JPH1094022A - Partial hand-over control system in mobile communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately control the hand-over of a part of calls among the plural calls in a mobile station capable of handling the plural calls by realizing the activation or end processing of software hand-over for respective communication units. SOLUTION: The plural calls are generated from plural terminals connected to one mobile station 10 and the calls are simultaneously connected to a base station 20 through individual radio channels. Then, for the radio channels, by the management table of the mobile station 10 and the base station 20, a radio channel number corresponding to a call number is managed. That is, by the correspondence of the call number and the radio channel number, the call 1 is connected through the radio channel 1, the call 2 is connected through the radio channel 2 and thereafter, the call 4 is connected through the radio channels 5, 6, 7 and 8 as shown in the figure. Also, the respective calls generated from the respective terminals of the mobile station 10 constitute one communication unit and such a communication unit is not limited to the call.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a partial handover control system in a mobile communication system capable of controlling a handover performed by a part of a plurality of calls in a mobile station capable of handling a plurality of calls. More specifically, a mobile communication system capable of simultaneously connecting a plurality of communication processes including a plurality of calls generated by a plurality of terminals in a mobile station accommodating a plurality of terminals to a base station via separate wireless lines. And a partial handover control method in a mobile communication system for controlling handover of a part of calls.

[0002]

2. Description of the Related Art When one mobile station handles a plurality of calls in a CDMA mobile communication system, more specifically, a plurality of terminals are connected to the mobile station by performing facsimile while performing voice communication in the mobile station. Considering a service configuration in which a terminal can freely perform an outgoing / incoming call connection, when one terminal communicates via a wireless line and the terminal is performing a soft handover, another terminal performs an outgoing / incoming call connection. Is performed, it is preferable to perform a soft handover also on a wireless line for another terminal that is set later by an outgoing / incoming call connection in consideration of a wireless channel capacity aspect. There is no function to perform handover only for some of the multiple wireless lines to be set,
Soft handover cannot be executed for a wireless line set later.

In a situation where a soft handover is triggered for a mobile station that is communicating with a plurality of calls and connections, the handover destination has sufficient space for realizing soft handover of all radio lines. When there is no wireless line capacity or free equipment, it is preferable to perform soft handover only for the wireless line for the idle line on the wireless line capacity. However, in the conventional mobile communication system, handover is performed for a part of the wireless line set by the mobile station. Is not provided, and it is not possible to perform soft handover of a wireless line for an empty line.

[0004]

As described above, in the conventional mobile communication system, handover cannot be performed only for a part of the radio channel set by the mobile station. There is a problem in that it is not possible to execute handover or to perform soft handover of a radio line for a vacant line at the handover destination, thereby reducing the radio channel capacity.

[0005] The present invention has been made in view of the above,
An object of the present invention is to provide a partial handover control method in a mobile communication system capable of appropriately controlling handover of some of a plurality of calls in a mobile station capable of handling a plurality of calls. is there.

[0006]

In order to achieve the above object, the present invention according to claim 1 is connected to a base station via a radio line, accommodates a plurality of terminals, and receives signals from the plurality of terminals. A mobile station that can simultaneously handle a plurality of communication processes including a plurality of calls via separate wireless lines respectively performs a handover in which a mobile station shifts from a cell under the control of the base station to a cell under the control of another base station. A partial handover control method in a mobile communication system to be controlled, wherein the mobile station and the base station each assign an identification number to each of the communication units, and the process for the communication unit to which the identification number is assigned ends. In this case, an identification number allocating release means for releasing an identification number allocated to the communication unit; and a communication unit to which the identification number and the identification number are allocated. Storage means for storing one or a plurality of wireless lines belonging to the same, and when an activation request or termination request for soft handover occurs, the identification number of a communication unit to be soft handed over is stored in a control signal related to soft handover control. The gist of the present invention is to have a soft handover processing means for realizing the activation or termination processing of the soft handover for each communication unit.

According to the first aspect of the present invention, an identification number is assigned to each of the set communication units, and a radio line belonging to the communication unit to which the identification number is assigned corresponds to the identification number. When a request for starting or ending a soft handover is issued for a communication unit to which an identification number is assigned, the identification number of the communication unit is included in a control signal related to soft handover control. On the other hand, transmission / reception is performed between the mobile station and the base station, and the wireless channel is identified from the identification number, thereby activating or terminating the soft handover for each communication unit. Handover can be accurately performed for a part of the wireless channel, and a reduction in the wireless channel capacity can be prevented.

[0008] The present invention according to claim 2 is based on claim 1.
In the invention described in the above, the storage means stores a predetermined identification number designating all communication units set in the mobile station, so that when all communication units simultaneously start or end soft handover, The gist of the present invention is to transmit and receive a predetermined identification number included in the control signal.

According to the second aspect of the present invention, when all communication units simultaneously start or end soft handover, a predetermined identification number is included in a control signal and transmitted / received, so that transmission / reception is performed. It is not necessary to transmit and receive the identification number of each time, and the soft handover process can be performed efficiently.

[0010] Further, the present invention according to claim 3 provides the invention according to claim 1.
In the invention according to the second aspect, the communication unit includes, in addition to a call, a connection in B-ISDN, a communication terminal, uplink / downlink communication, and one wireless line.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a communication situation between a mobile station and a base station in a CDMA mobile communication system implementing a partial handover control method according to an embodiment of the present invention.
As shown in FIG. 1, a plurality of terminals 31, 33, and 35 are accommodated in a mobile station 10, and the mobile station 10 is connected to a base station 20 via a plurality of wireless lines. Then, the first call 1 formed by the outgoing connection from the first terminal 31 or the incoming connection to the first terminal 31 of the plurality of terminals is transmitted from the mobile station 10 to the base station 20 via the wireless line 1. The base station 20 is connected to a terminal (not shown). The second call 2 formed by the outgoing / incoming connection at the second terminal 33 is transmitted to the base station 2 via the wireless line 2.
0, and is connected from the base station 20 to a terminal (not shown).

Similarly, the third terminal 35 generates the third and fourth calls 3 and 4 generated by the outgoing / incoming connection, and the third call 3 is transmitted via the two wireless lines 3 and 4. After being connected to the base station 20 and combining the signals of the two radio lines 3 and 4 at the base station 20, the call is connected to another terminal (not shown) as one call 3. Further, the fourth call 4 is transmitted via the four radio lines 5, 6, 7, and 8 to the base station 20.
After the signals of the four radio channels are combined at the base station 20, it is connected as one call 4 to another terminal (not shown).

As described above, in the CDMA mobile communication system according to the present embodiment, a plurality of calls are generated from a plurality of terminals connected to one mobile station 10, and the plurality of calls respectively use different radio channels. Are simultaneously connected to the base station 20 through the network. However, in this embodiment, in order to manage a plurality of calls and radio lines respectively used by the plurality of calls in correspondence with each other, as shown in FIG. The management table for correspondingly managing the radio line numbers is the
0.

That is, in the management table shown in FIG. 2, according to the correspondence between the call number and the radio line number, call 1 is connected via radio line 1, call 2 is connected via radio line 2, 3 is connected via wireless lines 3 and 4, and call 4 is connected via wireless lines 5, 6, 7, and 8. Note that each call generated from each terminal of the mobile station 10 constitutes one communication unit, and such a communication unit is not limited to a call. For example, a B-ISDN connection, a communication terminal, an uplink / downlink This includes communication, one wireless line, and the like. To identify such a communication unit, a communication unit identification number is used as shown in parentheses instead of the above-mentioned call number in the management table.

Using the management table, various processes performed by each call, for example, processes such as soft handover, are managed by call numbers, that is, communication unit identification numbers.
By referring to the management table based on the communication unit identification number, for example, a radio line to be controlled in response to a call for performing a soft handover process or the like is identified, so that only a corresponding radio line is associated with the process. Is controlled.

As described with reference to FIG. 1, in the process in which a plurality of calls are sequentially generated and processed in one mobile station 10, for example, only the first call 1 from the first terminal 31 is transmitted to the mobile station. In a state where the mobile station 10 is connected to the base station 20 via the wireless line 1 from the base station 20, the mobile station 10 shifts from a cell under the control of the base station 20 to a cell under the control of another base station. Base station 2 from 10 for soft handover
0 and the second terminal 33 starts outgoing / incoming connection under the base station 20 when performing soft handover simultaneously connected to both base stations of another base station which is a soft handover destination, Assuming that a second call 2 from the second terminal 33 is connected from the mobile station 10 to the base station 20 via the radio line 2, the second call 2 also receives a perch channel from another base station. Since the soft handover start condition is satisfied, the mobile station 10 generates a soft handover start request for the second call 2 as well.

Therefore, in order for the second call 2 in such a state to perform the soft handover properly, the second call 2 for performing the soft handover with reference to the management table described above.
The wireless line is identified from the communication unit identification number corresponding to call 2 of the above, and soft handover is performed using the identified wireless line. When a soft handover start request or a soft handover request is issued, the communication unit identification number of the second call 2 for performing the soft handover is included in a control signal related to the control of the soft handover, and the control signal is transmitted to the mobile station. 10 communicates with the base station 20 of the soft handover source and the another base station of the soft handover destination to identify a radio line to be controlled by the soft handover, thereby achieving the activation and termination processing of the soft handover. doing.

Next, referring to FIG. 3, as described above,
When the first call 1 is performing a soft handover from the mobile station 10 to the soft handover source base station 20 and the soft handover destination base station at the same time, the second terminal 33 originates under the base station 20. Incoming connection is started, and the second call 2 from the second terminal 33 performs soft handover from the state where the second call 2 is connected to the base station 20 from the mobile station 10 via the wireless line 2. The operation in the case will be described.

In FIG. 3, the first call 1 is in soft handover with the soft handover source base station 20 and the soft handover destination base station, and the communication unit identification number of the first call 2 is “1”. In this state, the second
Call 2 is originated and terminated at the mobile station 10 and the base station 2
Assume that it is connected to 0. The communication unit identification number of the second call 2 is “2”.

When the second call 2 is thus connected between the mobile station 10 and the base station 20, the second call 2 also receives a perch channel from another base station and starts soft handover activation. Since the condition is satisfied, a soft handover activation request is also generated in the mobile station 10 for the second call 2, so that the mobile station 10 includes the communication unit identification number “2” of the second call 2. A soft handover start signal is generated, and the start signal is notified to the base station 20 via the radio line 2, thereby notifying the base station 20 that the second call 2 is to be soft handed over.

When the base station 20 receives the soft handover activation signal including the communication unit identification number “2” from the mobile station 10, the second call 2 is transmitted from the communication unit identification number “2” included in the activation signal. It recognizes that soft handover will be performed, and notifies the activation signal to the soft handover destination base station. The soft handover destination base station is
Upon receiving the soft handover activation signal, the mobile station 10 selects a spreading code and a frequency to be used for a radio channel with the mobile station 10 and transmits a downlink radio channel to the mobile station 10. Also,
The soft handover destination base station transmits the selected spreading code and the communication unit identification number “2” or the like indicating the second call 2 to the radio line designation signal and transmits the soft handover destination base station 20 to the soft handover source base station 20. The soft handover source base station 20 transmits the radio channel designation signal to the mobile station 10.

The mobile station 10 receives the downlink radio channel, establishes synchronization, and then starts transmission on the uplink radio channel.
When the mobile station starts transmission on the uplink radio channel, the soft handover destination base station establishes synchronization of the uplink radio channel,
A notification of the completion of the wireless channel setup having the communication unit identification number "2" is sent to the soft handover source base station 20, whereby the second call 2 enters a soft handover state between the mobile station 10 and both base stations. Although the above processing is an explanation of the soft handover activation processing, it goes without saying that the soft handover termination processing can be similarly performed for each communication unit by including the communication unit identification number in the control signal. .

As described above, when a plurality of calls are generated in a mobile station and each of the plurality of calls is connected to a base station using a different radio line, only some of the calls are individually connected. When starting or ending soft handover using the wireless line of the above, the call for performing the process is identified by the communication unit identification number, and the wireless line used for this call is identified in the management table by the communication unit. The mobile handset and the base station respectively manage the communication number in accordance with the identification number, and the communication unit identification number is included in a control signal related to the control of the processing and transmitted. Start-up processing or termination processing can be performed accurately.

In the above embodiment, as shown in FIG. 1, when a plurality of calls from a plurality of terminals accommodated in the mobile station 10 are communicating using a plurality of different radio lines, Although the processing in the case where only some of the calls initiate or terminate the soft handover is described, not only some of the calls but also all the calls generated in the mobile station 10, that is, first to third in FIG. In preparation for the case where all of the fourth calls simultaneously activate or terminate the soft handover, a value indicating this is pre-assigned as an overall identification number, and this overall identification number is included in a control signal related to the soft handover control and transmitted and received. By doing
It is not necessary to set a plurality of communication unit identification numbers corresponding to all calls in the control signal, and the configuration of the control signal and the transmission and reception of the control signal can be simplified. As the overall identification number indicating all such calls, for example, “0” other than the above-mentioned call numbers 1, 2, 3,... Can be used.

Then, for example, as shown in FIG.
When a soft handover start trigger occurs in the mobile station 10 handling the fourth call 1, 2, 3, 4, the mobile station 10
In order to perform soft handover for all calls 1, 2, 3, and 4 handled by the above, the overall identification number for designating all calls is set in a control signal relating to the soft handover control, and the overall identification number is set. The control signal is transmitted to the mobile station 10
To the soft handover source base station 20, and further from the soft handover source base station 20 to the soft handover destination base station, whereby all calls 1, 2, 3, 4 handled by the mobile station 10 are performed as shown in FIG. The soft handover can be performed as described above.

As described above, when all of the calls 1, 2, 3, and 4 handled by the mobile station 10 are to be soft handed over, only the calls 1, 2, 3, and 4 are soft handed over. In some cases, there is no available wireless channel capacity in the soft handover destination base station, and there is only an idle wireless channel capable of performing soft handover of only some calls. For example, in order to perform the soft handover for all of the above-mentioned calls 1, 2, 3, and 4, as shown in FIG. 1, the soft handover destination base station needs eight empty radio lines. Suppose that there are only two free wireless lines. In such a case, the conventional mobile communication system does not have a function of performing a soft handover for a part of the wireless line set by the mobile station. It was not possible to make soft handover only for the radio lines for the number of vacancies,
In this embodiment, the above-mentioned communication unit identification number is assigned for each call, and the radio line number used corresponding to the communication unit identification number is stored and managed as a management table. By associating the number of idle wireless lines with the wireless line stored in the management table corresponding to the communication unit identification number, the soft handover destination base station can perform a soft handover from the number of idle wireless lines based on the number of idle wireless lines. Is specified, and only the communication unit identification number for the call is retransmitted instead of the overall communication unit identification number, so that only the specified call can be soft handed over.

Specifically, as described above, if it is assumed that there are only two free wireless channels in the soft handover destination base station, the two free wireless channels correspond to the wireless channels in the management table. The first and second calls 1 and 2 using the lines 1 and 2 respectively or the third call 3 using the wireless lines 3 and 4 at the same time can be selected. However, since the third call 3 is associated with the fourth call 4 at the third terminal 35, the first and second calls 1 and 2 are selected for the time being, and these calls 1 and 2 are selected. , 2 are connected to the soft handover destination base station at the soft handover destination base station using an empty radio line, so that only the first and second calls 1 and 2 can be soft handed over.

Although there is no free radio channel capacity in the soft handover destination base station enough to soft handover all calls handled by the mobile station 10, there is less free radio channel capacity in the soft handover destination base station. In this case, the selection of which call is to be soft handed over is arbitrary. For example, the call may be selected in the order of the oldest connection or in the order of the most calls.

[0030]

As described above, according to the present invention,
Assigning an identification number to each of the set communication units, storing and managing a wireless line belonging to the communication unit to which the identification number is assigned in a management table corresponding to the identification number,
When a soft handover activation request or a termination request is issued for a communication unit to which an identification number is assigned, the identification number of the communication unit is included in a control signal related to soft handover control, so that a communication between the mobile station and the base station is performed. Since the wireless line is identified from the identification number and the process of activating or terminating the soft handover is achieved for each communication unit, it is set corresponding to a plurality of calls generated in the mobile station. Handover can be performed accurately even for only a part of a plurality of radio channels, preventing a reduction in radio channel capacity, and when the free radio channel capacity in the soft handover destination base station is small. Also, only a part of the calls corresponding to the number of available wireless lines can be soft handed over.

Further, according to the present invention, when all communication units simultaneously activate or terminate soft handover, a predetermined identification number indicating that all communication units are simultaneously processed is included in the control signal for transmission / reception. By doing so, it is not necessary to transmit and receive the identification number for each communication unit, and the soft handover process can be performed efficiently.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a communication situation between a mobile station and a base station in a CDMA mobile communication system that implements a partial handover control method according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a management table indicating correspondence between call numbers (communication unit identification numbers) and wireless line numbers used in the embodiment of FIG. 1;

FIG. 3 is a diagram showing a soft handover processing sequence in the embodiment of FIG. 1;

[Explanation of symbols]

 1-8 Wireless link 10 Mobile station 20 Base station 31-35 Communication unit

Claims (3)

[Claims] 1. A communication system connected to a base station via a wireless line, accommodating a plurality of terminals, and simultaneously performing a plurality of communication processes including a plurality of calls from the plurality of terminals via separate wireless lines. A partial handover control method in a mobile communication system for controlling handover in which a mobile station that can be handled shifts from a cell under the control of the base station to a cell under the control of another base station, wherein the mobile station and the base station Assigns an identification number to each of the communication units, and releases the identification number assigned to the communication unit when the processing for the communication unit to which the identification number is assigned ends. Opening means, and storage means for storing the identification number and one or more wireless lines belonging to the communication unit to which the identification number is assigned, in a corresponding manner When the start request or termination request soft handover occurs, it is included in the control signal associated with the identification number of the communication unit to be soft handover the soft handover control,
A soft handover processing means for realizing a soft handover activation or termination process for each communication unit. 2. The storage means stores a predetermined identification number designating all communication units set in the mobile station, so that when all communication units start or end soft handover simultaneously, The partial handover control method in a mobile communication system according to claim 1, wherein transmission and reception are performed by including a predetermined identification number in the control signal. 3. The communication unit may be a B-ISD other than a call.
N, communication terminal, uplink / downlink communication,
3. A partial handover control system in a mobile communication system according to claim 1, wherein the system includes one radio line.