JPH0113257B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in an empty channel search method for a radio telephone device to which a multi-channel access method is applied.

[Technical background of the invention]

In recent years, in wireless telephone devices, such as cordless telephone devices, which consist of a set consisting of a parent device and a wireless telephone that are paired with each other, in order to effectively use frequencies and increase the call connection rate, multiple devices common to each set have been introduced. A device has been proposed that uses a so-called multi-channel access method, in which a user owns several wireless lines and selects an empty channel to make a call.

The search for an empty channel in such a device has conventionally been carried out, for example, by sequentially monitoring the reception status of all channels during standby, determining whether the channels are empty, and storing this, and each time the empty channel determination of all channels is completed, the parent device This is done by monitoring a connection control channel provided for connection control between the wireless telephone and the wireless telephone.

[Problems with background technology]

However, in order to detect an empty channel, for example, it is necessary to actually receive radio waves and determine that the electric field strength is below a certain value. Therefore, it takes a lot of time, including the time for switching channels, to determine whether all channels are empty. Therefore, in the conventional search method that monitors the connection control channel every time it is determined that all channels are free, there is a high probability that a call will be made or received while the search is being performed, and there will be a delay until a connection is made. The disadvantage was that it required a lot of time.

Further, in the conventional search method, when selecting stored empty channels, the selection order is fixedly set in advance, and, for example, the channels are selected and used in order of channel number. Therefore, for example, even if you select the first channel when it is stored as free, if a lot of time has passed since this channel was determined to be free, the first channel may already be free. There is a high probability that it is missing, and the probability that it can be selected immediately is low. Therefore, with such conventional search methods, the time required to complete the selection of an empty channel and actually establish a connection is probabilistically long, and it takes a lot of time to detect the outgoing or incoming calls. In addition to requiring a connection, it also had the disadvantage of requiring a lot of time to connect.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an empty channel search method that allows connection to be established in an extremely short time when a call is generated.

[Summary of the invention]

In order to achieve the above object, the present invention does not monitor connection control channels every time it is determined that all the communication channels are free, but rather every time it is determined that a certain number of communication channels among all the communication channels are free. The connection control channel is monitored to increase the probability of immediately detecting the occurrence of a call, and the memorized free channel number information is given read priority, so that the last channel determined to be free when making a connection is set. This is to increase the probability of immediately capturing an empty channel.

[Embodiments of the invention]

FIG. 1 is a block diagram of a wireless telephone device to which an empty channel search method is applied according to an embodiment of the present invention. In the figure, 1 is a master device connected to a subscriber line 2, Each of the wireless telephones connected to the parent device is shown.

The parent device 1 includes a transmitter 11 and a receiver 12 that form a pair, a hybrid circuit 13 that connects the transmitter 11 and the receiver 12 to the subscriber line 2,
A synthesizer 14 that specifies the transmission and reception channels of the transmitter 11 and the receiver 12, an empty judgment circuit 15 that judges whether the receiving channel is empty from the reception output of the receiver 12, and an empty judgment circuit 15 that determines whether the receiving channel is empty or not. It is composed of a storage circuit 16 that stores the determined channel number information, and a control circuit 17.

Here, the vacancy determination circuit 15 is configured to determine that the channel is vacant, for example, when the carrier level of the received signal is below a certain value. The storage circuit 16 is composed of a shift register that sequentially shifts and stores vacant channel number information each time a vacant channel is detected. Therefore, the register located at the input end of the shift register always stores the channel number information for which the channel number was last determined to be empty.

In addition to controlling the connection between the subscriber line 2 and the radio telephone 3, the control circuit 17 performs the following controls related to the search for an empty channel. That is, the control is as follows: (i) During standby, the synthesizer 14 is driven and controlled to sequentially and repeatedly generate a local oscillation frequency for reception on each communication channel, and the receiver 1
2. Control to perform reception for determining availability of each communication channel. At this time, the call channel to be determined to be free is selected from among all the call channels owned by the set (eg, 10 channels), and is repeatedly specified.

(ii) Control that introduces the judgment result of the vacancy judgment circuit 15 and stores the receiving channel number information in the storage circuit 16 when this result indicates vacancy. At this time, shift pulses are simultaneously outputted to the memory circuit 16 to sequentially shift and input the number information of empty channels.

(iii) Every time a free speech channel is determined in (i) and (ii) above, the frequency for receiving the connection control channel is specified to the synthesizer 14, and the receiver 12 is driven using this channel. This allows the connection control channel to be monitored. That is, the determination of availability of each communication channel and the monitoring of the connection control channel are performed alternately.

(iv) During the monitoring period of the connection control channel, when a call is made from the wireless telephone 3 to be described later and is detected, the channel number information is stored from the memory circuit 16 in the reverse order of the stored order, that is, from the newest to the oldest. control to read out the channel to determine whether it is free, and if it is free, specify this channel to the synthesizer 14 to determine the communication channel. At this time, the reading order of the channel number information may be designated in order from the register closest to the input end of the shift register constituting the storage circuit 16.

On the other hand, the radio telephone 3 includes a pair of transmitter 31 and receiver 32, a synthesizer 33 that specifies channels for these transmitters 31 and receivers 32, and controls the operations of these transmitters 31, 32 and synthesizer 33. It consists of a control circuit 34 and handsets 35 and 36. During standby, the control circuit 34 cuts off the power supply to the transmitter 31 and intermittently supplies power output to the receiver 32 and synthesizer 33 to perform an intermittent reception operation using the connection control channel. Perform battery saving operation.

Next, the empty channel search method of this embodiment will be explained based on the above configuration. When the main device 1 enters the standby state, the control circuit 17 controls the oscillation operation of the synthesizer 14 and the receiver 12
The receiving channel frequency is switched at regular intervals,
As a result, for example, as shown in FIG. 2a, the availability determination period for the communication channels S ₁ , S ₂ , and S ₃ and the monitoring period for the connection control channel C are alternately set. and,
During the availability determination period for the communication channels S ₁ , S ₂ , and S ₃ , the availability determination circuit 15 performs the availability determination, and if the channels are vacant, the channel number information is stored in the storage circuit 16 . Figure 3 is Figure 2a
This conceptual object shows the contents of the memory circuit 16 when S ₂ is stored at point ○a in ○a. S ₂ is stored in the register near the input end, and S ₁ and S ₃ are shifted respectively. There is. Also, during the monitoring period of the connection control channel C, the presence or absence of a call from the wireless telephone 3 is monitored. Thereby, when a call is made from the wireless telephone 3, the probability of detecting it immediately increases, and as a result, the time required for connection is shortened.

By the way, during an arbitrary connection control period C during standby, a control signal indicating a call is generated from the radio telephone 3, and this is transmitted to the receiver 12 and the control circuit 1.
7, the parent device 1 first reads out the number information of the channel that was last determined to be free from the storage circuit 16, and determines whether this channel is free. For example, when a call is detected on the connection control channel ◯◯ of Fig. 2a, channel _S2 , which is the newest channel to be determined to be free at that time, is read out and its vacancy is determined. If this channel _S2 is empty, the transmitter/receiver 11 and 12 are activated, and after that, well-known connection control is performed by sending and receiving control signals, and a call is made using the communication channel _S2 determined to be empty. form a road. On the other hand, when it is determined that the communication channel S ₂ is not vacant, the number information of the channel S ₁ that was determined to be vacant one time before is read from the memory circuit 16 to determine whether it is vacant, and if it is vacant, this channel is to form a communication path. Similarly, if channel S ₁ is also not free, channel S ₃ is used to form a communication path. Note that the above channel selection operation is performed in exactly the same way when an incoming call occurs from the subscriber line 2 side.

Therefore, when a call is made or an incoming call occurs, among the multiple channels stored as free, the most recent free judgment channel is always read out, so the channel with the highest probability of being free is read out. It becomes possible to perform a connection operation using a channel, and as a result, the probability of being able to connect immediately upon generation of a call increases, making it possible to shorten the time required for connection. By the way, if the reading order is fixed in advance, such as in ascending order of numbers, as in the past, it will often happen that a long time has passed since the read channel was checked for availability. If a long time has passed since then, there is a high probability that the channel is already in use, which is undesirable because the probability of being able to connect immediately decreases accordingly.

On the other hand, during the determination of availability of each of the communication channels S ₁ , S ₂ , and S ₃ , if it is determined that the communication channel S ₂ is not available, for example, at the time of ○A in FIG. 2a,
The parent device 1 does not store the number information of the communication channel _S2 in the storage circuit 16. In this case, as shown in FIG. 2b, the communication channels S ₃ and S ₁
After checking the availability of each channel, call channel S ₄ is selected instead of the above call channel S ₂ at time ○c.
Select and check whether this channel _S4 is available. The reason why S ₃ and S ₁ are checked for availability first is that they have a higher probability of being available than a new communication channel. If the channel _S4 is vacant, its number information is stored in the storage circuit 16, and thereafter, the vacantity determination is repeated in the order of the communication channels _S3 , _S1 , _S4 , . . . If a new call channel is selected and determined to be free, for example, if _S4 is not free at ○C in Figure 2b, then as shown in Figure 2c, After checking the availability of S ₃ and S ₁ , which are stored as being vacant, another new communication channel, S ₅ , is determined at the time of ○2.

The same applies when the communication channels S ₁ and S ₃ are no longer free. In other words, when a call channel that is stored as free is no longer free, a new call channel that has not been used for freeness determination is selected in its place, and from now on, freeness determination including this new call channel is performed. Do it repeatedly.

In this way, according to the method of this embodiment, since the determination of the availability of the communication channel and the monitoring of the connection control channel are performed alternately, it is possible to increase the probability of immediately detecting a call originating from the wireless telephone 3. . Furthermore, when reading out the free channel number information stored in the memory circuit 16, the one that was determined to be free last is read out first, so it is possible to increase the probability that a call channel can be immediately selected and set. can. Therefore, with this embodiment, it is possible to shorten the time from when a call is generated until it is detected, and the time from when a call is detected until a communication path is formed, and as a result, the time required for connection can be shortened. can be shortened.

Furthermore, in this embodiment, by setting the number of call channels for which the idle determination is made to be smaller than the total number of call channels, it is possible to further reduce the time required for connection. In other words, out of all communication channels, the number of communication channels corresponding to the average traffic density can be considered to be generally not free, and if the freeness determination is performed over all communication channels, these communication channels that are not free will be left unused. It will take time to decide. As a result, there is a high probability that an empty communication channel that should be up-to-date is no longer empty. On the other hand, if you set the number of call channels to be used to determine availability to be less than the total number of call channels, only call channels with a high probability of being free will be checked at all times, and when you decide to make a call, The elapsed time from when it was determined to be empty just before is shorter on average than in the above case, and there is a high probability that the communication channel that was determined to be empty just before is still empty. Therefore, the time required for connection can be shortened.

Note that the present invention is not limited to the above embodiments. For example, the relative lengths between the availability determination period of each call channel S ₁ , S ₂ , and S ₃ and the monitoring period of connection control channel C are set so that control channel C is longer than that of control channel C, as shown in FIG. Good too. In this way, the probability of immediately detecting the occurrence of a call, which is the most important factor in determining the time required for connection, can be increased, and as a result, the time required for connection can be further reduced. Further, in the above embodiment, the number of communication channels used for the vacant determination was set to three, but it may be set to two or four or more. Furthermore, in addition to alternately determining the availability of each call channel and monitoring the connection control channel, it is also possible to determine the availability of each call channel multiple times, such as determining the availability of two channels in a row and then monitoring the connection control channel. The connection control channel may be monitored after the monitoring has been performed several times in succession. However, the number of consecutive call channel determinations is set to be smaller than the total number of call channels. Furthermore, in the above embodiment, the availability of a communication channel is determined only in the parent device, but the wireless telephone is also provided with an availability determination circuit to determine the availability of a communication channel specified by the connection control channel from the parent device. You may also do this. Furthermore, the vacancy determination circuit may employ a method of monitoring a noise level instead of a method of monitoring a carrier level. Furthermore, in the embodiment, when a call is started, connection control is performed after determining the availability of the call channel that was determined to be vacant last (immediately), but this availability determination is omitted and connection control is performed immediately. You may also do this.
Alternatively, for example, when storing 3 channels, you can use only the latest 2 channels for connection control, and if the connection is not completed, you can stop connection control at that point and do not use all the stored information. good. In addition, regarding the configuration of the memory circuit, the means for setting read priority, the number of communication channels, etc.
Various modifications can be made without departing from the spirit of the invention.

〔Effect of the invention〕

As described in detail above, the present invention increases the probability of immediately detecting the occurrence of a call by monitoring the connection control channel every time it is determined that a certain number of communication channels among all communication channels are free. A read priority is set for the free channel number information, and when making a connection, the channel determined to be free last is read out and set as a call channel,
This increases the probability of immediately capturing an empty channel.

Therefore, according to the present invention, it is possible to provide an empty channel search method that can connect a call in an extremely short time.

[Brief explanation of drawings]

FIG. 1 is a block configuration diagram of a wireless telephone device to which an empty channel search method is applied in an embodiment of the present invention, FIGS. 2 a to c are timing diagrams for explaining the search method in FIG. 1, and FIG. 3 4 is a diagram conceptually showing the storage state of the storage circuit 16, and FIG. 4 is a timing chart for explaining an empty channel search method in another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Parent device, 2... Subscriber line, 3... Wireless telephone, 15... Availability determination circuit, 16... Memory circuit, 17... Control circuit.

Claims (1)

[Scope of Claims] 1. A plurality of sets consisting of a fixed device and a mobile device that are paired with each other are made to each have a plurality of common communication channels, and at least one connection control channel, and a call can be started for any set. In a wireless telephone device that sometimes selects an unused communication channel from another set to make a call,
At least one of the fixed device or the mobile device,
A space determination means for repeatedly determining whether a plurality of call channels are vacant based on the reception state of radio waves, and a storage means for storing channel number information determined to be vacant by this means are provided. The connection control channel is monitored each time a call channel is determined to be free, and the empty channel number information stored in the storage means is read out in order from the one determined to be free at the time of starting a call, and is set as a call channel. An empty channel search method characterized by the following. 2. Claim 1, characterized in that the certain number of communication channels is one communication channel.
Empty channel search method described in section. 3. The empty channel search method according to claim 2, wherein the vacancy determining means repeatedly determines whether a plurality of communication channels smaller than all the communication channels owned by the set are vacant. 4. When the availability determining means determines that a communication channel stored as vacant is not vacant,
A patent for determining the availability of the remaining communication channels that are stored as free, and then determining the availability of another communication channel that is not stored as free in place of the communication channel that was determined to be not free. An empty channel search method according to claim 3. 5. A patent characterized in that when another call channel that is not stored as free is judged to be free as a result of the check, the remaining call channels that are stored as free are checked again. An empty channel search method according to claim 4. 6. Claim 2, characterized in that the connection control channel monitoring period is set to be relatively longer than the period for determining availability of each call channel.
An empty channel search method according to any one of items 1 to 5.