JP2716002B2 - How to add wireless channels - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adding a radio channel when a radio channel is added in a mobile communication system having a plurality of radio zones.

[0002]

2. Description of the Related Art Generally, a mobile communication system has a plurality of radio zones. The size of such a wireless zone is determined in relation to the size of the service area and the number of given wireless channels. In particular, the number of mobile stations, their transmission output voltage, traffic distribution in each service area, radio waves It is determined in consideration of propagation characteristics and economics.

However, in an area where the number of mobile stations increases and the traffic distribution changes, a phenomenon occurs in which traffic exceeding the processing capacity is concentrated in each wireless zone. For this reason, a proposal has been made in which an existing wireless zone is further subdivided into a plurality of wireless zones to cope with the problem. Further, as a method of increasing the number of radio channels without dividing the existing radio zone, it has been proposed to develop a radio base station having a high channel capacity and exchange it with the existing base station.

[0004]

However, in such a method of adding a wireless channel by dividing a wireless zone, it is necessary to re-allocate the wireless channel with the addition of the wireless channel. Therefore, even if one base station is added, or even if the number of radio channels is increased by one, the radio wave is considered in consideration of the correlation with all other base stations. It is necessary to calculate the amount of interference, and there is a disadvantage that a large-scale operation is required. In addition, in the case where an existing base station is replaced with a base station having a high channel capacity to add a wireless channel, a new base station having a high channel capacity must be newly developed. Therefore, the present invention relates to a mobile communication system,
An object of the present invention is to easily and easily add a base station and a radio channel.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a plurality of mobile stations and a plurality of divided wireless zones which are wirelessly connected to the mobile stations via a control channel or a communication channel. In a mobile communication system including a plurality of first wireless base stations provided for each of the mobile stations, and a control station connected to the plurality of first wireless base stations by wire and controlling the mobile station, And a second radio base station having a control channel and a communication channel having a frequency different from each of the control channel and the communication channel of the first radio base station together with the first radio base station. The control channel of one of the control channels of the first and second radio base stations is based on the control channel structure information transmitted via the perch channel in the control channel of the base station. Which is a method to use. Further, the frequency numbers of the control channels of the first and second radio base stations are set as the control channel structure information, and the mobile station selects the control channel according to the unique number assigned to the own station. Is the way . Further, the perch channel is a method be provided only to the control channel of the first radio base station.

[0006]

A second radio base station having a control channel and a communication channel having frequencies different from the control channel and the communication channel of the existing first radio base station in the radio zone is provided together with the first radio base station. The mobile station, based on the control channel structure information transmitted via the perch channel in the control channel of the first radio base station, selects one of the control channels of the first and second radio base stations. The control channel of the radio base station is used. As a result, it is possible to easily and easily add a radio base station and a radio channel in the mobile communication system. Further, when receiving the control channel structure information in which the frequency numbers of the respective control channels of the first and second radio base stations are set, the mobile station determines the unique number assigned to the mobile station and the frequency number. Select a control channel based on As a result, the mobile station can easily select a control channel to be used by itself. The perch channel is provided only for the control channel of the first radio base station.
As a result, the selection of the radio zone of the mobile station depends on the information level of each perch channel, so that one of the radio zone of the first radio base station and the radio zone of the second radio base station is determined. Therefore, it is possible to avoid such a phenomenon that the traffic concentrates on each wireless zone, and accordingly, it is possible to accurately distribute traffic to each wireless zone.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 2 is a block diagram showing a configuration of the mobile communication system. In FIG.
Numeral 30 denotes a wireless zone which is a service area, 11, 21, 3
1 is a wireless base station having an omni-directional antenna, which is disposed substantially at the center of each of the wireless zones 10, 20, 30;
Reference numeral 0 denotes a control station connected to each of the radio base stations 11, 21, 31 via the line groups 1, 2, 3, respectively, and reference numeral 200 denotes a mobile station. Each of the line groups 1, 2, 3 includes a control line and a plurality of communication lines. Further, the mobile station 200 is controlled by the control station 100 via the radio base station 21, and is actually transmitted from the control station 100 via the control radio channel (control channel) from the radio base station 21. It is controlled by control information.

Next, FIG. 1 shows the addition of a radio channel according to the present invention.
FIG. 3 is a block diagram showing an embodiment of a mobile communication system to which the method is applied, and shows a configuration when the present invention is applied to the mobile communication system shown in FIG. That is, in FIG. 1, a wireless zone 40 is added to the existing wireless zone 20, and the same configuration as that of the existing wireless base station 21 in the wireless zone 40 (however, each frequency of the control channel and the communication channel is the same as that of the wireless base station 21). Wireless base station 2)
2 is arranged. In addition, each of such radio base stations 21 and
2 is called an overlay arrangement. In this case, the additional radio base station 22 is disposed in the same building as the existing radio base station 21.

[0009] Here, each of the existing radio base stations is provided with one channel called a perch channel among a plurality of control channels. For example, the broadcast information transmitted from the existing radio base station 21 via the perch channel includes control channel structure information as shown in FIG. In FIG. 3, Nc is the number of control channels in the zone, and Np is P
The number of CH groups, Ap is the number of PCH slots per group, Ab is the number of BCCH slots per control channel, As1 is the number of SCCH slots after BCCH, As
2 indicates the number of SCCH slots after PCH, respectively, which are defined by a predetermined standard.

In FIG. 3, F1 (s) to FNC
(S) indicates the frequency number of the control channel in the radio zone, and F1 (s) to Fn (s) are the control channel numbers of the radio zone 20 (that is, the radio base station 21). Fn (s) +1 to FNC (s) are control channel numbers of the wireless zone 40 (that is, the wireless base station 22). The PCH is a channel for notifying the mobile station of the number of the mobile station when a call is received. When the number of mobile stations is large, the PCH is notified in groups. Further, BCCH indicates a channel for performing synchronization probability with the mobile station, and SCCH indicates
6 shows a channel for allocating a communication channel at the time of arrival and departure.

When such control channel structure information is transmitted from the existing radio base station 21 to the radio zone 20 via the perch channel, the mobile station 200 moves from the peripheral zone to the radio zone 20. , Mobile station 20
0 selects a standby channel as follows. That is, the selection of the standby channel of such a mobile station is based on "P" which is a Japanese standard of the digital car telephone system.
CR STD-27B ". That is,
According to this standard, when there are a plurality of control channels in the same zone, it is necessary to switch from the perch channel to another control channel according to the grouping of mobile stations, and this operation is performed by the perch channel. This is performed based on the control channel structure information included in the broadcast information.

The mobile station 200 that has moved to the radio zone 20 first captures the perch channel, inputs control channel structure information transmitted by the perch channel, and based on the control channel structure information, Depending on the grouping, the control channel to be used by the own station is the control channel of the existing base station 21 or the base station 22 which has been added.
, And enters a standby state.

That is, as described above, the information broadcast by the control channel structure information includes the frequency numbers F1 (s) to FNC (s) of the control channels in the radio zone, the number Nc of control channels in the zone, And the number Np of PCH groups per control channel. Here, the mobile station 200
Let n be the decimal value of the value of the lower two octets of the unique mobile station number assigned to the mobile station 200, the mobile station 200 obtains the value n ′ by equation (1), Is determined by equation (2). That is, n ′ = (n−1) mod (Nc × Np) +1 (1) IF = (n′−1) modNc + 1 (2)

In the equations (1) and (2), mod indicates a modulo operation, and when n is "0", n is set to "1". If the number of the PCH group is Ip, the number I
P is defined as Ip = [(n′−1) / Nc] +1 (3) In this way, the mobile station 200 determines the frequency number of the control channel to be awaited and the number of the PCH group from the information of the control channel structure information and the value of its own number, and enters the standby state.

Therefore, as shown in FIG. 3, the frequency numbers F1 (s) to FNC (s) of the control channels of the zone are
Numbers F1 (s) to Fn (s) of existing radio base stations 21
And the numbers Fn (s) +1 to FNC of the additional radio base stations 22
(S), and by appropriately setting the grouping ratio of the mobile stations, the traffic amount to the wireless zone 20 and the wireless zone 40 becomes uniform. In addition, it is possible to add a wireless channel using an existing device as it is.

As described above, the existing radio base station 22 is arranged in the existing radio zone 20 on the overlay, the perch channel of the overlaid existing radio zone 20 is not provided in the expanded radio zone 40 without the perch channel. Since the control channel information of the wireless zone 40 to be added is set in the control channel structure information included in the broadcast information in addition to the control channel information of the existing wireless zone 20, it is not necessary to divide the wireless zone. It is not necessary to calculate the amount of interference and the like accompanying the addition, and the wireless channel can be easily added. In addition, since an existing device can be used as it is to add a wireless channel, development of a new wireless base station is not required, and the system can be economically configured.

[0017]

As described above, according to the present invention, the second control channel and the second communication channel having different frequencies from the control channel and the communication channel of the first radio base station existing in the radio zone are provided. A radio base station is provided together with the first radio base station, and the mobile station transmits the first and second radio base stations based on control channel structure information transmitted via a perch channel in a control channel of the first radio base station. Since the control channel of any one of the control channels of the radio base station is used, the radio base station and the radio channel can be easily and easily added in the mobile communication system. Further, when receiving the control channel structure information in which the frequency numbers of the respective control channels of the first and second radio base stations are set, the mobile station determines the unique number assigned to the mobile station and the frequency number. , The mobile station can easily select the control channel to be used by itself. Further, the perch channel is provided only in the control channel of the first radio base station, so that the selection of the radio zone of the mobile station depends on the information level of each perch channel.
A phenomenon that is concentrated in one of the wireless zone of the wireless base station and the wireless zone of the second wireless base station,
Therefore, traffic can be accurately distributed to each wireless zone.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a mobile communication system to which the present invention is applied.

FIG. 2 is a block diagram illustrating a configuration of a mobile communication system.

FIG. 3 is a diagram illustrating an example of control channel structure information transmitted via a perch channel of a radio base station in a mobile communication system.

[Explanation of symbols]

1-4: line group, 10, 20, 30, 40: wireless zone, 11, 22, 22, 31: wireless base station, 100: control station, 200: mobile station.

Claims (3)

(57) [Claims] 1. A plurality of mobile stations, and a plurality of first radios which are wirelessly connected to the mobile station via a control channel or a communication channel which is a radio channel and are respectively disposed in a plurality of divided radio zones. In a mobile communication system including a base station and a control station connected to a plurality of first wireless base stations by wire and controlling the mobile station, a control channel and a communication channel of the first wireless base station are provided in the wireless zone. A second radio base station having a control channel and a communication channel of a frequency different from each frequency is provided together with the first radio base station, and the mobile station sets a perch channel in the control channel of the first radio base station. The control channel of one of the first and second radio base stations is used based on the control channel structure information transmitted via the control channel. Expansion method for a wireless channel. 2. The method for adding a wireless channel according to claim 1, wherein a frequency number of each control channel of a first and a second wireless base station is set as the control channel structure information, adding method of a wireless channel and selects a control channel in accordance with a unique number assigned to the own station. 3. The expansion process <br/> radio channels according to claim 1, wherein the perch channel extension direction of a radio channel, characterized in that provided only on the control channel of the first radio base station
Law .