JP2002190761A - Standby reception control method for radio - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a standby reception control method for a wireless device so that sufficient power consumption can be suppressed even when the wireless device is out of a communicable area. A channel scan period (T ₁ , T ₂ ) and a sleep period (T ₃ , T ₂ ) during an intermittent channel scan operation are provided.
Regarding the ratio of ₄ ), T ₁ / T ₃ is set during the period from the start of the intermittent channel scan operation until the out-of-service timer times out, and T ₂ / T ₄ after the time over.
What was switched to. By setting (T ₁ / T ₃ )> (T ₂ / T ₄ ), power consumption after the time over can be further reduced.

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 having a plurality of mobile stations, and more particularly to a mobile communication system in which each mobile station selects a channel having the best reception state from among a plurality of communication channels, and performs a standby reception operation. The present invention relates to a control method of a wireless device which is adapted to enter the control mode.

[0002]

2. Description of the Related Art In a radio communication system in which a plurality of mobile stations communicate through a common base station, it is desirable that each mobile station can immediately respond to a call from the base station. It is necessary to constantly monitor the presence or absence of transmission from the base station to the own station, and this monitoring state is called standby reception.

[0003] In the case of a wireless communication system having a plurality of channels, in this standby reception, a channel having the best reception state at that time is selected from a plurality of communication channels, and then the standby is performed on that channel. It is customary to enter reception.

[0004] Incidentally, it is inevitable that power consumption is involved in this standby reception, but in a mobile station where low power consumption is strongly demanded, power consumption in such a case other than the original communication operation is required. Is to be avoided as much as possible. Therefore, in response to such a case, a wireless device using a so-called intermittent standby reception control method has been conventionally known.

[0005] In this intermittent standby reception control type radio, an intermittent channel scan operation is performed during standby reception. Therefore, an intermittent channel scanning operation according to the related art will be described with reference to the flowchart of FIG. First, although not shown, the processing in the flowchart of FIG. 3 is executed by a microcomputer (microcomputer) that controls the wireless device, and is started when the power of the wireless device is turned on.

Then, first, the scan timer is started.
(S1), and then sequentially scan (S2) a plurality of channels assigned to the mobile station. That is, the receiving frequency of the receiving device (not shown) of the wireless device is sequentially tuned to each channel, and the receiving electric field strength is measured each time, and when a channel in which the receiving electric field strength exceeds a predetermined threshold appears, the number is changed. The table is arranged in order from the one with the largest electric field strength and is made into a table.

Next, this table is searched, and it is determined whether or not a channel number exists in the table (S3). Then, when there is a channel number, after selecting the first channel in the number (S4), it is determined whether or not the channel is usable (S5).

Here, the determination as to whether or not the channel can be used may be made based on whether or not the received electric field strength of the channel is equal to or higher than a predetermined level when the radio communication system is an analog system. On the other hand, in the case of a digital system such as the FDMA system, the determination may be made based on whether or not synchronization with the base station can be established on the channel or whether the content of the received control data is normal.

[0009] Here, the FDMA system is specified in the following document, and should be followed. “Annex B of ARIB STD-T61 Mobile station standby transition operation Attached figure B.2 Standby channel selection operation” Note that the determination as to whether this channel can be used may be omitted.

If it is determined in step S5 that the channel is usable, the process shifts to a standby operation.
(S6), and thereafter, the standby operation (S6) is continued while confirming whether or not the channel is usable (S7).

On the other hand, if it is determined in step S5 that the channel cannot be used, the channel is shifted to the channel of the next number in the table (S8), and it is determined that the channel is not the last channel (S9). Then, the process returns to step S7. When it is determined in step S7 that the channel cannot be used, the channel is shifted to the channel of the next number in the table (S8).
Similarly, after determining that the channel is not the last channel (S9), the process returns to step S7.

Therefore, in the case of this prior art, after a channel scan is started by turning on the power, if there is a channel having a received electric field strength equal to or higher than a predetermined threshold, the channel number is assigned to each channel. Are arranged in the order of the received electric field strength. Then, it is determined whether or not the channel at the head of this table is available. If it is available, the operation shifts to a standby operation on that channel. Then, once the selected channel becomes unusable after shifting to the standby operation, the channel shifts to the next numbered channel in the table,
Similarly, it checks whether or not the channel is usable. If the channel is usable, a standby operation is performed on the channel.

On the other hand, if the channel cannot be used, the process proceeds to the channel having the next number in the table, and it is similarly checked whether the channel can be used. Then, when all the channels in the table become unusable, the processing S
The process returns to 1 and the process is started again from the scanning of the channel.

Here, returning to FIG. 3, further description will be given including the role of the scan timer started in the processing S1. In this conventional technique, as is apparent from FIG. 3, the processing is started, and in processing S2 following processing S1,
Despite having finished scanning all channels,
If no channel having a reception electric field strength equal to or higher than the threshold value is found, this is determined in step S3.
The processing shifts to the processing after 10.

Therefore, a state in which the processing shifts to the processing after S10 is called an out-of-service state, and the processing after S10 is called an out-of-service processing. When the process shifts to the out-of-service processing, first, at this time, the measurement time of the scan timer is checked to determine whether the time is over (S1).
1) Do it. Then, the channel scan processing in S2 and the determination processing in S3 are repeated until the time is over, and when an available channel is detected during this time,
Then, the process shifts to the standby operation by the processing after S4.

On the other hand, if no usable channel is detected during this period, that is, before the scan timer expires, the process proceeds to step S12, in which the sleep timer is started first, and then the mode shifts to sleep.
(S13). Here, this sleep (Sleep)
This means that power supply to at least the receiving unit and the transmitting unit of the wireless device in the mobile station is stopped, and the power consumption is reduced to the extent possible.

When the low power consumption state is entered, the sleep time (low power consumption state) is continued while checking the measured time of the sleep timer and determining whether or not the sleep time has elapsed (S14). The process returns to the processing S1 at the time of the overrun.

Therefore, according to this prior art, even if the scanning of all the channels assigned to the mobile station is completed, if a channel having a reception electric field strength equal to or higher than the threshold value cannot be detected, first the channel scanning is performed. Enters the out-of-service state where is repeated.

In this out-of-service state, when the scan time reaches a predetermined value set in advance and the scan timer expires, the apparatus shifts to sleep and enters a low power consumption state. Here, the sleep timer is started. Thereafter, this low power consumption state is continued for a certain period. Then, when the sleep timer times out, scanning is started again.

Then, the operation of the receiving unit in the out-of-service state becomes an operation state in which channel scanning and sleep are alternately repeated as shown in FIG. Therefore, this operation state is referred to as an intermittent channel scan operation as described above.

Here, FIG. 4 shows an example in which the measurement time of the scan timer is set to 4 seconds and the measurement time of the sleep timer is set to 3 seconds. Therefore, as shown in FIG. After the scan, the power consumption becomes low for 3 seconds, and this is repeated.

Note that the measurement time of the scan timer at this time is usually set from the time required to scan all the channels allocated to the mobile station. Therefore,
Now, assuming that the time required for scanning one channel is 100 ms and the number of assigned channels is 35 waves, the measurement time of the scan timer is 3.5 seconds (= 35 × 10
0 ms), and if there is some margin, the measurement time of the scan timer is 4 seconds.

In this case, the average power consumption in the intermittent channel scanning operation state is simply about 4/7 (7/4 +) of the power consumption of the receiving unit during the normal communication operation.
As a result, the power consumption at the mobile station can be reduced, and the power capacity required for a power source such as a battery can be suppressed.

[0024]

The prior art described above has a problem that the operation when the mobile station is out of the communicable area is not considered, and there is still a complaint in suppressing the power consumption. In the related art, a channel assigned to the own station is scanned, and an intermittent channel scanning operation is repeated as long as no channel showing a reception electric field strength equal to or higher than a predetermined threshold level is found.

Therefore, according to the prior art, even when the mobile station is out of the service area of the base station and communication cannot be performed, the intermittent channel scanning operation is continued indefinitely. Dissatisfaction occurs in suppressing power consumption. SUMMARY OF THE INVENTION An object of the present invention is to provide a standby reception control method for a wireless device that can sufficiently suppress power consumption even when the wireless device is out of a communication range.

[0026]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a standby reception control system for a radio device in which an intermittent channel scan operation is performed at the time of standby reception. This is achieved by changing the length according to the elapsed time after entering the intermittent channel scan operation, and making the sleep period longer than the channel scan period after entering the intermittent channel scan operation.

At this time, the above object can be achieved even if the length of the channel scan period is changed according to the number of available channels assigned to the radio device.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an intermittent reception control system of a radio device according to the present invention will be described in detail with reference to the illustrated embodiments. FIG. 1 is a flowchart for explaining the operation of an embodiment of the present invention. In the case of this embodiment, steps S2 to S11, and steps S13 and S14 are performed.
Is the same as in the prior art of FIG.

The intermittent reception control processing of the wireless device according to this flowchart is executed by a microcomputer (not shown) provided in the wireless device, and is started when the wireless device is turned on. This is the same as the prior art of FIG. However, this embodiment differs from the prior art of FIG. 3 in that there are a first difference and a second difference described below.

First, the first difference is that the power is turned on,
When the process is started, the out-of-service timer is started (S20)
And the time out of the out-of-service timer is determined (S21).
Then, the process is divided into S22 and S23, and thereafter, the process proceeds to S2 and subsequent processes.

In this embodiment, due to this first difference, the time set in the scan timer is changed before and after the out-of-service timer times out, and is switched to time T ₁ and time T _2. After that, the process proceeds to S2 and subsequent steps.

In the following description of the present embodiment, time T ₁ = T ₂ will be described, but T ₁ ≠ T ₂ may be set. However,
Since this first difference is not particularly essential in the present invention, it may be provided as necessary. Here, the processes from S2 to S10 are the same as those in the prior art in FIG.

In step S2, a plurality of channels assigned to the mobile station are sequentially scanned. That is,
The receiving frequency of the receiving device is sequentially tuned to each channel,
In each case, the received electric field strength is measured, and when a channel having a measured electric field strength equal to or more than a predetermined threshold appears, the numbers are arranged in order from the one with the largest electric field strength to make a table.

Next, this table is searched, and it is determined whether or not a channel number exists in the table (S3). If there is a channel number, the head channel is selected from the table.
After (S4), determine whether the channel is usable
(S5) If it is determined that the channel is usable, the process shifts to a standby operation (S6).
While checking whether or not the channel is usable (S7),
The standby operation (S6) is continued.

On the other hand, if it is determined in step S5 that the channel cannot be used, the process shifts to the channel of the next number in the table (S8) and returns to step S7. Also, when it is determined in step S7 that the channel cannot be used, the channel is shifted to the channel with the next number in the table (S8).
After that, the process returns to step S7.

Therefore, in this embodiment as well, channel scanning is started when the power is turned on, and if there is a channel having a reception electric field strength equal to or higher than a predetermined threshold, the channel numbers are arranged in the order of the reception electric field strength. A table is created. Then, it is determined whether or not the channel at the head of this table is usable. If the channel is usable, the operation shifts to a standby operation on that channel.

If the selected channel becomes unusable after the transition to the standby operation, the channel shifts to the next numbered channel in the table.
Similarly, it checks whether or not the channel is usable. If the channel is usable, a standby operation is performed on the channel.

On the other hand, if the channel cannot be used, the process proceeds to the channel with the next number in the table, and it is similarly checked whether the channel can be used. Then, when all the channels in the table become unusable, the processing S
The process returns to 1 and the process is started again from the scanning of the channel.

Next, the second difference will be described. Also in this embodiment, as is clear from FIG.
Thus, even though the scanning of all the channels has been completed, no channel having the reception electric field strength equal to or higher than the predetermined threshold value is found, and this is determined in the processing S3.
The point of shifting to the out-of-service processing after 0 is the same as in the prior art of FIG.

When the process shifts to the out-of-service processing after S10, the measurement time of the scan timer is checked, and it is determined whether or not the time is over (S11). Until the time is over, the channel scan processing in S2 and S3 are performed. Is repeated, and if an available channel is detected during this time, the process shifts to a standby operation by the processing of S4 and thereafter, which is the same as the prior art of FIG.

In the embodiment of FIG. 1, however, when no usable channel is detected during this time, that is, before the scan timer times out,
Simply start the sleep timer and go to sleep
Instead of performing (S13), first, it is determined whether or not the out-of-service timer has timed out (S24), and according to the determination result, the processing is divided into S25 and S26.
The process proceeds to step S13 for transition to sleep, which is a second difference.

At this time, the processing in S25 and the processing in S26 are performed so that the time set in the sleep timer is switched to time T ₃ and time T ₄ before and after the out-of-service timer times out. When the process proceeds to the sleep process, a function of giving a difference in sleep time is obtained. Here, the time T ₃ and the time T ₄ are (T ₃ <T _{3 4} ) It is set to be.

Thereafter, the sleep time (low power consumption state) is continued while checking the measured time of the sleep timer and judging whether or not the time is over (S14), and the process returns to the processing S1 when the sleep time is over. However, this is the same as in the case of the prior art.

As a result, even in this embodiment, even if all the channels assigned to the mobile station have been scanned, if a channel having a reception electric field strength equal to or higher than the threshold cannot be detected, first, The point of entering the out-of-service state where scanning is repeated is the same as in the related art.

In this out-of-service state, when the scan time reaches a predetermined value set in advance and the scan timer expires, the apparatus shifts to sleep and enters a low power consumption state. Here, the sleep timer is started. rear,
The low power consumption state is continued for a certain period of time, and the scan is started again when the sleep timer times out, which is also the same as the related art.

However, in this embodiment, at this time, the scan timer times out and shifts to sleep, and the time in the low power consumption state, that is, the sleep period is equal to the time T ₃ before and after the time out of the out-of-service timer. When switched to the time T _4, wherein, since it is set to (T ₃ <T _4), until the out-of-service timer timed out, but the sleep period is shorter, for example, 3 seconds, after the time-over For a long time, for example, 16 seconds.

Therefore, the operation of the receiving unit in the out-of-service state in this embodiment, that is, the intermittent channel scanning operation,
As shown in FIG. Here, FIG. 4 shows, in this embodiment, as an example, the measurement times T ₁ and T ₂ of the scan timer are set to T ₁ = T ₂ = 4 seconds, and among the measurement times of the sleep timer, In addition, the time T ₃ is 3 seconds, and the time T ₄ is an intermittent channel scanning operation when the time is set to 16 seconds.

That is, in the case of this embodiment, after entering the intermittent channel scanning operation, as shown in FIG.
After the channel scan for 2 seconds, the power consumption state becomes low for 3 seconds, and this state is repeated, but this state has continued for more than a certain time, that is, for more than a predetermined time previously set in the out-of-service timer. Sometimes, the sleep period is extended to 16 seconds.

Here, the set time of the out-of-service timer at this time is generally based on the time at which it can be determined that the mobile station has left the service area of the base station, and based on the number of repetitions of the intermittent channel scan corresponding thereto. Just set it. That is, in this embodiment, whether or not the mobile station has left the service area of the base station is estimated based on the number of repetitions of the intermittent channel scan.

In this embodiment, as is apparent from FIG. 4, the out-of-service timer expires when the number of repetitions of the intermittent channel scan becomes three as an example. As described above, the measurement time of the scan timer at this time is usually set from the time required to scan all the channels allocated to the mobile station.

Then, in the case of this embodiment, the average power consumption in the intermittent channel scanning operation state is simply about 4/7 of the power consumption of the receiving unit in the normal communication operation at first. Thereafter, the power is reduced to approximately 4 / (4 + 16). As a result, the power capacity required for the power supply of the mobile station can be further reduced.

As a result, when a battery is used as a power source, the operating time for the same battery capacity can be extended, while the same operating time requires only a small-capacity battery. Weight reduction will be obtained. It is to be noted that each time shown in FIG. 4 is a case of the embodiment of the present invention, and it is needless to say that it can be arbitrarily set as needed.

[0053]

According to the present invention, the time in the low power consumption state in the intermittent channel scanning operation is extended according to the elapsed time when the mobile station goes out of the service area, so that the standby reception is performed. Power consumption can be further suppressed.

As a result, the power capacity required for the power supply of the mobile station can be further reduced, and as a result, when a battery is used as the power supply, the use time for the same battery capacity can be extended. On the other hand, if the use time is the same, a battery with a small capacity is sufficient, and the cost reduction and the reduction in size and weight can be more sufficiently achieved.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating an operation according to an embodiment of a standby reception control method for a wireless device according to the present invention.

FIG. 2 is a time chart for explaining an operation according to an embodiment of a standby reception control method for a wireless device according to the present invention.

FIG. 3 is a flowchart illustrating a standby reception operation in a wireless communication system according to the related art.

FIG. 4 is a time chart for explaining a standby reception operation in a wireless communication system according to the related art.

[Explanation of symbols]

 S1 to S14, S20 to S26 processing steps

Claims (2)

[Claims] In a standby reception control method for a wireless device that performs an intermittent channel scan operation during standby reception, a length of a channel scan period and a length of a sleep period in the intermittent channel scan operation are set to the intermittent channel scan operation. A standby reception control method for a wireless device, wherein the standby period is changed in accordance with an elapsed time after the entry, and the sleep period is extended relative to the channel scan period after the intermittent channel scan operation is started. 2. The invention according to claim 1, wherein the length of the channel scan period is changed in accordance with the number of available channels assigned to the wireless device. Standby reception control method for radio equipment.