JP2516309B2 - Control information competitive control system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control for avoiding collision of uplink control information in an application of a digital mobile communication system for transmitting uplink control information transmitted from a plurality of mobile stations through one time division communication channel. Information competition control system.

[0002]

2. Description of the Related Art In a digitized cordless telephone system, a so-called second-generation cordless telephone system, when transmitting control information from a plurality of mobile stations to a base station accommodating the same, a single channel is used. Possible applications.

In such a configuration, for example, when a plurality of mobile devices are called all at once (paging service), uplink control information transmitted from a plurality of mobile devices to a base station or the like may collide. To be

In order to solve such a problem, a competition control method such as an echo back method, a polling method, or a response monitoring method has been considered in the wired section interface.

Here, the echo back method is a method in which, when a plurality of pieces of uplink control information collide with each other, one of them is selected and who is effective is returned. The polling method is a method of urging each mobile device to transmit control information by polling. Furthermore, the response monitoring method means that after each mobile device transmits control information, it waits for a response to this transmission, and if there is no response after a certain period of time, it is assumed that the control information transmitted by itself has been lost. It is a method.

Among the contention control methods, the response monitoring method usually takes an echo back method or a polling method because it takes a long time to connect a call.
Therefore, even in the wireless section interface of the second generation cordless telephone system, it is preferable to adopt the echo back method or the polling method in order to avoid the collision of the upstream control information when realizing the application.

[0007]

However, generally, the wireless section interface of the cordless telephone system has a limitation that errors on the transmission path are larger than those of the wired section interface.

Therefore, if the contention control system such as the echo back system or the polling system is adopted in this wireless section interface, there is a problem that the echo information for confirmation and the polling information are likely to be erroneous.

Further, in this wireless section interface, although the channel is divided into a communication channel and a control channel, there is a restriction that call control must be performed not on the control channel but on the communication channel.

Therefore, if the polling method is adopted in this wireless section interface, in the case of a voice call, there is a problem that voice information and polling information are mixed and it becomes impossible to perform contention control.

In the conventional system, in the case of such a voice call, the reference timing signal is sent to the mobile device before the voice information is transmitted, and thereafter, the mobile device takes timing to send the reference timing signal. Although there is a system that avoids collision of control signals, if the mobile device cannot receive the reference timing signal due to fading, etc., or if the timing is lost due to internal circumstances, there is a problem that there is no choice but to lose the call. is there.

The present invention has been made in order to cope with the above-mentioned circumstances, and even under the condition that the transmission quality is poor and the voice information is mixed, the control information of the control information transmitted from one mobile station through one channel is transmitted. An object of the present invention is to provide a competitive control system for control information that can avoid collision.

[0013]

In order to achieve the above object, in the present invention, the accommodating device is provided with the reference timing signal transmitting means, and the reference timing signal for giving the reference timing at which the mobile device transmits the control information is moved to a plurality of positions. Send to the machine regularly or irregularly. Further, each of the plurality of mobile units is provided with control information transmitting means, and when transmitting the control information to the accommodating device, the downlink time slot indicated by the reference timing signal is used as a reference and the serial number assigned to each mobile unit is used. The data is transmitted in the upstream slot at a fixed timing.

[0014]

The plurality of mobile units each receive the reference timing signal transmitted from the accommodating device regularly or irregularly as the reference timing, and transmit the control information based on the serial number given to each unit. Determine the upstream slot to be used. Therefore, even when a plurality of mobile devices desire to transmit control information at the same time, it is possible to effectively prevent control information from being transmitted from each mobile device in different uplink slots and colliding with each other.

Since the reference timing information is not limited to once, even if the mobile station loses the transmission timing of the uplink control signal, the timing can be taken again. As a result, the call loss probability can be reduced.

[0016]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a cordless telephone system equipped with a control information competition control system according to the first embodiment of the present invention. In addition, in FIG. 1, as a cordless telephone system, a system including a master unit and a slave unit is shown as a representative.

Referring to FIG. 1, first, the configuration of the cordless telephone system will be described.

In the figure, 10 is a master unit, and 20 (n)
(N = 1, 2, ...) Are slave units (mobile units) accommodated in this master unit 10. In FIG. 1, this child device 20 (n) has three
The case where there is one is shown as a representative. Reference numeral 30 is, for example, a private branch exchange that accommodates the parent device 20. Reference numeral 40 is a wireless line that connects the master device 10 and each slave device 20 (n). 50 is
A wired line connects the parent device 10 and the private branch exchange 30.

In the base unit 10, 101 is a wireless unit for performing wireless communication with the handset 20. 102
Is a control unit that controls transmission / reception operations of voice information and control information. An information collection buffer 103 stores the control information and the like sent from the child device 20.

In each child device 20 (n), 201 is a wireless unit for performing wireless communication with the parent device 10.
A control unit 202 controls the transmission / reception operation of voice information and control information. In addition, in FIG. 1, a child device 20 (1) is shown.
However, it goes without saying that other slave units 20 (2), 20 (3) also have the same structure as slave unit 20 (1).

The above is the configuration of the cordless telephone system. Next, the configuration of the control information competition control system provided in this system will be described.

The control unit 102 of the base unit 10 has a function of outputting the reference timing information R. Here, the reference timing information R is information indicating the reference timing when each child device 20 (n) transmits control information to the parent device 10. The reference timing information R is intermittently output at a constant cycle and transmitted from the wireless unit 101 to each slave unit 20 (n).

On the other hand, when each slave unit 20 (n) receives the reference timing information R, it has a function of outputting control information in a predetermined upstream time slot with reference to the downstream time slot indicated by this information R. Have. This control information is transmitted from the wireless unit 201 to the master device 10.

The control information transmission timing of each slave unit 20 is
It is defined by the schedule number SN given to each child device 20 (n) in advance. Here, schedule number SN
Indicates the transmission order of control information in each child device 20 (n).

This schedule number SN is, for example, when each slave unit 20 (n) notifies the master unit 10 that it has arrived (at the time of location registration, etc.), the master unit 10 sends the slave unit 20 (n). Granted to. Accordingly, among the plurality of child devices 20 (1), 20 (2), 20 (3) accommodated in one parent device 10, the child device 20 assigned with the same schedule number SN.
Since (n) does not exist, collision of uplink control information can be avoided.

The schedule number SN assigned to each slave unit 20 (n) is stored in the schedule number storage memory 203 provided in this slave unit 20 (n). Each cordless handset 20
Upon receiving the reference timing information R, (n) determines the timing of its own transmission slot based on the schedule number SN stored in this memory 203, and outputs the control information at this timing.

The above is the configuration of the control information competition control system. The control unit 10 related to this system
The functions of 2, 202 will be described later with reference to FIGS.
This will be described in more detail.

The competition control operation of control information in the above configuration will be described. First, the overall operation of the contention control operation will be described with reference to FIGS. 2 and 3.

In the protocol of the second generation cordless telephone system, a control channel and a communication channel are prepared as channels. Where the control channel is
It is used to instruct the communication channel to be used from now on.
The communication channel is also used for transmitting call control information and voice information.

That is, the control channel is the slave unit 20.
In the transmission sequence from (n), the slave unit 20
It is used for requesting a communication channel from (n) to master device 10 and transmitting a response signal from master device 10 to slave device 20 (n) in response to this request. In this case, the communication channel indication is
It is made by the response signal.

On the other hand, in the incoming sequence to the slave 20 (n), the incoming signal is transmitted from the master 10 to the slave 20 (n) and the slave 20 (n) responds to this incoming signal.
Is used for requesting a communication channel from the master unit 10 to the master unit 10 and transmitting a response signal from the master unit 10 to the slave unit 20 (n) in response to the request. In this case, the communication channel is instructed by the response signal.

The communication channel is used to transmit a call signal, a disconnection signal, a secret identification signal, and a secret signal from the slave unit 20 (n) to the master unit 10 at the time of call control in the transmission sequence, and the master unit 10
Used to transmit a call acceptance signal, a ringing signal, a response signal, and a disconnection signal from the slave unit 20 (n).

On the other hand, during call control in the incoming sequence to the slave unit 20 (n), an incoming call acceptance signal, a ringing signal, a secret signal, a secret signal, and a response signal from the slave unit 20 (n) to the master unit 10. , A disconnection signal is transmitted, and the master unit 10 to the slave unit 2
It is used to transmit an incoming call signal to 0 (n), a response confirmation signal, and a disconnection signal.

Further, this communication channel is used for transmitting voice information during a call.

In the control signal competition control system of this embodiment, the slave unit 20 (n) to the master unit 10 in the control channel are used.
It can be used for both the contention control of the uplink control information to the master device 10 and the contention control of the uplink control information to the master device 10 in the communication channel.

FIG. 2 is a timing chart showing the operation when this embodiment is applied to contention control of uplink control information in a control channel.

As described above, the second-generation cordless telephone system is a digital cordless telephone system, and therefore, the transmission from the handset 20 (n) to the base unit 10 in the upstream direction and the handset 10 to the handset. The downlink transmission to 20 (n) is performed alternately in time division.

FIG. 2A shows this state. here,
D1, D2, D3, ... Are from the master unit 10 to the slave unit 20 (n)
Indicates a time slot used for downlink transmission to the master unit 10, and U1, U2, U3, ... Represent time slots used for uplink transmission from the slave unit 20 (n) to the master unit 10.

FIG. 2B shows the transmission timing of the reference timing information R output from the control unit 101 of the master device 10. As shown in the figure, the reference timing information R is output intermittently at a constant cycle. In the figure, as a representative, when viewed in the downlink time slot, the case where the data is output at intervals of six time slots.

FIG. 2C shows the transmission timing of the uplink control information output from the control unit 201 of each slave unit 20 (n). In the figure, this uplink control information is shown as C. As described above, the control information C includes a request for a communication channel in the originating sequence or the terminating sequence.

Now, the slave units 20 (1), 20 (2), 20
The schedule numbers SN assigned to (3) are 0, 1, and 2, respectively. Here, 0 indicates the earliest transmission order, 1 indicates the next earliest transmission order, and 2 indicates the latest transmission order.

In such a setting, first, SN =
Uplink control information C is transmitted from the slave unit 20 (1) to which 0 is assigned, then the upstream control information C is transmitted from the slave unit 20 (2) to which SN = 1 is assigned, and finally SN = Uplink control information C is transmitted from the child device 20 (3) assigned with 2.

In FIG. 2, the transmission timing of the slave unit 20 (1) is set to, for example, the upstream time slots U1, U7, ... Immediately after the transmission time slots D1, D7, ... Of the reference timing information R. Then, the transmission timing of the slave unit 20 (2) is set to the next uplink time slot U2, U2.
8, the transmission timing of the slave unit 20 (3) is set to the next uplink time slot U3, ... As a representative example.

FIG. 2 shows a case where each slave unit 20 (n) outputs the upstream control information C only once each time the reference timing information R is received.

FIG. 3 is a timing chart showing the operation when this embodiment is applied to the contention control of the uplink control information C in the communication channel. That is, it is a timing chart showing the operation in the case of controlling the competition such as the incoming call acceptance signal, the password signal, and the disconnection signal as described above.

Also in this case, the same operation as in the case of the control channel is performed. However, in this case, the time slots DI, D2, ..., U1, U2, ... In each direction are time-divided for each communication channel. And each child device 20
Communication between (n) and the base unit 10 is performed using the communication channel designated by the control channel. Therefore, each child device 2
The transmission of the reference timing information R for 0 (n) is also performed using the communication channel assigned to each child device 20 (n).

In this case, the voice information may already be sent from the base unit 10 to a certain handset unit 20 (n). That is, there is a case in which a certain slave device 20 (n) is calling by voice. Unlike the control information (outgoing response signal or incoming signal) transmitted from the parent device 10 to the child device 20 (n) on the control channel, this voice information is generally continuously transmitted. Therefore, in this case, it becomes difficult to transmit the reference timing information R using the empty time slot.

Therefore, in this case, in this embodiment, as in the case of transmitting the call control information from the master unit 10 to the slave unit 20 (n), the voice information is temporarily stolen by the reference timing information R. The information R is transmitted.

In such a structure, the quality of voice information becomes a problem. However, there is no problem because the number of times of stealing due to the transmission of the reference timing information R can be easily adjusted to a level having practically no trouble by the control of the master device 10.

When the reference timing information R is transmitted by stealing the voice information, the information R can be, for example, fast associated control channel information (FACCH).

In addition to this, for example, the reference timing information R is transmitted using an optional channel type (CI) (an identifier indicating whether the information inserted in the information section is voice information or control information). You can In this case, the voice information can be left as it is in the information section. Therefore, in this case, although the channel type (CI) is different from the normal voice channel type (CI) indicating that the information is voice information, there is an advantage that the voice information can be transmitted without being cut off. .

The above is the overall operation of the embodiment. Next, the control unit 102 of the parent device 10 and the child device 2 relating to the competition control.
The operation of the 0 (n) control unit 202 will be described.

FIG. 4 is a flow chart showing a process of transmitting the reference timing information R in the control unit 102 of the base unit 10. However, FIG. 4 shows transmission processing in each of the time slots D1, D2, D3, ... In the downlink direction.

In this transmission process, it is first determined whether or not it is the transmission timing of the reference timing information R (step S11). If it is not the transmission timing, the process ends. On the other hand, if it is the transmission timing, the reception timing counter is reset (step S1).
2).

Here, the reception timing counter is a counter indicating the period after the reference timing information R is transmitted. This counter is reset at the transmission timing of the reference timing information R as described above, and then, as will be described later, time slots U1, U2, U in the up direction.
Each time 3, ... Is switched, it is incremented by one. Therefore, by looking at the value of this counter,
It is possible to know from which child device 20 (n) the control information C sent is sent.

When the reset of the reception timing counter is completed, the reference timing information R is transmitted (step S13). Hereinafter, similarly, every time the downlink time slots D1, D2, D3, ... Are switched, the above-described processing is repeated.

FIG. 5 is a flow chart showing a transmission process of the upstream control information C in the control unit 202 of the slave unit 20. However, in FIG. 5, each time slot U in the upstream direction is shown.
1, the transmission process in U2, U3, ...

In this transmission processing, it is determined whether or not the timing for transmitting the uplink control information C has arrived (steps S21 to S25), and the uplink control signal C to be transmitted.
For determining whether or not exists (step S26)
And a process of transmitting the uplink control information C (step S27)
Consists of

In the process of determining whether or not it is the own transmission timing, first, the transmission timing counter is incremented by "1" (step S21). Here, the transmission timing counter is a counter that indicates a period after receiving the reference timing information R.

This counter is reset when the reference timing information R is received, and thereafter, is incremented by "1" each time the uplink time slot is switched. Therefore, by comparing the value of this counter with the schedule number SN given to itself, it is possible to determine whether or not it is the own transmission timing.

When the increment of this counter is completed, it is judged whether or not the information has been sent from the base unit 10 in the immediately preceding time slot in the down direction (step S2).
2). This information includes control information and reference timing information R in the control channel, and voice information in addition to these in the communication channel.

If it is determined that the information has been sent, the process of step S23 is executed, and if it is determined that the information has not been sent, the process of step S25 is executed. In step S23, it is determined whether the sent information is the reference timing information R or not.

If it is the reference timing information R, the transmission timing counter is reset (step S24).
Then, the process of step S25 is executed. On the other hand, if it is not the reference timing information R, step S25.
Is performed.

In step S25, it is determined whether or not it is the own transmission timing. This determination is made by comparing the value of the transmission timing counter with the own schedule number SN stored in the memory 203, as described above.

In this case, if they match, it is determined to be the own transmission timing, and if they do not match, it is determined not to be the own transmission timing. Therefore, for example, the child device 20 (n) assigned the schedule number “0” has the uplink time slot (eg, U1) next to the downlink time slot (eg, D1) that has received the reference timing information R. ), It is determined to be the own transmission timing.

When it is determined that the transmission timing is the own transmission timing, it is determined whether there is uplink control information C to be transmitted (step S
26), if there is uplink control information C, it is transmitted (step S27). On the other hand, if it is not the own transmission timing or if there is no uplink control information C to be transmitted, the process ends. Hereinafter, similarly, each time the tom slot in the up direction is switched, the above-described processing is repeated.

FIG. 6 is a flow chart showing the receiving process of the upstream control information C in the control unit 101 of the base unit 10. However, in FIG. 6, each time slot U in the upstream direction is shown.
1, the reception process in U2, U3, ...

In this reception process, it is first determined whether or not the uplink control information C has been received (step S3).
1). If it is determined that the uplink control information C is not received, the process ends. On the other hand, when it is determined that the uplink control information C has been received, the uplink control information C is stored in the information collection buffer 103 (step S32). in this case,
As shown in FIG. 7, the uplink control information C is stored at an address corresponding to the count value of the reception timing counter, for example.

After this, this counter is incremented by "1" (step S33), and the process ends. Hereinafter, similarly, each time the uplink time slot is switched, the above-described processing is repeated.

According to this embodiment described in detail above, the following effects can be obtained.

(1) First, the reference timing information R is sent from the master unit 10 at a constant cycle, and each slave unit 20 (n) uses this timing as indicated by this information R as a reference. Since the control information C is transmitted at the timing defined by the schedule number SN given in advance to each of the slave units 20 (n), the uplink control information C can be transmitted at different timing. As a result, even when each slave device 20 (n) desires to send the uplink control information C at the same time, it is possible to avoid the collision of the uplink control information C.

(2) Since the reference timing information R is periodically transmitted in this case, the slave unit 20 (n)
However, for example, even if the user returns to the communication range after going out of the communication range, the call can be continued if the reference timing information R can be received.

(3) Further, the number of times the reference timing information R is transmitted is smaller than the number of times echo information is transmitted in the echo back method or the number of times polling information is transmitted in the polling method. It is possible to reduce the possibility of malfunction. Similarly, deterioration of voice quality can be suppressed to a low level.

(4) Further, since the reference timing information R can be transmitted using, for example, the channel type (CI) as described above, the voice quality is deteriorated even under the condition that the voice information is mixed. Surely without
Contention control can be performed.

(5) Further, in the embodiment, the description is such that the reference timing information R is sent out periodically. However, even if this timing is irregular, the slave unit 20 (n) will start from the reference timing information R. Since the control information is transmitted at the delay time of the upstream time slot of, the reference timing of the reference timing information R can be changed by the judgment of the master device 10.

FIG. 8 is a timing chart showing the operation of the second embodiment of the present invention.

In the above embodiment, the case where each slave unit 20 (n) sends the upstream control information C only once each time the reference timing information R is sent has been described. On the other hand, in this embodiment, as shown in FIG. 8, the data is transmitted a plurality of times.

This is achieved, for example, by resetting the transmission timing counter as described above not only when the reference timing information R is received but also when the value of this counter reaches the number n of the slave units 20 (n). It is possible.

In the case of the example of FIG. 8, the transmission cycle of the reference timing information R is 6 slots at the time slot interval in the down direction, and the number of slave units 20 (n) is 3, so that each slave unit 20 ( In 1), the uplink control information C can be transmitted twice each time the reference timing information R is received.

According to such a configuration, it is possible to obtain the same effect as that of the previous embodiment, and it is possible to further improve the transmission efficiency of the upstream control information C as compared with the polling method.

Further, a single mode for outputting the upstream control information C only once and a repeat mode for outputting the upstream control information C are set to each slave unit 20 (n), and, for example, when shifting from the control channel to the communication channel, By instructing the mode from the device 10 to the child device 20 (n), the repeat mode is set when the number of the child devices 20 (n) accommodated in the parent device 10 is small,
If there are many, you can use it like setting a one-shot mode.

Although the two embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments.

(1) For example, in the above embodiment, the case where the present invention is applied to the cordless telephone system including the master device 10 and the slave device 20 (n) has been described. However, the present invention can also be applied to a cordless telephone system such as a portable telephone system or a car telephone system, as long as the upstream and downstream time slots are synchronized.

(2) Further, in the above embodiment, the case where the present invention is applied to the cordless telephone system has been described. However, the present invention can be applied to general applications of mobile communication systems that transmit uplink control information from a plurality of mobile devices via one time division communication channel.

(3) In addition to this, it is needless to say that the present invention can be variously modified and implemented without departing from the scope of the invention.

[0087]

As described above in detail, according to the present invention,
It is possible to provide a control information contention control system capable of avoiding collision of uplink control information from a plurality of mobile devices even under conditions where transmission quality is poor and voice information is mixed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a timing chart showing a contention control operation in a control channel.

FIG. 3 is a timing chart showing a competition control operation in a communication channel.

FIG. 4 is a flowchart showing a transmission process of a master unit.

FIG. 5 is a flowchart showing a transmission process of a child device.

FIG. 6 is a flowchart showing a reception process of the parent device.

FIG. 7 is a diagram showing storage of control information.

FIG. 8 is a timing chart showing a competition control operation according to the second embodiment of the present invention.

[Explanation of symbols]

10 ... Parent machine, 20 (1), 20 (2), 20 (3) ... Child machine, 30 ... Private branch exchange, 40 ... Wireless line, 50 ... Wired line, 101, 201 ... Wireless section, 102, 202 ... Control Part, 103 ... Information collection buffer, 203 ... Schedule number storage memory.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akihiro Sawada 1-7-12 Toranomon, Minato-ku, Tokyo Within Oki Electric Industry Co., Ltd. Nippon Telegraph and Telephone Corporation (72) Inventor Noriaki Nagashima 5-7 Shiba, Minato-ku, Tokyo NEC Corporation (72) Inventor Junichi Kojima 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi, Ltd. (56) Reference JP 62-230126 (JP, A) JP 4-23525 (JP, A) JP 4-200024 (JP, A) JP 5-259970 ( JP, A) JP-A-4-68925 (JP, A)

Claims (1)

(57) [Claims] 1. A plurality of mobile units, each of which is provided with a serial number, and a storage device for storing the plurality of mobile units, and the plurality of mobile units are provided between the mobile units and the storage unit. In a digital mobile communication system in which a mobile device and the accommodating device transmit and receive control information on one time division communication channel, the accommodating device transmits a reference timing signal that gives a reference timing at which the mobile device transmits the control information. , Having a reference timing signal transmitting means for transmitting to the plurality of mobile units regularly or irregularly, each of the plurality of mobile units, in reference to the downlink time slot indicated by the reference timing signal, to the serial number Therefore, the control information is characterized by having control information transmitting means for transmitting the control information to the accommodating device in an upstream slot at a predetermined timing. Competition control system