JP2000341742A - Mobile communication system, and method for assigning channel of base station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile communication system capable of effectively using transmission channels between a base station controller(BSC) and a base station (BTS) in the real time change of traffic in each BTS. SOLUTION: In this mobile communication system, plural BTSs are together connected to a link between the BSC and a certain BTS. The BSC has a means for monitoring the channel using state of each BTS and a means for commanding a transmission channel setting change to each BTS by using variation in the channel using state of each BTS as a trigger. Each BTS increases/decreases channels to be used for its own base station on the basis of an application state command from the BSC.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication system in which a plurality of base stations are sequentially connected in a daisy chain, and more particularly, to a base station controller and a plurality of base stations based on traffic information for each base station BTS. The present invention relates to an improvement in an apparatus and a method for effectively utilizing a channel on an assigned transmission path.

[0002]

2. Description of the Related Art In a conventional mobile communication system, for example, a base station control device BSC (Base Station Control Device) disclosed in Japanese Patent Application Laid-Open No. 56-156034.
equipment and base station BTS (Base Transceiver Statio)
A method is known in which a plurality of base stations BTS are sequentially connected to one link between the base station BTS and the base station BTS. In this mobile communication system,
For example, traffic of each base station BTS is predicted from conditions such as the installation location of each base station BTS, and channels are fixedly allocated to each base station BTS according to the prediction. According to this method, there is an effect that the channel between the base station controller BSC and the base station BTS is effectively used, and the transmission path is simplified and the cost is reduced.

[0003]

The base station BT
The traffic of each S has the property of changing in real time. On the other hand, in the related art, since the channel assigned to each base station BTS is fixed, there is a problem that the channel assignment cannot be made to correspond to a change in base station traffic. That is, the base station controller BS
There is a problem that the transmission channel between C and the base station BTS is not effectively used up.

The present invention solves the above-mentioned problems, and
An object of the present invention is to provide a mobile communication system in which a transmission channel between a base station controller BSC and a base station BTS is effectively used while traffic of each base station BTS changes in real time.

[0005]

According to the present invention, there is provided a mobile communication system in which a plurality of base stations are connected in a daisy chain to one link between a base station controller and a base station. The base station control device, means for monitoring the channel use state for each base station, and means for instructing each base station to change the transmission channel setting using the amount of change in the channel use state in each base station as a trigger Wherein the base station includes means for increasing or decreasing the number of channels used by the base station based on a command from the base station control device in an operating state.

Preferably, when the amount of change in the channel use state is constituted by the amount of change in traffic at regular time intervals, the channel use state is confirmed at certain time intervals, thereby increasing reliability. Further, if the change amount of the channel use state is constituted by the absolute value of the traffic, a large change in the channel use state can be dealt with immediately. Furthermore, if the configuration is such that a trigger is output when the amount of change in the channel use state has increased or decreased beyond a predetermined threshold, the base station only has to deal with the trigger in response to the trigger. It's easy. Preferably, when the transmission channel setting change includes the number of channels to be reduced or added, channel resources in the entire mobile communication system are effectively allocated.

A base station channel assignment method according to the present invention for solving the above-mentioned problems is a base station channel used in a mobile communication system in which a plurality of base stations are connected in a daisy chain to one link between a base station controller and a base station. An assignment method, wherein the base station controller monitors a channel use state for each base station, and a step of determining whether a change amount of the channel use state is a value required to change a transmission channel setting. And, when it is determined that the transmission channel setting change needs to be performed in the determination step, a step of instructing each of the base stations of the transmission channel setting change, and the base station, from the base station control device in the operating state, And the step of increasing or decreasing the number of channels used by the base station based on the instruction.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration block diagram illustrating an embodiment of the present invention. In the figure, the base station BT
S1 is a data code conversion / transmission device 11, a DLP (transmission channel drop / insert device) 12, a BTS control device 13, an INF (transmission path interface device) 1.
4 and a DLP control device 15. Base station B
TS2 is a data code conversion / transmission device 21, a DLP (transmission channel drop / insert device) 22, a BTS
Control device 23, INF (transmission path interface device) 2
4 and a DLP control device 25.

The base station control unit BSC comprises a base station interface unit 31, a data code conversion / transmission unit 32, an MS
C-INF (MSC interface device) 33, transmission channel control device 34, base station traffic information storage device 35, base station use channel information storage device 36, and B
An SC control device 37 is provided.

Next, each component of the base station controller BSC will be described in detail. The base station interface device 31
The wireless communication between the base station controller BSC and the base stations BTS1 and BTS2 is interfaced. Data code conversion / transmission device 3
2 has a channel resource for communication data inside the base station controller BSC, and in accordance with an instruction from the BSC controller 37, the mobile station MS (Mobile Stati
on), channel resources are allocated. The MSC-INF 33 is a mobile communication switching center MS
Interfaces with C (Mobile-Services Switching Center). The BSC control device 37 controls the data flow of the base station interface device 31, the data code conversion / transmission device 32, and the MSC-INF 33.

The transmission channel control unit 34 determines whether to change the channel allocated to each of the base stations BTS1 and 2 based on the information from the base station traffic information storage unit 35, and determines that a channel change is necessary. If you do
Based on the information from the base station used channel information storage device 36, what kind of channel change is to be performed is determined.

Here, the transmission channel control device 34 internally sets a "threshold" for the traffic variation. This “threshold of change” can be set to any value inside the transmission channel control device 34. Further, the transmission channel control device 34 has a management table for judging the number of channels to be reduced / added according to the magnitude of the amount of change in traffic.

The base station traffic information storage device 35 includes:
The usage information of the transmission channel between the base station controller BSC and the base stations BTS1 and BTS2, that is, the traffic information is transmitted to the base station B
It is managed and stored for each of TS1 and TS2. Then, when a request for providing traffic information is received from the transmission channel controller 34, the traffic information is reported to the transmission channel controller 34 in base station BTS units.

The base station used channel information storage device 36
Base station BTS indicating how many transmission channels are allocated to each base station BTS1 and 2
The assigned channels for each of 1 and 2 are managed and stored. When the channel assignment is changed, the stored contents are updated as needed in accordance with the change. Then, when receiving the information provision request of the channel allocation state from the transmission channel control device 34, it reports the stored channel allocation information to the transmission channel control device 34.

Next, details of each component of the base stations BTS1 and BTS2 will be described. Here, the base station BTS1 will be described, and the base station BTS2 will not be described because it is the same as the base station BTS1. The data code conversion / transmission device 11 has a channel resource for communication data inside the base station BTS, and in accordance with an instruction from the BTS control device 13, sends a call to a mobile station MS (Mobile Station) that has made a call. Implementing channel resource allocation.

The DLP 12 extracts a channel specified by the DLP controller 15 from the transmission channel input to the INF 14. In addition, the DLP 12 transmits its own base station BT on a transmission channel designated by the DLP control device 15.
In addition to the insertion of the data of S, the closing / deletion of the currently used transmission channel or the instruction of adding a new transmission channel is performed according to an instruction from the DLP control device 15. Perform delete or add work.

The BTS controller 13 performs data code conversion and
The data flow between the transmission device 11 and the DLP 12 is controlled. The INF 14 is a relay device of a transmission path, which is provided between the base station BTS and the base station control device BSC and the base station B
It relays the transmission path between the TS and the base station BTS. DLP
The control device 15 controls the DLP 12 based on various requests from the base station control device BSC.

The operation of the apparatus having the above-described structure will be described below. FIG. 2 is a sequence diagram for explaining the operation of the apparatus shown in FIG.
(B) is a transmission channel control device 34, (C) is a base station use channel information storage device 36, (D) is a base station traffic information storage device 35, and (E1) is a DLP control device 1.
5, (E2) shows the DLP12, (F1) shows the DLP controller 25, and (F2) shows the DLP22.

In FIG. 2, the transmission channel control unit 34
Is transmitted to the base station traffic information storage device 35 by t
In [s] cycle, go to refer to the traffic status of each base station BTS (transmit BTS TAR.REQ). In contrast, the base station traffic information storage device 35
TAR. An ACK is transmitted to the transmission channel controller 34 to report the traffic status. And a certain time T
During a fixed time t [s] from [s] to T + t [s],
If the traffic volume of the base station BTS1 has decreased and the traffic volume of the base station BTS2 has increased,
The transmission channel control device 34 determines that the channels used by the base station BTS1 are to be reduced and the reduced channels are used by the base station BTS2.

Next, the transmission channel control device 34 requests the base station used channel information storage device 36 to report the channel information currently allocated to the base stations BTS1 and BTS2 (CH STA.REQ transmission). )do. The base station used channel information storage device 36
STA. Upon receiving the REQ, the latest channel allocation information at that time is reported to the transmission channel controller 34 (C
H STA. ACK). The transmission channel control device 34
Based on this channel information, the number of channels to be reduced and the number of channels to be expanded are determined by referring to a management table held in the own device.

FIGS. 3A and 3B are explanatory diagrams of the reduction / increase operation of the number of channels of the transmission channel controller. FIG.
(B) shows a state during blockage, and (C) shows a state after change. Now
As shown in FIG. 3, the base station BTS1 and the base station BTS2 are CH1 to CH7 and the base station BTS2.
Use CH8 to CH12. The transmission channel control device 34 firstly transmits the data code conversion / transmission device 3
2, the C of the base station interface device 31 (transmission path) accommodating the base station BTS1 and the base station BTS2.
Instruct to block H6 and CH7 (CH BL
K. REQ transmission). The data code conversion / transmission device 32
The above-mentioned CH6 and CH7 are searched for a free state, and CH6 and CH7 are searched.
H7 If it is vacant at that time, it is closed so that it cannot be used as it is. If CH6 and CH7 are in use at that time, the data code conversion / transmission device 32 waits for the in-use CH to become available, and as soon as the in-use CH becomes available,
Perform blockage.

Returning to FIG. 2, description will be continued. The data code conversion / transmission device 32 includes a transmission channel control device 34
When the blocking of all the CHs specified by is completed, a response (CH BLK.ACK) indicating the completion of blocking is returned to the transmission channel control device 34. The transmission channel control device 34 sends the CH BLK. ACK
Is received next, the base station BTS1 is likewise
H6, CH7 blocking request (CH BLK.REQ transmission)
do. When the blocking of all the CHs (CHs 6 and 7) instructed by the base station controller BSC is completed, the base station BTS1 sends a response (CH BLK.ACK) indicating the completion of blocking to the base station controller BSC (transmission channel controller 34). ). With the above processing, the closing of both the up and down of the CHs 6 and 7 has been completed.

Subsequently, the transmission channel control device 34 issues a request to the base station BTS2 to newly enable the use of CH6 and CH7 (CH
UNBLK. REQ transmission). DLP in base station BTS2
The control device 15 controls the CH_UNBLK. When receiving the REQ, the transmission channel drop / insert device DLP is ready to use CH6 and CH7 (CH6, CH7).
Is set in a state where extraction / insertion is possible), and after this setting is completed, an instruction is issued to block this CH. When the DLP control device 15 receives from the transmission channel drop / insert device DLP a report (CH_UNBLLK.ACK) that the above processes are all completed, the DLP control device 15 is ready for the base station control device BSC as the base station BTS2. Meaning response (CH_UNBLK.AC)
K) is returned.

Upon receiving this response, the transmission channel control device 34 and the data code conversion / transmission device 32 and the base station BT
Notify S2 of permission to start using CH6 and CH7 (transmit CH OPEN.REQ). In this way, the transmission channel controller 34 stores the base station BT in the base station traffic information storage 35 at regular intervals.
The traffic state of each S is checked, and the transmission channel control device 34 increases or decreases the number of channels based on the contents of the check.

In the above embodiment, the transmission channel control device 34 is provided with the base station traffic information storage device 35.
In contrast, the transmission channel control unit 34 checks the traffic status of each base station BTS at regular intervals, and the transmission channel control device 34 increases or decreases the channels based on the content of the confirmation. From the control device 34) to the lower order (base station traffic information storage device 35)], but the present invention is not limited to this. Any configuration may be used as long as the number is increased or decreased.

For example, when an event occurs, a method of reporting from the lower order (base station traffic information storage device 35) to the upper order (transmission channel control device 34) may be used. That is, the transmission channel control device 34 sets a “threshold value of the amount of change within a certain time” in the base station traffic information storage device 35 in advance without confirming the period. The base station traffic information storage device 35 reports to the transmission channel control device 34 that the traffic change amount within a certain period of time exceeds the threshold value when the traffic change amount exceeds the threshold value. The transmission channel control device 34 starts the sequence operation shown in FIG. 2 with this report as a trigger. With such a configuration, there is an advantage that the transmission channel control device 34 does not need to check the period.

Further, a higher order (transmission channel control device 34)
From the lower (base station traffic information storage device 35) to the upper (transmission channel control device 34) when an event occurs. . With this configuration, the real-time property is increased, so that the transmission channel can be more effectively used.

[0028]

As described above, according to the mobile communication system of the present invention, the base station control device monitors the channel use state of each base station and the amount of change of the channel use state in each base station. Means for instructing each base station to change the transmission channel setting by using a trigger as a trigger, and the base station implements increase or decrease of the channel used by its own base station based on a command from the base station control device in the operating state Means, it is possible to periodically determine the traffic state of each base station, and to increase or decrease the channels assigned to each base station in a timely manner based on the determination. Effective use of the transmission channel becomes possible.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram illustrating an embodiment of the present invention.

FIG. 2 is a sequence diagram illustrating an operation of the device of FIG. 1;

FIG. 3 Reduction of the number of channels of the transmission channel controller /
It is an explanatory view of an extension operation.

[Explanation of symbols]

BSC base station controller BTS base station 11, 21 Data code converter / transmitter 12, 22 DLP (transmission channel drop / insert device) 13, 23 BTS controller 14, 24 INF (transmission path interface device) 15, 25 DLP Control device 31 Base station interface device 32 Data code conversion / transmission device 33 MSC-INF (MSC interface device) 34 Transmission channel control device 35 Base station traffic information storage device 36 Base station used channel information storage device 37 BSC control device

Claims (6)

[Claims] 1. A mobile communication system in which a plurality of base stations are connected in a daisy chain on one link between the base station control device and the base station, wherein the base station control device monitors a channel use state of each of the base stations. And a means for instructing each of the base stations to change the transmission channel setting by using the amount of change in the channel usage state in each of the base stations as a trigger, wherein the base station receives an instruction from the base station control device in an operating state. A mobile communication system comprising means for increasing or decreasing the number of channels used by a base station based on a command. 2. The mobile communication system according to claim 1, wherein the amount of change in the channel use state is an amount of change in traffic at predetermined time intervals. 3. The mobile communication system according to claim 1, wherein the amount of change in the channel use state is an absolute value of traffic. 4. The trigger according to claim 1, wherein the trigger is output when the amount of change in the channel use state increases and decreases beyond a predetermined threshold value. A mobile communication system according to claim 1. 5. The mobile communication system according to claim 1, wherein the transmission channel setting change includes the number of channels to be reduced or increased. 6. A base station channel assignment method used in a mobile communication system in which a plurality of base stations are connected in a daisy chain on one link between the base station control device and the base station, wherein the base station control device is A step of monitoring the channel usage state for each base station; a step of determining whether the amount of change in the channel usage state is a value that requires a change in the transmission channel setting; and a step of changing the transmission channel setting in the determination step. When it is determined that there is, the step of instructing each of the base stations to change the transmission channel setting, the base station, based on a command from the base station control device in the operating state, the channel used by its own base station Performing a process of increasing or decreasing the number of channels.