JPH09149450A - In-communication channel switching method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To switch channels across exchange stations without making a mobile station hold routing information to the exchange station of a switching source. SOLUTION: An optional exchange station previously stores positional information of a mobile station being information capable of connecting to the exchange station 6 of a traveling source in a storage device. Then when the exchange station receives a channel switching request signal from the mobile station communicating in the radio zone of a base station connected to a different exchange station, the exchange station obtains positional information of the mobile station from this storage device and transmits the channel switching request signal to the exchange station 6 of a traveling source. Then the exchange station 6 of the traveling source executes channel switching to the exchange station of the traveling destination based on the received channel switching request signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication channel switching method suitable for a mobile communication system having a minimum zone configuration, and in particular, switching is performed even if the mobile station does not have routing information to the switching source switching station. The present invention relates to a communication channel switching method capable of switching channels between stations.

[0002]

2. Description of the Related Art In a conventional mobile station, when performing channel switching across switching stations during communication, the mobile station receives information from the switching station that the mobile station can connect to the switching source switching station in advance, It was necessary to always store information on the switching center being connected. FIG. 12 is a configuration diagram of a conventional mobile communication system. In FIG. 12, 3 is a mobile station, 1
Is a wireless zone in which the mobile station 3 is currently communicating (old wireless zone), 2 is a wireless zone in which the mobile station 3 is moving (new wireless zone), 4 is a base station to which the old wireless zone 1 belongs, and 5 is a new wireless zone. The base station to which the zone belongs, 6 is an exchange station connected to the base station 4, 7 is an exchange station connected to the base station 5, 8 is a communication line connected between the base stations 4 and 6, and 9 is A communication line connected between the base station 5 and the switching center 7, 10 is a communication network connecting the switching center 6 and the switching center 7, 13 is a partner subscriber with which the mobile station 3 is communicating, and fixed communication This includes general subscribers of the network and mobile stations of mobile communication systems. 11
Is a communication line connected to the other subscriber via the exchange 6 and the fixed communication network or the mobile communication network. Mobile station 3
And the other subscriber 13 are in a call, the mobile station 3 has a wireless zone 1 belonging to the base station 4 to a wireless zone 2 belonging to the base station 5.
Consider the operation when switching from the old zone 1 to the new zone 2 when shifting to. The mobile station 3 and the other subscriber 13
Calls to and from the other subscriber 13 to the communication line 11 to the exchange 6
-It is performed by the route of the communication line 8-the base station 4-the mobile station 3.

FIG. 13 is a sequence chart showing the procedure of the conventional communication channel switching method in FIG. As shown in FIG. 13, the in-communication channel switching operation includes S1 (communication level deterioration detection processing step), S2 (channel hold timer setting processing step), S3 (base station 5 selecting processing step), and S4 ( Channel switch request processing step), S5 (Channel switch control exchange 6 determination step S6 (Channel switch server request processing step), S7
(Processing process for channel switching determination), S8 (processing process for executing channel switching), S9 (processing process for response), and S10 (processing process for disconnection recovery). When the mobile station 3 moves away from the base station 4 and approaches the base station 5 in the adjacent zone while communicating with the other subscriber 13 via the base station 4 and the exchange 6, the reception level of the communication signal from the base station 4 Is coming down. The mobile station 3 constantly or periodically monitors the reception level during communication, and when this level drops below a certain value, the mobile station 3 detects that fact and shifts to the communication channel switching operation (the above is the processing step S1. ). Next, the base station 4 sets a timer for immediately holding the communication channel for a certain period of time without disconnecting the communication channel even if the reception level is lowered to the extent that communication becomes impossible because the mobile station 3 has moved to the new wireless zone 2. (Processing step S2). Next, the mobile station 3 receives a signal from another base station, and recognizes the base station 5 approaching itself based on the level of the signal (processing step S3).

Next, in process step S4, the mobile station 3 transmits a channel switching request signal to the new base station 5. This signal includes a mobile station identification number and routing information to the switching source switching station (here, position information of the switching center 6). Next, the switching center 7 receives the channel switching request signal and recognizes the old switching center 6 from the routing information for the switching source switching center included in it (processing step S5). next,
In the processing step S6, the channel switching request signal is transferred from the exchange 7 to the old exchange 6. This includes the mobile station identification number and routing information. Next, when the switching center 6 in communication receives the channel switching request signal, it determines whether or not the channel switching is possible (processing step S
7) If possible, the communication line connected to the old base station 4 is switched to the new exchange 7 (process step S8). When the old exchange 6 completes the switching, it notifies the new exchange 7 of that fact, and when the new exchange 7 receives this signal, it transmits a response signal to the mobile station 3 (processing step S9).
As a result, the communication line is connected through the route of the mobile station 3, the new base station 5, the new exchange station 7, the old exchange station 6 and the partner subscriber 13,
Channel switching is completed and the call continues.
Finally, in process step S10, the exchange 6 instructs the old base station 4 to disconnect in order to restore the old wireless channel.

[0005]

As described above, in the conventional channel switching method during communication, the mobile station has previously received information from the old exchange station so that the mobile station can connect to the exchange station of the switching source, and the information is transmitted to the channel switch request signal. There is a problem in that it is necessary to transmit the information including this information, and therefore the mobile station must always store the position information of the exchange station to which it is connected. It is an object of the present invention to solve such a conventional problem and to perform channel switching across switching centers even if the mobile station does not have routing information for the switching source switching center. It is to provide a medium channel switching method.

[0006]

In order to achieve the above object, in the communicating channel switching method of the present invention, when the switching center receives the channel switching request signal, the switching center is in communication within its own switching center and the communication device. If it is determined to be a channel switching request signal from, the channel in communication is switched to the channel connected to the communication device, and if it is determined to be a channel switching request signal from another switching center,
Switch the channel in communication to the channel connected to another exchange. When the exchange receives the channel switching request signal, it determines whether the communication device is communicating within its own exchange, and if it is not communicating within its own exchange, it receives the location information of that communication device from the storage device. By transmitting a channel switching request signal to the channel switching source switching center, a response is received from the switching center, a response signal is transmitted to the communication device, and the communication device and the channel switching source switching center are connected. When the communication device is communicating with a switching center B other than the switching center A to which it is connected, the communication device transmits a channel switching request signal to the switching center A, and the switching center A receiving this signal stores the position information of the communication device. Requests the device, acquires it, and the switching source switching center B
To the switching destination switching center B, and the switching source switching center B switches the channel in communication to the channel of the communication line connected to the switching destination switching center A, and sends a switching completion report to the switching destination switching center A. Then, the switching destination switching center A, upon receiving it, connects the channel of the communication line from the switching source switching center B and the channel connected to the communication device, and continues the communication. When the mobile station detects that the signal reception level from the base station located in the wireless zone in communication has deteriorated, it determines that it has moved from the wireless zone in communication to the adjacent wireless zone, A channel switching request signal is transmitted to the device.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, when a certain exchange station receives a channel switching request signal from a mobile station communicating in a radio zone of a base station connected to a different exchange station, the transition is made. The location information of the mobile station, which is the information that can connect to the original switching center, is acquired from the storage device, the channel switching signal is sent to the switching center of the migration source, and the switching center of the migration source transfers the channel based on the received channel switching signal. Channel switching to the switching center of. The destination exchange is
Since the routing information for the source switching center is obtained from the storage device in the form of the position information of the mobile station, the exchange can be performed even if the mobile station does not hold the information for connecting from the source switching center to the source switching center. Channel switching can be performed across stations.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a configuration diagram of a communication system showing a first embodiment of the present invention. In FIG. 1, 6 is an exchange,
Reference numerals 8 and 9 are communication lines connected between a communication device (for example, a mobile station) and the exchange 6, and 12 is a storage device that stores position information of the communication device. This position information is routing information to a communicable exchange or communication line necessary for receiving an incoming call to the communication device, and is always stored in advance in the storage device 12 by the communication device. Note 1 in Figure 1
Is the switch operation in the case of channel switching within the own exchange station, and Note 2 is the switch operation in the case of channel switching at another exchange station. FIG. 2 is a sequence chart showing a communication channel switching procedure in FIG. FIG.
Then, it is divided into an operation when the communication device requesting the channel switching of Note 1 is in communication with the local exchange and an operation when the communication device requesting the channel switching of Note 2 is not in communication with the local exchange. In the former case, the processing step S41,
It consists of the operations of S51, S8, S9, and S10. In the latter case, the processing steps S41, S51, S52, S5 are performed.
3, S5, S6, and S10. The numbers are skipped in order to match the numbers of the same processing steps in FIG. 13, and it means that the processing steps can be realized with fewer processing steps than before.

In the processing step S41, the communication device 3 operates the exchange 6
Is a step of transmitting a channel switching request signal to the. This signal contains the communication device identification number.
The processing step S51 is a processing step in which the exchange 6 receives the channel switching request signal and determines whether or not the communication device 3 specified by the communication device identification signal is already communicating with the exchange 6. When the communication is already in progress, the exchange 6 executes the channel switching according to the channel switching request signal (processing step S8), and transmits the response signal to the communication device 3 (processing step S9). Then, the communication is continued by the channel of the switching destination. Finally, the switching center 6 restores the disconnection of the switching source channel (processing step S10). On the other hand, in the process step S51, if the communication device 3 specified by the communication device identification number included in the channel switching request signal is not in communication at the exchange 6, the process shifts to Note 2, and the exchange 6 does not It is determined that the signal is a channel switching request signal from the communication device 3 that is in communication at the exchange, and a request for position information of the communication device identification number is transmitted to the storage device 12 (processing step S52). Next, the exchange 6 receives the response of the position information of the communication device 3 from the storage device 12 (processing step S53),
Determine the switching station from which the channel is switched (process step S
5). Then, a channel switching request signal is transmitted to the switching source switching center via the communication network 10 (processing step S
6), the response signal is received (process step S10). According to the result included in the response signal, if the switching is OK,
The communication device 3 and the communication network 10 are connected.

FIG. 3 is a flow chart showing the operating procedure of the switching center in FIG. 1 for carrying out the present invention. Here, the operation after receiving the channel switching request signal in the processing step S41 is shown. Processing steps S41, S5, S6,
S8 is the same number as in FIG. First, the processing step S2
At 0, when the channel switching request signal is received, it is determined whether the communication device is in communication. This is shown in FIG.
This is an operation corresponding to the processing step S51. In particular,
The switching center always stores the communication state for the communication device identification number in the communication management memory 40, and searches the memory 40 based on the communication device identification number included in the channel switching request signal. Then, when it is recognized that this communication device is using the communication channel, the process proceeds to the processing step S8 for executing the channel switching. On the other hand, when the communication channel is not being used, it is determined that the channel is switched to another switching center, and the process proceeds to processing step S30 for receiving the position information of the communication device. That is, at the exchange,
Identify whether or not channel switching is in the local exchange, switch channels within the local exchange if channel switching is in the local exchange, and receive routing information to the transfer source if it is not the local exchange. To control. Processing step S30
Then, this is a process of receiving the position information of the communication device from the storage device 12, and corresponds to the processing steps S52 and S53 in FIG. Specifically, the storage device 12 is searched based on the communication device identification number included in the channel switching request signal, the routing information for the transfer source is received, and the process proceeds to the processing step S5 for determining the transfer source switching center. To do. According to the present embodiment, the communication device transmits the channel switching request signal to the switching station that executes the channel switching, even if the channel switching request signal does not include the routing information for the switching source or switching destination. Can be performed (processing step S6).

FIG. 4 is a block diagram of a communication system showing a second embodiment of the present invention, and FIG. 5 is a sequence chart showing a channel switching procedure during communication in FIG.
As shown in FIG. 5, in this embodiment, the processing steps are divided into Note 1 and Note 2, the former being the operation when a channel switching signal is received from under the control of the local exchange, and the latter being the channel from the communication network. This is the operation when the switching signal is received. Therefore, as shown in FIG. 4, the channel switching in the switching center switches the connection between the partner subscriber 13 and the communication line 9 as shown by the first arrow if requested by the switching center. If the request is from the communication network, connection switching between the partner subscriber 13 and the communication network is performed as indicated by the second arrow. First, the operation when a channel switching signal is received from under the control of the own exchange will be described. First, in process step 41, the communication device 3 transmits a channel switching request signal to the exchange 6. This signal includes the communication device identification number. When receiving the channel switching request from the communication device 3, the exchange 6 determines whether or not the communication device 3 is already communicating with the exchange 6 (processing step S51). When the communication is already in progress, the switching center 6 switches the channel according to the channel switching request signal (processing step S8) and transmits a response signal to the communication device 3 (processing step S9). And
Communication is continued by the channel of the switching destination. Finally, in process step S10, the switching center disconnects and restores the channel that is the switching source. Next, the operation when a channel switching request signal is received from the communication network 10 will be described. The processing step S6 is a step of transmitting a channel switching request signal from the communication network 10 to the exchange 6. This signal includes the communication device identification number and the routing information to the switching center of the switching source (here, the position information of the switching center 6). At exchange 6,
According to the communication device identification number included in the signal, it is determined whether or not this communication device is in communication at the exchange 6 (processing step S7). When the communication is in progress, the switching center 6 switches the channel currently connected to the own switching center to the line to the communication network 10 according to the channel switching request signal (processing step S8), A response signal is transmitted (processing step S9). Finally, in the processing step S10, the exchange 6
Disconnects and restores the switching source channel.

FIG. 6 is a flow chart showing the operating procedure of the switching center for executing the second embodiment. The operation after receiving the channel switching request signal in the processing step S41 or S6 is shown. Processing steps S41, S6, S8, S10
Is the number of the same operation in FIG. The processing step S20 is the same as the operation of the first embodiment. In the processing step S50, it is determined whether the transmission source of the channel switching request signal is under the control of the own exchange or from the communication network. This corresponds to the processing steps S51 and S7 in FIG. Whether it is under the control of the own exchange or from the communication network, the process proceeds to the processing step S20. The switching center always stores the communication state for the communication device identification number in the communication management memory 40, and based on the communication device identification number included in the channel switching request signal,
This memory 40 is searched. This operation is the same as in the first embodiment. In the case of a request from the subordinate switching station, channel switching is executed in process step S8. In the case of a request from the communication network, in process step S60, the channel connected between the other subscriber and the communication device under the control of the own exchange is changed to the channel connected to another exchange through the communication network. Switch. This is a process corresponding to the process step S8 in FIG. Then, the process proceeds to the processing step S10 after switching, and the response is transmitted. As described above, according to the present embodiment, communication is not cut off regardless of whether the transmission source of the channel switching request signal is a communication device under its own switching center or another switching center via the communication network 10. Channel switching can be performed.

FIG. 7 is a block diagram of a communication system showing a third embodiment of the present invention, and FIG. 8 is a sequence chart showing a channel switching procedure during communication in FIG.
In FIG. 7, a switching center 6 is a channel switching source switching center, and a switching center 7 is a switching center which has received a channel switching request signal from a communication device. The exchanges 6 and 7 are exchanges having the functions of the first and second embodiments. In FIG. 7 as well, since the storage device 12 is connected to the exchange station 7 and the location information of the mobile station is stored therein, the mobile station connects from the source exchange station to the destination exchange station. You don't have to keep information about. In FIG. 8, a processing step S41
Then, the communication device 3 transmits a channel switching request signal to the exchange 7. Next, in processing step S51, the exchange 7 receives the channel switching request signal, and determines whether or not the communication device identified by the communication device identification number is already communicating with the exchange 7. If this communication device 3 is not in communication with the exchange 7, the exchange 7 determines that it is a channel switching request signal of a communication device in communication with another exchange,
A request for the position information of the communication device is transmitted to the storage device 12 (processing step S52). When the location information of the communication device is sent from the storage device 12, the exchange 7 receives it (process step S53) and determines the exchange station of the channel switching source (process step S5). In the case of FIG. 7, since the switching center of the channel switching source is the switching center 6, the channel switching request signal is transmitted to this switching center 6 (process step S6).
When the exchange 6 receives the channel switching request signal,
The communication device specified by the communication device identification number is the exchange 6.
Then, it is determined whether or not communication is in progress (processing step S7). If the result of determination is that communication is in progress, the switching center 6 switches the channel currently connected under its own switching center to the line to the switching center 7 according to the channel switching request signal (processing step S
8) Then, a response signal is transmitted to the exchange 7 (processing step S9). If the result of the response signal is OK, the exchange 7 connects the line from the communication device 3 to the exchange 6. Finally, in process step S10, the switching center 6 restores disconnection of the switching source channel.

FIG. 9 shows an exchange station 6 according to the third embodiment.
7 is a flowchart showing an operation procedure of No. 7. here,
This is an operation after the processing steps S41 and S6 of receiving a channel switching request signal from the communication device 3 or another switching center. Each processing step is the same as the processing shown in the first and second embodiments. That is, S20, S8, S30, S
5 and S6 are the same as those in the first embodiment, and S50,
The processing of S20, S8, S60 and S10 is the same as that of the second embodiment. That is, the third embodiment corresponds to the case where the first and second embodiments are combined. According to the third embodiment, even if the communication device does not include the routing information for the source or destination switching center in the channel switching request signal, it does not disconnect the communication regardless of whether it is in the switching center or between the switching centers. , Channel switching can be performed.
Further, in the description of the embodiment, the channel switching request from the switching center 7 to the switching center 6 involves the connection of the line.
The channel switching can be realized even if the line connection processing between the exchanges is newly performed after receiving the channel switching request and its response.

FIG. 10 is a block diagram of a communication system showing a fourth embodiment of the present invention, and FIG. 11 is a sequence chart showing a channel switching procedure during communication in FIG. As apparent from comparison with FIG. 12, the system configuration of FIG. 10 is a system in which a storage device 12 is newly connected to the exchange 7 in the conventional system. Therefore, also in the sequence of FIG. 11, as apparent from comparison with FIG. 13, the processing steps S51,
S52 and S53 are added. That is, in FIG. 11, in the process step 51, when the destination switching center 7 receives the channel switching request signal, this signal is transmitted from the mobile station 3 which is in communication with the other switching army and is in communication. Is determined. In the processing step S52,
The mobile station 3 which is information that the exchange 7 can connect to the exchange 6.
The request for the position information of is sent to the storage device 12. In processing step 53, the exchange 7 receives a response of the location information of the mobile station 3 from the storage device 12. As described above, according to the fourth embodiment, the mobile station does not have to include the routing information for the switching center of the transfer source in the channel switching request signal, so that the routing information is not received and stored from the switching center. However, it is possible to switch channels across exchanges.

[0016]

As described above, according to the present invention,
A communication device such as a mobile station can carry out channel switching while continuing communication between the exchanges without holding the routing information for the switching source or the switching destination in the memory. The number of processing steps is reduced, and the memory capacity for holding the above information is reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a communication system showing a first embodiment of the present invention.

FIG. 2 is a sequence chart showing a channel switching procedure in FIG.

FIG. 3 is a flowchart showing a channel switching operation of the exchange in FIG.

FIG. 4 is a configuration diagram of a communication system showing a second embodiment of the present invention.

5 is a sequence chart showing a channel switching procedure in FIG.

6 is a flowchart showing a channel switching operation of the exchange in FIG.

FIG. 7 is a configuration diagram of a communication system showing a third embodiment of the present invention.

8 is a sequence chart showing a channel switching procedure in FIG.

9 is a flowchart showing a channel switching operation of the exchange in FIG.

FIG. 10 is a configuration diagram of a communication system showing a fourth embodiment of the present invention.

11 is a sequence chart showing a channel switching procedure in FIG.

FIG. 12 is a configuration diagram of a communication system using a conventional channel switching method.

13 is a sequence chart showing a channel switching procedure in FIG.

[Explanation of symbols]

1 ... Source wireless zone (old wireless zone), 3 ... Mobile station or communication device, 2 ... Destination wireless zone (new wireless zone), 4 ... Source base station (old base station), 5 ... Destination base station (New base station), 6 ... Source switching center (old switching center), 7 ...
Destination switching center (new switching center), 8, 9, 11 ... communication line,
10 ... communication network, 12 ... storage device, 13 ... partner subscriber, 4
0 ... Communication management memory.

Claims (4)

[Claims] 1. A communication system comprising a communication device and an exchange station which is connected to the communication device via a communication means and performs communication control, wherein the exchange station is the communication device or another exchange. When a channel switching request signal including a communication device identification number is received from the station, it is determined whether or not the communication device identified by the communication device identification number is communicating within the own exchange station. If the channel switching request signal is transmitted from the communication device of the own exchange station, the channel being communicated is switched to a channel connected to the communication device in the own exchange station. Is transmitted from the communication device of the other switching center, the in-communication channel switching method is characterized in that the channel in communication is switched to the channel connected to the other switching center. 2. A communication device, an exchange station which is connected to the communication device via a communication means, and which controls communication, and stores position information of the communication device, and the communication is performed in response to a request from the exchange station. A communication system comprising a storage device for notifying the location information of the device to the exchange, wherein the communication device uses the communication during communication when the communication channel is switched by the communication device or another communication device. When a channel switching request signal including a device identification number is transmitted to the exchange, the switching center receives the channel switching request signal and the communication device identified by the communication device identification number included in the signal identifies itself. It is determined whether or not communication is being performed within the exchange, and if the result of the determination is that communication is not being performed within the local exchange, the location information of the communication device is requested by requesting the storage device location information. The communication device A channel connection request signal including a channel switching request is sent to the channel switching source switching center connected to the station, and if the response from the channel switching source switching center is normally connected, the channel switching request signal is sent. A method of switching a channel during communication, characterized in that a response signal is transmitted to the communication device that has transmitted the message to connect the communication device and the channel switching source exchange. 3. A communication device, an exchange A which is connected to the communication device via a communication means and controls communication, and position information of the communication device is stored, and in response to a request from the exchange A. A communication system comprising a storage device for notifying the exchange station of position information of the communication device, wherein the communication device communicates with an exchange station B other than the exchange station A to which the communication device is connected. When switching the communication channel of the communication device in communication, a channel switch request signal including the identification number of the communication device in communication is transmitted to the exchange A, and the exchange A receives the channel switch request signal. , Determining that the communication device specified by the communication device identification number included in the signal is in communication at the exchange B, and requesting the storage device for position information of the communication device specified by the communication device identification number. The location information by Then, the channel switching request signal is transmitted to the switching source switching center B which is connected to the communication device which is in communication specified by the position information, and the switching center B receives the channel switching request signal. Then, it is determined that the communication device identified by the communication device identification number included in the signal is in communication with its own switching center, and the channel in communication is switched to the switching center A that is the source of the channel switching request signal. To the channel of the communication line connected to the switch, and sends a switching completion report to the switching destination switching center A. When the switching center A receives the switching completion report, A channel switching method during communication, characterized by connecting a channel and a channel connected to the communication device to continue communication. 4. A mobile communication device, a base station in which the communication device is arbitrarily movable in a wireless zone, and a base station connected to the base station via communication means to control communication. A mobile communication system composed of an exchange A to perform and a storage device that stores the position information of the communication device and notifies the exchange of the position information of the communication device in response to a request from the exchange A. Then, the communication device detects that the signal reception level from the first base station in the first wireless zone in communication is deteriorated, and thereby the second wireless zone in the first wireless zone in communication is detected. When it is determined that the zone has been moved to the zone, the channel switching request signal including the identification number of the communication device is transmitted to the second wireless zone, and the switching center A connected to the second wireless zone , When the channel switching request signal is received, the signal Communication device identified by the communication device identification number other switching center B contained
It is determined that the communication device is in communication, and the position information of the communication device specified by the communication device identification number is requested to the storage device to acquire the position information, When a channel switching request signal is transmitted to the switching source switching center B connecting the communication device, and the switching source switching center B receives the channel switching request signal, it identifies the communication device included in the signal. It is determined that the communication device specified by the number is communicating at its own exchange station B, and the communicating channel is changed to the channel of the communication line connected to the switching destination exchange station A that is the transmission source of the channel switching request signal. Switching, transmitting a switching completion report to the switching destination switching center A, and the switching destination switching center A receiving the switching completion report,
A channel switching method during communication, characterized by connecting a channel of a communication line from a switching source switching center B and a channel connected to the communication device to continue communication.