JPH09200838A - Mobile communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain the design of station (base station) arrangement with the high degree of freedom by grouping cells in the design of the station arrangement instead of design in each cell unit constituting a service area and allocating a channel group to each group unit. SOLUTION: Base stations 151 to 153 respectively execute the service of cells managed by themselves and transmit/receive radio signals to/from mobile stations 181 to 183 in respective cells. Control stations 191 to 193 respectively control the base stations 151 to 153 managed by themselves so as to manage radio channels to be used by respective base channels 151 to 153 without recognizing the arrangement state of the base stations 151 to 153. An integration station 11 controls the control stations 191 to 193 managed by itself so as to manage the radio channel groups to be used by respective control stations 191 to 193 and the arrangement information of cell groups served by the control stations 191 to 193. The existence of interference is monitored by a radio wave monitoring means built in each base station and each corresponding control station is informed of the monitored result. At the time of receiving the information of interference, the corresponding control station reallocates radio channels.

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 such as a car phone / mobile phone, and more particularly to simplifying the cell station design to save the time and labor required for the cell station design, and to make a base station in a cell group. The present invention relates to a mobile communication system capable of increasing the degree of freedom of installation.

[0002]

2. Description of the Related Art A mobile communication system such as a PDC divides a service area into a plurality of cells and arranges a base station serving the range of each cell to enable communication with a mobile station moving between cells. There is.

However, if the base stations of adjacent cells use radio channels of the same frequency, or if the base stations of adjacent cells use the adjacent channels in a system in which radio channels are interleaved, the adjacent channels of adjacent cells Since the base stations interfere with each other, in the station placement design for determining the radio channel to be used by the base station of each cell in the service area, it is necessary to avoid the above-mentioned interference and to perform the necessary operation within the service area. It is necessary to consider so that the line quality can be secured. Therefore, as stated in NTT DoCoMo Technical Journal Vol.2 No.4, we are constructing a mobile communication system by using tools that support station design to save labor.

Since the base station constantly transmits a radio wave signal to the mobile station on a common control channel called a perch channel, each base station is based on the radio channel arrangement determined by the station placement design. Since the perch channel around the own station can be notified to, the mobile station-initiated handover can be executed.

FIG. 16 shows a conventional mobile communication system. Base stations 1621, 1622, 1623 serve cells under their control, and mobile stations 1631, 16 within each cell.
It transmits and receives radio signals to and from 32 and 1633.

[0006] The control station 161 controls the subordinate base stations, and at least controls the radio channel control by assigning the radio channel used by each base station and the radio channel used by the neighboring cells of each cell (base station). to manage.

Even when the mobile stations 1631, 1632, 1633 move within the service area, they can receive and transmit services such as voice calls and data communications by transmitting and receiving radio signals to and from any of the base stations.

In FIG. 16, the control station 161 has at least radio channels assigned to each base station in the station design,
FIG. 17 shows a block relating to the allocation of wireless channels, which has a function of managing the wireless channels allocated to the peripheral base stations, and is a part of its configuration.

The control station 161 has a base station assignment channel storage means 171 having a function of storing the result of channel assignment to each base station determined by the station placement design, and the channels assigned to the cells around it, and the base station assignment. The base station communication means 172 has a function of notifying each base station of the information stored in the channel storage means 171.

In the conventional mobile communication system configured as described above, the control station notifies each base station of the radio channel to be used, and also notifies the radio channel to be used in the neighboring cells, so that each base station is notified. Perform radio channel allocation.

[0011]

Since the characteristic of radio wave propagation in mobile communication is a complicated propagation path, it is very complicated to design a station in advance, and the experience of a skilled person is great. In addition, the demand for mobile communications in recent years has increased dramatically, especially in large cities, and in order to meet this demand with limited frequency resources, microcells with a minimized cell radius should be used to improve frequency reuse efficiency. However, this has the problem that the number of base stations will increase and it will take an enormous amount of time to design a station.

[0012] The present invention solves the above-mentioned conventional problem, in which a plurality of cells forming a service area are grouped to form a cell group, and a channel group which is a radio channel group is assigned to this cell group. An object of the present invention is to provide a mobile communication system which enables a simplified station placement design, saves time and labor required for station placement design, and has a high degree of freedom in installing base stations in a cell group.

[0013]

In order to solve the above-mentioned problems, the present invention does not design station placement on a cell-by-cell basis, but rather assigns a radio channel group on a cell group basis to a cell group (control station). An integrated mobile station that manages the channel group allocation and the adjacency relationship of the cell group and a control station that allocates the channel to the cell (base station) can provide an excellent mobile communication system that can simplify the station placement design.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention divides a mobile station and a service area into a plurality of cells,
A base station that serves each cell, and a control station that manages at least the radio channel used by each base station and recognizes a plurality of base stations without recognizing the arrangement status of the base stations under its control. Recognize the location of control stations under its control and manage at least the adjacency relationship between the wireless channel groups used by each control station and the cell group served by each control station to perform control integration for multiple control stations. A mobile communication system characterized by comprising an integrated station, and assigning a radio channel to each cell in consideration of complicated radio wave propagation peculiar to mobile communication, which is performed in a conventional cellular mobile communication system. It has an effect that a mobile communication system can be constructed by a simplified station placement design without the need to strictly design the station placement.

The invention according to claim 2 is characterized in that the base station responds to a radio channel designated by the control station.
Having means for performing radio wave monitoring for determining the presence or absence of interference, the control station receives the determination result of the presence or absence of interference from the base station, if the interference is reported, to the base station concerned. On the other hand, the mobile communication system according to claim 1, further comprising means for reassigning a radio channel, wherein in addition to the operation described in the invention of claim 1, the radio channel of each base station is provided. Since the interference between the base stations is detected in the allocation, there is an effect that it is possible to construct a mobile communication system in which the risk of occurrence of interference is further reduced.

Further, the invention according to claim 3 is characterized in that the control station sequentially performs radio channel allocation to each base station and confirmation of interference determination in an order determined by the control station. The mobile communication system according to claim 2, wherein, regarding the interference detection between the base stations described in the invention of claim 2, the control station controls the execution timing of the radio wave monitoring of each base station, so that the plurality of base stations are At the same time, it is possible to more reliably detect interference by not performing radio wave monitoring.

Further, in order to manage the adjacency relationship of the cell groups to be serviced, the integrated station sequentially selects the subordinate control stations in a predetermined order, and the selected control. The station has means for sequentially selecting subordinate base stations in a predetermined order, and the selected base station has means for measuring a reception level of a downlink radio wave transmitted by a peripheral base station. For each cell, regarding the radio channel to be used in the adjacent cell to any cell after the radio channel allocation to the base stations under its control is completed and all the base stations start transmitting radio waves The mobile communication system according to any one of claims 2 and 3 is characterized in that a mobile station-initiated handover is performed by obtaining information, and the cell station design is simplified. , Strictly in advance In the mobile communication system according to any one of claims 2 and 3, which does not design the arrangement of the mobile stations, in order to perform a mobile station-initiated handover, a channel to be monitored for a reception level is previously transmitted to the mobile station. It has an effect that the wireless channel used in the neighboring cells can be reported.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 shows the overall configuration of a mobile communication system according to the present invention. Base station 15
1, 152, 153 serve cells under the control of their own stations, and transmit / receive radio signals to / from mobile stations 181, 182, 183 in their respective cells.

Each of the control stations 191, 192, and 193 controls a base station under its control, and serves a cell group serviced by a plurality of base stations under its control. The control station manages at least a wireless channel used by each base station under its control as a wireless channel control.

The integrated station 11 controls a control station under its control, and a plurality of control stations under its control provide service for all cell groups to form a service area of the mobile communication system of the present invention. The integrated station manages at least the placement information of the wireless channel group used by each control station under its control and the cell group serviced by the control station as a wireless channel control.

Even if the mobile stations 181, 182, 183 move within the service area, they can receive and transmit services such as voice calls and data communications by transmitting and receiving radio signals to and from any of the base stations.

In FIG. 1, the integrated station 11 assigns a radio channel group to each control station and manages the adjacency relationship of the cell groups serviced by the control station. The blocks involved in the allocation of the are shown in FIG.

The function for allocating radio channels in the integrated station 11 is assigned candidate channel storage means 21 having a function of storing candidates for all wireless channels used in the mobile communication system, and all the subordinate stations under the control of the integrated station. Control station ID storage means 22 having the function of storing the ID of the control station
And, for each control station (cell group), control station adjacency relation storage means having the function of storing the adjacent control station (cell group).
23, a radio channel group assigning means 24 having an action of assigning a radio channel group to each control station under the control of the integrated station, and a control station having an action of storing the radio channel group assigned to each control station by the radio channel assigning means 24. It comprises allocation channel group storage means 25 and control station communication means 26 for notifying allocation of the wireless channel group to each control station based on the stored contents of the control station allocation channel group storage means 25.

The control stations 191, 192, and 193 have the function of allocating radio channels to the subordinate base stations, but do not manage the arrangement state (cell adjacency relationship) of each base station. The blocks associated with radio channel allocation as part of the control station configuration are shown in FIG.

The function for allocating wireless channels in the control station is assigned from the integrated station, and means for communicating with the integrated station 31, which has a function of communicating with the integrated station and receiving an instruction to allocate a wireless channel group. Radio channel group storage means 32 for storing the radio channel group, and base station ID storage means 33 for storing the IDs of all base stations under the control station
Wireless channel assigning means 34 for assigning wireless channels of the wireless channel group stored in the wireless channel group storing means 32 to each base station stored in the base station ID storing means 33, and wireless channel assigning means 34. Base station allocation channel storage means 35 for storing the radio channel allocated to each base station, and base station communication means for notifying each base station of the radio channel allocation based on the stored contents of the base station allocation channel storage means 35. It consists of 36.

The operation of radio channel allocation according to the simplified station placement design of the mobile communication system configured as described above will be described with reference to FIGS. 2, 3 and 4. FIG. 4 is a diagram showing a sequence of an integrated station, a control station, and a base station in radio channel allocation of the mobile communication system of the present invention, and the operation will be described below in the order of step 1 to step 4 in FIG.

The integrated station stores candidate CHRs of all radio channels usable in the mobile communication system of the present invention. In addition, the integrated station is the ID of all control stations under its own station.
It stores a list (used to identify the control station).

Step 1: Allocation of radio channel group by integrated station (1) CH stored in allocation candidate channel storage means 21 in FIG.
R is divided into a plurality of sets (radio channel group CHG) (number of divisions = number of control stations = n), and control channel ID storage means 22 stores the radio channel group CHG _i to each control station BSC _i under its control. Assign (i = 1,
2, ..., n). This allocation is a wireless channel allocation means
The wireless channel group allocation of the integrated station is performed by 24 so that interference does not occur in the cell group or between adjacent cell groups based on the information of the adjacency relationship of the cell groups stored in the control station adjacency storage unit 23. Assignment shall be made. That is, the radio channel is divided so as to satisfy the following condition 1 and assigned to each control station BSC _i . (Condition 1) Do not include the same radio channel in the same cell group and between adjacent cell groups.
When interleaving wireless channels, it is necessary to perform wireless channel group allocation so as to satisfy the following condition 2. (Condition 2) Adjacent channels are not included in the cell group and between adjacent cell groups. (2) The result of the radio channel group allocating means 24 allocating the radio channel group to each control station is stored in the control station allocating channel group storage means 25. I'll do it. (3) In accordance with the content stored in the control station assigned channel group storage means 25, the control station communication means 26 notifies each control station of the assigned wireless channel group.

Step 2: Integrated station specifies radio channel group to each control station According to the radio channel group assignment result of step 1 stored in the control station assigned channel group storage means 25, the control station communication means 26 causes each control station to communicate with each control station. to notify the CHG _i assigned to the BSC _i.

Step 3: Radio Channel Allocation by Control Station (1) The integrated station communication means 31 receives the radio channel group designation from the integrated station and registers CHG _i in the radio channel group storage means 32. (2) The radio channel allocation means 34 uses the designated CHG
_i (group consisting of 1 radio channel) is allocated to each base station BS _ij under its own control having the ID stored in the base station ID storage means 32 (j = 1,2, ..., m: m = the number of base stations), and register in the base station assigned channel storage means 35 (l ≧ m) At this time, allocation is performed so that the radio channel CH (∈ CHG _i ) and BS _ij have a one-to-one correspondence. Here, a method of allocating the j-th radio channel CH _ij of the own station CHG _i to the base station BS _ij will be described as an example, but the method is not limited to this method.

Step 4 :, (The control station designates a radio channel to each base station (1) The base station communication means 36 allocates to each base station BS _ij according to the contents stored in the base station allocation channel storage means 35. Wireless channel CH _ij is notified.

As an example of radio channel allocation, the integrated station assigns 21 radio channels to seven control stations (cell groups CG # 1 to #
Fig. 5 shows the case of allocation to 7). This example shows a case where radio channel interleaving is not performed and radio channel frequency reuse is not performed between cell groups.

However, the condition 1 shown in step 1
The frequency can be reused as long as the above condition is satisfied, and by satisfying the condition 2, the frequency can be reused even when the interleave of the radio channel is performed.

As described above, according to the first embodiment of the present invention, the station placement design in the mobile communication system is simplified,
It is necessary to manage the arrangement status in units of radio channels, but not to manage the arrangement status in units of radio channels. Therefore, the location of each base station in the cell group is free, and it is not necessary to design the station in advance. That is, in the example of FIG. 5, base stations that belong to the cell group CG # 1 and use the radio channel CH ₁ can be freely installed within the range of CG # 1.

(Second Embodiment) The present invention replaces the block related to radio channel allocation, which is a part of the configuration of the control station of the mobile communication system according to claim 1, with the configuration shown in FIG. The block related to radio channel allocation, which is a part of the station configuration, is configured as shown in FIG. The configuration and operation of the integrated station is the first
It is similar to that described in the embodiment.

The function of the control station for allocating wireless channels according to the present invention is to perform communication with the integrated station and to receive an instruction to allocate a wireless channel group. A wireless channel group storage means 62 having a function of storing a wireless channel group assigned from the integrated station by the communication means 61, and a base station ID storage means 63 having a function of storing IDs of all base stations under the control station.
A radio channel allocating means 64 having a function of allocating a radio channel of a radio channel group instructed by the integrated station to each base station stored in the base station ID storage means 63, and a radio channel allocating means 64. Base station assigned channel storage means 65 having a function of storing the radio channel assigned to each base station, and base station assigned channel storage means 65
Based on the stored content of, the base station communication means 66 having the function of notifying each base station of the radio channel allocation and receiving the interference determination result from the base station, and the interference of the radio channel allocated to the base station. Based on the judgment result,
In case of "interference", to the wireless channel allocation means 64,
The interference determination processing means 67 has a function of requesting reassignment of a wireless channel to a base station determined to have "interference".

The function of the base station for allocating radio channels according to the present invention is to perform communication with the control station,
While receiving the radio channel allocation instruction, the control station communication means 71 having the function of reporting the interference determination result to the control station, and the radio monitoring of the radio channel assigned by the control station are instructed, and it is determined that there is no interference. If used, the use channel determining means 72 having the function of determining the use of the wireless channel, the receiving means 73 having the function of receiving the wireless channel designated by the use channel determining means 72, and the receiving means 73 By comparing the reception level measuring means 74 having a function of measuring the reception level of the radio wave signal with the reception level measured by the reception level measuring means 74 with a threshold value for determining the presence or absence of preset interference. The interference determining means 75 has a function of determining the presence or absence of interference.

The operation of radio channel allocation in the mobile communication system configured as described above will be described with reference to FIGS. 6, 7 and 8.

FIG. 8 is a diagram showing a sequence of the integrated station, the control station, and the base station in radio channel allocation of the mobile communication system of the present invention. Below, the operation will be described in the order of step 1 to step 9 in FIG. To do.

Step 1: Allocation of wireless channel group by integrated station Step 2: Integrated station specifies wireless channel group for each control station Step 3: Allocation of wireless channel by control station Step 4: Wireless communication by control station to each base station Designation of Channel The operations in steps 1 to 4 are the same as the operations in steps 1 to 4 described in the first embodiment.

Step 5: Base station measures reception level The reception level of the radio channel CH _n designated by the control station BSC _i is measured. Downlink signal transmitted by the base station and the mobile station when the bandwidth of an uplink signal to be transmitted are different, it receives the downlink band signal of CH _n. (1) The control station communication means 71 in FIG. 7 receives the radio channel designation from the control station and notifies the used channel determination means 72 of the designated radio channel CH _n . (2) The used channel determination means 72 instructs the reception means 73 to receive the radio channel CH _n . (3) The receiving means 73 receives the radio wave signal of the radio channel CH _n and outputs the received signal to the reception level measuring means 74. (4) The reception level measuring means 74 measures the level of the reception signal from the receiving means 73 and notifies the interference determination means 75 of the measurement result.

Step 6: Interference determination by the base station In the interference determination, the level is compared with a preset threshold value used as a reference for determining the presence / absence of interference. (1) The interference determination means 75 compares the reception level measurement result from the reception level measurement means 74 with the interference determination threshold value. (2) When there is interference, the interference determination means 75 instructs the used channel determination means 72 to cancel the channel assignment.
When there is no interference, the interference determination means 75 instructs the used channel determination means 72 to confirm channel assignment.

Step 7: The base station reports the interference determination result to the control station. The interference determination means 75 reports the interference presence / absence determination result to the control station BSC _i by the control station communication means 71. The content of the report is “with interference” or “without interference”.

Step 8: Process after interference judgment by control station (1) The base station communication means 66 notifies the interference judgment means 67 of the received interference judgment report. (2) When there is no interference, the interference determination means 67 instructs the wireless channel allocation means 64 to confirm the wireless channel allocation. If there is interference, to the wireless channel allocation means 64,
It instructs the reallocation of the radio channel to the base station BS that has reported that there is interference.

Step 9: Reassignment of radio channels (1) The radio channel assignment means 64 stores the radio channel assignment information for each base station stored in the base station assignment channel storage means 65 and the radio channel group storage means 62. By storing the radio channel group assigned to the control station BSC _i , the BS
To BSC _i Radio channel CH not assigned to other BS
Allocate _m (m ≠ n). (2) Of the storage contents of the base station assigned channel storage means 65,
The channel allocation to the base station BS updates from CH _n to CH _m. (3) From then on, step 4 and subsequent steps are executed.

As described above, according to the second embodiment of the present invention, each base station is provided with the function of performing interference determination by radio wave monitoring, so that each base station can monitor radio waves of the wireless channel of the candidate for use. The use channel is determined after determining the presence or absence of interference and confirming that there is no interference.

As described above, by adding the processing for determining the presence or absence of interference in the radio channel allocation, the propagation path of the radio wave is complicated, especially in the mobile communication system composed of microcells having a cell radius of about 100 m. When it is difficult to predict the range of radio waves from a base station in advance, it is possible to reuse frequencies between cell groups, or a mobile communication system that can coexist with a mobile communication system that uses the same frequency band. It is possible to avoid interference even when constructing.

Furthermore, condition 2 shown in the first embodiment is relaxed, and it becomes possible to use adjacent channels within a cell group and between adjacent cell groups when performing interleaving of radio channels.

(Third Embodiment) In the present invention, the control station of the mobile communication system according to the second aspect allocates a radio channel to each base station under its control, and confirms the determination result of the presence or absence of interference from the base station. In the processing, the control station controls the timing so that the timings at which the base stations perform radio monitoring for interference determination do not overlap (multiple base stations do not perform radio monitoring at the same time). is there.

As a concrete configuration for realizing this,
The wireless channel allocating means 64 in FIG. 6 is realized by a block configuration as shown by 94 in FIG.

That is, FIG. 9 shows the structure of the radio channel allocating means of the present invention.
From the list of base station IDs stored by the base station selection means 941 which has the function of sequentially reading the unselected base station IDs, and the wireless channel group (list of wireless channels) stored by the wireless channel group storage means 92. , Has a function of sequentially selecting wireless channels, and a function of storing unused (unallocated) wireless channels among channels included in the wireless channel group in association with the function of the channel selecting means 942 An unsearched channel list having an operation of storing an unsearched channel as a channel candidate when an attempt is made to assign a channel to a certain base station in association with the operations of the unused wireless channel list storage means 943 and the channel selection means 942. The storage means 944 and the base station selected by the base station selection means 941 are instructed to specify the radio channel selected by the channel selection means 942 to the base station. It is composed of a channel designating means 945 having an action of sending to the communication means 97, and a channel assignment control means 946 having an action of controlling the operation timing by instructing each means constituting the wireless channel assigning means 94 to execute processing. .

The operation of the radio channel allocating means 94 configured as described above will be described with reference to the operations of the control station and the base station. First, the operation in the control station will be mainly described with reference to FIGS. 9 and 10, and then the operation timing between the plurality of base stations and the control station will be described with reference to FIG.

FIG. 10 is a flow chart showing the operation of the control station in the radio channel allocation of the mobile communication system of the present invention, and the operation will be described below in the order of step 1 to step 12.

Step 1: Initial setting (1) In response to an instruction from the channel allocation control means 946, the channel selection means 942 reads out the wireless channel group from the wireless channel group storage means 92, and the unused channel list storage means 943 stores the unused channels. Register as the initial value of the channel list. (2) In response to an instruction from the channel allocation control means 946, the base station selection means 941 reads out the number of base stations (the number of base station IDs) m included in this list from the base station ID storage means 93. (3) Set to read the 0th base station first (i
← 0).

Step 2: Selection of base station (1) In accordance with an instruction from the channel allocation control means 946, the base station selection means 941 reads the ID of the i-th base station from the base station ID storage means 93 (base station ID BS _i is the i-th base station registered in the storage means 93).

Step 3: Initialization of unsearched channel list (1) The channel selection means 942 registers the contents of the unused channel list storage means 943 as the initial value of the unsearched channel list storage means 944. (2) The channel selection means 942 obtains the number of channels n registered in the unsearched channel list storage means 944. (3) First, the 0th channel of the unsearched channel list storage means 944 is set to be read (j ← 0).

Step 4: Channel Selection (1) The channel selection means 942 selects the j-th radio channel CH _j from the unsearched channel list storage means 944.

Step 5: Notify the channel to the base station BS (1) By an instruction from the channel allocation control means 946,
The channel designating means 945 issues a command to the base station communication means 97 for instructing the base station BS _i selected by the base station selecting means 941 to execute the interference determination of the radio channel CH _j selected by the channel selecting means 942. Output. (2) The base station communication means 97 transmits the command of (1) to the base station BS _i .

Step 6: Process interference judgment report from the base station BS (1) If the interference judgment processing means 96 instructs the reallocation of the radio channel to the base station BS _i , the process branches to step 7 and the Steps if not assigned
Branch to 10. Steps 7 and 8: Select next candidate channel (1) The channel allocation control means 946 instructs the channel selection means 942 to read the j + 1th channel from the unsearched channel list storage means 944. (2) When the channel selection means 942 succeeds in reading the j + 1-th channel (when there is an unsearched channel),
Go to step 4. At this time, the value of j is incremented by 1. When the channel selection means 942 fails to read the j + 1-th channel (when there is no unsearched channel), the process proceeds to step 9.

[0061] Step 9: Channel allocation failure (1) channel assignment control unit 946 determines that the assignable radio channel to the base station BS _i does not exist, the base station assigned channel storage unit 95, the base station BS _i Record channel allocation failure to.

Step 10: Update unused channel list (1) The channel assignment control means 946 sends the unused channel list storage means 943 to the channel selection means 942 as a process after the successful assignment of the channel CH _{j to} the base station BS _i . From CH
Instruct to delete _j .

Steps 11 and 12: Select next base station (1) Channel allocation control means 946 causes base station selection means 941
To the i + 1th base station. (2) When the base station selection means 941 succeeds in reading the i + 1-th base station (when there is an unallocated base station), the process proceeds to step 2. When the base station selecting means 941 fails to read the i + 1-th base station (when there is no unallocated base station), it determines that the channel allocation to all the base stations is completed and ends.

FIG. 11 shows a control station BSC under the control of the integrated station BSI.
BSI, BS when there are _three base stations BS ₁ , BS ₂ , BS ₃
It is a sequence diagram showing an outline of the operation timing of C, BS ₁ , BS ₂ , BS ₃ , and the operation will be described below in the order of step 1 to step 22. It should be noted that this example shows a case where the wireless channels are interleaved.

Step 1: Allocation of radio channel group to each BSC by BSI In this example, attention is paid to one control station BSC, and the radio channel group <CH ₁ , CH ₂ , CH ₅ > is assigned to this control station BSC.

When there are a plurality of control stations BSC, one control station BSC is selected and it is confirmed that the control station BSC has completed the radio channel allocation to the subordinate base station BS. Shall notify the allocation of the radio channel group to the next control station BSC.

Step 2: Notification of radio channel group to control station BSC From the integrated station BSI to the control station BSC as a radio channel group <C
H ₁ , CH ₂ , CH ₅ > are indicated.

Step 3: Radio channel allocation to base station BS _{1 The} control station BSC allocates CH ₁ to the base station BS ₁ by the above-mentioned channel allocation operation.

Unused channel list = <CH ₁ , CH ₂ , CH ₅ > m = base station ID number = 3 i = assigned base station number = 0 Unsearched channel list = <CH ₁ , CH ₂ , CH ₅ >.

[0070] Step 4: instructing to use the CH ₁ to the radio channel set base station BS ₁ to the base station BS _1.

[0071] Step 5: collision detection base station BS ₁ of the base station BS ₁ performs radio monitoring of CH _1, and determines that no interference.

Step 6: Interference determination report from base station BS _{1 The} control station BSC receives "no interference" as an interference determination report from the base station BS ₁ .

[0073] Step 7: radio channel assignment complete controller BSC of the base station BS ₁ determines that allocation of the channel CH ₁ to the base station BS ₁ is successful.

Delete CH ₁ from unused channel list i = number of allocated base stations = 1 Step 8: Radio channel allocation to base station BS _{2 The} control station BSC performs CH ₂ to base station BS ₂ by the above-mentioned channel allocation operation. Assign

Unused channel list = <CH ₂ , CH ₅ > Unsearched channel list = <CH ₂ , CH ₅ >.

[0076] Step 9: instructs to the radio channel set base station BS ₂ to the base station BS ₂ using CH _2.

[0077] Step 10: interference determining the base station BS ₂ of the base station BS ₂ performs radio monitoring of CH _2, and evaluates the interference there between.

Step 11: Interference determination report from base station BS _{2 The} control station BSC receives “interference present” as the interference determination report from the base station BS ₂ .

Step 12: Radio channel reassignment to base station BS _{2 The} control station BSC executes channel reassignment to the base station BS ₂ by the above-mentioned channel assignment operation and assigns CH ₅ .

Unused channel list = <CH ₂ , CH ₅ > Unsearched channel list = <CH ₅ >.

[0081] Step 13: as a channel reassignment to a radio channel reassignment base station BS ₂ to the base station BS _2, and instructs to use the CH _5.

[0082] Step 14: interference determining the base station BS ₂ of the base station BS ₂ performs radio monitoring of CH _5, and determines that no interference.

Step 15: Interference determination report from base station BS _{2 The} control station BSC receives “no interference” as the interference determination report from BS ₂ .

[0084] Step 16: radio channel assignment complete controller BSC of the base station BS ₂ determines that allocation of the channel CH ₅ to the base station BS ₂ is successful.

Delete CH ₅ from the unused channel list i = number of assigned base stations = 2.

Step 17: Radio channel allocation to base station BS _{3 The} control station BSC allocates CH ₂ to the base station BS ₃ by the above-mentioned channel allocation operation.

Unused channel list = <CH ₂ > Unsearched channel list = <CH ₂ >.

[0088] Step 18: an instruction to the radio channel set base station BS ₃ to the base station BS ₃ using CH _2.

[0089] Step 19: interference determining the base station BS ₃ of the base station BS ₃ performs radio monitoring of CH _2, and determines that no interference.

Step 20: Interference determination report from base station BS _{3 The} control station BSC receives “no interference” as an interference determination report from the base station BS ₃ .

[0091] Step 21: radio channel assignment complete controller BSC of the base station BS ₃ determines the allocation of the channel CH ₂ to the base station BS ₃ was successful.

Delete CH ₂ from the unused channel list i = number of assigned base stations = 3.

Step 22: Completion of radio channel allocation The control station BSC judges that the allocation to the base stations is completed because the number i of allocated base stations has reached m = 3, terminates the radio channel allocation, and the control station BSC Notifies the integrated station BSI of a radio channel allocation completion report.

In the example shown in FIG. 11, there are the following two reasons that the allocation of the radio channel CH ₂ to the base station BS ₂ has failed.

Since the base station BS ₁ and the base station BS ₂ are installed adjacent to each other, since CH ₂ is an adjacent channel to the base station BS ₁ using CH ₁ , interference is detected in the cell to which the base station BS ₂ belongs. There is a base station that uses CH ₃ which is an adjacent channel of CH _{2 in} the adjacent cell group of the group, and detects interference from this channel, in particular,
In the former case, if the base station BS ₁ and the base station BS ₂ perform radio wave monitoring at the same time, they both perform reception level detection in the wave stop state, and therefore, they detect even if there is an interfering station. Is impossible.

However, the third aspect of the present invention is as described above.
According to the embodiment of the present invention, the control station BSC controls the execution timing of the radio wave monitoring so as to perform the radio wave monitoring of the base stations BS at the same time so that the radio waves are not monitored in the same cell group. Even if there is a base station that uses the adjacent channel, it is possible to reliably detect the interference and avoid the interference.

The time ΔT ₁ from when each base station starts transmission after interference judgment is the time ΔT ₂ assigned to the base station.
If it is greater than, after receiving the interference-free decision report from the base station BS ₁ , sufficient delay time ΔT ₃ (> ΔT ₁ −ΔT ₂ )
Then, the wireless channel designation to the base station BS ₂ is performed (after the delay time of ΔT ₃ after the wireless channel of the arbitrary base station BS is determined, the wireless channel designation of the next base station BS is performed). It is possible to perform reliable interference detection such as.

(Fourth Embodiment) The present invention is a mobile communication system in which the cell station design according to claim 2 or 3 is simplified, and the mobile communication is performed in a conventional mobile communication system such as PDC. In order to enable the station-initiated handover, each control station is provided with means for a cell belonging to a subordinate cell group to obtain a radio channel used in the adjacent cell.

In the time division multiple access method, there is a free time during which transmission / reception is not performed even while the mobile station is communicating with the base station such as voice data. In the full rate system of PDC, this free time is about 1 slot, about 5.6 m
Since s exists, it is possible to perform reception level measurement of channels other than the wireless channel in communication at this time.

In the PDC, since the cell station design is strictly performed, the cells around the cell are known to an arbitrary cell. Therefore, each base station has a radio channel of a cell around the own station (a radio channel to be monitored). ) Is notified to the mobile station by broadcast information, and the mobile station can measure the reception level of the wireless channel.

The mobile station periodically measures the reception level of the radio channel to be monitored, and the reception level of the radio channel CH to be monitored is higher than a certain threshold value A from the reception level from the base station of the cell in the service area. If it becomes, the CH and its reception level are reported to the base station side.

On the side of the base station that has received the above report, since the base station using the radio channel CH is known, this base station can be selected as the transfer destination.

FIG. 12 shows, as a part of the configuration of the control station of the present invention, the configuration of means for obtaining the information on the adjacency relation of cells belonging to the cell group under the control of the local station, and communication with the integrated station. To the integrated station communication means 121 having the function of performing
A base station ID storage means 122 having the function of storing the IDs of base stations under its control, a base station selection means 123 having the function of sequentially selecting base stations from the base station ID storage means 122, and an integrated station. Radio channel group storage means 124 having the function of storing the assigned radio channel group, and base station selection means 1
Wireless channel group storage means for the base station selected by 23.
The radio channel used by the cell group under its own control stored in 124, and the radio channel used by the integrated station communication means 121 in the peripheral cell group of the own station obtained from the integrated station, the radio channel for measuring the reception level. Level measurement channel designating means 125 having a function of designating as a base station, base station communication means 126 having a function of communicating with a base station, and report of the level measurement result performed by the base station by the base station communication means 126. The adjacent cell use channel determining means 127 having the function of determining the radio channel used in the adjacent cell based on the result of the level measurement report, and the adjacent relationship between the cells determined by the adjacent cell use channel determining means 127. Consistency channel storage means 128 having the function of storing information regarding

FIG. 13 shows, as a part of the configuration of the base station of the present invention, the configuration of means for measuring the reception level of the radio channel designated by the control station, which communicates with the control station. Control station communication means 131 having action
A monitoring target channel storage means 132 having a function of storing a monitoring target wireless channel designated by the control station,
A channel setting means 133 having a function of designating a wireless channel for performing reception level measurement, a receiving means 134 having a function of receiving a wireless channel designated by the channel setting means 133, and reception of a radio wave signal received by the receiving means 134. Reception level measuring means 135 having a function of measuring the level,
It comprises level measurement result storage means 136 having a function of storing the level measurement result of the wireless channel to be monitored, and radio wave monitoring control means 137 for controlling the operation timing of radio wave monitoring in the base station.

FIG. 14 shows, as a part of the configuration of the integrated station of the present invention, a configuration for controlling the timing at which each control station acquires the cell placement information, and for each control station (cell group). The control station adjacency relation storage means 141 for storing the adjacent control station, the control station assigned channel group storage means 142 for storing the radio channel group assigned to each control station under the control of the integrated station, and the control for the integrated station. Control station ID storage means 143 having the function of storing the ID of the control station
Information and control stored in the control station adjacency storage means 141 for the control station selection means 144 having a function of sequentially selecting control stations from the storage means 143 and the control station BSC * selected by the control station selection means 144 From the information stored in the station-allocated channel group storage means 142, a list CGL of wireless channel groups allocated to the peripheral control stations is obtained, and an adjacent control station-allocated channel group information generation means 145 having a function of notifying the CGL to the BSC *. , Control station communication means 14 having the function of communicating with the control station
Consists of six.

The operation of the means for acquiring the information regarding the cell adjacency relationship in the integrated station, control station and base station configured as described above will be described with reference to FIG.

FIG. 15 shows a sequence between the integrated station BSI, the control station BSC and the base station BS. Here, the control station BS
An example will be described in which BS ₁₁ , BS ₁₂ , and BS ₁₃ exist as three base stations BS under C ₁ .

The operation for obtaining the cell arrangement information is performed after the radio channel allocation for all base stations BS is completed.

Step 1: The integrated station BSI notifies the control station BSC ₁ of the channels of the peripheral cell group (1) The adjacent control station assigned channel group information generation means 145
The control station selection means 144 is instructed to select the control station. (2) The control station selection means 144 selects the control station BSC ₁ from the control station ID storage means 143 and outputs it to the adjacent control station assigned channel group information generation means 145. (3) The adjacent control station allocation channel group information generation means 145
Adjacent control stations of the control station BSC ₁ are obtained from the control station adjacency storage means 141, and the radio channel groups assigned to these control stations are obtained from the control station assigned channel group storage means 142. (4) The adjacent control station allocation channel group information generation means 145
The control station communication means 146 notifies the control station BSC _{1 of} the channel group allocated to the peripheral cell group.

Step 2: Request radio wave monitoring from the base station BS ₁₁ (1) When the control station BSC ₁ receives the cell placement information acquisition request from the integrated station BSI by the integrated station communication means 121, it is included in this message. The level measurement channel designating means 125 is notified of the channels used in the peripheral cell group. (2) The level measuring means 125 requests the base station selecting means 123 to select a base station. (3) The base station selection means 123 selects the base station BS ₁₁ from the base station ID storage means 122 and outputs it to the level measurement channel designation means 125. (4) In addition to the radio channel used by the cell group under the control station BSC ₁ stored in the radio channel group storage means 124 in the base station BS ₁₁ by the base station communication means 126, the level measuring means 125, in addition to the control station BSC ₁ Requests that the monitoring of the radio channel used by the group of cells in the vicinity be performed.

Step 3: Radio wave monitoring of base station BS ₁₁ Each base station BS is supposed to stop the transmission during the radio wave monitoring in order to avoid the influence of the transmission wave of its own station. (1) When the base station BS ₁₁ receives the radio wave monitoring request from the control station BSC ₁ by the control station communication means 131, the channel to be monitored included in this message (the channel in the cell group of the control station BSC ₁ + (Intra-peripheral cell group channel) is registered in the monitored channel storage means 132, and the radio wave monitoring control means 1
Notify 37 that radio wave monitoring was instructed. (2) The radio wave monitoring control means 137 selects a channel CH from the monitored channel storage means 132 so that there is no duplication, and notifies the channel setting means 133 of the CH. (3) The channel setting means 133 sets the receiving means 134 to receive CH. (4) Receiving means 134 receives CH and receives level measuring means 1
Output to 35. (5) The reception level measuring means 135 measures the reception level of CH and outputs it to the radio wave monitoring control means 137. (6) The radio wave monitoring control means 137 registers the reception level measurement result of CH in the level measurement result storage means 136. After (7), the processes of (3) to (6) are repeated for all the channels stored in the monitored channel storage unit 132. (8) The radio wave monitoring control means 137 is the level measurement result storage means 1
The radio wave monitoring result stored in 36 is reported to the control station BSC ₁ by the control station communication means 131.

Step 4: The control station BSC ₁ judges the peripheral channel of the base station BS ₁₁ (1) The control station BSC ₁ receives the radio wave monitoring report from the base station BS ₁₁ by means of the base station communication means 126, and this message The reception levels of the in-cell-group channel and the peripheral-cell-group channel included in are output to the adjacent cell use channel determination means 127. (2) Adjacent cell use channel determination means 127 compares a threshold value T for determining whether or not a channel used by an adjacent cell, which is set in advance, with a reception level of each channel, and T It is determined that a channel having a reception level exceeding that is a channel used by an adjacent cell. The channel determined to be used in the adjacent cell is registered in the adjacent cell used channel storage means 128 as the adjacent cell used channel of the base station BS ₁₁ .

Step 5: Request radio wave monitoring to the base station BS ₁₂ (1) Request radio wave monitoring to the base station BS ₁₂ after determining the channel used in the adjacent cell of the base station BS ₁₁ . (2) The same as (2) and subsequent steps in step 2 above.

Step 6: Same as step 3 of radio wave monitoring of the base station BS ₁₂ .

Step 7: Control station BSC ₁ determines peripheral channel of base station BS ₁₂ Same as step 4.

Step 8: Request radio wave monitoring from the base station BS ₁₃ Same as step 5.

Step 9: Same as step 3 of radio wave monitoring of the base station BS ₁₃ .

[0118] Step 10: the cell arrangement information acquisition completion (1) the control station BSC ₁ control station BSC ₁ reports that the acquisition of the cell arrangement information to the integrated station BSI is completed.

Step 11: The integrated station BSI notifies the control station BSC ₂ of the channels of the peripheral cell group. Similarly to step 1, the integrated station BSI requests the control station BSC ₂ to acquire the cell arrangement information. Subsequent processing is control station BSC ₁
As for.

As described above, according to the fourth embodiment of the present invention, even in a mobile communication system in which the cell station design is simplified, each control station has all cells belonging to the cell group under its control ( Since it is possible to obtain information on the radio channel used in the adjacent cell (including the radio channel used in the adjacent cell group of the control station) from the base station), the conventional strict station design is required. A mobile station-initiated handover similar to that of a mobile communication system can be executed.

[0121]

As described above, according to the present invention, a mobile station, a service area is divided into a plurality of cells, a base station servicing each cell, and an arrangement situation of a base station under its control are recognized. Without recognizing at least the control station that manages the radio channel used by each base station and controls multiple base stations and the arrangement status of the control stations under its control, at least use each control station It is a mobile communication system characterized by comprising an integrated station that manages the adjacency relationship between a wireless channel group and a cell group served by each control station, and performs control integration for a plurality of control stations. By the simplification, not only the time and labor required for the station placement design can be saved, but also an excellent mobile communication system having a high degree of freedom in installing the base station in the cell group can be constructed.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a mobile communication system according to a first embodiment of the present invention,

FIG. 2 is a block diagram of an integrated station according to the first embodiment of the present invention,

FIG. 3 is a block diagram of a control station according to the first embodiment of the present invention,

FIG. 4 is a sequence diagram of radio channel allocation according to the first embodiment of the present invention,

FIG. 5 is a diagram showing a wireless channel allocation result in the first embodiment of the present invention,

FIG. 6 is a block diagram of a control station according to the second embodiment of the present invention,

FIG. 7 is a block diagram of a base station according to the second embodiment of the present invention,

FIG. 8 is a sequence diagram of radio channel allocation according to the second embodiment of the present invention,

FIG. 9 is a block diagram of a radio channel allocating means of a control station according to the third embodiment of the present invention,

FIG. 10 is a flowchart of radio channel allocation of a control station according to the third embodiment of the present invention,

FIG. 11 is a sequence diagram of radio channel allocation according to the third embodiment of the present invention,

FIG. 12 is a block diagram of a control station according to a fourth embodiment of the present invention,

FIG. 13 is a block diagram of a base station according to a fourth embodiment of the present invention,

FIG. 14 is a block diagram of an integrated station according to a fourth embodiment of the present invention,

FIG. 15 is a sequence diagram of cell arrangement information acquisition according to the fourth embodiment of the present invention,

FIG. 16 is a configuration diagram of a conventional mobile communication system,

FIG. 17 is a block diagram of a control station of a conventional mobile communication system.

[Explanation of symbols]

 11 integrated station 21 allocation candidate channel storage means 22, 143 control station ID storage means 23, 141 control station adjacency storage means 24 radio channel group allocation means 25, 142 control station allocation channel group storage means 26, 71, 131, 146 pairs Control station communication means 31, 61, 121 vs. integrated station communication means 32, 62, 92, 124 Radio channel group storage means 33, 63, 93, 122 Base station ID storage means 34, 64, 94 Radio channel allocation means 35, 65 , 95, 171 Base station assigned channel storage means 36, 66, 97, 126, 172 to base station communication means 67, 96 Interference determination processing means 72 Used channel determination means 73, 134 Receiving means 74, 135 Reception level measuring means 75 Interference Judgment means 123, 941 Base station selection means 125 Level measurement channel specification means 127 Adjacent cell used channel judgment means 128 Adjacent cell used channel storage means 132 Monitoring target channel storage means 133 Channel setting means 136 Level measurement result storage means 137 Electricity Monitor control means 144 Control station selection means 145 Adjacent control station allocation channel group information generation means 151, 152, 153, 1621, 1622, 1623 Base station 161, 191, 192, 193 Control station 181, 182, 183, 1631, 1632, 1633 Mobile station 942 Channel selection means 943 Unused channel list storage means 944 Unsearched channel list storage means 945 Channel designation means 946 Channel allocation control means

Claims (4)

[Claims] 1. A mobile station, a base station that divides a service area into a plurality of cells, and services each cell, and at least each base station without recognizing the arrangement status of the base stations under its control. It recognizes the control station that manages the wireless channels used and controls multiple base stations and the status of the control stations under its control, and at least the wireless channel group used by each control station and each control station are serviced. A mobile communication system, comprising: an integrated station that manages the adjacency relationship of the cell groups and performs control integration for a plurality of control stations. 2. The base station includes means for executing radio wave monitoring for determining the presence or absence of interference with respect to a radio channel designated by the control station, wherein the control station is The mobile communication according to claim 1, further comprising means for reassigning a radio channel to the base station when the determination result of the presence or absence of interference is received and it is reported that there is interference. system. 3. The mobile communication according to claim 2, wherein the control station sequentially performs radio channel allocation and interference determination confirmation for each base station according to an order determined by the control station. system. 4. In order to manage the adjacency relationship of a cell group to be served, the integrated station sequentially selects a subordinate control station in a predetermined order, and the selected control station sequentially in a predetermined order, A means for selecting a subordinate base station, and the selected base station has a means for measuring a reception level of a downlink radio wave transmitted by a peripheral base station, and each control station under the control of the integrated station is its own station. After the wireless channel allocation to the subordinate base stations is completed and all the base stations start transmitting radio waves, the mobile station takes initiative to obtain information about the wireless channel used in the adjacent cell for any cell. The mobile communication system according to any one of claims 2 and 3, wherein the mobile communication is performed.