Providing individual subscriber services in a cellular mobile communications network

Claims

What is claimed is:

1. In a mobile communications system comprising a home location register coupled to a mobile services switching center, a method for providing a supplementary service to a calling subscriber, comprising the steps of:

sending a supplementary service category for the calling subscriber from the home location register to the mobile services switching center;

detecting, in the mobile services switching center, initiation of a call from the calling subscriber and presence of the supplementary service category for the calling subscriber;

sending a supplementary service request from the mobile services switching center to the home location register in response to said detecting step;

receiving the supplementary service request in the home location register, and in response thereto, determining, in the home location register, call routing information in accordance with supplementary service parameters; and

sending the call routing information from the home location register to the mobile services switching center.

2. The method of claim 1, wherein the step of determining call routing information comprises translating a short number into a full number corresponding to a called subscriber.

3. In a mobile communications system comprising a home location register coupled to a mobile services switching center, a method for providing a supplementary service to a called subscriber, comprising the steps of:

detecting, in the mobile services switching center, initiation of a call from a calling subscriber to the called subscriber;

sending in response to the detected call initiation, from the mobile services switching center to the home location register, a request for a roaming number corresponding to the called subscriber;

sending in response to the request for a roaming number, from the home location register to the mobile services switching center, the roaming number and a call monitor command for the called subscriber;

using the roaming number in the mobile services switching center to route a call from the calling subscriber to the called subscriber;

detecting, in the mobile services switching center, a status condition and presence of the call monitor command for the called subscriber, the status condition being indicative of non-completion of the call from the calling subscriber to the called subscriber;

sending a supplementary service request and the status condition from the mobile services switching center to the home location register in response to said detecting step;

receiving the supplementary service request and the status condition in the home location register, and in response thereto, determining, in the home location register, supplementary call routing information in accordance with supplementary service parameters; and

sending the supplementary call routing information from the home location register to the mobile services switching center.

4. The method of claim 3, wherein the status condition is a busy indication, and the supplementary service is a call forwarding on busy supplementary service.

5. The method of claim 3, wherein the step of determining supplementary call routing information in accordance with supplementary service parameters comprises determining a first supplementary call routing information if the supplementary service request is received during a first time period, and determining a second supplementary call routing information if the supplementary service request is received during a second time period.

6. In a mobile communications system comprising a home location register coupled to a mobile services switching center, a method for providing a supplementary service to a called subscriber, comprising the steps of:

detecting, in the mobile services switching center, initiation of a call from a calling subscriber to the called subscriber;

sending in response to the detected call initiation, from the mobile services switching center to the home location register, a request for a roaming number corresponding to the called subscriber;

detecting, in the home location register in response to the request for a roaming number, an availability condition for the called subscriber;

sending, in response to the detected availability condition, an information request from the home location register to the mobile services switching center;

in the mobile services switching center, in response to receiving the information request, soliciting and subsequently receiving requested information from the calling subscriber;

sending the requested information from the mobile services switching center to the home location register;

using, in the home location register, the requested information to determine supplementary call routing information to a selected destination in accordance with supplementary service parameters;

sending, from the home location register to the mobile services switching center, the supplementary call routing information;

using the supplementary call routing information in the mobile services switching center to route a call from the calling subscriber to the selected destination.

7. The method of claim 6, wherein the requested information received by the mobile services switching center from the calling subscriber is in the form of a dual tone multi-frequency signal.

8. The method of claim 7, wherein the mobile services switching center converts the dual tone multi-frequency signal into a message containing the requested information for sending to the home location register.

9. The method of claim 6, wherein the availability condition indicates that the called subscriber is to receive only an important call, and that an unimportant call is to be routed to an alternative destination.

10. The method of claim 9, wherein the requested information indicates whether the calling subscriber is initiating the important call or the unimportant call.

11. In a mobile communications system comprising a home location register coupled to a mobile services switching center, a system for providing a supplementary service to a calling subscriber, comprising:

means for sending a supplementary service category for the calling subscriber from the home location register to the mobile services switching center;

means for detecting, in the mobile services switching center, initiation of a call from the calling subscriber and presence of the supplementary service category for the calling subscriber;

means, responsive to an output of said means for detecting, for sending a supplementary service request from the mobile services switching center to the home location register;

means for receiving the supplementary service request in the home location register, and in response thereto, determining, in the home location register, call routing information in accordance with supplementary service parameters; and

means for sending the call routing information from the home location register to the mobile services switching center.

12. The system of claim 11, wherein the means for determining call routing information comprises means for translating a short number into a full number corresponding to a called subscriber.

13. In a mobile communications system comprising a home location register coupled to a mobile services switching center, a system for providing a supplementary service to a called subscriber, comprising:

means for detecting, in the mobile services switching center, initiation of a call from a calling subscriber to the called subscriber;

means for sending in response to the detected call initiation, from the mobile services switching center to the home location register, a request for a roaming number corresponding to the called subscriber;

means for sending in response to the request for a roaming number, from the home location register to the mobile services switching center, the roaming number and a call monitor command for the called subscriber;

means for using the roaming number in the mobile services switching center to route a call from the calling subscriber to the called subscriber;

means for detecting, in the mobile services switching center, a status condition and presence of the call monitor command for the called subscriber, the status condition being indicative of non-completion of the call from the calling subscriber to the called subscriber;

means, responsive to an output of said means for detecting, for sending a supplementary service request and the status condition from the mobile services switching center to the home location register;

means for receiving the supplementary service request in the home location register, and in response thereto, determining, in the home location register, supplementary call routing information in accordance with supplementary service parameters; and

means for sending the supplementary call routing information from the home location register to the mobile services switching center.

14. The system of claim 13, wherein the status condition is a busy indication, and the supplementary service is a call forwarding on busy supplementary service.

15. The system of claim 13, wherein the means for determining supplementary call routing information in accordance with supplementary service parameters comprises means for determining a first supplementary call routing information if the supplementary service request is received during a first time period, and means for determining a second supplementary call routing information if the supplementary service request is received during a second time period.

16. In a mobile communications system comprising a home location register coupled to a mobile services switching center, a system for providing a supplementary service to a called subscriber, comprising:

means for detecting, in the mobile services switching center, initiation of a call from a calling subscriber to the called subscriber;

means for sending in response to the detected call initiation, from the mobile services switching center to the home location register, a request for a roaming number corresponding to the called subscriber;

means for detecting, in the home location register in response to the request for a roaming number, an availability condition for the called subscriber;

means for sending, in response to the detected availability condition, an information request from the home location register to the mobile services switching center;

means, responsive to receiving an information request in the mobile services switching center, for soliciting and subsequently receiving requested information from the calling subscriber;

means for sending the requested information from the mobile services switching center to the home location register;

means for using, in the home location register, the requested information to determine supplementary call routing information to a selected destination in accordance with supplementary service parameters;

means for sending, from the home location register to the mobile services switching center, the supplementary call routing information; and

means for using the supplementary call routing information in the mobile services switching center to route a call from the calling subscriber to the selected destination.

17. The system of claim 16, wherein the requested information received by the mobile services switching center from the calling subscriber is in the form of a dual tone multi-frequency signal.

18. The system of claim 17, wherein the means for sending the requested information from the mobile services switching center to the home location register converts the dual tone multi-frequency signal into a message containing the requested information for sending to the home location register.

19. The system of claim 16, wherein the availability condition indicates that the called subscriber is to receive only an important call, and that an unimportant call is to be routed to an alternative destination.

20. The system of claim 19, wherein the requested information indicates whether the calling subscriber is initiating the important call or the unimportant call.

21. A mobile services switching center, comprising:

means for receiving, from the home location register, a supplementary service category for a calling subscriber;

means for detecting initiation of a call from the calling subscriber and presence of the supplementary service category for the calling subscriber;

means, responsive to an output of said means for detecting, for sending a supplementary service request from the mobile services switching center to the home location register;

means for receiving, from the home location register, call routing information that has been determined in accordance with supplementary service parameters.

22. The mobile services switching center of claim 21, wherein initiation of a call from a calling subscriber includes receiving a short number corresponding to a called subscriber, and wherein the call routing information is a full number corresponding to the called subscriber.

23. A mobile services switching center, comprising:

means for detecting initiation of a call from a calling subscriber to a called subscriber;

means for sending in response to the detected call initiation, from the mobile services switching center to a home location register, a request for a roaming number corresponding to the called subscriber;

means for receiving, from the home location register, the roaming number and a call monitor command for the called subscriber;

means for using the roaming number to route a call from the calling subscriber to the called subscriber;

means for detecting a status condition and presence of the call monitor command for the called subscriber, the status condition being indicative of non-completion of the call from the calling subscriber to the called subscriber;

means, responsive to an output of said means for detecting, for sending a supplementary service request and the status condition from the mobile services switching center to the home location register; and

means for receiving, from the home location register, supplementary call routing information that is determined in accordance with supplementary service parameters.

24. The mobile services switching center of claim 23, wherein the status condition is a busy indication, and the supplementary service is a call forwarding on busy supplementary service.

25. The mobile services switching center of claim 23, wherein the supplementary call routing information is a first supplementary call routing information if the supplementary service request is sent during a first time period, and a second supplementary call routing information if the supplementary service request is sent during a second time period.

26. A mobile services switching center, comprising:

means for detecting initiation of a call from a calling subscriber to a called subscriber;

means for sending to a home location register in response to the detected call initiation, a request for a roaming number corresponding to the called subscriber;

means for receiving an information request from the home location register;

means, responsive to receiving an information request, for soliciting and subsequently receiving requested information from the calling subscriber;

means for sending the requested information from the mobile services switching center to the home location register;

means for receiving, from the home location register, supplementary call routing information to a destination that is selected in response to the requested information; and

means for using the supplementary call routing information in the mobile services switching center to route a call from the calling subscriber to the selected destination.

27. The mobile services switching center of claim 26, wherein the requested information received by the mobile services switching center from the calling subscriber is in the form of a dual tone multi-frequency signal.

28. The mobile services switching center of claim 27, wherein the means for sending the requested information from the mobile services switching center to the home location register converts the dual tone multi-frequency signal into a message containing the requested information for sending to the home location register.

29. The mobile services switching center of claim 26, wherein the requested information indicates whether the calling subscriber is initiating an important call or an unimportant call.

30. A home location register, comprising:

means for receiving a supplementary service request from a mobile services switching center, the supplementary service request indicating that a calling subscriber is initiating a call;

means, responsive to receipt of the supplementary service request, for determining call routing information in accordance with supplementary service parameters; and

means for sending the call routing information from the home location register to the mobile services switching center.

31. The home location register of claim 30, wherein the means for determining call routing information comprises means for translating a short number into a full number corresponding to a called subscriber.

32. A home location register, comprising:

means for receiving, from a mobile services switching center, a request for a roaming number corresponding to a called subscriber;

means, responsive to the roaming number request means, for determining that the called subscriber is to receive a called subscriber supplementary service;

means, responsive to an output of the determining means, for sending, to the mobile services switching center, the roaming number for routing a call from a calling subscriber to the called subscriber, and a call monitor command for the called subscriber;

means for receiving, from the mobile services switching center, a supplementary service request and a status condition indicative of non-completion of the call from the calling subscriber to the called subscriber;

means, responsive to an output of the supplementary service request receiving means, for determining supplementary call routing information in accordance with supplementary service parameters; and

means for sending the supplementary call routing information from the home location register to the mobile services switching center.

33. The home location register of claim 32, wherein the status condition is a busy indication, and the supplementary service parameters correspond to a call forwarding on busy supplementary service.

34. The home location register of claim 32, wherein the means for determining supplementary call routing information in accordance with supplementary service parameters comprises means for determining a first supplementary call routing information if the supplementary service request is received during a first time period, and means for determining a second supplementary call routing information if the supplementary service request is received during a second time period.

35. A home location register, comprising:

means for receiving, from the mobile services switching center, a request for a roaming number corresponding to a called subscriber;

means for detecting, in response to an output of the roaming number request receiving means, an availability condition for the called subscriber;

means for sending, in response to the detected availability condition, an information request from the home location register to the mobile services switching center;

means for receiving the requested information from the mobile services switching center;

means for using the requested information to determine supplementary call routing information to a selected destination in accordance with supplementary service parameters; and

means for sending the supplementary call routing information to the mobile services switching center.

36. The home location register of claim 35, wherein the availability condition indicates that the called subscriber is to receive only an important call, and that an unimportant call is to be routed to an alternative destination.

37. The home location register of claim 36, wherein the requested information indicates whether the calling subscriber is initiating the important call or the unimportant call.

BACKGROUND

The present invention relates to a system for providing individual supplementary subscriber services in a cellular mobile communications network, and more particularly to the use of a home location register for implementing individual supplementary subscriber services in a cellular mobile communications network.

A primary characteristic of a mobile communications system, such as a cellular telephone system, is the fact that subscribers to the system may move around. Accordingly, such systems are typically realized as a network of neighboring radio cells which together provide complete coverage of the area to be serviced. Each cell has a Base Station (BS) operating on a set of radio channels. The set of radio channels assigned to a given cell is different from the channels used in neighboring cells in order to avoid interference. A group of BS's is controlled by a Mobile services Switching Center (MSC), which controls calls to and from the Public Switched Telephone Network (PSTN), Integrated Services Digital Network (ISDN), and Public Land Mobile Network (PLMN). In a cellular telephone system, the role of the MSC is equivalent to that of the local exchange in the fixed network. That is, the MSC is responsible for handling tasks such as switching, routing and charging.

It is desirable to provide a mobile subscriber with a uniform set of services that he can use independent not only of his current location, but also independent of which operator is serving his current location. For this reason, well-known cellular systems such as the Nordic Mobile Telephone System (NMT), the Total Access Communication System (TACS), Advanced Mobile Phone System (AMPS), American Digital Cellular System (ADC), the Global System for Mobile Communication (GSM), and the Pacific Digital Cellular System (PDC) have all adopted standardized techniques for providing both basic as well as supplementary services to a roaming subscriber. As used in this specification, the term "basic service" refers to the ability of a communication network to simply establish a call. The term "basic service" will also refer here to those services, such as three party calling, which are available to all subscribers without requiring an individual subscription to a service. In contrast, the term "supplementary service" refers to all of those capabilities, in mobile as well as fixed networks, which go beyond those services which are considered "basic", and which do require an individual subscription before that service can be invoked. Individual supplementary subscriber services may be divided into two types: those which modify or supplement the process of originating a call (referred to here as "A-subscriber services"), and those which modify or supplement the process of terminating (i.e., receiving) a call, referred to here as "B-subscriber services"). A-subscriber services include, but are not limited to: barring of outgoing calls, and private numbering plans. B-subscriber services may be broken down into those which are invoked unconditionally, regardless of the status of the called subscriber or the network, and those whose invocation depends on a particular status or condition being present at the subscriber or in the network. Unconditional B-subscriber services include, but are not limited to: barring of incoming calls; call forwarding, unconditional. Conditional B-subscriber services include: call forwarding on busy; call forwarding on no reply; call forwarding on congestion; and call waiting. The operations and implementations of such cellular systems are well known in the art, and described in numerous publications. For example, the GSM standard is described as part of the ETSI standard. GSM specifications 02.82-02.89, 03.81-03.90, 04.10, and 04.80-04.90 are hereby incorporated by reference. ADC is based on the IS-54 standard. A detailed description of any of these well-known systems is beyond the scope of the present discussion. However, features of these systems which are pertinent to the present invention will be briefly outlined below.

In order to be able to place a call which terminates at a mobile station (MS) whose whereabouts may be continually changing, a data base is required in the network for keeping track of a particular MS. The above cellular systems have adopted the use of a data base called the Home Location Register (HLR), which is implemented as a node in the mobile radio communication network. The HLR for use in GSM is described in GSM specifications 09.02, 03.12 and 03.08, which are hereby incorporated by reference. When someone subscribes to receive service from an operator, such as any of the ones mentioned above, his subscription is entered in the HLR of that operator. The HLR contains subscriber information, such as supplementary services. Furthermore, the HLR stores information about the location of the MS, which information identifies the MSC serving the present location of the MS. This information is updated as the MS moves around by having the MS send location information to its HLR by means of an MSC.

Thus, when an MS roams into a new MSC area, it registers with that MSC, which in turn requests data about the MS from the HLR. At the same time, the HLR is informed of which MSC area the MS is presently located in. If, later on, the MS wants to make a call, the MSC will already have the information needed for the call set-up without having to interrogate the HLR each time.

In addition to basic subscriber services, individual supplementary subscriber services may also be supported. As mentioned above, these include, for example, call forwarding on busy, and private numbering plans (i.e., the MS's use of a personally selected "short number" for placing a call to a recipient whose full number is known and used by the system). The HLR typically plays a part in managing individual supplementary subscriber services in that, in addition to storing the present location of a roaming subscriber as described above, the HLR may also store subscriber categories and call forwarding numbers. The HLR updates subscriber category information and forwarding numbers (i.e., "C-numbers") in its memory when requested to do so by an authorized terminal (i.e., a terminal in the wirebound network with the associated subscription number, or a mobile radio terminal which has authenticated itself as the subscriber terminal). The HLR transmits selected parts of this information to an interrogating MSC on the occasion of registration of a roaming MS, and to a gateway MSC (GMSC) on the occasion of MS-terminated calls as explained in more detail below. However, no information is transmitted to an MSC merely because an MS is originating the call (e.g., a mobile station calling a wirebound subscriber).

In a typical network, then, A-subscriber services and conditional B-subscriber services are provided by the MSC, based on the subscriber categories provided to the VMSC by the HLR at the time of registration. There is no need for the MSC to again contact the HLR at the time of call setup. Also, in the prior art, the HLR is not capable of making conditional decisions because the standardized MSC-HLR interface does not include the ability to report subscriber status (e.g., busy, no answer, etc.) to the HLR, nor does it allow the conveyance of commands depending on such input. By contrast, unconditional B-subscriber services are invoked by the HLR because a call to a mobile subscriber always means that the first MSC contacted (i.e., the GMSC) will consult the HLR in order to learn the whereabouts of the subscriber. At this time, the HLR is in the best position to handle unconditional services such as barring an incoming call, or sending to the GMSC the C-number to which the call is to be unconditionally forwarded.

In order to standardize the means of communication between an HLR and an MSC, cellular communications systems have adopted the use of the Mobile Application Part (MAP) of the communications protocol known as CCITT Signaling System No. 7. Recommendations Q.701-707, Q.711-714 and Q.771-775 in CCITT's "Blue Book" are hereby incorporated by reference. There are different variants of the MAP protocols for use with correspondingly different cellular standards (GSM, ADC, PDC, etc.).

As new supplementary services are developed, it is necessary to be able to quickly incorporate them into existing mobile and non-mobile (i.e. "fixed") communications networks. In fixed networks, rapid service development is achieved by the use of a network definition known as Intelligent Network (IN). The idea of IN is to provide intelligent nodes in the network which may be consulted by other nodes in the network and updated from other nodes. Intelligent nodes consist of data processing equipment connected to other nodes only via data links for signaling. Intelligent nodes do not have switched user connections for speech or for user data transfer. Consequently, they may be accessed via data links only from particular other nodes in the network, such as service switching points (SSPs) in the PSTN. In accordance with the IN concept of functional entities, new services are introduced by adding new program modules in the IN-nodes, each corresponding to an IN functional entity. For example, a services control point (SCP) is the node in the network where most of the service logic resides. A services switching point (SSP), as described above, is the node that handles the switching functions necessary to enable the services invoked by the SCP.

These nodes correspond to functional entities which have been defined by the IN standards presented in CCITT Recommendation Q.1218, which is hereby incorporated by reference. The SCP is the hardware node corresponding to the service control function (SCF), and the SSP is the hardware node corresponding to the service switching function (SSF). Another function, the service data function (SDF), is also implemented in the SCP. It stores the service data needed for the SCF. Communication between the SSF and the SCF (and therefore, between the SSP and the SCP) is by means of a protocol called the Intelligent Network Application Part (INAP), which is also an application on CCITT no. 7.

The use of the IN network addresses the problem of how to rapidly implement new supplementary services in a fixed network. However, the IN network has been developed without consideration for the problem of how to provide these same new supplementary services in a cellular environment, in which subscribers are mobile. As a result, a number of proprietary solutions for use in the cellular environment now exist, producing a situation in which some supplementary services are implemented in the HLR, and other services are implemented in the SCP. Furthermore, management and implementation of most supplementary services within the cellular environment is distributed between the MSC and the HLR.

This approach impedes the rapid development of new services because the introduction of a supplementary service often not only requires a change to the HLR for management of the service and a change to the MSC for invocation of the service, but it also often requires a modification of the MAP protocol between the HLR and the MSC in order to permit the transferring of the supplementary services data between the HLR and the MSC. Consequently, the introduction of supplementary services in a cellular system requires a very long lead time, due to the number of nodes that must be updated with new software, and the fact that the operator usually wants the new service to be available throughout the entire network before being offered to the subscribers, so that all MSC's in the network must be updated before a new service is offered to the mobile subscribers.

As mentioned above, the IN solutions in the fixed network environment achieve rapid introduction of new services as a result of the functional division between the SCF and the SSF, in which the complete individual service logic resides in the SCF, and the SSF only performs generic switching functions (e.g., monitor and report call events, se