WO2001015419A1

WO2001015419A1 - Controlling connection of queuing subscribers

Info

Publication number: WO2001015419A1
Application number: PCT/FI2000/000703
Authority: WO
Inventors: Harri Aalto
Original assignee: Nokia Corporation
Priority date: 1999-08-20
Filing date: 2000-08-18
Publication date: 2001-03-01
Also published as: AU6574500A

Abstract

By means of the invention, first parties (A1, A2,...) waiting for a second party (B) to become free are controlled in a telecommunication system. In the method, a priority, i.e. an urgency value, is given to at least some of the first parties (A1, A2,...), and when the second party becomes free, the first party (A1, A2,...) in a call-back queue to which a connection is established from the second party is selected at least partly on the basis of the priority.

Description

CONTROLLING CONNECTION OF QUEUING SUBSCRIBERS

BACKGROUND OF THE INVENTION

The invention relates to a mechanism for connecting queuing subscribers and providing subscribers with a service. To illustrate the invention, but not, however, to restrict it, the invention will be described in connection with a mobile communication system, particularly the GSM system (Global System for Mobile Communications), but it can also be used for other telecommunication systems. Figure 1 shows parts of a prior art system diagram of the GSM system, which are essential for un- derstanding the invention. The figure also illustrates cases where a subscriber A calls a subscriber B who is busy, the subscriber A activates a CCBS service (Call Completion to Busy Subscriber) and the subscriber A remains to queue for a call-back from the subscriber B.

The CCBS refers to a service comprising many different functions (e.g. activation, monitoring, free indication, queuing and recall), whereby a first subscriber has first called a second subscriber who is busy and a call is made from the second subscriber to the first subscriber after the second subscriber becomes free, if the first subscriber has remained to queue for the second subscriber to become free. A call-back queue refers to a queue formed of first subscribers who wait for the second subscriber to become free.

For a more detailed description of the GSM system, it is referred to the work "The GSM System for Mobile Communications", M. Mouly and M. Pautet, Palaiseau, France, 1992, ISBN:2-9507190-0-0-7. For a more specific description of the CCBS service, it is referred to the GSM recommendations Completion of Calls to Busy Subscriber (CCBS); Stage2 (GSM 03.93, version 6.0.0) and Completion of Calls to Busy Subscriber (CCBS); Stage3 (GSM 04.93, version 6.0.0; Release97).

In Figure 1 , MSa (MS, Mobile Station) represents a mobile station of a subscriber A and MSb represents a mobile station of a subscriber B. In this example, the mobile stations are located in networks having different operators. As the subscriber A calls the subscriber B, the MSa transmits in step 1-2 a call establishment request to that centre MSCa/VLRa (MSCΛ/LR, Mobile Switching Centre/Visitor Location Register) to which the subscriber A belongs at the moment of transmission. The centre MSCaVLRa communicates with other centres, and it is connected via the gateway mobile services switching centre GMSC to other networks, such as the public switched telephone network PSTN or another mobile telephone network PLMN (Public Land-based Mobile Network).

The call is routed in step 1-4 from the centre MSCa/VLRa to the first centre of the network of the subscriber B, i.e. to the gateway mobile services switching centre GMSC, which requests in the next step 1-6 for call routing data for the subscriber B from the home location register HLRb of the subscriber B. On the basis of the signalling between the home location register HLRb of the subscriber B and the centre MSCb/VLRb, the call can be directed to the proper centre in step 1-8, and by means of the routing data of the subscriber B, which is returned in step 1 -10 to the gateway mobile services switching centre GMSC, the GMSC routes the call in step 1-12 to that centre MSCb/VLRb, in whose area the subscriber B is.

Since the subscriber B is busy, information on connection release is transmitted from the centre MSCb/VLRb to the gateway mobile services switching centre GMSC in step 1-14 and further to the centre MSCa/VLRa in step 1-16. In step 1-18, the MSa user hears a busy tone. As the centre MSCa/VLRa receives the information on the connection release, it also receives the information that the subscriber B uses the CCBS property and that the CCBS service can be activated. If the subscriber A wants to activate itself to a call-back queue, it transmits in step 1 -20 a CCBS activation request to its own centre MSCa/VLRa, from which the request is routed in step 1-22 to the home location register HLRa of the subscriber A and further in step 1-24 to the home location register HLRb of the subscriber B. According to the prior art, a call-back queue 1-40 is formed to the home location register of the subscriber B of calls arrived at the subscriber B in chronological order such that the call that has arrived first is the first in the queue. The above prior art CCBS functionality allows the GSM system to have five different subscribers queuing for a call-back from the subscriber B. When the subscriber B is busy, the centre MSCb/VLRb monitors the state of the subscriber B. After the subscriber B becomes free, the centre MSCb/VLRb transmits the HLRb the information that the subscriber B is free and available. The HLRb transmits the information on the free subscriber B (RemoteUserFree, RUF) to the subscriber A that is first in the queue, and the call of the subscriber A is routed to the centre of the subscriber B and further to the mobile station MSb of the subscriber B in step 1-30. A network element performing a certain service switching function (SSF) of the intelligent network, called a service switching point SSP, can also be connected to the centre MSCb/VLRb. An intelligent network service is achieved such that when detection points associated with the services are en- countered, the service switching point SSP requests the service control point SCP for instructions by means of messages, i.e. operations, to be transmitted over the SSP/SCP interface. In connection with the intelligent network service, a service program is started in the service control point SCP, the operation of which service program defines the operations that are transmitted by the SCP to the SSP at each stage of a call.

If the mobile stations MSa and MSb are located in the area of the same network, the call establishment via the gateway mobile services switching centre GMSC is not required. In such a case, routing data are requested directly from the home location register HLRb. If the mobile stations MSa and MSb are located in the area of the same centre, also the signalling between the centres, i.e. steps 1-4, 1-6, 1-10 ... 1-16, are left out.

The problem in the above arrangements is that the subscriber B cannot influence on the order in which he receives queuing calls. Thereby a possible call from a subscriber which is more significant to the subscriber B may have to wait a relatively long time.

BRIEF DESCRIPTION OF THE INVENTION

The object of the invention is to develop a method and an apparatus implementing the method in such a manner that the above problem can be solved. The objects of the invention are achieved by a method and a system which are characterized in what is said in the independent claims. The preferred embodiments of the invention are disclosed in the dependent claims.

The invention is based on controlling the order in which queuing calls are connected according to the priority given by a subscriber B. This provides the advantage that the subscriber B can advance a possible important call in the queue.

According to a preferred embodiment of the invention, a priority list is stored in the home location register of the subscriber B. This provides the advantage that the arrangement of the list of queuers and the release of the queue can be performed rapidly. According to another preferred embodiment of the invention, a mobile station contains a menu from which a subscriber can give a priority list. This provides the advantage that the subscriber can easily configure a priority list without using difficult special characters, e.g. # and *. According to yet another preferred embodiment of the invention, the subscriber can check the priority list he has given from the home location register. This provides the advantage that the subscriber can correct the priorities he has given wrongly.

BRIEF DESCRIPTION OF THE FIGURES The invention will now be described in greater detail in connection with the preferred embodiments, with reference to the attached drawings, in which

Figure 1 shows a prior art system diagram and the steps in which a subscriber A calls a busy subscriber B; Figure 2 shows a signalling diagram associated with storage of a priority list according to an embodiment of the invention;

Figure 3 shows a signalling diagram according to an embodiment of the invention, whereby several subscribers A call the busy subscriber B;

Figure 4 shows how a priority list according to an embodiment of the invention is formed in the home location register of the subscriber B.

DETAILED DESCRIPTION OF THE INVENTION

The invention will be described in the following by using the functions and structure of the GSM mobile communication system as an example, but the invention can also be applied to other telecommunication systems which support a CCBS service or a corresponding service, to a fixed telephone network, for example.

After a subscriber B has performed a desired priorisation, the priority list is stored. The storage is made before a call is received. Figure 2 shows the signalling diagram associated with the storage of the priority list given by the subscriber. In step 2-2, the subscriber B MSb transmits subscriber numbers (e.g. IMSI, International Mobile Subscriber Identity) and priority values associated with the numbers, i.e. the priority list, to that centre MSCb/VLRb in whose area the subscriber B is. In step 2-4, these subscriber numbers and the priority list are forwarded to the home location register HLRb of the subscriber B to be stored. The priority list can be given directly from the menus of the mobile station by means of the interface MMI (Man Machine Interface) between the subscriber and the mobile station. Alternatively, for example a USSD message (Unstructured Supplementary Service Data) comprising a function, a sub- scriber number and a priority can be transmitted. This message can for example have the form #function#subscriber number#priohty#. Also the operator can update the subscriber numbers stated by the subscriber B and the desired priorities to the subscriber data of the HLRb.

If the list of prioritised subscribers is desired to be stored in the service control point SCP, instead of the home location register HLRb, the subscriber can enter the subscriber numbers and the related priorities via the mobile station MMI, which numbers and priorities are transferred in step 2-6 by means of a USSD operation from the HLRb to the SCP. In step 2-8, the HLRb is transmitted the information that the priorities are stored in the SCP. In step 2-10, either a positive or a negative acknowledgement is received from the home location register, in response to successful or unsuccessful storage of the priority, and the corresponding information is transmitted in step 2-12 to the mobile station.

When the subscriber B is free to receive a new call, the HLRb does not request for the connection of a call of the subscriber that is next in order, but checks the queuers according to the priority and the queuing order. The call of that subscriber A who has the highest priority and whose call is the first in the queue is established next.

If the SCP includes priority data, the HLRb requests for the priority data each time there is a new subscriber A in the queue. Alternatively, the HLRb retrieves all defined priority data when the first subscriber A appears in the queue. Then the HLRb stores the priority list it has received from the SCP, and the SCP inquiry need only be made in connection with the first queuer. After the subscriber B has replied to all queuing calls and is free of queuers, the home location register HLRb can delete the priority list that is retrieved to the HLRb. Compared to the SCP storage, the storage of the list in the home location register provides the advantage that the priority list need not be separately checked from the SCP, when a subscriber A appears in the queue.

If desired, the subscriber B can also scan and/or change the priority list it has given. In such a case, the subscriber B sets up a connection through the centre MSCb/VLRb to its home location register HLRb in which the priority list is stored. The subscriber B can give, add, delete or change subscriber numbers and/or priorities associated with them via a connectionless connection, e.g. as a short message, a USSD message or as some other signalling by means of a mobile station user interface, i.e. by utilizing mobile station menus. Alternatively, he can use a connection-oriented connection, e.g. a WAP protocol or even a personal computer by means of a network navigator, for example.

Figure 3 shows a signalling diagram according to an embodiment of the invention, whereby two subscribers A, A1 and A2, call a busy subscriber B. Details of a call establishment are explained in connection with Figure 1. Step 3-2 illustrates a normal call establishment between the subscriber A1 and the subscriber B. Since the subscriber B is busy, the CCBS service is possible and the subscriber A1 has a right to queue, A1 activates itself to a call-back queue in the home location register HLRb of the subscriber B. Step 3-4 illustrates a normal call establishment between the subscriber A2 and the subscriber B. Since the subscriber B is busy, the CCBS service is possible and the subscriber A2 has a right to queue, A2 also activates itself to the call-back queue in the home location register HLRb of the subscriber B.

In step 3-6, the subscriber B becomes free and the call-back queue is started to be released. In step 3-8, the centre MSCb of the subscriber B requests for a priority list from the HLRb, which priority list is returned to the centre MSCb in step 3-10. In step 3-12, the calls that queue to be connected to the subscriber B in the centre are arranged as a queue according to their priority and chronological order. Thus, a call is established first to that queuer on the list who has the highest priority and who has come to the queue first among those on the same priority level. Alternatively, the HLRb can arrange the list of queuers to its right order of release each time a new subscriber A appears in the queue, and according to the order of release the HLRb transmits the next subscriber A the information that the subscriber B is free. If the subscriber A2 has a higher priority than the subscriber A1 , a call is established between the subscriber A2 and the subscriber B in step 3- 14. As this call ends in step 3-16, the HLRb transmits the next subscriber A in the queue the information that the subscriber B is free. Thereafter, a call is established between the subscriber A1 and the subscriber B in step 3-18. If desired, the subscriber B can also prevent a subscriber A from coming to the queue by means of a specific character to be stored in the prior- ity list, for example. In such a case the HLRb of the subscriber B does not place the subscriber A to the queue but tells the subscriber A for example that the CCBS service has not been successful. If the subscriber B has not given priority to some subscriber A and the subscriber B has not prevented the sub- scriber A from coming to the queue, a default priority, e.g. the lowest priority, can be given to the subscriber A.

Figure 4 shows how a priority list according to an embodiment of the invention is formed in the home location register HLRb of the subscriber B. The column 4-2 contains the identifier of queuing subscribers A and the col- umn 4-4 contains the priority values given to these subscribers A. For example, the value 4 is given as a priority to the subscriber A2. Since the subscriber A3 has no right to queue, he does not get any priority value. This is indicated by the character -.

Steps 4-6 ... 4-10 illustrate a new call coming to the subscriber B and steps 4-20 ... 4-24 illustrate a new call-back queue in the HLRb. The callback queue comprises a new queuer, if the new queuer has a permission to queue, and previous queuers, if there are previous calls in the queue. The queue is arranged according to the priorities of the calls, and the calls with the same priority are also arranged according to the order in which the calls have arrived. The time axis 4-40 illustrates the course of events.

In step 4-6, A1 calls the subscriber B, who is busy. Since the subscriber B has the CCBS service and the subscriber B has not prevented the subscriber A1 from queuing, A1 is allowed to activate itself to the call-back queue. Further, since A1 is the first queuer, the new call-back queue only comprises the subscriber A1. This is illustrated as the subscriber A1 in the column 4-20.

In step 4-8, the subscriber A2 calls the subscriber B, who is still busy. A2 is also allowed to queue, and A2 activates itself to the call-back queue. Since A2 is the second queuer, the new call-back queue comprises the subscriber A1 and the subscriber A2. Further, since the priority of A2 is higher than that of A1 , A2 is before A1 in the new call-back queue. This is illustrated in the column 4-22.

In step 4-10, the subscriber A3 calls the subscriber B, who is still busy. Since the subscriber A3 has no right to queue, A3 cannot activate itself to the call-back queue either, and the call of A3 is disconnected. In step 4-24 there are two subscribers, the subscribers A2 and A1 , in the order indicated by their priorities, that queue to be connected to the subscriber B who is busy after the above situation.

It is obvious to a person skilled in the art that as technology devel- ops, the basic idea of the invention can be implemented in various ways. The invention and the embodiments thereof are thus not restricted to the above examples, but may vary within the scope of the claims.

Claims

1. A method of controlling first parties (A1, A2,...) waiting for a second party (B) to become free in a telecommunication system, in which method the first parties try to establish a connection with the second party, and when the second party is busy, information on attempts of at least some of the first parties is stored in a queue (4-20...4-24); and when the second party (B) becomes free, a connection is established from the second party to such a first party (A1, A2, ...) on whose attempt the information is stored in the queue, characterized in that per at least one second party (B), a corresponding priority is set for at least some of the first parties (A1, A2,...); if the queue contains information on attempts of several first parties when the second party becomes free, the selection of the first party (A1, A2,...) to which a connection is established from the second party is per- formed at least partly on the basis of the priority.

2. A method as claimed in claim ^characterized by storing the first party (A1, A2,...) in the queue on the basis of the priority.

3. A method as claimed in claim 1, characterized by releasing the first party (A1, A2,...) from the queue on the basis of the priority.

4. A method as claimed in claim 1, characterized by the telecommunication system comprising a digital mobile communication network.

5. A method as claimed in claim 1, characterized by the second party (B) setting the priorities, preferably by means of a mobile station user interface.

6. A method as claimed in claim 5, characterized by the second party setting, adding, deleting or changing the priority by means of a connectionless connection, preferably a short message or a USSD message.

7. A method as claimed in claim 5, characterized by the second party setting, adding, deleting or changing the priority by means of a connection-oriented connection, preferably a WAP protocol or a protocol used by a network navigator.

8. A method as claimed in claim 4, 5, 6 or 7, characterized by the set priorities being stored (2-4) in a home location register (HLRb).

9. A method as claimed in claim 4, 5, 6 or 7, characterized by the set priorities being stored (2-6) in a network element of the intelligent network, preferably in a service control point (SCP).

10. A method as claimed in claim 1, characterized by the operator of the telecommunication system setting the priorities.

11. A switching centre (MSCb/VLRb) which is arranged to control first parties (A1, A2,...) waiting for a second party (B) to become free in a telecommunication system, which first parties try to establish a connection with the second party; and when the second party (B) is busy, store information on attempts of at least some of the first parties in a queue (4-20...4-24); and when the second party (B) becomes free, establish a connection from the second party to such a first party (A1, A2, ...) on whose attempt the information is stored in the queue, characterized in that the switching centre (MSCb/VLRb) is arranged to receive and store a corresponding priority that is set for at least some of the first parties (A1, A2,...) per at least one second party (B); and if the queue contains information on attempts of several first parties when the second party becomes free, select at least partly on the basis of the priority the first party (A1 , A2,...) to which a connection is established from the second party.

12. A mobile station (MSb), characterized in that it comprises: a user interface for setting priorities to several subscribers A; and means for transmitting the set priorities to a mobile communication network to select the subscriber A to which a connection is established after the mobile station frees from the busy state, after several subscribers A have tried to establish a connection with the mobile station (MSb).