reception state are established.
[0013]
  Claim4The wireless communication system according to claim3In the wireless communication system described in the above, the slave station performs an intermittent reception operation for the control channel at a preset time interval during standby, and shifts from a reception stop state to a reception operation state during the intermittent reception operation. The reception status notification data is transmitted by the reception status notification data transmission means.
[0014]
  According to the present invention, the slave station performs intermittent reception on the control channel at a preset time interval while waiting, and transmits reception state notification data to the master station at a timing when the reception state is switched from OFF to ON. did. Therefore, the slave station can reliably acquire necessary empty channel information while updating it every intermittent reception cycle.
[0015]
  Claim5The wireless communication system according to claim4In the wireless communication system described in the above, the slave station performs an intermittent reception operation during standby when the battery is not charging, and continuously performs a reception operation without performing the intermittent reception operation during charging. And
[0016]
  According to the present invention, the slave station does not perform the intermittent reception operation when not charging, and performs the above-described transmission / reception by performing the intermittent reception operation only when charging. Therefore, it is possible to acquire information on necessary vacant channels at optimum timings suitable for the case where the slave station is charging or not charging.
[0017]
  Claim6The wireless communication system according to claim4Or5In the wireless communication system described in the above, the slave station further includes reception timing setting means for randomly setting a timing for shifting from the reception stop state to the reception operation state during the intermittent reception operation for each slave station. To do.
[0018]
  According to this invention, in the intermittent reception operation, the slave station performs the above-described transmission / reception after randomly setting the timing at which the reception state is switched from OFF to ON for each slave station. Therefore, when different slave stations are turned on at the same timing, even if the transmission of the reception state notification data collides, it is possible to avoid a situation in which the transmission continues to repeatedly collide thereafter.
[0019]
[0020]
[0021]
  Claim7The wireless communication system according to claim 1.Thru 6EitherOne paragraphThe wireless communication system according to claim 1, wherein the wireless communication system is a cordless telephone system connected to a telephone line.
[0022]
  According to the present invention, in the cordless telephone system, the above-described processing is performed between the master station and the slave station, for example, when an incoming call is received on the telephone line. Therefore, in the cordless telephone system, it is possible to quickly establish a wireless connection while accurately determining an empty channel.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. Here, a master station and a plurality of slave stations are provided, and a wireless connection is established between the master station and the slave stations by a multi-channel access method using a 250 MHz band / 380 MHz band, and audio signals and various data are transmitted and received. An embodiment when the present invention is applied to an analog cordless telephone system to be performed will be described.
[0024]
  FIG. 1 is a block diagram showing a system configuration of a cordless telephone system according to the present embodiment. As shown in FIG. 1, the cordless telephone system according to this embodiment includes a master station 1 connected to a telephone line, a slave station 2 and a slave station 3 that are wirelessly connected to the master station 1. . Although the number of slave stations may be further increased, a case where only two slave stations are included will be described for simplicity.
[0025]
  In FIG. 1, in the wireless connection between the master station 1 and the slave stations 2 and 3, the transmission frequency of the master station 1 and the reception frequency of the slave stations 2 and 3 use the 380 MHz band. And the reception frequency of the master station 1 uses the 250 MHz band. In each frequency band, a total of 89 radio channels are secured. Most of the radio channels are assigned as call channels, but some predetermined radio channels are used as control channels. First, the master station 1 and the slave stations 2 and 3 establish a wireless connection using the control channel, and perform subsequent wireless communication using the one call channel that is confirmed to be an empty channel.
[0026]
  Before starting wireless communication using the communication channel between the master station 1 and the slave stations 2 and 3, various control data are transmitted and received by the half-duplex method using the control channel. Then, MSK modulation is performed on the control channel based on the control data, and transmission is performed from the master station 1 to the slave stations 2 and 3, or from the slave stations 2 and 3 to the master station 1. The control data to be transmitted / received includes various types of information regarding the idle channel for the call channel, which will be described in detail later.
[0027]
  On the other hand, it is assumed that the wireless connection is established, and for example, the slave stations 2 and 3 start a telephone call via the master station 1 via the telephone line. At this time, a predetermined call channel in the 250 MHz band is FM-modulated and transmitted to the master station 1 by a voice input signal such as a microphone from the slave stations 2 and 3, and is received by the master station 1 and then demodulated and then telephoned Send to the line. On the other hand, a predetermined call channel in the 380 MHz band is FM-modulated by a voice signal arriving at the master station 1 from the telephone line and transmitted to the slave stations 2 and 3. Output audio from a receiver. As described above, between the master station 1 and the slave stations 2 and 3, the audio signal is transmitted and received by the full duplex method using two frequencies.
[0028]
  FIG. 2 is a timing chart when various kinds of idle channel information for notifying each other of the idle channel status are transmitted and received between the master station 1 and the slave stations 2 and 3. In the present specification, the hatched portions in the timing chart mean the transition to the call channel. In the example of FIG. 2, an operation when transmitting / receiving free channel information to / from the master station 1 in a state where the slave stations 2 and 3 perform intermittent reception while waiting is shown.
[0029]
  Prior to transmitting the idle channel notification data to the slave stations 2 and 3, the master station 1 performs an idle channel determination process for a predetermined call channel. Therefore, at timing t0 shown in FIG. 2, the shift to the reception operation for the call channel to be checked is started. Before and after the actual vacant channel determination process, as shown by the diagonal lines in the figure, it takes a certain time to switch the control channel and the communication channel and stabilize the reception frequency. The specific empty channel determination process may be determined as an empty channel when the reception level is equal to or lower than a predetermined set value, and may be determined as channel busy when exceeding this value. Here, the following description will be made assuming that this call channel is determined to be an empty channel.
[0030]
  On the other hand, the slave stations 2 and 3 perform an intermittent reception operation for the control channel. That is, the control channel is received from the reception-off state to the reception-on state at regular time intervals. That is, power supply to the wireless system is started, the reception frequency is stabilized at the frequency of the control channel, and processing described later is performed. Usually, the time interval of this intermittent reception is appropriately set based on the power consumption of the slave stations 2 and 3 and the response time limit. Note that the slave stations 2 and 3 according to the present embodiment not only receive the control channel but also transmit predetermined control data. Therefore, when transmitting control data when reception is on, it is necessary to simultaneously perform transmission operations. There is.
[0031]
  The slave station 2 transmits reception-on notification data as reception state notification data to the master station 1 at timing t1 after reception is turned on. This is control data transmitted to notify the master station 1 that the slave station 2 can receive the empty channel notification data.
[0032]
  When the master station 1 receives the reception ON notification data from the slave station 2, the master station 1 can determine that the determined idle channel can be used as a communication channel with the slave station 2, so immediately at timing t2, the idle channel notification data. Is transmitted to the slave station 2 through the control channel. This is control data transmitted to inform the slave station 2 of an available channel that can be used as a call channel.
[0033]
  Subsequently, when receiving the idle channel notification data from the master station 1, the slave station 2 determines whether or not the call channel indicated by the idle channel notification data is also an idle channel in the slave station 2 after the timing t3. That is, this call channel is determined to be an empty channel by the master station 1 in the 250 MHz band, which is the reception frequency band of the master station 1, but is also an empty channel in the 380 MHz band, which is the reception frequency band of the slave station 2. Since it is not limited, it is confirmed on the slave station 2 side. Also in this case, before and after the empty channel determination process, it takes a certain time to stabilize the reception frequency by switching between the control channel and the speech channel as indicated by the hatched lines in the figure.
[0034]
  As a result, idle channel confirmation data is transmitted to the master station 1 via the control channel at timing t4 after it is determined that this call channel is an idle channel. This is control data transmitted to notify the master station 1 that the call channel notified from the master station 1 as an empty channel has been confirmed to be a free channel in the slave station 2 as well. If the slave station 2 does not determine that the call channel is an empty channel, the idle channel busy notification data indicating that the call channel is busy (in use) is used instead of the empty channel confirmation data. Just send it.
[0035]
  On the other hand, after the slave station 3 is turned on after the slave station 2, the slave station 3 transmits the reception on notification data to the master station 1 through the control channel at the timing t5 in the same manner as the slave station 2. Thereafter, the transmission of the idle channel notification data from the master station 1 to the slave station 3, the confirmation of the idle channel performed in the slave station 3, and the transmission of the idle channel confirmation data from the slave station 3 to the master station 1 are performed as described above. Since it is performed in the same manner as in the case of the station 2, the description is omitted.
[0036]
  As described above, a call channel that is a free channel between the master station 1 and the slave station 2 and a call channel that is a free channel between the master station 1 and the slave station 3 are the master station 1, the slave station 2, 3 may be held in the memory means. Thereby, when the master station 1 and the slave station 2 or the slave station 3 subsequently establish a wireless connection, it can be effectively used as free channel information.
[0037]
  In FIG. 2, the case where the slave stations 2 and 3 perform the intermittent reception operation at regular time intervals has been described, but this time interval may be set at random for each slave station. That is, when the slave station 2 and the slave station 3 are shifted from the reception-off state to the reception-on state almost simultaneously, the transmission of the reception-on notification data may collide with each other. At this time, if the time interval of intermittent reception is set at random each time, the probability that the reception on notification data continuously collides is very low, and the reception on notification data is promptly transmitted to the master station 1. be able to.
[0038]
  Therefore, the slave stations 2 and 3 may be provided with, for example, random number generation means to calculate the time interval between intermittent receptions and perform timing control. Since it is not preferable that the time interval fluctuates extremely, the above-described effect can be obtained even if a certain fluctuation range is provided before and after a certain time interval.
[0039]
  FIG. 2 illustrates the case where the slave stations 2 and 3 transmit the reception on notification data to the master station 1 after the reception is turned on in the intermittent reception. The master station 1 may continuously transmit the idle channel notification data to the slave stations 2 and 3 without transmitting data. In this case, when the slave stations 2 and 3 receive empty channel notification data at a timing when reception is turned on, the above-described empty channel confirmation data is transmitted to the master station 1.
[0040]
  Further, it is desirable to set so that the processing of the slave stations 2 and 3 described in FIG. 2 is performed only by the slave station that is being charged. In other words, in the above-described processing, it is necessary to turn on the transmission power source for a certain period of time in order to transmit predetermined control data in the reception-on state during intermittent reception. growing. Therefore, in order to avoid a reduction in standby time due to an increase in power consumption in the slave stations 2 and 3, only the slave station that is being charged placed on the charging stand or the like performs the above-described processing, It is desirable that the slave station does not perform the above processing. Even in this case, if at least one slave station is being charged, the above-described processing can be performed, and the effects of the present invention can be obtained. If it is not necessary to lengthen the standby time due to the usage status of the slave stations 2 and 3, the slave station that is not being charged may perform the above processing.
[0041]
  Furthermore, when the slave station being charged performs the above-described processing, the intermittent reception control described above may be switched to a continuous reception operation without being performed during charging. As a result, the timing at which the slave station transmits the reception-on notification data can be determined without being restricted by the intermittent reception time interval, so that it is possible to transmit and receive free channel information with a high degree of freedom.
[0042]
  Next, FIG. 3 is a timing chart until a wireless connection is established between the master station 1 and the slave stations 2 and 3 when the master station 1 receives an incoming call from the telephone line. Also in the example of FIG. 3, it is assumed that the slave stations 2 and 3 are performing intermittent reception during standby, and the master station 1 has received an outside line call.
[0043]
  When the master station 1 receives an incoming incoming call from the telephone line at timing t10, the master station 1 performs the above-described free channel determination process for a predetermined call channel. Next, the vacant channel designation data designating the vacant channel determined at the timing t11 is transmitted to the slave station 2 through the control channel. This is control data transmitted to inform the slave station 2 of an available channel that can be used as a call channel to be connected as a call channel.
[0044]
  At this time, as shown in FIG. 3, at the timing t11, the slave station 2 is turned off in the intermittent reception. Therefore, the slave station 2 cannot receive the empty channel designation data from the master station 1.
[0045]
  Since the vacant channel confirmation data is not transmitted from the slave station 2, the master station 1 subsequently transmits the vacant channel designation data to the slave station 3 through the control channel at timing t12. Since the slave station 3 is turned on at timing t12 as shown in FIG. 3, it can receive this empty channel designation data.
[0046]
  The slave station 3 has already confirmed that the call channel indicated by the empty channel designation data is an empty channel by the processing shown in FIG. Channel confirmation data is transmitted to the master station 1 through the control channel. Thereafter, the slave station 3 shifts to the designated call channel and enters a reception standby state.
[0047]
  Subsequently, the master station 1 transmits the empty channel designation data again to the slave station 2 through the control channel at timing t14. At this time, as shown in FIG. 3, since the slave station 2 is turned on at timing t14, it can receive this empty channel designation data. Since the slave station 2 has already confirmed that the corresponding call channel is an empty channel, similar to the slave station 3, the idle channel confirmation data is immediately transmitted to the master station 1 through the control channel at timing t15. Thereafter, the master station 1 and the slave station 2 perform transition to the designated call channel.
[0048]
  The master station 1 transmits a bell ring command to the slave stations 2 and 3 through the call channel at timing t16. The slave stations 2 and 3 receive this bell ringing command, actually ring the bell, and wait for the user to go off-hook. Thereafter, when the slave station 2 or the slave station 3 is off-hooked, a call with the other party on the telephone line is started.
[0049]
  Next, processing performed by the master station 1 in the present embodiment will be described using the flowcharts of FIGS. In FIG. 4 to FIG. 6, the processes performed from the state where the master station 1 is not wirelessly connected to the slave stations 2 and 3 until the wireless connection is finally established and the call of the slave stations 2 and 3 is started. A description will be made sequentially.
[0050]
  In FIG. 4, the master station 1 starts a reception operation for the control channel (step S1), and determines whether or not the call data from the slave stations 2 and 3 is received by the control channel (step S2). If the determination result is “YES”, the process proceeds to Step S17.
[0051]
  On the other hand, if the determination result in step S2 is “NO”, it is subsequently determined whether or not an outside line call is received from the telephone line (step S3). If the determination result in step S3 is “YES”, the process proceeds to step S25, and if “NO”, in order to perform an empty channel determination, the reception frequency is switched to shift to a predetermined call channel (step S4). .
[0052]
  Next, the above-described free channel determination process is performed for this call channel, and it is determined whether or not it is a free channel (step S5). If the determination result in step S5 is “NO”, the call channel is busy and cannot be used for wireless connection with the slave stations 2 and 3, and the reception frequency is further switched to shift to another call channel. (Step S6). Again, a free channel determination process is similarly performed on the transferred call channel to determine whether or not the channel is a free channel (step S7). If the determination result in step S7 is “NO”, step S6 and step S7 are repeated to continue searching for a call channel that is an empty channel while switching the call channel.
[0053]
  When the determination result in step S5 or step S7 is “YES” and an empty channel is found, the reception frequency is switched and the control channel is shifted to (step S8). Then, in order to receive various control data transmitted from the slave stations 2 and 3, the reception standby state for the control channel is maintained (step S 9), and whether or not the above reception ON notification data is received from the slave stations 2 and 3. Is determined (step S10). If the determination result in step S10 is “NO”, step S9 and step S10 are repeated to continue waiting for the reception on notification data.
[0054]
  When the reception ON notification data from the slave stations 2 and 3 is received and the determination result in step S10 is “YES”, the empty channel notification data including the empty channel determined in step S5 or step S7 is stored. It transmits to the slave station 2 or the slave station 3 (step S11). Subsequently, it is determined whether or not the above-mentioned empty channel confirmation data is received from the slave station 2 or the slave station 3 (step S12).
[0055]
  If the determination result in step S12 is “NO”, since the corresponding call channel has not been confirmed as an empty channel in the slave station 2 or the slave station 3, the reception frequency is further switched to move to another call channel. (Step S13), similarly, an empty channel determination process is performed to determine whether the channel is an empty channel (Step S14). If the determination result in step S14 is “NO”, steps S13 and S14 are repeated, and the call channel which is an empty channel is continuously searched while switching the call channel. If the determination result in step S14 is “YES”, the process returns to step S11, and the empty channel notification data using the newly determined empty channel as data is transmitted again to the slave station 2 or slave station 3.
[0056]
  On the other hand, if the determination result in step S12 is “YES”, it is determined whether or not the transmission of the empty channel notification data to all the slave stations 2 and 3 is completed (step S15). If the determination result in step S15 is “NO”, it is determined whether or not a predetermined time set in advance has elapsed (step S16). If the determination result in step S16 is “NO”, the processing from step S9 is repeated, and if “YES”, a timeout occurs and the processing ends. Also, if the determination result in step S15 is “YES”, since the empty channel notification data has been transmitted to all the slave stations 2 and 3, the processes in and after step S9 are repeated. Note that the processing shown in FIG. 3 is repeatedly performed by the master station 1 as appropriate.
[0057]
  Next, referring to FIG. 5, a process when moving from step S <b> 2 to step S <b> 17 will be described. Here, the description will be made on the assumption that the master station 1 has received the call data from the slave station 2.
[0058]
  First, the master station 1 shifts to one call channel for performing wireless communication so as to correspond to the call data from the slave station 2 (step S17). The call channel determination process described above is performed for the call channel, and it is determined whether the call channel is a free channel (step S18). If the determination result in step S18 is “NO”, the process proceeds to another call channel (step S19), and an empty channel determination process is similarly performed (step S20) to continue searching for an empty channel.
[0059]
  When the determination result of step S18 or step S20 is “YES” and an empty channel is found, the control channel is shifted to (step S21), and empty channel designation data for designating this empty channel is sent to the slave station 2. Transmit (step S22). Thereafter, the communication channel is changed to the corresponding call channel (step S23), and when the slave station 2 similarly changes to the call channel, a predetermined communication process is started (step S24).
[0060]
  Next, referring to FIG. 6, the processing in the case of moving from step S3 to step S25 will be described. Here, processing when the master station 1 designates a call channel in the order of the slave station 2 and the slave station 3 will be described.
[0061]
  First, the master station 1 shifts to one communication channel for performing wireless communication with the slave stations 2 and 3 in order to perform processing corresponding to the incoming line call (step S25). The call channel determination process described above is similarly performed for this call channel, and it is determined whether or not the call channel is a free channel (step S26). If the determination result in step S26 is “NO”, the process proceeds to another call channel (step S27), the empty channel determination process is similarly performed (step S28), and the search for an empty channel is continued.
[0062]
  If the determination result in step S26 or step S28 is “YES” and an empty channel is found, the control channel is shifted (step S29), and empty channel specifying data for specifying this empty channel is sent to the slave station 2. Transmit (step S30). Then, it is determined whether or not the empty channel confirmation data for the empty channel designation data has been received for all the slave stations 2 and 3 (step S31). At this stage, since empty channel designation data is not transmitted to the slave station 3, even if empty channel confirmation data is immediately received from the slave station 2, it is determined as “NO” in step S31.
[0063]
  Subsequently, it is determined whether or not a predetermined time elapses from the start of processing and a timeout occurs (step S32). If the determination result in step S32 is “NO”, the process returns to step S30 and the same processing is continued for the next slave station 3. For example, when the slave station 2 or the slave station 3 is out of battery or placed outside the radio wave coverage area, the idle channel confirmation data is not received and a time-out occurs. The predetermined time until the timeout is determined in consideration of the intermittent reception time interval of the slave stations 2 and 3, but is usually set to about 2 or 3 seconds.
[0064]
  If the determination result in step S31 or step S32 is “YES”, the process proceeds to the corresponding call channel (step S33), and when the slave stations 2 and 3 similarly shift to the call channel, a predetermined communication process is performed. The process is started (step S34).
[0065]
  Next, processing performed by the slave station 2 in the present embodiment will be described using the flowcharts of FIGS. 7 to 9, processes performed from the state in which the slave station 2 is performing the intermittent reception operation to when the wireless connection is finally established and a call with the master station 1 is started will be sequentially described. Since the same processing is performed for the slave station 3, the case of the slave station 2 will be described as a representative.
[0066]
  In FIG. 7, the slave station 2 performs an intermittent reception operation. When a predetermined timing arrives, the slave station 2 shifts from a reception-off state to a reception-on state (step S41), and starts a reception operation for the control channel (step S42). Then, it is determined whether or not the call data from the master station 1 has been received (step S43). If the determination result is “YES”, the process proceeds to step S56.
[0067]
  On the other hand, if the determination result in step S43 is “NO”, it is subsequently determined whether or not to send call data to the master station 1 (step S44). For example, when the slave station 2 is off-hooked by the user, call data is transmitted to the master station 1 to connect to the telephone line. If the determination result of step S44 is “YES”, the process proceeds to step S61.
[0068]
  On the other hand, if the determination result in step S44 is “NO”, it is determined whether or not a carrier is detected for the control channel prior to transmitting the reception on notification data to the master station 1 (step S45). ). That is, it waits for the completion of reception of control data from the master station 1. If the determination result in step S45 is “YES”, the processing from step S42 to step S45 is repeated until no carrier is detected. If the determination result is “NO”, reception on notification data is transmitted to the master station 1. (Step S46).
[0069]
  Subsequently, in order to receive the empty channel notification data transmitted from the master station 1, the reception standby state for the control channel is maintained (step S47), and it is determined whether or not the empty channel notification data is received from the master station 1 ( Step S48). If the determination result in step S48 is “NO”, step S47 and step S48 are repeated to continue waiting for reception of empty channel notification data.
[0070]
  When the free channel notification data is received from the master station 1 and the determination result in step S48 is “YES”, the reception frequency is switched to the corresponding call channel, the free channel determination process is performed, and the free channel is used. It is determined whether or not there is (step S50). If the determination result in step S50 is “YES”, the reception frequency is switched again to shift to the control channel (step S51), and empty channel confirmation data is transmitted to the master station 1 (step S52). Thereafter, in the intermittent reception operation, the reception is returned to the reception OFF state (step S55).
[0071]
  On the other hand, if the determination result in step S50 is “NO”, the control channel is similarly shifted (step S53), and it is determined that the call channel is being used instead of the empty channel confirmation data for the master station 1. The indicated channel busy notification data is transmitted (step S54). Thereafter, the process proceeds to step S47 to wait for reception of new empty channel notification data.
[0072]
  Next, processing in the case of moving from step S43 to step S56 will be described with reference to FIG. First, the slave station 2 receives the control channel (step S56), and determines whether or not empty channel designation data is received from the master station 1 (step S57). If the determination result in step S57 is “NO”, step S56 and step S57 are repeated to continue waiting for reception of empty channel designation data.
[0073]
  On the other hand, if the determination result in step S57 is “YES”, the idle channel confirmation data is immediately transmitted to the master station 1 without performing the idle channel determination process on the slave station 2 side (step S58). Subsequently, the reception frequency is switched to shift to the corresponding call channel (step S59), and when the master station 1 similarly shifts to the call channel, a predetermined communication process is started (step S60).
[0074]
  Next, referring to FIG. 9, a process when moving from step S44 to step S61 will be described. First, the slave station 2 receives the control channel (step S61), and determines whether or not a carrier is detected for the control channel prior to transmitting control data to be described later to the master station 1 (step S61). Step S62). If the decision result in the step S62 is “YES”, the processes after the step S42 are repeated.
[0075]
  On the other hand, if the determination result in step S62 is “NO”, the call data is transmitted to the master station 1 through the control channel (step S63), and subsequently whether or not the empty channel designation data is received from the master station 1 is determined. Judgment is made (step S64). If the determination result in step S64 is “NO”, step S63 and step S64 are repeated to continue waiting for reception of empty channel designation data.
[0076]
  On the other hand, if the determination result in step S64 is “YES”, the reception frequency is switched to shift to the corresponding call channel (step S65), and when the master station 1 similarly shifts to the call channel, a predetermined communication process is performed. The process is started (step S66).
[0077]
  As described above, according to the present embodiment, before the master station 1 and the slave stations 2 and 3 establish a wireless connection, the master station 1 and the slave stations are preliminarily received during the intermittent reception of the slave stations 2 and 3. The call channel that becomes an empty channel is confirmed on both sides 2 and 3. Therefore, when the wireless connection between the master station 1 and the slave stations 2 and 3 is actually established, it can be performed in a short time, and the usability of the cordless telephone system can be improved.
[0078]
  In the above embodiment, the case where the number of slave stations in the cordless telephone system is two has been described. However, the present invention is similarly applied to a cordless telephone system having a larger number of slave stations. Can do.
[0079]
  In the above-described 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 a multi-channel access technique is used to control between a master station and a slave station. The present invention can be widely applied to a wireless communication system that performs wireless communication between a master station and a slave station after establishing a wireless connection.
[0080]
【The invention's effect】
  According to the first aspect of the present invention, both the master station and the slave station determine in advance whether or not the call channel is an empty channel in accordance with transmission / reception processing., FurtherIn addition, since each of the master station and the slave station makes an empty channel determination, the wireless communication can be started in a short time when establishing a wireless connection thereafter, and a highly convenient wireless communication system can be realized. It becomes.In addition, the master station transmits empty channel notification data when receiving the reception on notification data from the slave station, and transmits empty channel designation data when the reception on notification data from the slave station is not received, When the master station and the slave station establish a wireless connection, the master station sends empty channel specification data to the slave station, and the slave station uses the determination result of the empty channel already confirmed between the master station and the slave station. Since the wireless connection is established by the mobile station, it is not necessary for both the master station and the slave station to determine an empty channel, and the call operation can be quickly performed. If the slave station receives the empty channel confirmation data from the slave station and transmits it to the master station, the slave station can shift to the call channel, and a wireless communication system with good usability can be realized.
[0081]
  Claim2Since the transmission / reception process as described above is performed only when the slave station is charging, the increase in power consumption of the slave station is suppressed while the slave station is charging. A wireless connection can be established in a short time.
[0082]
  Claim3According to the invention described in the above, since the slave station repeatedly transmits the reception state notification data to the master station at a predetermined timing and then performs the above-described transmission / reception processing, Free channel information can be acquired at an appropriate timing when conditions are satisfied.
[0083]
  Claim4According to the invention described in the above, since the slave station is in intermittent reception, the reception status notification data is transmitted to the master station at a timing when the reception status is switched from off to on. It is possible to reliably acquire the information while updating the information of the empty channel.
[0084]
  Claim5According to the invention described in the above, since the above-described transmission / reception is performed by performing the intermittent reception operation only when the slave station is charging, the slave station is required at an optimal timing suitable for both charging and non-charging. It is possible to acquire information on a free channel.
[0085]
  Claim6According to the invention described in the above, since the slave station randomly sets the timing at which the reception state is switched from OFF to ON in the intermittent reception operation for each slave station, the reception status notification data between the different slave stations is set. Even when transmissions collide, it is possible to avoid a situation in which transmissions continue to collide thereafter, and it is possible to reliably transmit / receive information on empty channels.
[0086]
[0087]
  Claim7In the cordless telephone system, since the above-described processing is performed, it is possible to accurately determine an empty channel and quickly establish a wireless connection, and to provide a cordless telephone with high quality and good usability. A telephone system can be realized.
[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 timing chart when idle channel information is transmitted and received between a master station and a slave station.
FIG. 3 is a timing chart in the case of establishing a wireless connection between a master station and a slave station when an incoming call is received by the master station.
FIG. 4 is a flowchart showing processing performed by the master station.
FIG. 5 is a flowchart performed by the master station when call data is received from the slave station.
FIG. 6 is a flowchart performed by the master station when an incoming call is received.
FIG. 7 is a flowchart showing processing performed by a slave station.
FIG. 8 is a flowchart executed by a slave station when call data is received from the master station.
FIG. 9 is a flowchart performed by a slave station when calling data is transmitted to the master station.
[Explanation of symbols]
1 ... Master station
2, 3 ... Slave stations

Claims (7)

A master station and one or a plurality of slave stations are provided, and the master station and the slave stations use one call channel set out of the plurality of call channels in accordance with control data transmitted and received by a predetermined control channel. Wireless communication system for performing wireless communication,
The master station is
A master station vacant channel determining means for determining whether or not there is a vacant channel among the plurality of call channels;
Free channel notification data transmission means for transmitting free channel notification data indicating a free channel based on the determination result of the free channel determination means to the receivable slave station by the control channel;
When the reception ON notification data as the reception status notification data from the slave station is received, the empty channel notification data is transmitted, and when the reception ON notification data from the slave station is not received, the empty channel designation data is transmitted. Data transmission means for transmitting
When establishing a wireless connection with the slave station, the idle channel designation data for designating an idle channel based on a determination result of the idle station decision unit of the master station as a call channel to be connected to the slave station is sent to the slave station. Free channel designation data transmission means for transmitting by the control channel ,
The slave station is
After receiving the empty channel notification data from the master station, a slave station empty channel determination means for performing a determination process as to whether or not the call channel corresponding to the empty channel notification data is an empty channel;
Empty channel confirmation data transmitting means for transmitting, to the master station, empty channel confirmation data indicating the determination result of the slave station empty channel determining means, using the control channel,
When the slave station has received the idle channel designation data from the master station, it has been confirmed by the slave station idle channel determination means that the call channel corresponding to the idle channel designation data is already an idle channel. Transmits empty channel confirmation data indicating the confirmation result to the parent station by the empty channel confirmation data transmission means, establishes a wireless connection using the communication channel with the parent station,
The idle channel indication data and the transmission and reception of free channels confirmation data, a wireless communication system, characterized in that it is repeated at a predetermined timing between the master station and the slave station. 2. The wireless communication system according to claim 1 , wherein the idle channel notification data and the idle channel confirmation data are transmitted and received between the master station and the slave station only when the slave station is being charged. . The slave station further includes reception status notification data transmission means for repeatedly transmitting reception status notification data to the master station via a control channel at a predetermined timing to notify that the empty channel notification data can be received.
3. The wireless communication according to claim 1, wherein the master station transmits the idle channel notification data by the idle channel notification data transmission unit when receiving the reception state notification data from the slave station. system. The slave station performs an intermittent reception operation with respect to the control channel at a preset time interval during standby, and receives the reception state notification data when transitioning from a reception stop state to a reception operation state during the intermittent reception operation. the wireless communication system according to claim 3, characterized in that transmitting by the reception state notification data transmitting means. 5. The slave station according to claim 4, wherein the slave station performs an intermittent reception operation when the battery is not being charged, and continuously performs a reception operation without performing the intermittent reception operation when the battery is being charged . Wireless communication system. The said slave station is further equipped with the reception timing setting means which sets the timing which transfers to a receiving operation state from a reception stop state during an intermittent reception operation | movement at every substation at random. Wireless communication system. The wireless communication system according to any one of claims 1 to 6, wherein the wireless communication system is a cordless telephone system connected to a telephone line .

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