JP4103992B2 - Method for providing a call signal from switching means to mobile communication means - Google Patents

Description

  The present invention relates to mobile communication. The present invention relates to a method for providing a paging signal from a first type of switching means to mobile communication means located in a cellular communication network. Furthermore, the present invention provides a network node element provided as a first type switching means of a cellular communication network, a network node element provided as a second type switching means of a cellular communication network, and a network node of a cellular communication network It is about. Finally, the present invention relates to cellular communication networks, computer programs, and machine readable media.

  Regarding the terminology used in this document, the Japanese “Personal Digital Cellular” (PDC) system, as well as the system called “Pacific Digital Cellular” system, is well known in the H edition of the Radio Industries Association (ARIB). Based on the RCR-STD27 standard. The personal digital cellular system has at least one mobile switching center (MSC) that serves a plurality of cells by means of a base station system (BSS).

  The methods, networks and devices described above are well known. In a personal digital cellular system, when a call arrives at a mobile station, a traffic channel is assigned during call setup. In order to assign this traffic channel, the location of the mobile station needs to be known. That is, it is necessary to know the cell where the mobile station is located. If the mobile switching center does not know the location of the mobile station, the mobile switching center delivers a call request to the base station system and obtains location information from the base station system. This distribution may be performed together, i.e. to all base station systems, i.e. all cells controlled by the mobile switching center, or locally, i.e. one cell or a group of cells. It may be executed in the area that has.

  The call request is delivered on a common control channel (CCH) that the mobile station listens to while in idle mode. When the mobile station receives the call request, the mobile station also responds to the network with a common control channel. As a result, the mobile switching center acquires information on the used common control channel. Knowing to which cell this common control channel belongs, the mobile switching center can thus identify the cell in which the mobile station is located.

  The provision of packet data within a personal digital cellular standard network involves, for example, a packet mobile service switching center (PMSC) that handles the exchange of data packets such as Transmission Control Protocol / Internet Protocol (TCP / IP) packets. is doing. Since it is connected to the same wireless network equipment as the mobile service switching center, the packet mobile service switching center can share the radio network resources (TRX) of the base station system with the mobile service switching center. A personal digital cellular (PDC) system providing a packet data communication service is also called a packet personal digital cellular (packet PDC or PPDC) system.

  The mobile service switching center constitutes a wireless network resource. If the radio network resource is configured to carry a user packet channel (UPCH), a path between the packet mobile switching center and the radio network resource is set up. The packet mobile service switching center obtains the identity of the wireless network resource. The packet mobile service switching center controls the user packet channel.

  When the mobile station is in packet data mode, the packet mobile service switching center controls the communication between the network and the mobile station. If a mobile station moves around in the network during a packet data session, the mobile station can perform “cell reselection” for the user packet channel in another cell with better channel strength, which is circuit switched. Similar to handover during a voice call. The packet mobile service switching center is updated with the current location of the mobile station. However, after cell reselection, the mobile service switching center does not know the current location of the mobile station.

  If the mobile service switching center does not know the current location of the mobile station, if there is an incoming voice call or incoming short message service (SMS), the mobile service switching center will locate the mobile station. The traffic channel must be assigned in the network cell in which the mobile communication means is currently located. If the mobile station is engaged in a packet data session, the mobile switching center can only reach the mobile station on the common control channel because the mobile station is only communicating with the packet mobile switching center via the user packet channel. Can not. Therefore, according to the prior art, while a mobile station is engaged in a packet data session, it is impossible to accept a circuit-switched communication service such as a voice call when it arrives.

  The problem underlying the present invention is to provide a method and system that can call a mobile station while engaging in a packet-switched communication session.

Viewed from one aspect of the invention, this problem is solved by a method of providing a paging signal from a first type of switching means to mobile communication means located in a cellular communication network. The paging signal is provided as a paging signal in a first mode, and the mobile communication means engages in a second mode suitable for communication with a second type switching means connected to the first type switching means. The cellular network has a plurality of wireless transmission means for wireless communication with the mobile communication means. The method is
An identifying step of identifying wireless communication means currently assigned to the mobile communication means;
Providing the call signal from the first type switching means to the identified wireless communication means;
Transmitting the call signal from the identified wireless communication means to the mobile communication means,
The identification step includes
The first type switching means requesting wireless transmission means information from the second type switching means;
The second type switching means responding to transmit the requested wireless transmission means information;
The information of the wireless transmission means has an identity of the wireless transmission means currently assigned to the mobile communication means.

  In order for the mobile communication means to engage in a second mode suitable for communication with the second type of exchange means, the mobile communication means may actually transmit information to the second type of exchange means or In addition to having mobile communication means for actually receiving information from the type of exchange means, such transmission if the mobile communication means is “online” in the second mode, for example. Mobile communication means ready for at least one of reception and reception. Radio resources may be provided as transmission means for transmitting signals from the transmission means to the mobile communication means. In particular, in a convenient embodiment, at least one wireless transmission means is provided as a transceiver for transmitting and receiving signals. The radio resource may further include means for executing a channel setup procedure for signal transmission from the radio transmission means to the mobile communication means. With respect to the allocation of radio resources to mobile communication means, this means that the radio resources are currently dedicated to transmitting information to the mobile communication means. In one embodiment, for communication with the mobile communication means, the first type switching means is physically different from the wireless transmission means currently assigned to the second type switching means. Wireless transmission means may be used.

  According to the method of the invention, the first type of switching means identifies what radio transmission means are assigned to the mobile communication means. If necessary, the first type of switching means can conclude in which cell of the cellular communication network the mobile communication means is located. Therefore, a traffic channel is allocated for communication indicated by a paging signal between the first type switching means and the mobile communication means. In order to accomplish this identification, the first type of exchange means asks the second type of exchange means to provide location information regarding the mobile communication means. Since the mobile communication means engages in a second mode suitable for communication with the second type switching means, a communication path between the second type mobile switching center and the wireless transmission means is set up. The second type of switching means "knows" this route, after which the second type of switching means can identify the wireless transmission means. Therefore, the second type switching means must call the mobile communication means in order to find the searched mobile communication means. The second type exchange means returns information about the identity of the wireless transmission means to the first type exchange means. As a result, the first type of exchange means "knows" to which cell the identified wireless transmission means belongs. Therefore, the first type of switching means can conclude about the identity of the cell in which the mobile communication means is currently located. In one embodiment, in addition to providing information about the cell in which the mobile communication means is currently located, the second type of switching means further includes a cell covered by the identified wireless transmission means. It provides location information about the location of some mobile communication means.

  According to the present invention, the identity of the cell in which the mobile communication means is located is obtained without sending any signal to the mobile station. As a result, compared to the prior art method, the response to the request of the first switching means is quicker and the traffic load on the air interface is reduced.

The providing step includes
The first type switching means generating a second mode paging signal having information of the first mode paging signal and the identity of the wireless transmission means;
The first type of switching means providing the second mode call signal to the second type of switching means;
Preferably, the second type switching means provides the second mode call signal to the identified wireless transmission means.

  In this embodiment, the transmission of the information contained in the paging signal of the first mode via the communication path already allocated between the first type switching means and the identified wireless transmission means is an additional This is possible so that no communication channel needs to be used. This is advantageous because the connection is set up particularly quickly.

In one embodiment, the providing step of providing a call signal comprises:
The first type switching means requesting channel reservation and correspondence information from the identified wireless transmission means;
Transmitting the requested channel information in response to the wireless transmission means;
The first type switching means provides the reserved channel identity to the second mode paging signal, and the identified radio transmitting means sends the second mode paging signal to the second mode paging signal. Transmitting to the mobile communication means via a channel used for communication in the mode of
The channel information identifies a channel reserved for communication between the identified wireless transmission means and the mobile communication means.

  In this embodiment, the transmission of the information contained in the first mode paging signal is made via an additional communication channel via a communication path reserved between the first type switching means and the mobile communication means, This is possible, for example, without having to use a common control channel. This reduces the load on the common control channel. Furthermore, the successful transmission of the paging signal to the mobile communication means implicitly verifies the information about the location of the mobile communication means. The information may indicate a channel reserved for communication between the identified wireless transmission means and the mobile communication means, or in one embodiment this information may be a first type switching center. The communication channel reservation may be confirmed as required by.

  In one embodiment, the first type of switching means is provided as circuit switching means, and the first mode is a circuit switching mode. Preferably, a second type switching means is provided as a packet switching means, and the second mode is a packet switching mode. The mobile communication means may be provided, for example, as a mobile phone, as a personal digital assistant (PDA), or as a laptop computer adapted to communicate with a communication network. The mobile communication means can communicate in both the first mode and the second mode.

  In one embodiment, a paging signal is provided for signaling an incoming request for communication in the first mode, eg, a voice call request. Alternatively, the paging signal is provided for signaling an incoming message, for example a short message service (SMS) message or a multimedia service (MMS) message.

  In one embodiment, for communication with the mobile communication means in the first mode, the first type of communication means is physically different from the transmission means currently assigned to the second type of switching means. Different transmission means may be used.

In another aspect of the invention, a network node element is provided as a first type of switching means in a cellular communication network. The cellular communication network has a plurality of wireless transmission means for wireless communication with mobile communication means placed on the network. The mobile communication means engages in a second mode for communication with a second type switching means connected to the first type switching means. The mobile communication means can be provided with a first mode paging signal. The network node element is adapted to perform a method having the following steps. That is,
The method is
An identifying step of identifying wireless communication means currently assigned to the mobile communication means;
Providing the call signal to the identified wireless transmission means for transmitting the call signal from the wireless communication means to the mobile communication means;
The identification step includes
Requesting wireless transmission means information from the second type of exchange means;
Receiving the requested wireless transmission means information,
The requested wireless transmission means information comprises the identity of the wireless transmission means currently assigned to the mobile communication means;
The providing step includes
Generating a second mode paging signal having information of the first mode paging signal and the identity of the wireless transmission means;
Providing said second mode call signal to said second type switching means, wherein said second type switching means provides said second mode call signal to said identified radio transmission means; And providing a process.

Preferably, the network node element is further adapted to perform a method having the following steps. That is,
The method is
Requesting channel reservation and correspondence information from the identified wireless transmission means;
Transmitting the requested channel information;
Providing said reserved channel identity to said second mode paging signal, and said identified radio transmitting means sends said second mode paging signal over a channel used for communication in said second mode. And transmitting to the mobile communication means
The channel information identifies a channel reserved for communication between the identified wireless transmission means and the mobile communication means.

  In one embodiment, the second mode paging signal is transmitted via the same channel currently used by the identified wireless communication means used by the mobile communication means for communication in the second mode. It may be transmitted to the mobile communication means.

According to a further aspect of the invention, a second type of cellular communication network with mobile communication means connected to a first type of switching means and adapted to carry out a method having the following steps: A network node element is provided as an exchange means. That is,
The method is
Receiving a request for information of a wireless transmission means from the first type of exchange means;
In response to the request, transmitting information of the requested wireless transmission means;
Receiving a second mode paging signal from the first type of switching means;
Providing said second mode call signal to the identified radio transmitting means, and said identified radio transmitting means via said channel used for communication in said second mode said mobile communication means Transmitting a call signal of the second mode to
The wireless transmission means information comprises the identity of the wireless transmission means currently assigned to the mobile communication means;
The second mode call signal includes information of the first mode call signal;
The second mode paging signal is provided with the identity of the wireless transmission means;
The second mode call signal further comprises a channel identity reserved for communication between the identified radio transmission means and the mobile communication means.

Preferably, this network node element is adapted to perform a method having the following steps. That is,
The method is
Receiving a request for channel information from said first type switching means;
Transmitting the requested channel information in response to the request,
The channel information includes the identity of the channel reserved for communication between the identified wireless transmission means and the mobile communication means.

  In one embodiment, in particular, a first type of switching means provided as a circuit switched circuit mobile service switching center and in particular a second type of switching means provided as a packet switched packet mobile service center; Are physically integrated into one network node. The distribution of these node elements, ie the differences between these node elements, is in this case based on the logical differences between the integrated node elements.

  Yet another aspect of the invention relates to a network node of a cellular communication network. This network node has a first network node element provided as the above-described first type switching means and a network node element provided as the above-mentioned second type switching means.

  Yet another aspect of the invention relates to a cellular communication network. This network has at least one network node element as described above. For example, the mobile communication network is provided as a personal cellular digital (PDC) network or as a packet-switched packet personal cellular digital (packet PDC, PPDC) network.

  One aspect of the present invention relates to a computer program that can be loaded into the internal memory of a digital processing unit. The computer program has software code adapted to control the process according to any of the methods described above when it is executed on the digital processing unit. Therefore, the present invention is realized by software. Preferably, the computer program is stored on a machine readable medium, such as in particular a computer readable medium. This medium may be, for example, a compact disk read only memory (CD-ROM), a floppy disk, an optical disk, or a hard disk. Therefore, good physical portability of the control software is provided. The software is easily upgraded.

  Finally, the present invention relates to a machine readable medium having the above computer program.

  The present invention applies to all communication systems as defined by the 3rd Generation Partnership Project (3GPP) in the 1999 release version and in all future releases, as well as worldwide mobile communication services (UMTS). It is preferably used in a network. In addition, this includes personal cellular digital (PDC) and packet personal cellular digital (PPDC) as well as pan-European digital mobile telephone (GSM) networks, core networks, wireless local area access networks (WLANs), and corresponding user equipment including. These and other features of the present invention will be more fully understood with reference to the following detailed description and accompanying drawings.

  FIG. 1 illustrates an embodiment of the invention to be described. In particular, FIG. 1 shows the elements of a system in accordance with the Personal Cellular Digital (PDC) standard and the Packet Personal Cellular Digital (PPDC) standard. This system has a gateway node GN and a mobile service switching center (MSC) linked to the gateway node GN. The gateway node GN is a circuit-switched call between a personal cellular digital (PDC) network and a public switched telephone network (PSTN), ie, a fixed telephone network (not shown in FIG. 1) to which the gateway node GN can be connected. Circuit switching gateway mobile service switching center (GMSC). The mobile service switching center also performs a mobile station call function when it receives a voice call or short message service (SMS) message.

  The system further comprises a packet mobile service switching center PMSC connected to the mobile service switching center MSC. The packet mobile service switching center controls many radio resources TRX accommodated in the base station system BSS. In order to simplify the explanation, the base station system is only one base station system BSS, although it is not limited. For example, a mobile station MS such as a mobile phone, a personal digital assistant (PDA), or a computer adapted to perform mobile communications is linked to the base station system BSS by a radio link. The mobile station MS is registered in the terminal registration area (TRA) of the packet mobile service switching center PMSC. The terminal registration area is a geographical area covered by the packet mobile service switching center PMSC. The packet mobile service switching center PMSC stores and provides a packet data exchange function between the mobile station MS and the network, in particular, Internet Protocol (IP) content for the mobile station MS (not shown in FIG. 1). Control the server. In addition, the packet mobile service switching center PMSC assigns a dynamic internet protocol address to the mobile station MS when the mobile station wishes to sign up an end-to-end packet data session to the application server. Provides a connection based on the Internet protocol of the mobile station MS. The packet mobile service switching center routes and forwards Internet protocol packets that leave the mobile station MS or arrive from the mobile station MS.

  Therefore, the registered mobile station MS is engaged in a packet data session with the packet mobile service switching center PMSC. That is, the mobile station MS goes “online”. When engaged in a packet data session with the packet mobile service switching center PMSC, at least one of the radio link and the packet data channel is shared, and other mobile stations (not shown in FIG. 1) also have this You may enable it to use at least any one of a link or this channel.

  Still referring to FIG. 1, the mobile service switching center MSC receives a circuit call request signal 1, i.e. a call message signal, e.g. an incoming voice call from the gateway node GN, or an incoming short message service (SMS) message. A voice call message signal indicating is received. A traffic channel, ie, a point-to-point bi-directional channel used to transfer voice / circuit user data and provide directed incoming voice calls or short message service (SMS) messages to the mobile station MS The mobile service switching center MSC finds in which cell the mobile station MS is located by identifying radio resources contained in the base station system BSS linked to the mobile station MS. Since the mobile service switching center MSC “knows” to which cell the identified radio resource belongs, the mobile service switching center MSC can conclude about the identity of the cell in which the mobile station MS is currently located. Thus, the cell itself in which the mobile station MS is located can be identified.

  In order to identify the radio resource, the mobile service switching center MSC sends a request signal 2 including a radio resource information signal request 3 to the packet mobile service switching center PMSC. The packet mobile service switching center PMSC has a mobile station currently connected to which user packet channel (UPCH for transferring user packet data point-to-point) for packet data session with the packet mobile service switching center PMSC. That is, that is, assigned. Furthermore, the packet mobile service switching center PMSC knows the identity of the radio resource (TRX) carrying this user packet channel. Accordingly, the packet mobile service switching center PMSC sends the requested radio resource information signal 3 to the circuit mobile service switching center MSC. The radio resource information signal 3 has information for identifying a radio resource (TRX) currently serving the mobile station MS. The mobile service switching center MSC therefore concludes with the identity of the cell in which the mobile station is located, and thus the geographical location where the mobile station MS is located. If the packet mobile service switching center PMSC further provides location information, the mobile service switching center MSC can conclude even the exact location of the mobile station MS in the identified cell. The mobile service switching center MSC achieves at least one of the identification of the cell in which the mobile station MS is located and the transmission resource linked to the mobile station MS without transmitting any signal to the mobile station MS. Therefore, a load on the air interface between the mobile station and the network is avoided.

  The mobile service switching center MSC then selects the radio resource TRX of the base station system that provides the traffic channel for the circuit-switched communication service indicated by the voice call message, for example for a voice call. Based on this selection, the mobile service switching center MSC may determine which traffic channel is closest to the packet channel in which the mobile station MS is engaged in an ongoing packet communication session. In this example shown in FIG. 1, the mobile service switching center MSC uses the same base station system BSS that already carries a packet data session between the mobile station MS and the packet mobile service switching center PMSC to transmit the radio resource TRX. select. The mobile service switching center MSC transmits a request signal 4 including a traffic channel information signal request 5 to the base station system BSS that accommodates the identified radio resource TRX. However, in some cases (not shown in FIG. 1), the mobile service switching center MSC, as described above, provides the same base station system BSS or BSS that provided the radio resource information signal 3 having information identifying the radio resource TRX. The traffic channel information signal 5 from the radio resource TRX is not requested. Another base station system BSS or radio resource TRX may provide a traffic channel located geographically closer to the packet data session channel. The base station system BSS sends the requested traffic channel information signal 5 having the identity of the traffic channel currently reserved for circuit switched communication between the mobile station MS and the network to the mobile service switching center MSC.

  The circuit mobile service switching center MSC forms a packet data call signal 6 having the information of the circuit call request signal 1 and at least the traffic channel information of the traffic channel information signal 5. The circuit mobile service switching center MSC transmits a packet data call signal 6 to the packet mobile service switching center PMSC. The packet mobile service switching center PMSC transmits the packet data call signal 6 to the base station system BSS having the identified radio resource TRX. The base station system BSS transmits a packet data call signal 6 to the mobile station MS. Preferably, the transmission is performed on a user packet channel (UPCH) used for ongoing packet data sessions between the mobile station MS and the packet mobile service switching center PMSC. However, in some cases, another packet data channel may be used for transmission. The mobile station MS uses the channel information included in the received packet data call signal 6 and responds to the information of the circuit call request signal 1 included in the received packet data call signal 6 in response to the indicated circuit switching communication. Can start.

  Although not shown in FIG. 1, in another embodiment of the present invention, the first type of switching means is provided as a switching means in a code division multiple access (CDMA) system, and the second type of switching means is A wireless local area network (also called a wireless LAN, WLAN), an exchange means often also called a wireless local area access network is provided. In particular, the first type of switching means is GGSN (Gateway GPRS (General Packet Radio Service) support node) or SGSN (Regional GPRS Support Node), as a mobile service switching node, or Home Location Registration (HLR) or It is provided as a node having a database that holds subscription information for each user who subscribes to the service of the network operator. The second type of switching means is provided as a wireless local area network management station or as a wireless local network control station. The wireless transmission means is preferably provided as a wireless local area network access point having a transceiver.

  Although not shown in FIG. 1, in one embodiment of the present invention, the first type of switching means is provided as a switching means in a code division multiple access 2000 (CDMA2000) system, and the second type of switching means. Is provided as a wireless local area network (wireless LAN) switching means.

  Although not shown in FIG. 1, in one embodiment of the present invention, the first type of switching means is provided as a global mobile communications service (UMTS) switching means and the second type of switching is provided. The means is provided as an exchange means for a wireless local area network (wireless LAN).

  Although not shown in FIG. 1, in another embodiment of the present invention, the first type of switching means is provided as a switching means for a pan-European digital mobile telephone system (GSM) system, and the second type of switching is provided. The means is provided as an exchange means for a wireless local area network (wireless LAN).

  Although not shown in FIG. 1, in another embodiment of the present invention, the first type of switching means is provided as a switching means for a worldwide mobile telecommunications service (UMTS) system and the second type of switching means. The exchange means is provided as an exchange means for a pan-European digital mobile telephone system (GSM) system.

It is a figure which shows the Example of this invention.

Claims (14)

From a first switching means (MSC) placed in a cellular communication network having a plurality of wireless transmitting means (TRX) for wireless communication with a mobile communication means (MS) to a second switching means (PMSC) A method of providing a paging signal to the mobile communication means (MS) engaged in the communication of:
An identification step in which the first switching means (MSC) identifies a radio transmission means (TRX) currently assigned to the mobile communication means (MS);
It said first exchange means (MSC) is providing the call signal the identified radio transmitting means (TRX), the call signal the mobile communication unit (MS) from the identified wireless transmitting means (TRX) And a providing step of transmitting
The identification step includes
The first exchange means (MSC) requesting wireless transmission means information (3) from the second exchange means (PMSC);
The first switching means (MSC) receiving the requested wireless transmission means information (3) including the identity of the wireless transmission means (TRX) currently assigned to the mobile communication means (MS). And
In the providing step, the first switching means (MSC) is further connected between the identified wireless transmission means (TRX) and the mobile communication means (MS) from the identified wireless transmission means (TRX). Requesting channel information (5) identifying a channel reserved for communication;
The first switching means (MSC) receiving the requested channel information (5) ;
Method according to claim 1, characterized in that the paging signal provided from the first switching means (MSC) to the identified radio transmitting means (TRX) has the identity of the reserved channel . The providing step includes
The first switching means (MSC) generating a second call signal (6) including the call signal, (1) and the identity of the wireless transmission means;
The second switching means wherein the first switching means (MSC) provides the second calling signal (6) and the second calling signal (6) to the identified radio transmitting means (TRX). (PMSC) and the identified radio transmission means (TRX) sends the second call signal (6) between the identified radio transmission means (TRX) and the mobile communication means (MS). the method according to claim 1, characterized in that a step of transmitting the mobile communication unit (MS) via a channel used for communication. 3. Method according to claim 1 or 2 , characterized in that the first switching means (MSC) are provided as circuit switching means operating in circuit switching mode . The method according to any one of claims 1 to 3 wherein the second replacement means (PMSC) is characterized in that it is provided as a packet-switching means operating in a packet switched mode. It said call signal A method according to any one of claims 1 to 4, characterized in that it is provided for signaling an incoming request for communication in the circuit-switched mode. It said call signal A method according to any one of claims 1 to 5, characterized in that it is equipped with incoming messages to signaling. A network node element provided as a first switching means (MSC) of a cellular communication network having a plurality of radio transmission means (TRX) for radio communication with mobile communication means (MS) placed in a network. And
The network node element is:
Identifying means for identifying radio transmitting means (TRX) currently assigned to said mobile communication means (MS);
Providing means for providing the call signal to the identified radio transmission means (TRX) for transmitting the call signal from the identified radio transmission means (TRX) to the mobile communication means (MS); ,
The identification means includes
It means for requesting the information of the wireless transmitting means (3) from the second exchange means (PMSC),
Wherein including the identity of the wireless transmitting means (TRX), and a step of receiving information (3) of the radio transmitting means to said request,
The providing means includes:
Channel information (5) for identifying a channel reserved for communication between the identified radio transmission means (TRX) and the mobile communication means (MS) from the identified radio transmission means (TRX) Means to request,
Means for receiving the requested channel information (5).
The network node element, wherein the call signal includes an identity of the reserved channel . The identification means further includes
Means for generating a second call signal (6) comprising said call signal, (1) and the identity of said wireless transmission means;
The identification means provides the second paging signal (6) to the second switching means (PMSC) for providing the second paging signal (6) to the identified radio transmission means (TRX). Then, the identified radio transmission means (TRX) uses the second mode paging signal (6) for communication between the identified radio transmission means (TRX) and the mobile communication means (MS). The network node element according to claim 7 , wherein the network node element transmits to the mobile communication means (MS) via a used channel. 9. The network node element according to claim 7 or 8, wherein the network node element is a circuit switching means adapted to operate in a circuit switching mode. A communication system comprising the network node element according to any one of claims 7 to 9 and second switching means. 11. The communication system according to claim 10, wherein the second switching means is a wireless local area network (WLAN) switching means. The communication system according to claim 10 or 11, wherein the first switching means is a gateway general packet radio service support node or a visited general packet radio service support node. The computer program which performs control which makes each said process of any one of Claims 1 thru | or 6 perform the said 1st exchange means (MSC) . A machine-readable medium having the computer program according to claim 13 .

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