WO2002039768A1

WO2002039768A1 - Method and arrangement for improved interwoven transfer of voice traffic and data traffic in a cellular telephony network

Info

Publication number: WO2002039768A1
Application number: PCT/SE2001/002486
Authority: WO
Inventors: Dave Larson
Original assignee: Telefonaktiebolaget Lm Ericsson
Priority date: 2000-11-13
Filing date: 2001-11-09
Publication date: 2002-05-16
Also published as: SE0004135D0; AU2002214479A1; SE0004135L; SE519689C2

Abstract

The invention relates to a method for improved interwoven transfer of voice traffic and data traffic in a cellular network of the GPRS-type, in which an incoming voice call to a subscriber terminal (MS) is given priority over an ongoing data call. The voice call is set up by a location request sent from a first switching center (G-MSC) to an HLR and a paging message sent from the HLR to a second switching center (S-MSC). The second switching center (S-MSC) pages the subscriber terminal (MS), and the second switching center (S-MSC) sends a TLDN (Temporary Location Directory Number) to the HLR, following which the HLR sends the TLDN to the first switching center (G-MSC) and the first switching center (G-MSC) sets up a direct connection (T1) to the subscriber terminal (MS). According to the invention, a message is sent to the subscriber terminal (MS) in connection with the paging, said message being intended for use by the user of the subscriber terminal.

Description

TITLE

Method and arrangement for improved interwoven transfer of voice traffic and data traffic in a cellular telephony network.

TECHNICAL FIELD

The present invention relates to a method and an arrangement for improved interwoven transfer of voice traffic and data traffic in a cellular telephony network, the invention making it possible to avoid an annoying "freeze-up" of a subscriber terminal, caused by an incoming voice call during an ongoing data call.

BACKGROUND

In modern cellular telephony networks, it is possible for users to utilize their mobile terminals for traditional voice calls, or alternatively for the transfer of data, for example for using the Internet. In certain such networks, for example the EGPRS-136, an incoming voice call to a subscriber is always given priority over an ongoing data call. This means that an incoming voice call will always be allowed to interrupt the data call, which will be disconnected or suspended, and replaced by the voice call.

In some systems, the incoming voice call is "paged" to the user, meaning that a message is sent from the system to the user's terminal, the cellular telephone, which helps the system to locate the user, and alerts the terminal to the fact that there is an incoming voice call. Following the paging, a regular connection is established between the switching center from which the voice call originates and the serving switching center for the subscriber. A drawback of this method is that in the time interval between the paging and the set-up of the direct connection, the user's terminal may be perceived by the user as having "frozen", i.e. it will not be possible for the user to transfer or receive any data without the user knowing why, which in turn will lead to the user being dissatisfied with the system and/or the terminal. SUMMARY OF THE INVENTION

There is thus a need for a solution to the problem described above, i.e. that in a cellular mobile telephony network in which an incoming voice call to a subscriber is given priority over an ongoing data call, with the subscriber being paged via a switching center, following which a direct connection is established to the subscriber, the subscriber's terminal will be perceived as "freezing up" in the interval leading up to the establishing of the direct connection to the calling party.

This problem is solved by the present invention in that it provides a method whereby a message is sent to the subscriber's terminal in connection with the paging, said message being intended for use by the user of the subscriber terminal.

Since the message is intended for the user of the subscriber terminal, as opposed to system messages which are intended for the terminal as such and which are never displayed to the user, the method according to the invention allows the system to, for example, include information regarding the incoming call, which opens up for a large number of possible services for the user. The user can, for example, simply be alerted to the existence of the incoming voice call, but there is also a wide variety of other possibilities which will be explored in depth in the detailed description below.

DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail below, with reference to the appended figures, in which

Fig 1 shows a rough block diagram of a system in which the invention can be applied, and Fig 2 shows a possible sequence of events in a system which uses the method according to the invention, including messages which may be exchanged in a system in order to implement the invention. EMBODIMENTS

Fig 1 shows a rough block diagram of a telephone system in which the invention may be used, and fig 2 shows a possible sequence of events in a method according to the invention and some messages which may be used in order to carry out the invention. Figs 1 and 2 will be used together in order to describe the invention, and the following abbreviations will be used in the figures and in the text below in order to describe the invention:

G-MSC: Gateway Mobile Switching Center

HLR: Home Location register

LOQ REQ: Location Request

MS: Mobile Station, e.g. a cellular telephone.

PSTN: Public Switched Telephony Network ROUT REQ: Routing Request

S-MSC: Serving Mobile Switching Center

TLDN: Temporary Location Directory Number

The invention is intended for use in a system in which a voice call has automatic priority over an ongoing data call, i.e. an incoming voice call to a subscriber will always be allowed to interrupt an ongoing data call. For this reason, in the following description of the invention, it will be assumed that initially the mobile subscriber (MS) in fig 1 , said mobile subscriber for example being a user of a of a cellular telephone, is using his telephone for the transfer of data, for example for viewing pages on the Internet.

As the subscriber is transferring data via his telephone (MS), a voice call intended for him is made at another point in the system. This call can originate at a variety of different locations and networks, but is shown in fig 1 as being switched via the PSTN, i.e. via a "landline". The PSTN realizes that the call is intended for a mobile subscriber, and forwards the call to a O- MSC, i.e. an Originating Mobile Switching Center. In order to find out where the subscriber for whom the call is intended is located, the O-MSC in turn sends a location request, LOG REQ, to an HLR, i. e. a Home Location Register.

The HLR knows where the subscriber is located, and sends a routing request, ROUT REQ, to the proper S-MSC, i.e. a Serving Mobile Switching Center, also known as a G/S-MSC. This can also be sent via a so called VLR. The S-MSC alerts the terminal, the cellular telephone, to the fact that there is an incoming voice call intended for that particular subscriber, which it does by sending a paging message, PAGE, to the terminal via an SGSN. In fig 1, antennas are also symbolically shown.

At this point in the procedure, according to the prior art, the terminal will interrupt the data call, and assume a "waif-position, i.e. the terminal will wait for the voice call to be connected, said connection being carried out in a fashion which will be described in more detail below.

The user of the terminal, the subscriber, will thus notice that the data transfer has ceased and that the terminal's activity is unaffected by his input until some time later, when the voice call is put through. The time span during which the terminal's activity is unaffected by the user's input can be in the order of seconds, and will be annoying to many users, causing dissatisfaction with the telephone as such, and with the operator of the cellular telephony network.

The present invention addresses the problem of user dissatisfaction caused by these factors by inserting a message, CALL ACCEPT, intended for the user of the terminal (MS) in connection with the paging, as shown in fig 2. Since the CALL ACCEPT message, as opposed to the messages used in the prior art, is intended for the user of the terminal, e.g. the mobile phone, it can be utilized to alert the user to the fact that he has an incoming voice call, and also in a wide variety of other ways, some of which will be listed below, but others ways of using this message will also become apparent to those skilled in the art. Preferably, the Call Accept message originates in the SGSN, although it can be made to originate in a number of different places in the system.

The message according to the invention can thus be used in order to display a text message or some other visual indication to alert the user to the fact that an incoming voice call has interrupted the data transfer. In connection with this, the user may also be given the choice of accepting the voice call or not. If he chooses to reject the voice call, he may be given the opportunity to redirect the voice call to another number, either a predefined number which can be chosen using only one button, or a number which the user chooses then and there. If the incoming voice call is to be connected to the user (MS), a "please wait" message could be displayed while the user waits for the voice call to be connected.

Another possibility of using a message according to the invention would, for example, be to let the CALL ACCEPT message include information about the origin of the incoming voice call, commonly known as "caller id", so that the subscriber may base his choice of whether to accept the voice call or not on this information.

The user's choice of how to handle the incoming voice call can be sent to the system in a message called "Call Accept acknowledge", as shown in fig 2. Both the Call Accept and the Call Accept acknowledge are shown in bold fonts in fig 2, to underline the fact that these are new messages enabled by to the invention.

In order to further facilitate the understanding of the system in which the invention is applied, the description will now briefly turn to steps known in the prior art: If the voice call is to be put through to the user (MS) following the paging, the S-MSC which has carried out the pre-routing returns a TLDN (Temporary Location Directory Number) to the HLR, which then forwards the TLDN to the O-MSC, following which a direct connection (T1) is set up between the O-MSC and the MS, enabling the calling party to communicate with the mobile subscriber (MS) via the PSTN which communicates with the O-MSC.

On the other hand, if the user chooses to reject the incoming voice call, there is no need for a TLDN to be returned to the HLR or the G-MSC. Instead, for example, another message could be returned, carrying information for the system on what to do with the incoming voice call, for example instructions to re-direct the incoming call to another number, or to a voice mail system etc. Alternatively, this information could be included in the TLDN-message which is returned by the MS.

Claims

1. Method for improved interwoven transfer of voice traffic and data traffic in a cellular telephony network of the GPRS-type, in which network an incoming voice call to a subscriber terminal (MS) is given priority over an ongoing data call, said voice call being set up in the following manner:

- a location request is sent from a first switching center (O-MSC) to an HLR,

- a routing request is sent from the HLR to a second switching center (S-MSC),

- the second switching center (S-MSC) pages the incoming voice call to the subscriber terminal (MS),

- the second switching center (S-MSC) sends a TLDN (Temporary Location Directory Number) to the HLR, - the HLR sends the TLDN to the first switching center (G-MSC),

- the first switching center (G-MSC) sets up a direct connection (T1) to the subscriber terminal (MS), characterized in that a message is sent to the subscriber terminal (MS) in connection with the paging, said message being intended for use by the user of the subscriber terminal.

2. A method according to claim 1 , in which method the message sent to the user alerts the user to the existence of the incoming voice call.

3. A method according to claim 2, in which method the message which is sent to the user is made to contain information regarding the incoming call.

4. A method according to claim 3, in which method the message sent to the user gives the user the opportunity to accept or reject the incoming voice call.

5. A method according to claim 3, according to which the user is given the opportunity to redirect the incoming voice call.

6. Method for improved interwoven transfer of voice traffic and data traffic in a cellular telephony network, in which network an incoming voice call to a subscriber's terminal (MS) is given priority over an ongoing data call, the subscriber (MS) being paged via a switching center (G-MSC, S-MSC), following which a direct connection (T1) is established to the subscriber (MS), the method being c h a r a c t e r i z e d i n that a message is sent to the subscriber's terminal (MS) in connection with the paging, said message being intended for use by the user of the subscriber terminal.

7. A method according to claim 6, in which method the message sent to the user alerts the user to the existence of the incoming voice call.

8. A method according to claim 7, in which method the message which is sent to the user is made to contain information regarding the incoming call.

9. A method according to claim 8, in which method the message sent to the user gives the user the opportunity to accept or reject the incoming voice call.