JP2845307B2 - Channel switching method during mobile communication - Google Patents

Abstract

PURPOSE:To facilitate communication consecution (channel switching) processing through a common control channel of a transfer destination zone. CONSTITUTION:When communication through a base station 121 of a zone 111 is started, a resident zone number and a call management number of a base are sent to a mobile station 13 and the mobile station 13 receives and stores the numbers. The mobile station 13 enters a zone 112 and a common control channel is used to make re-connection request. In this case, the stored zone number and call management number are added. A controller 172 receiving them through a base station 122 recognizes a controller 171 of an original zone 111 before switching and informs a channel switching request with a call management number added thereto to the controller 171. The controller 171 makes a channel switching request to an exchange 15 based on the call management number. The succeeding processing is similar to that of usual channel switching. It is not required to read sequentially a call management table to seek a call management number corresponding to the mobile station number.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a mobile communication system such as a car telephone, a portable telephone, a cordless telephone, etc., and a service area is constituted by a plurality of zones. The present invention relates to a communication channel switching method of mobile communication in which a communication channel is switched by transmitting and receiving a control signal to and from a switching destination base station.

[0002]

2. Description of the Related Art In a conventional FDMA system mobile phone,
When communication is going to be difficult due to crossing the zone boundary during communication, the base station requests channel switching using the communication channel in use, and the base side adjusts the reception level of radio waves from the mobile station. The zone is detected, the destination zone is determined, a free communication channel in the zone is searched, and this is notified to the mobile station to switch to the new communication channel. The communication channel switching may fail, or the wireless channel may be disconnected before performing the channel switching during communication due to the rapid deterioration of the quality of the wireless channel.In this case, the mobile phone may need to make a call again. I needed to.

On the other hand, in the conventional office cordless telephone system, when a mobile terminal shifts a zone during communication and switches base stations to communicate with, a control signal is transmitted and received on a control channel of a switching destination zone. Accordingly, a method is adopted in which a communication channel of the switching destination zone is designated to the mobile terminal and communication is continued. In this switching, a request signal for continuing communication on the control channel of the switching destination zone is transmitted from the mobile terminal to the base station device together with a number (mobile terminal number) identifying the mobile terminal.
The mobile terminal number is searched from the management table managing the call in communication, the line of the old base station is specified based on the information in the management table, the old line is switched to the switching destination line, and the mobile terminal is switched. By specifying a wireless channel for communication corresponding to the new line. The base station assigns a call management number to the call each time a call is generated, and information necessary for the call processing, a mobile terminal number, a zone number in the serving area, and a partner terminal number in the call management table for each call management number. Others are stored.

[0004]

When a channel switching request is made in the office cordless telephone system, the mobile terminal number is sequentially read out from each call management number in the call management table, and the mobile terminal number is searched for. The information necessary for the call processing obtained is obtained because the information of the old line is obtained. Therefore, generally, the search processing has a large amount of processing, has a disadvantage in that the control ability is squeezed, and the processing takes time. This method can be used with a relatively small system such as a cordless telephone system at a business office. Since the number of calls is large, it is difficult to specify the old line in the search processing.

[0005] In addition, due to the system configuration, it is common that control devices for managing communication calls are distributed and arranged, and it is necessary to search for such control devices, and an old line is specified by a search process. In general, it is difficult to perform communication continuation (switching the channel during communication) by the conventional method using the control channel of the movement destination zone due to switching failure due to processing power and processing time. There is.

An object of the present invention is to provide a method for switching channels during communication triggered by access to a control channel of a switching destination zone, which can be easily applied to a relatively large-scale mobile communication system. .

[0007]

According to the present invention, when a communication channel is set, a number required for specifying a zone in communication and a call management number used for call control on the base side. And the corresponding number are transmitted from the base station to the mobile station as call management information, and the mobile station receives and stores this call management information, and when the mobile station switches the channel during communication, the mobile station performs switching on the control channel of the switching destination. The stored information is added to the requested signal and transmitted, and the base station performs channel switching based on the received call management information.

[0008]

1A shows a mobile communication system to which the present invention is applied.
Here is an example of a system. Multiple zones 11₁, 11_Two, …… to
The service area is composed of
Base station 12₁, 12_Two, …… are provided and within that zone
So that it can communicate with the mobile station 13 that moves
Have been. Each base station 12₁, 12_Two, …… are communication lines
14₁, 14_Two, ..., connected to the switching device 15
The switching device 15 communicates with the network 16 through communication lines and controls.
Connected through your line. In addition, each base station 12₁,
12_Two,... Are control devices 17 respectively.₁, 17_Two, ……
And control line 18 ₁, 18_Two, ……, connected via
Control device 17₁, 17_Two, …… are exchanged through a control
15 is connected. Control device 17₁, 17_Two,…
… Are provided with a call management table 19, respectively.
Each time a call is made, a call control number is assigned to the call.
Call information (calling terminal required for call processing) for each call management number
Number, called terminal number, visited zone number,
Etc.) are stored. Similarly, the exchange device 15
A call management table 21 is provided for each service or control device.
Have been. In the call management tables 19 and 21, the same call management number
The call information has the same content for
There is also management information that differs depending on the processing and control. On the base side
Is a control device, and the switching device performs call processing using the call management number.

[0009] As shown in FIG.
5, a control unit 26, and an information storage unit 27.
Next, the operation of the embodiment of the present invention will be described with reference to FIGS. When mobile station 13 enters a state of communicating through the base station 12 _1, the control unit 17 ₁ that controls the base station 12 ₁ in this invention, for identifying the communication call between the exchange unit 15 The call management number and the zone number where the mobile station 13 is located are transmitted to the mobile station 13 as call management information. The mobile station 13 receives the call management information by the radio unit 25, extracts the call management number and the zone number by the control unit 26, and stores them in the information storage unit 27. Here, the call management number is, as described above, the information about the call in the call management tables 19 and 21 in the control device 17 _i (i = 1, 2,...) And the switching device 15 using the number as an address. There are various methods, such as a method of assigning a number that can be accessed each time a communication call occurs and a method of substituting the number with a telephone line number. The present invention can be applied to any of these methods.

[0010] The base station 12 the mobile station 13 from the base station 12 _{1
If 2} is moved to the zone 11 ₂ covering, in the channel switching general communication will be carried out switch to specify a switching destination of the radio channel in transmission and reception of signals between the base station 12 _1, common channel switch The present invention is applied to a case in which the wireless channel is cut off before performing general communication channel switching due to a rapid wireless channel quality deterioration. That is, common channel switch to or failure, due to rapid radio channel quality degradation, when the communication with the base station 12 ₁ becomes impossible, the mobile station 13, similar to the frequency scan carried out at normal standby state operation by selecting communicable zone 11 _2. Base station 12 covering the zone 11 _2
2 , a reconnection request signal including the mobile station number is transmitted using the common control channel.
Configure the zone number and the call control number to the information storage unit 27 are stored in the control unit 26 signal added to the reconnection request signal, and transmits the radio unit 25 to the base station 12 _2. Base station 12 ₂ controller 17 ₂ which has received the reconnection request signal via the reconnection request signal to the added switching source of the call control number, to obtain a zone number. Since this enables specific switching source zone, the control unit 17 ₁ that controls the base station 12 ₁ that covers the zone 11 _1, the request signal for starting the channel switching, with a call control number transmission I do. In the switching source controller 17 _1, so informed to call control number, it performed substantially the same signal exchange between communicating channel switching in general between the switching device 15, i.e. for the mobile station 13 in the zone 11 ₂ set the communication channel, which notifies the control unit 17 _2, the control device 17 ₂ base station 1 starts the radio corresponding to the channel of the base station 12 _2, also to the mobile station 13
By 2 ₂ specifies the radio channel for communication,
Base station 12 ₂ and the mobile station 13 moves to a state of communicating and releases the communication line of the base station 12 _1.

As described above, according to the present invention, the mobile station carries around the switching source zone number and the call management number of the controlling device, and sends this to the base station via the control channel when a channel switching request is made. On the base side, call information can be easily known without successively reading and searching each management number in the call management table, and no search processing of the old line is required, and communication with the base station of the switching source becomes impossible. In this case, channel switching can be realized by simple processing.

[0012] In the sequence shown in FIG. 2, a sequence after sending a channel switch start control unit 17 ₁ is substantially the same as the common channel switching, base station transmitting the radio channel set signal is generally in the channel switching, while a switching source base station 12 _1, in this embodiment, it is possible to point at which the switching destination base station 12 ₂ is different only. In realizing a system having a plurality of channel switching procedures of reconnection-type channel switching in addition to general channel switching, since the procedures are similar, it is possible to share processing, and the system The complexity can be avoided.

In the above description, an example has been described in which the call management number is directly added to the signal transmitted and received between the control device and the switching device. However, the number table is obtained by the call management number to obtain the address of the call management table, and the address is obtained by the address. There are various methods such as access to call information. In this case, instead of the call management number stored in the mobile station 13, the number table obtained by referring to the number table used in the internal processing of the control device or the switching device is obtained. An address (number) or the like may be sent to the mobile station instead of the call management number and stored. That is, the number corresponding to the call management number may be stored in the mobile station. Further, even when the control device and the switching device are configured as one device, the management number used in the internal processing may be treated as the call management number.

Although the description has been given of the example in which the control device controls one zone and one base station, a case where one control device controls a plurality of base stations and one base station has a plurality of zones is also described. The present invention can be applied by providing a call management table for each zone. Since the zone number is a number that can specify the zone in the service area, the number of the switching device or the number of the control device may be given as necessary. If the call management is collectively managed for each device, the zone number may be interpreted as a device number. In short, it is sufficient to send a number capable of specifying the zone in which the zone is located to the mobile station and store it.

[0015] The type of wireless channel is different in transmission speed,
When there are a plurality of channels, such as facsimile-only and call-only, when selecting a wireless channel after a reconnection request, it is necessary to select the same type of channel as before switching. The information on the type of the radio channel used is usually included in the call information in the call management table. However, the information on the type of the radio channel, that is, the information on the line in use is added to the mobile station together with the call management number. , Without waiting for access to the switching source control device,
When information is obtained from the mobile station, it is possible to proceed to the process of selecting a channel.

Although the case where the mobile station moves and shifts to a zone has been described, the present invention can be applied to a case where interference is detected and channels are switched within the same zone in order to avoid the interference.

[0017]

As described above, according to the present invention, the mobile station carries a number that can specify the zone number of the switching source and a number corresponding to the call management number in the controlling device that controls the mobile station. At the time of channel switching request, these zone numbers and call management numbers can be easily known,
There is an effect that channel switching can be realized even in a case where communication with the switching source base station becomes impossible by simple processing without the need to search for the old line.

[Brief description of the drawings]

FIG. 1A is a block diagram illustrating a configuration of a mobile communication system to which an embodiment of the present invention is applied, and FIG. 1B is a block diagram illustrating a configuration of a mobile station.

FIG. 2 is a diagram showing an example of a control sequence in the embodiment of the present invention.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Katsumi Kobayashi Inventor NTT Mobile Communication Network Co., Ltd. 2-1-1 Toranomon, Minato-ku, Tokyo (56) References JP-A-5-218953 (JP) , A) (58) Field surveyed (Int. Cl. ⁶ , DB name) H04B 7/24-7/26 H04Q 7/00-7/38

Claims (2)

(57) [Claims] A mobile station comprising a service area composed of a plurality of zones, and when a mobile station switches a communication zone during communication, the mobile station exchanges a control signal with a base station of a switching destination zone to switch a communication channel. In the communication switching method, after setting the communication channel, the number corresponding to the number of the zone being communicated and the number corresponding to the call management number used for call control at the base side are used as call management information. Notify the mobile station from the base station, receive and store the call management information at the mobile station, and when requesting channel switching, the mobile station adds the stored call management information to the request and sends the request to the base station. transmitted, the base station receives the received channel switching request, the communication in the channel cutting of mobile communication, characterized by carrying out the channel switching based on said call control information For example method. 2. The system according to claim 1, wherein information on a used line is added to said call management information, and information on the used line in said call management information is used when selecting a channel. The method for switching a channel during communication of the mobile communication described in the above.