JP3238091B2 - PHS incoming call transfer processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a PHS (Personal Handy Phone System) PHS incoming call transfer technique for transferring an incoming call to a predetermined transfer destination based on preset call transfer information. , PHS at wireless base station
The present invention relates to a PHS call transfer processing method suitable for improving call transfer efficiency in a PHS network in which a call transfer setting of a terminal is registered.

[0002]

2. Description of the Related Art At present, automobile phones and mobile phones, and P
Communication networks that can be used while moving terminals, such as HS, have been constructed. For such a communication network, see, for example, Kohiyama, Hattori, et al., “Private Communication Technology” (published by Ohmsha on November 1, 1995). 1
64-175. In particular, in the PHS network, there is an area that cannot be used during high-speed movement or cannot be connected (outside the service area) due to its configuration. As a service for addressing such a problem,
There is a call transfer service. In other words, when the PHS terminal receives an incoming call, if the PHS terminal is out of the service area or is in a state where connection is impossible due to power cutoff or the like, it is a service for connecting to a preset transfer destination terminal.

[0003] Regarding the incoming call transfer technology in the PHS network, different technologies are used depending on the system form of the PHS network. The PHS network includes a public network connection type and a public network dependent type. In the public network dependent type, a wireless base station is connected to a digital public network, and connection control to a public line and location information management are performed. For example, there is a form in which most of the control other than the radio line control is performed in the digital public network, and a form in which a subscriber data management function such as authentication information is provided on the radio base station side. Hereinafter, the call transfer technology in which the subscriber data management function is provided on the wireless base station side even in such a public network dependent type, and most control other than the wireless network control in the public network dependent type are digitally implemented. The difference from the incoming call transfer technology in the form performed in the public network will be described with reference to FIGS.

First, a PHS incoming call transfer technology in a public network dependent type in which most control other than radio line control is performed in a digital public network will be described with reference to FIG. FIG. 6 is a block diagram showing a conventional configuration example of a public network-dependent PHS network in which control other than wireless channel control is performed in a digital public network. In FIG. 6, 61 and 72 are terminals as general fixed telephones, 62 is a PHS terminal, 63 and 71 are subscriber line exchanges for general telephone lines (described as "LS" in the figure),
64 is a wireless area where the PHS terminal 62 can be used;
a is a wireless base station that performs wireless connection control with the PHS terminal 62 (described as “CS” in the figure), 65 is a network connecting between exchanges (described as “NW” in the figure), and 66 is Digital electronic exchange (described as "D70" in the figure), 67
Is added to the digital electronic exchange 66 and ISDN (Integr
An I-interface subscriber module (shown as "ISM" in the figure) having circuit switching and additional service functions for providing a connection in an ated Services Digital Network (Integrated Services Digital Network). “ISM” is an abbreviation for “I-interface Subscriber Module”.

Further, in FIG. 6, reference numeral 68 denotes an I-interface subscriber module adapter (hereinafter, referred to as "ISM 67") for connecting the radio base station 64a and the I-interface subscriber module 67 (hereinafter referred to as "ISM 67") in the PHS service. “H-ISMA”), 69 designates various information of each PHS terminal managed by an I-interface subscriber module adapter 68 (hereinafter, “H-ISMA 68”) such as the PHS terminal 62 as subscriber data. A database to be stored (described as “ISMA-DB” in the figure), 70 is subscriber data stored in the database 69. Hereinafter, the PHS incoming call transfer processing operation in such a configuration will be described.

When a call is made from the terminal 61 to the PHS terminal 62, the subscriber's line exchange 63 sends the call to the network 65, the digital electronic exchange 66, the ISM 67, and the H-IS.
MA68, PHS terminal 62 via radio base station 64a
A connection request is made to the wireless area 64 where exists. At this time, if the PHS terminal 62 is out of the service area or in a power-off state, this state is changed to the H-IS
The H-ISMA 68 refers to the subscriber data 70 registered in advance in the database 69, and determines the registration contents of the subscriber data 70 (whether or not there is a transfer function contract,
For example, the ISM 67 is requested to connect to the terminal 72 housed in the local exchange 71 based on the transfer destination telephone number and the presence or absence of the transfer talkie.

On the basis of this request, the ISM 67
And the terminal 72 are connected. Thus, the PHS terminal 62
When the PHS terminal 62 is out of the service area or in a power-off state when the call arrives at the terminal, the terminal is connected to the transfer destination terminal 72 with the ISM 67 as a return point.
The user of the PHS terminal 62 can communicate with the terminal 61 using the terminal 72 even outside the service area.
Next, with reference to FIG. 7, a description will be given of a call transfer technology in a form in which a subscriber data management function is provided on the wireless base station side even if it is a public network dependent type.

FIG. 7 is a block diagram showing a conventional configuration example of a public network-dependent PHS network in which a subscriber data management function is provided on a radio base station side. The configuration in FIG.
Is the same as the PHS network in the above, except that a subscriber data management function such as authentication information is provided on the radio base station side.
PH within the network, that is, H-ISMA68
It does not have the subscriber data of the S terminal 82. for that reason,
In the PHS network having such a configuration, the PHS
When a call arrives at the terminal 82, if the PHS terminal 82 is out of the service area or is in a power-off state, the radio base station 84a determines this state. Then, the wireless base station 84a reads the call transfer destination telephone number set corresponding to the PHS terminal 82, and, for example, makes a call to the terminal 72 housed in the subscriber line switch 71, and 84a as a turning point, H-ISMA6
8. The terminal 61 and the terminal 72 are connected via the ISM 67, the digital electronic exchange 66, and the network 65.

[0009] As described above, a PHS in which the subscriber data management function is provided in the radio base station side even if it is a public network dependent type.
In the network, the call transfer function is realized by loopback at the radio base station 84a, so that two lines between the radio base station 84a and the H-ISMA 68 are used for call transfer. The wireless base station 84a and the H-ISMA 68
The number of lines is small during the period,
As a result, the transmission / reception of other users in 4 is suppressed.

[0010]

The problem to be solved is that, in the prior art, even in a PHS network or the like in which a subscriber data management function is provided in a radio base station side even if it is a public network dependent type, Another point is that call transfer is performed by loopback at the wireless base station. An object of the present invention is to solve the problems of the prior art, and to enable efficient use of a line in a PHS network or the like in which a subscriber data management function is provided on a wireless base station side even if it is a public network dependent type. Is to provide a PHS incoming call transfer processing method.

[0011]

In order to achieve the above object, a PHS call transfer processing method according to the present invention has no subscriber data in a network, and has a PHS side at a radio base station (CS) side.
A call transfer processing method in a PHS network for registering call transfer settings of an HS terminal, wherein the radio base station (CS) receives an incoming call to a PHS terminal that has registered call transfer settings,
A step of requesting, by a facility message (FAC), a call transfer to an exchange (ISM, ISMA) that has notified the radio base station (CS) of the incoming call to the PHS terminal; Exchange (ISM,
In ISMA), there is at least a step of making a call (IAM) to a call transfer destination terminal, and a step of sending a disconnection message (DISC) from the exchange (ISM, ISMA) to the radio base station (CS). Exchange (ISM, ISM) that notifies a radio base station (CS) of an incoming call to a PHS terminal.
In A), a call connection control is performed between the terminal of the call source to the PHS terminal and the terminal of the call transfer destination, and the switching center (ISM, ISM).
It is characterized in that a path for call transfer between A) and the radio base station (CS) is released.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 and 2 show the PH of the present invention.
FIG. 3 is a sequence diagram showing a first embodiment of the processing operation according to the present invention of the S incoming call transfer processing method, and FIG.
It is a block diagram which shows the example of a structure of the PHS network to which the S-call transfer processing method was applied. FIG. 3 shows an example in which the PHS incoming call transfer processing according to the present invention is performed in a public network-dependent PHS network in which a subscriber data management function is provided on the wireless base station side.

In FIG. 3, 1 is a PHS terminal and 2 is a PHS terminal.
In the PHS service, a wireless base station (referred to as “CS” in the figure) that performs wireless connection control with the HS terminal 1
An I-interface subscriber module adapter (hereinafter referred to as "ISMA" in the figure) for connecting the accommodated wireless base station 2 and the I-interface subscriber module;
Reference numeral 4 denotes an I-interface subscriber system module (shown in the figure and hereinafter referred to as "ISM") having a circuit switching and additional service function for providing an INDS connection service added to the digital electronic exchange.

5 is a digital electronic exchange (“D” in the figure).
70)), 6 and 7 are terminals as general fixed telephones, 8 and 9 are subscriber line exchanges for general telephone lines accommodating terminals 6 and 7, respectively (described as "LS" in the figure), 10
Is a network connecting the exchanges ("NW" in the figure)
Described). Digital electronic exchange 5, ISMA3,
The ISM 4 constitutes the exchange according to the present invention. In the PHS network having such a configuration, a user communicates via the PHS terminal 1 with another PHS terminal (not shown) and terminals 6 and 7 which are ordinary fixed terminals, and
The call transfer service according to the present invention can be used. Hereinafter, the operation related to the PHS incoming call transfer processing will be described.

When the user of the PHS terminal 1 goes out of the service area, or when it is necessary to turn off the power to avoid use in a hospital or the like, the PHS terminal 1
The wireless base station 2 is requested in advance for a call transfer service so that the S call transfer service can be used. Wireless base station 2
Registers the number of the transfer destination terminal, for example, the number of the terminal 7 based on this request. In the state where the call transfer service is set as described above, the PHS terminal 1
Is called, the subscriber's line switch 8, network 10, digital electronic switch 5, ISM4, ISMA3
Is notified to the wireless base station 2 via.

The radio base station 2 transmits the call destination PHS
It confirms that the request for the call transfer service has been set for the terminal 1 and makes a request for the call transfer to the PHS terminal 1 to the ISMA 3. PHS from wireless base station 2
ISMA3 that received a call transfer request for terminal 1
Sends this request to ISM4 and requests the call transfer process. Based on the request from ISMA 3, ISM 4 transmits a transfer call to terminal 7, which is a call transfer destination, via digital electronic exchange 5, network 10, and subscriber line exchange 9. Then, based on the response from the terminal 7, the IS
M4 connects the terminal 6 and the terminal 7.

As described above, in the present embodiment, even if the call is forwarded to the PHS terminal 1 in the PHS network in which the subscriber data management function is provided on the radio base station side even if it is a public network dependent type, ISM between source terminal 6 and destination terminal 7
Connect within 4. As a result, it is possible to avoid using the line between the ISMA 3 and the wireless base station 2 for call transfer. Further, the ISM 4 connecting the terminal 6 and the terminal 7
When there is a response from the transfer destination terminal 7 to the incoming transfer call, information indicating that there is a response and the start of the call transfer is transmitted to the radio base station 2 via the ISMA 3.
In addition, when the call between the terminal 6 and the terminal 7 ends, the information indicating the end of the call is notified to the radio base station 2 via the ISMA 3. Based on the notification from the ISM 4, the wireless base station 2 can grasp the connection status of the PHS terminal 1 and, for example, calculate the charge for the PHS terminal 1 during call transfer.

Hereinafter, the operation relating to the incoming call transfer process will be described in detail with reference to FIGS. First, the operation illustrated in FIG. 1 will be described. The ISM that has received the address signal (IAM) from the calling side (switch) sends a call setup message (SETUP) to the ISMA. Upon receiving the call setup message (SETUP), the ISMA sends a call setup message (SETUP) to the radio base station (CS), and also issues a call setup acceptance message (CALLPR).
OC) to the ISM. This call setup acceptance message (C
Based on ALLPROC), the ISM returns an address completion signal (ACM) to the caller.

A call setup message (SETU) from ISMA
The radio base station (CS) that has received P) returns a call setting acceptance message (CALLPROC) to ISMA. The operation so far is the same as the conventional operation. In this example, a call transfer request is set for the destination terminal in the radio base station (CS), and the radio base station (CS) that has received the call setup message (SETUP) from the ISMA receives the call transfer request. Recognizing the setting of the request, it requests the ISMA to forward the call using a facility message (FAC).
In this example, the facility message (FAC) includes “link ID”, “transfer destination number”, “transfer destination subaddress”, “talkie type”, “transfer source number notification condition”,
And "call setting information". The “transfer destination subaddress”, “talkie type”, “transfer source number notification condition”, “call setting information (priority / general)”, and the like include
Granted as needed.

Upon receiving the facility message (FAC) from the radio base station (CS), the ISMA adds the "neighboring network type" information to the facility message (FAC) and sends it to the ISM, requesting the incoming call transfer processing. I do. When the ISM receives the facility message (FAC) from the ISMA, it indicates to the calling party that a call progress message (CPG: Call Progress Message, an important event to be forwarded to the calling or called party has occurred). For this purpose, a message transmitted in both directions during the call setup or communication phase) and a transfer talk (if the talk function is used) are sent, and an address signal (IAM) is sent to the transfer destination network, and A disconnect message (DISC) signal is returned to ISMA. The ISMA returns a release message (REL) corresponding to the disconnect message (DISC) to the ISM, and sends the disconnect message (DISC) to the radio base station (CS).

The disconnection message (DIS) from ISMA
The radio base station (CS) receiving C) returns a release message (REL) to ISMA. Also, upon receiving the release message (REL) from ISMA, the ISM correspondingly releases a release completion message (RELCOMP).
And the ISMA responds to the release message (REL) from the radio base station (CS) by a release completion message (R
ELCOMP) is returned to the radio base station (CS). As a result, the line between the ISM and the ISMA and the radio base station (CS) is released, and can be used for another connection other than the call transfer.

The address signal (IAM) transmitted from the ISM to the transfer destination network is generated based on a facility message (FAC) from the ISMA. ), "Originating user type: general / highest priority",
"Calling number: ISMA-ID (identification information) of transfer source",
It is composed of “calling user number: transfer source PSN (switch)”, “destination number: transfer destination number”, “access transfer: transfer destination subaddress”, and the like. The operation after transmitting such an address signal (IAM) to the transfer destination network will be described below with reference to FIG.
Perform based on.

As shown in FIG. 2, the transfer destination network which has received the address signal (IAM) from the ISM includes "destination number: transfer destination number" and "access transfer: transfer destination subaddress".
Normal call setup processing is performed on the call transfer destination terminal specified by the information such as an address completion signal (ACM), a call progress message (CPG), a ring tone (RBT), and a response signal ( ANM) is returned. Based on this, the ISM sends a call progress message (CP
G), a ring tone (RBT), and a response signal (AN
M), the response signal (ANM) is transmitted. As a result, the originating terminal and the destination transfer destination terminal of the transfer destination network are connected via the ISM, and thereafter, the disconnection based on the release message (REL) from the caller and the corresponding recovery completion message (RLC) is performed. Until processing takes place,
The communication state is established. It should be noted that the ISM may be configured to send a transfer source talk to the transfer destination network when receiving the response signal (ANM) from the transfer destination network.

When the destination location information is notified by the address completion signal (ACM) received from the transfer destination network,
The SM notifies the radio base station (CS) of the arrival position information via the registration message (REG) including the “link ID” and “the arrival position information” via the ISMA, and further transmits the response signal (ANM) to the transfer destination. At the time of receiving from the network, the start of connection is notified to the radio base station (CS) via ISMA by a registration message (REG). In addition, if the incoming location information is not notified by the address completion signal (ACM), it is notified by the response signal (ANM). At this time, the “link ID” and the “incoming location” are registered by the registration message (REG). Information ”via ISMA to a radio base station (C
S).

Further, a release message (RE
L), upon receiving the LSM, the ISM gives a “link ID” via the ISMA and informs the radio base station (CS) of the termination of the line connection by a registration message (REG).
Notify. Based on this end notification and the above-mentioned connection start notification, the radio base station (CS) can perform charging processing and the like for call transfer. Note that the radio base station (CS) sends a release completion message (RELCOMP) after receiving the end notification or every time a notification of the arrival position information and a connection start notification are sent from ISM via ISMA. And release the line between ISM and ISMA.

FIG. 4 is a sequence diagram showing a second embodiment of the processing operation according to the present invention of the PHS incoming call transfer processing method of the present invention. In this example, in the processing operation shown in FIGS. 1 and 2, if there is no call transfer request from the transfer source wireless base station within a pre-registered time, call transfer is not accepted. That is, when an address signal (IAM) is sent from the calling side to the ISM, the radio base station (CS) is transmitted via the ISMA in the same manner as the operation in FIGS.
, A call setup message (SETUP) is transmitted. At this time, the ISM issues a call setup message (SET
At the time of transmission of (UP), counting is started for a predetermined time, up to 40 seconds in this example.

The radio base station (CS) returns a call setup acceptance message (CALLPROC) to ISMA in response to the call setup message (SETUP), and sends a call signal (ALERT) to ISM via ISMA. The ISM uses a calling signal (ALER) from ISMA.
Upon receiving T), a call progress message (CPG) and a ring tone (RBT) are sent to the caller. Further, when the call destination request indicated by the call setup message (SETUP) received from the ISMA has been set to the call transfer request, the radio base station (CS) performs the call transfer by the facility message (FAC) to the ISMA. A request is made, and each process is performed in the same manner as described with reference to FIGS.

However, in this example, this radio base station (C
The facility message (FAC) from S)
If the message arrives at the ISM within 40 seconds after sending the call setup message (SETUP) to the MA, the ISM shall not accept a call transfer request based on this facility message (FAC). The calling state (transmission of ALERT and RBT) to the calling side is continued.

FIG. 5 is a sequence diagram showing a third embodiment of the processing operation according to the present invention of the PHS incoming call transfer processing method of the present invention. This example shows an example in which a call transfer request based on the facility message (FAC) shown in FIGS. 1 and 2 is applied to a public network-dependent PHS network in which control other than wireless line control is performed in a digital public network. Things. That is, the address signal (IAM) is transmitted from the originating exchange to IS
M, when it is sent to M in the same manner as in the operation of FIGS.
A call setup message (SETUP) is sent to the radio base station (CS) via the SMA.

If the PHS terminal is out of the area of the radio base station (CS), the PHS terminal inquires of the ISMA holding the subscriber data of the PHS terminal about the position of the PHS terminal, ) In the call setup message (S
ETUP). At this time, if a call transfer request is set corresponding to the destination PHS terminal, in this example,
A facility message (FAC) is generated in the ISMA and sent to the ISM. In this case, the facility message (FAC) includes “transfer destination number”, “talkie type”, “call setting information”, and “adjacent network type”.
Etc. is included.

In this way, the ISM receiving the facility message (FAC) from the ISMA,
The same processing as the processing operation shown in FIGS. still,
In response to the call setup message (SETUP) from ISMA, the call setup acceptance message (CALLPROC) and the like from the radio base station (CS) have not been transmitted.
Since the MA and the radio base station (CS) are not originally connected, each processing operation for releasing the line between the ISMA and the radio base station (CS) shown in FIGS. 1 and 2 is not performed.

As described above with reference to FIGS. 1 to 5, in the PHS incoming call transfer processing method of this embodiment, a PHS dependent on a public network in which a subscriber data management function is provided on the radio base station side. In a call transfer processing method for a PHS terminal connected to a PHS network that does not have subscriber data in the network, such as a network, a call switching signal in the network corresponding to a call setting signal from a calling terminal connected to the network. A facility message (FAC) requesting a transfer start is transmitted from a radio base station (CS) accommodating a PHS terminal to a station (ISMA, ISM).
The call connection between the destination terminal and the calling terminal requested by the facility message (FAC) is performed. At this time, the switching center (ISM) receives the call transfer request signal from the transfer source radio base station (CS) after transmitting the call setup signal (SETUP) and exceeding the pre-registered time (40 seconds). In this case, the call transfer activation is not performed.

The switching center (ISM) holds the transfer information relating to the call transfer request when the call transfer is activated, and notifies the start and end of the call connection between the calling terminal and the transfer destination called terminal. The information to be notified is transmitted to the transfer source radio base station (CS), and the radio base station (CS) can perform charging processing. When the switching center (ISMA, ISM) receives the position information of the terminal from the call transfer destination terminal, it sends the position information of the call transfer destination terminal to the transfer source radio base station (CS). I do.

The present invention is not limited to the embodiment described with reference to FIGS. 1 to 5, but can be variously modified without departing from the gist thereof. For example, in this example, the PHS incoming call transfer processing in the public network dependent PHS network in which the subscriber data management function is provided on the radio base station side has been described. However, in the case of a configuration in which the call transfer is looped back by the radio base station (CS), the PHS call transfer processing method of the present invention can be applied.

[0035]

According to the present invention, in a PHS network having no subscriber data in a network, such as a public network-dependent PHS network in which a subscriber data management function is provided on a radio base station side. Also, call transfer can be performed by returning at the exchange (ISM), and the line between the exchange and the radio base station is not used for call transfer, and the line can be used efficiently.

[Brief description of the drawings]

FIG. 1 is a sequence diagram showing a first half of a first embodiment of a processing operation according to the present invention of a PHS incoming call transfer processing method of the present invention.

FIG. 2 is a sequence diagram showing the latter half of the first embodiment of the processing operation according to the present invention of the PHS incoming call transfer processing method of the present invention.

FIG. 3 shows a P to which the PHS call transfer processing method of the present invention is applied.
FIG. 2 is a block diagram illustrating a configuration example of an HS network.

FIG. 4 is a sequence diagram showing a second embodiment of the processing operation according to the present invention of the PHS incoming call transfer processing method of the present invention.

FIG. 5 is a sequence diagram showing a third embodiment of the processing operation according to the present invention of the PHS incoming call transfer processing method of the present invention.

FIG. 6 is a block diagram showing a conventional configuration example of a public network-dependent PHS network in which control other than wireless channel control is performed in a digital public network.

FIG. 7 is a block diagram showing a conventional configuration example of a public network-dependent PHS network in which a subscriber data management function is provided on a wireless base station side.

[Explanation of symbols]

1: PHS terminal, 2: wireless base station, 3: I interface subscriber system module, 4: I interface subscriber system module, 5: digital electronic exchange, 6: sender terminal, 7: transfer destination terminal, 8, 9: subscriber line exchange,
10: Network, 61, 72: Terminal, 62, 82:
PHS terminals, 63, 71: local exchange, 64, 8
4: wireless area, 64a, 84a: wireless base station, 65:
Network, 66: digital electronic exchange, 67: I-interface subscriber module, 68: I-interface subscriber module adapter, 69: database, 70: subscriber data.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Fumio Muto, Inventor Nippon Telegraph and Telephone Corporation 3-9-1-2, Nishishinjuku, Shinjuku-ku, Tokyo (72) Inventor Akio Kawano 3-19, Nishishinjuku, Shinjuku-ku, Tokyo No. 2 Nippon Telegraph and Telephone Corporation Examiner Masashi Fukasawa (56) References JP-A-3-26196 (JP, A) JP-A-4-301954 (JP, A) JP-A-8-1772659 (JP, A Japanese Patent Application Laid-Open No. 6-141081 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04Q 7/38

Claims (5)

(57) [Claims] An incoming call transfer processing method in a PHS network in which a wireless base station registers an incoming call transfer setting of a PHS (Personal Handy Phone System) terminal, the method comprising: Requesting a call transfer from the radio base station that received the call to the exchange that has notified the radio base station of the call to the PHS terminal; and from the exchange based on the call transfer request, Originating a call to a call transfer destination terminal, and transmitting a disconnection message from the exchange to the radio base station, notifying the radio base station of an incoming call to the PHS terminal. The switching center performs call connection control between the call originating terminal to the PHS terminal and the call transfer destination terminal, and sets a path for the call transfer between the switching center and the radio base station. Solve A PHS incoming call transfer processing method characterized by releasing. 2. The PHS call transfer processing method according to claim 1, wherein the radio base station requests the call transfer to the exchange by using a facility message.
The PHS incoming call transfer processing method, wherein the exchange makes a call to the call transfer destination terminal based on the facility message from the wireless base station. 3. The PHS incoming call transfer processing method according to claim 1, wherein the switching center transmits an elapsed time after notifying the radio base station of an incoming call to the PHS terminal. When the call transfer request from the wireless base station is received within the pre-registered time, a call to the call transfer destination terminal based on the call transfer request and a call to the wireless base station Sending a disconnection message as described above. 4. The PHS incoming call transfer processing method according to claim 1, wherein said exchange exchanges a connection between a terminal of a call source to said PHS terminal and a terminal of said incoming call transfer destination. A PHS incoming call transfer processing method comprising: notifying the radio base station of the start of the connection and the end of the connection. 5. The PHS call transfer processing method according to claim 1, wherein the switching center transmits position information of the terminal received from the call transfer destination terminal to the radio base station. PHS characterized by sending to a station
Call transfer processing method.