JP2000032560A - Call control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set flexibly plural radio channels to be a radio communication channel between a mobile station and a base station without increasing number of control channels used for a conventional time division multiple access TDMA system, in a mobile communication system using plural radio channels simultaneously. SOLUTION: A mobile station measures the electric field strength of a perch channel and uses idle radio channel information included in the perch channel to decide four radio channels used by the mobile station itself, when the measured value is greater than a preset threshold level. Then the mobile station makes a request for setting the radio communication channels to a base station (S2). Then the base station makes an authentication request to the mobile station (S3), and the mobile station makes a prescribed arithmetic processing to reply the base station (S4). The base station collates the result of a reply with an authentication key and permits the use of the radio channel, when the base station decides the mobile station to be a regular mobile station (S5).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a call control method of a mobile communication system using a plurality of radio channels between a base station and a mobile station.

[0002]

2. Description of the Related Art In a mobile radio communication system, a time division multiple access (TDMA) system or a frequency division multiple access (Frequency Division Mu1ti) system is used.
It is known to use a perch channel for call control in the ple Access (FDMA) system. The perch channel is always broadcast in the radio communication area by each base station using a unique carrier. The mobile station detects the perch channel and sets up a radio channel with the base station.

[0003]

In a mobile radio communication system in which a plurality of radio channels are adaptively and simultaneously used according to the state of a radio channel, call control between a mobile station and a base station is performed by a conventional TDMA system. It is assumed that this is performed by the same method as the FDMA method. In this case, it is necessary to perform the same number of call controls as the number of radio channels used simultaneously by the mobile station and the base station.

[0004] However, in the present day when the number of users of mobile communication is rapidly increasing, a call control method in which the number of control channels is increased more than necessary or the number of control sequences is large is inefficient. On the other hand, even if an attempt is made to cope with such a problem, call control in which a plurality of radio channels are simultaneously assigned to a mobile station is impossible in the conventional TDMA system and FDMA system.

Accordingly, a first object of the present invention is to provide a mobile communication system which uses a plurality of radio channels simultaneously without increasing the number of control channels used in the conventional TDMA system and the TDMA system without increasing the number of control channels. It is an object of the present invention to provide a call control method capable of setting a wireless channel of a mobile station and a base station as a wireless communication line.

A second object of the present invention is to make it possible to set up a radio communication line with the same number of call control sequences as in the prior art, to make effective use of a limited bandwidth, and to improve frequency control. It is an object of the present invention to provide a call control method capable of improving utilization efficiency.

[0007]

According to a first aspect of the present invention, there is provided a call control method for setting a plurality of radio channels between a base station and a mobile station. A first step in which the mobile station receives a control channel transmitted from the base station and specifies a service area of the mobile station;
A second step of measuring the electric field strength of the control channel in the first step, and if the electric field strength of the control channel measured in the second step is higher than a preset threshold, A third step of reporting to the base station that a plurality of wireless channels specified by a control channel transmitted from the base station are to be set as a wireless communication line between the mobile station and the base station; And a fourth step of allocating the radio channel to the mobile station and setting up a radio communication line. With this call control method, the conventional TDMA system and FDMA
A plurality of radio channels can be set with the same number of control channels as the scheme.

A second aspect of the call control method according to the present invention is characterized in that, when setting a plurality of radio channels between a base station and a mobile station, the mobile station uses a control channel transmitted from the base station. A first step of receiving and specifying the area in which the mobile station is located, a second step of measuring the electric field strength of the control channel in the first step, and a control channel of the control channel measured in the second step. If the electric field strength is higher than a preset threshold value, the mobile station searches for a free radio channel in the serving area and its surrounding area and performs wireless communication with the base station in the serving area. And a plurality of radio channels specified by a control channel transmitted from the base station, and a third step of determining a radio channel to perform In the area where you are A fourth step of reporting to the base station that it is to be set as a wireless communication line with the base station, and the base station having received the report in the fourth step allocates the radio channel to the mobile station, and 5th setting of communication line
Process. With this call control method, a plurality of radio channels can be set with the same number of control channels as the conventional TDMA system and FDMA system.

[0009] In the first and second call control methods described above, the plurality of radio channels designated by the control channel include a radio channel uniquely used in each cell and a radio channel used in the plurality of cells. It is possible to configure with a channel. In addition, the control channel may have a function of notifying a mobile station of all radio channels available in a base station that notifies the control channel.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 shows an area illustrating the relationship between a base station and a mobile station to which the present invention is applied. As shown in the figure, it is assumed that the mobile station is now out of the service area of the base station. Then, the mobile station moves toward the service area of the base station,
The case where the mobile station reaches the service area using the four radio channels of the base station will be described below.

A in FIG. 1 indicates an area using two radio channels, and B indicates an area using four radio channels.

FIG. 2 shows a radio line setting sequence in the case shown in FIG. First, the mobile station receives the perch channel broadcast from the base station (S1).
Then, the mobile station measures the electric field strength of this perch channel, and when the measured value is larger than a preset threshold of the electric field strength, the mobile station is included in the perch channel with respect to the base station. The four wireless channels used by the mobile station white body are determined using the available wireless channel information. After the determination, the mobile station requests the base station to set a wireless communication line (S2).

Next, an authentication request is issued from the base station to the mobile station (S3), and the mobile station performs a predetermined calculation process and replies to the base station (S4). The base station compares the response result with the authentication key, and when it is determined that the mobile station is a legitimate mobile station, the base station permits use of the wireless channel requested by the mobile station (S
5). Thereby, a plurality of wireless channels can be set by one control, and wireless communication between the mobile station and the base station can be started (S6).

FIG. 3 shows a generalization of the sequence shown in FIG. 2 in the form of a flowchart. First,
In block B1, the mobile station receives a control channel. Next, the electric field strength of the received control channel is measured (B2), and if the measured value is equal to or less than a predetermined threshold value, no line setting is performed (B4). Is transferred to block B5.

In block B5, a radio channel to be used by the mobile station is determined according to the information on the idle radio channel by the control channel. Next, the mobile station requests the base station to allocate a wireless channel (B6), and completes the line setting (B7).

The free radio channel broadcast by the perch channel may be constituted by a radio channel that can be used uniquely for each cell and a radio channel that can be used by a plurality of cells.

Embodiment 2 The second embodiment of the present invention will also be described assuming an area state as shown in FIG.

FIG. 4 shows a radio line setting sequence in the case shown in FIG. First, when the mobile station enters the service area of the base station, it receives a perch channel broadcast by the base station (S21). Then, the mobile station measures the electric field strength of the perch channel, and if it is higher than a preset threshold, the mobile station searches for a free radio channel. At this time, two free wireless channels are detected from the four wireless channels in FIG. When two free wireless channels are detected, two more free wireless channels are found from the number of free wireless channels included in the perch channel.
Select one radio channel. The use of the selected two radio channels and the detected two radio channels is permitted to the base station (S22).

Next, an authentication request is issued from the base station to the mobile station (S23), and the mobile station performs a predetermined calculation process and replies to the base station (S24). The base station compares the authentication result with the authentication key, and when it is determined that the mobile station is a legitimate mobile station, the base station permits use of the wireless channel requested by the mobile station (S25). Thereby, a plurality of wireless channels can be set by one control, and wireless communication can be started between the mobile station and the base station (S26).

The free radio channel broadcast by the perch channel may be constituted by a radio channel usable uniquely for each cell and a radio channel usable for a plurality of cells.

Also, in the second embodiment, the call control flowchart shown in FIG. 3 can be applied.

[0022]

By implementing the present invention, the following effects can be obtained.

1) A plurality of wireless channels can be set efficiently.

2) By utilizing a control channel broadcast by the base station such as a perch channel, it is possible to minimize the change in the existing wireless communication line setting method.

3) Compatible with existing wireless communication line setting methods.

4) The radio channel can be efficiently used by the radio channel management in the base station.

[Brief description of the drawings]

FIG. 1 is an area diagram illustrating a relationship between a base station and a mobile station to which the present invention is applied.

FIG. 2 is a diagram showing a control sequence according to the first embodiment of the present invention.

FIG. 3 is a flowchart showing call control according to Embodiment 1 of the present invention.

FIG. 4 is a diagram showing a control sequence according to Embodiment 2 of the present invention.

[Explanation of symbols]

 A Area using 2 radio channels B Area using 4 radio channels

Continued on the front page F term (reference) 5K028 AA11 BB06 DD01 DD02 LL02 MM12 RR01 5K067 AA11 BB02 CC04 DD34 EE02 EE10 EE54 EE56 EE65 GG01 HH24 JJ03 JJ13 JJ22 JJ52

Claims (4)

[Claims] 1. A method for setting a plurality of radio channels between a base station and a mobile station, the mobile station receiving a control channel transmitted from the base station,
A first step of specifying the area where the mobile station is located, a second step of measuring the electric field strength of the control channel in the first step, and an electric field strength of the control channel measured in the second step. If the threshold value is higher than a preset threshold value, a plurality of wireless channels specified by a control channel transmitted from the base station are set as wireless communication lines between the mobile station and the base station. And a fourth step of setting the wireless communication line by allocating the wireless channel to the mobile station in the base station that has received the report in the third step. A call control method characterized by the above-mentioned. 2. When setting a plurality of radio channels between a base station and a mobile station, the mobile station receives a control channel transmitted from the base station,
A first step of specifying the area where the mobile station is located, a second step of measuring the electric field strength of the control channel in the first step, and an electric field strength of the control channel measured in the second step. If the threshold is higher than a preset threshold, the mobile station searches for a free wireless channel in the service area and its surrounding area and performs wireless communication with the base station in the service area. A third step of determining a channel, the wireless channel determined in the third step, and a plurality of wireless channels designated by a control channel transmitted from the base station, the mobile station and the serving area A fourth step of reporting to the base station that it is to be set as a wireless communication line with the base station, and the base station receiving the report in the fourth step allocates the radio channel to the mobile station. Wireless communication A fifth step of setting a line. 3. The call control method according to claim 1, wherein the plurality of radio channels specified by the control channel include a radio channel uniquely used in each cell, and a radio channel specified by the plurality of cells. A call control method, comprising: a wireless channel to be used. 4. The call control method according to claim 1, wherein the control channel broadcasts to the mobile station all radio channels available at the base station that broadcasts the control channel. A call control method comprising: