JP4616868B2 - Radio channel allocation method, apparatus and program capable of avoiding overreach interference - Google Patents

Description

  In the present invention, when a base station is newly established in an environment where one or a plurality of existing base stations use all the radio channels, the same radio channel capable of avoiding interference with the existing base station is arranged in the new base station. The present invention relates to a radio channel allocation method, apparatus, and program.

  Non-Patent Document 1 describes a radio channel arrangement method for a base station when radio communication is performed between a fixedly installed base station and a subscriber station. According to Non-Patent Document 1, the arrangement of radio channels, that is, the allocation of radio channels to base stations, minimizes the sum of interference amounts between any two base stations, and any two base stations. The amount of interference between them does not exceed a certain threshold value.

  Also, the same radio channel that satisfies the required propagation loss by calculating the propagation loss between any two base stations as a radio channel arrangement with high frequency utilization efficiency that can reuse the same radio channel in a narrower area There is also a method of allocating as many base stations as possible.

Tanaka, Yasuaki, Maruyama, Hideyuki, “Optimum Wireless Channel Allocation Method in Wireless IP Access System”, IEICE General Conference 2005 Communication Society Conference Proceedings 1, B-5-199, pp. 599, September 2005

  In the prior art, it is possible to arrange base stations with high frequency utilization efficiency on the assumption that the required propagation loss is satisfied (no influence by interference). However, when all existing radio channels are used by existing base stations and there are no free channels, when a new base station is established due to an increase in demand, etc., the same radio channel that can avoid interference with the existing base station is newly established. There is no idea how to place it in the base station. In the above situation, if there is a radio channel that satisfies the required propagation loss, it can be serviced by placing the radio channel in the newly installed base station, but not all radio channels satisfy the required propagation loss. In such a case, it was only possible to take measures such as applying for a new wireless channel and increasing the number of usable wireless channels or changing the location of the newly installed base station. In the former, there is a problem that the operation and time required for applying for a new radio channel are large, and the service start is delayed. In the latter case, the work of selecting a new installation location and negotiating with the site due to the change of the base station installation location This also has a problem that the service start is delayed because it takes time and operation.

  Therefore, in the present invention, in order to solve the above-mentioned problem, the same radio channel capable of avoiding interference with the existing base station in an environment where one or a plurality of existing base stations use all the radio channels is newly installed. An object of the present invention is to provide a radio channel arrangement method, apparatus, and program arranged in a station.

According to the method of the present invention,
If there is one or more fixed base stations for wireless communication with the subscriber station and the base station uses all the radio channels, the base station will be installed In a radio channel arrangement method in which the same radio channel capable of avoiding interference with a base station is arranged in a newly installed base station, the distance between the existing base station and the newly installed base station is determined, and the radio wave is calculated from the distance between the base stations. A first step of obtaining a desired propagation loss necessary for satisfying the required propagation loss from the propagation loss, a mounting region of a radio wave absorber for avoiding interference from the desired propagation loss, and A second step of obtaining a region (suppression region) in which radio waves are suppressed by the radio wave absorber; a radio channel is arranged so that a center of the suppression region is located in the direction of the existing base station (interference direction), and the suppression A third step of obtaining the number of households existing in the area and determining whether or not the wireless channel covers the demand user area, and the existing base station from the first step to the third step And a fourth step of performing in all the wireless channels used by the wireless base station, and arranging the wireless channels having the smallest number of households in the suppression area and covering the demand user area in the newly installed base station. It is characterized by.

  In the first step, the inter-base station distance between the existing base station and the newly installed base station is determined from the longitude and latitude of the existing base station and the latitude and longitude of the newly installed base station. Is also preferable.

In addition, when the propagation loss obtained in the first step satisfies the required propagation loss, the number of users accommodated in the existing base station that satisfies the required propagation loss, and the service area of the existing base station From the fifth step of obtaining the number of households existing in the network, the number of accommodated users, the number of households in the service area, and the capacity limit user number of the existing base station,
Capacity ratio = (number of households in service area-number of accommodated users) /
(Number of users in the capacity limit of existing base stations-number of users accommodated)
The sixth step obtained in step 5, the fifth step and the sixth step are performed for all radio channels satisfying the required propagation loss, and the radio channel of the existing base station having the largest accommodable magnification is established. It is also preferable to further include a seventh step of arranging in the base station.

  Further, in the case where there is no radio channel covering the demand user area in the fourth step, a plurality of radio channels are combined, and the plurality of combined radio channels are arranged on the newly installed base station, A plurality of eighth steps for determining whether or not the demand user area is covered and the eighth step in order of decreasing number of households in the suppression area until the demand user area can be covered. It is also preferable that the method further includes a ninth step of arranging a plurality of wireless channels determined to be coverable in the newly installed base station.

  Further, the eighth step is to determine whether the demand user area can be covered by arranging two radio channels in an overlapping manner, and then arranging three radio channels in an overlapping manner, It is determined whether or not the demand user area can be covered, the wireless channels to be sequentially overlapped are increased one by one, and finally all the wireless channels are overlapped and arranged to determine whether or not the demand user area can be covered. It is also preferable to judge.

According to the apparatus of the present invention,
If there is one or more fixed base stations for wireless communication with the subscriber station and the base station uses all the radio channels, the base station will be installed In a radio channel placement apparatus that places the same radio channel capable of avoiding interference with a base station in a newly installed base station, the distance between the existing base station and the newly installed base station is obtained, and the radio wave is calculated from the distance between the base stations. A desired propagation loss calculating means for obtaining a desired propagation loss necessary for satisfying the required propagation loss from the propagation loss, and a mounting area of the radio wave absorber for avoiding interference from the desired propagation loss. And a suppression region calculation means for obtaining a region (suppression region) in which radio waves are suppressed by the radio wave absorber, and a radio channel is arranged so that the center of the suppression region is in the direction of the existing base station (interference direction), Determining the number of households existing in the suppression area, and further determining whether or not the wireless channel covers the demand user area; demanding user area determining means; and the desired propagation loss calculating means; the suppression area The calculation means and the household number calculation demand user area determination means are performed for all the wireless channels used by existing base stations, and the number of households in the suppression area is the smallest and the wireless channel covering the demand user area A radio channel arrangement means for arranging a new base station in the new base station;
It is characterized by having.

According to the program of the present invention,
If there is one or more fixed base stations for wireless communication with the subscriber station and the base station uses all the radio channels, the base station will be installed As a program in a computer that arranges the same radio channel that can avoid interference with a base station in a newly installed base station, the distance between the existing base station and the location of the newly installed base station is obtained, and the radio A first step of obtaining a propagation loss, obtaining a desired propagation loss necessary for satisfying the required propagation loss from the propagation loss, a mounting area of a radio wave absorber for avoiding interference from the desired propagation loss, and the A second step of obtaining a region (suppression region) in which radio waves are suppressed by the radio wave absorber, and arranging a radio channel so that the center of the suppression region is in the direction of the existing base station (interference direction), A third step of obtaining the number of households existing in the suppression area and determining whether the wireless channel covers the demand user area, and from the first step to the third step, And a fourth step of performing in all the radio channels used by the station, arranging the radio channel having the smallest number of households in the suppression area and covering the demand user area in the newly established base station, and Is made to function.

  The loss required for interference avoidance is obtained from the propagation loss between the newly installed base station and the existing base station and the required propagation loss, and a radio wave absorber is attached to the newly installed base station. By suppressing, arrangement on the same radio channel becomes possible. Furthermore, it is possible to select radio channels efficiently by arranging radio channels that have the fewest number of households in the suppression region generated by the installation of the radio wave absorber and can cover the demand user area.

  In addition, when there are a plurality of radio channels that satisfy the required propagation loss, an existing base station that determines the number of users accommodated from the accommodable magnification of the existing base station that uses the radio channel and is likely to be tight. By arranging the same radio channel in the newly installed base station, it becomes possible to create a situation where it is easy to select a radio channel to be arranged in a further newly installed base station when the existing base station is tight.

  In addition, by overlapping multiple wireless channels in order of decreasing number of households in the suppression area, even if the demand user area cannot be covered by a single wireless channel, multiple wireless channels can be placed in the newly installed base station. The user area can be covered.

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

  First, as a precondition of the embodiment, in an area where a fixed wireless communication service has already been performed between a base station and a subscriber station, an existing base station (the number of base stations is one or more, 1, 2, .., N) use all radio channels that can be used in the area (hereinafter referred to as fn, f1 is the radio channel of the existing base station 1, and fn represents the radio channel of the existing base station n) In a situation where there is no free wireless channel, a base station is newly established due to a further increase in demand users. The new base station is arranged to cover the demand user area. In addition, it is assumed that information on the longitude and latitude of existing and new base stations and propagation loss between all base stations is obtained in advance. Furthermore, it is assumed that a predetermined propagation loss (required propagation loss) necessary between all wireless channels is known in advance. The required propagation loss refers to a propagation loss necessary to prevent interference between base stations using the same radio channel. If the propagation loss between any base stations exceeds the required propagation loss, This means that there is no influence on the communication quality due to interference between stations, and the same radio channel can be arranged between the respective base stations.

  The first embodiment of the present invention will be described below based on the flowchart (S1 to S9) in FIG.

  S1 is a step of calculating distances from the longitudes and latitudes of newly established base stations and existing base stations (the number of base stations is 1, 2,..., N) and calculating propagation loss at the distances.

  S2 is a required propagation loss (hereinafter referred to as Ln). L1 represents a required propagation loss between the new base station and the existing base station 1, and Ln is a required propagation between the new base station and the existing base station n. Hereinafter, the notation Xn refers to the existing base station n) and the propagation loss calculated in S1 (hereinafter referred to as Rn), and if there is no Rn greater than Ln, the required propagation This means that there is no radio channel that satisfies the loss (see FIG. 4). If there is an Rn greater than Ln, it corresponds to the second embodiment of the present invention. This will be described separately with reference to the flowchart of FIG. If there is no radio channel that satisfies the required propagation loss, interference with the existing base station will occur and communication quality will deteriorate, so as described above, you can either apply for a new radio channel or install a new base station Has been dealt with by changing. The embodiment of the present invention is described in “Naoto Takahashi, Ryutaro Omoto,“ Study on Beam Forming Technology Applying Wave Absorber Sheet in Quasi-Millimeter Wave Wireless Access System ”, IEICE 2006 General Conference”. The “antenna pattern control method” is used. In S3 and subsequent steps, the method is described.

  In S3, a difference between Ln and Rn is calculated, and a desired propagation loss (hereinafter referred to as Dn) for satisfying Ln is calculated.

  In S4, based on the concept of “antenna pattern control method”, a radio wave absorber mounting area that can obtain Dn is determined, and from there, a suppression area (from the drop of the antenna pattern due to the radio wave absorber to the return to the original antenna pattern) Area, hereinafter referred to as Yn). FIG. 5 shows a relationship between Dn and the radio wave absorber mounting area and Yn modeled on FIG. 4 and a horizontal antenna pattern representing Dn in the radio wave absorber mounting area 45 °.

  In S5, when the same radio channel fn with Yn is arranged in the newly installed base station, the number of households included in Yn (in this case, potential users who may provide services in the future are included in addition to demand users) , All households). At this time, fn having Yn is arranged so that the center of Yn comes in the interference direction (see FIG. 5).

  In S6, fn with the smallest number of households included in Yn is selected. The smaller the number of households included in Yn, the more potential users can be secured, and there is a possibility that more users will be enclosed in the new base station in the future.

  In S7, it is determined whether or not the demand user can be covered by the selected arrangement of fn. If it cannot be covered, fn having the next smallest number of households in the Yn area is selected (S8). If there is the next smallest fn, the fn is arranged and it is determined whether the demand user can be covered (see FIG. 6). Thereafter, S7 and S8 are repeated until there is a coverable fn. If there is not, it will be described with reference to the flowchart of FIG.

  In S9, when the demand user can be covered with the fn selected in S7, this is the most efficient fn arrangement. The fn is arranged and the work is completed.

  Next, a second embodiment of the present invention in the case where there is an fn whose Rn is larger than Ln will be described using the flowchart of FIG.

  When there is one radio channel fn of Rn larger than Ln, that fn is preferentially arranged in the newly installed base station. When there are a plurality of radio channels fn of Rn larger than Ln, it is examined which fn among a plurality of fn that can be arranged is arranged (S10).

  In S11 and S12, for a plurality of assignable fn, the number of users accommodated in the existing base station corresponding to fn (referred to as the number of users currently receiving service, hereinafter referred to as An) and the base Confirm the total number of households that the station can accommodate (all households including potential users who may provide services in the future, hereinafter referred to as Bn).

  In S13, assuming that the limit number of users per base station is X, the accommodable magnification of the existing base station corresponding to fn is calculated for a plurality of assignable fn.

  The accommodation capacity ratio refers to the ratio of the potential users in the service area to the number of users that the existing base station can accommodate at the present time. It becomes difficult to accommodate at the base station).

The accommodable magnification is expressed by the following formula.
Accommodable magnification = potential users / number of users that can be accommodated in existing base station
= (Bn-An) / (X-An)

  The accommodable magnification is calculated for the existing base station, and the fn of the existing base station that maximizes the accommodable magnification is arranged in the new base station. Since existing base stations with larger capacity can easily reach the limit capacity, there is a high possibility of installing new base stations that respond to further increases in demand. In that case, existing base stations that have reached the limit capacity In order to facilitate the use of a radio channel other than the radio channel being used, it is desirable that the radio channel used for the newly installed base station is a radio channel of an existing base station having a capacity that can be accommodated as much as possible. When using a radio channel of an existing base station with a small capacity that can be accommodated in a new base station, if the existing base station with a large capacity is saturated and a base station is installed, the capacity can be accommodated in the new base station first. This is because there is a high possibility that the radio channel of the existing base station with a small magnification cannot be used.

  Next, a third embodiment of the present invention when a demand user cannot be covered with one selected fn will be described with reference to the flowchart of FIG.

  If the demanded user cannot be covered by the selected fn, two new base stations are set, and the fn with the smallest number of households in Yn and the next smallest fn are allocated (S14). If the demand user can be covered by this, the above two wireless channels are arranged so as to overlap the two wireless base stations, and this work is completed. If the demand user cannot be covered even at S14, it is determined whether or not it is possible to cover with the combination of fn having the smallest number of Yn households and the third smallest fn. Thereafter, the combination of the two radio channels that can be covered is determined brute force (S15). If you still cannot cover the demand users, determine whether you can cover with the combination of the three wireless channels, and then determine the brute force while increasing the number of combined wireless channels until you can cover the demand users. (S16). A plurality of wireless channels determined in this work will be arranged so as to overlap the newly established base station, and the service will be developed. In addition, in the situation where a demand user cannot be covered even if all the radio channels are combined, it is dealt with by changing the installation location of the new base station or applying for a new radio channel.

  Note that the above-described method of arranging the radio channels can be realized by a program that causes a computer to operate as described above. More specifically, the program is read into the main memory and executed by the processor, and causes the computer to execute each process of the above-described radio channel arrangement method. The program may be provided by being recorded on a recording medium, or may be provided via a network.

  Moreover, all the embodiment described above shows the present invention exemplarily, and does not limit the present invention, and the present invention can be implemented in other various modifications and changes. Therefore, the scope of the present invention is defined only by the claims and their equivalents.

1 shows a flowchart of a first embodiment of the present invention. The flowchart of the 2nd Embodiment of this invention is shown. 7 shows a flowchart of a third embodiment of the present invention. An example of calculating the propagation loss Rn and the desired propagation loss Dn is shown. FIG. 5 shows a relationship between a desired propagation loss Dn, a wave absorber mounting region angle, and a suppression region angle in the model of FIG. 4 and a horizontal antenna pattern representing the desired propagation loss Dn at a wave absorber mounting region angle of 45 °. The positional relationship with Yn, the number of households in Yn, and a demand user area in the model of FIG. 4 is shown.

Claims (7)

If there is one or more fixed base stations for wireless communication with the subscriber station and the base station uses all the radio channels, the base station will be installed In the radio channel arrangement method of arranging the same radio channel capable of avoiding interference with the base station in the newly installed base station,
Obtain the distance between base stations between the existing base station and the location where the new base station is installed, obtain the propagation loss of radio waves from the distance between the base stations, and obtain the desired propagation loss necessary to satisfy the required propagation loss from the propagation loss A first step;
A second step of determining, from the desired propagation loss, a mounting region of a radio wave absorber and a region where a radio wave is suppressed by the radio wave absorber (a suppression region) in order to avoid interference;
Whether a radio channel is arranged so that the center of the suppression area is in the direction of the existing base station (interference direction), the number of households existing in the suppression area is obtained, and whether the radio channel covers the demand user area A third step of determining whether or not;
The first to third steps are performed for all radio channels used by existing base stations, the radio channel having the smallest number of households in the suppression area and covering the demand user area A fourth step of locating at the new base station;
A radio channel arrangement method capable of avoiding overreach interference.   In the first step, the inter-base station distance between the existing base station and the newly installed base station is determined from the longitude and latitude of the existing base station and the latitude and longitude of the newly installed base station. The method according to claim 1. When the propagation loss obtained in the first step satisfies the required propagation loss,
A fifth step of determining the number of users accommodated in an existing base station satisfying the required propagation loss and the number of households existing in the service area of the existing base station;
From the number of accommodated users, the number of households in the service area, and the number of accommodated users of the existing base station, the accommodable magnification is
Capacity ratio = (number of households in service area-number of accommodated users) /
(Number of users in the capacity limit of existing base stations-number of users accommodated)
The sixth step determined in
The fifth step and the sixth step are performed for all radio channels satisfying the required propagation loss, and the radio channel of the existing base station having the largest accommodable magnification is arranged in the new base station. Steps,
The method according to claim 1, further comprising: In the case where there is no radio channel covering the demand user area in the fourth step,
An eighth step of combining a plurality of wireless channels, determining whether or not the plurality of combined wireless channels are overlaid on the newly installed base station and cover the demand user area;
The eighth step is performed by combining a plurality of radio channels in ascending order of the number of households in the suppression area until the demand user area can be covered, and a plurality of radio channels determined to be coverable A ninth step of locating at the new base station;
The method according to claim 1, further comprising:   The eighth step determines whether the demand user area can be covered by arranging two wireless channels in an overlapping manner, and then arranging the three wireless channels in an overlapping manner. Judge whether the user area can be covered, sequentially increase the radio channels to be overlapped one by one, and finally arrange all the radio channels so as to determine whether the demand user area can be covered The method according to claim 4. If there is one or more fixed base stations for wireless communication with the subscriber station and the base station uses all the radio channels, the base station will be installed In a radio channel arrangement device that arranges the same radio channel that can avoid interference with a base station in a newly installed base station,
Obtain the distance between base stations between the existing base station and the location where the new base station is installed, obtain the propagation loss of radio waves from the distance between the base stations, and obtain the desired propagation loss necessary to satisfy the required propagation loss from the propagation loss A desired propagation loss calculation means;
A suppression region calculation means for obtaining a mounting region of a radio wave absorber and a region where a radio wave is suppressed by the radio wave absorber (suppression region) in order to avoid interference from the desired propagation loss;
Whether a radio channel is arranged so that the center of the suppression area is in the direction of the existing base station (interference direction), the number of households existing in the suppression area is obtained, and whether the radio channel covers the demand user area Household number calculation demand user area determination means to determine whether or not,
The desired propagation loss calculation means, the suppression area calculation means and the household number calculation demand user area determination means are performed for all radio channels used by existing base stations, the number of households in the suppression area is the smallest, and the A radio channel arrangement means for arranging a radio channel covering a demand user area in the new base station;
A radio channel arrangement apparatus capable of avoiding overreach interference. If there is one or more fixed base stations for wireless communication with the subscriber station and the base station uses all the radio channels, the base station will be installed As a program in a computer that places the same wireless channel that can avoid interference with a base station in a newly installed base station,
Obtain the distance between base stations between the existing base station and the location where the new base station is installed, obtain the propagation loss of radio waves from the distance between the base stations, and obtain the desired propagation loss necessary to satisfy the required propagation loss from the propagation loss A first step;
A second step of determining, from the desired propagation loss, a mounting region of a radio wave absorber and a region where a radio wave is suppressed by the radio wave absorber (a suppression region) in order to avoid interference;
Whether a radio channel is arranged so that the center of the suppression area is in the direction of the existing base station (interference direction), the number of households existing in the suppression area is obtained, and whether the radio channel covers the demand user area A third step of determining whether or not
The first to third steps are performed for all radio channels used by existing base stations, the radio channel having the smallest number of households in the suppression area and covering the demand user area A fourth step of locating at the new base station;
A program characterized by causing a computer to function.

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