HK1087281B - Reporting credit/charging information to a mobile subscriber - Google Patents

Description

Method and apparatus for transmitting deposit/charge information to mobile station

The application is a divisional application of an invention patent application with Chinese patent application No. 99811466.9, application date 28/9 1999, and a title "reporting deposit/charge information to mobile users".

The technical field is as follows:

the present invention relates to methods and apparatus for reporting billing information to mobile subscribers, including, for example, reporting the total value of available credit to a prepaid subscriber. In mobile communication systems such as GSM, the use of prepaid SIM (Subscriber Identity Module) cards is increasing. The prepaid SIM card frees the network operator of the deposit loss. They enable parents to preset an upper limit on their children's phone bills. As a third benefit, they enable roaming users to pay their local calls according to a local tariff, while the use of the SIM card of their home operator results in paying an international tariff for the network of their home.

Background art:

one problem with prepaid SIMs is: current mobile stations (handsets) are not equipped with means for automatically displaying deposit related information such as the current deposit status immediately after a call is ended. Some operators allow users to call an Interactive Voice Response (IVR) service to report a valid credit through an integrated report. Such services cause another problem: the use of IVR results in a significant amount of overhead traffic in the radio interface. This non-billable traffic consumes resources that could be better used on pay phones.

The invention content is as follows:

it is an object of the present invention to provide a means for reporting available credit status to a prepaid subscriber, in part allowing for a reduction in the overhead traffic load in the radio interface. In order to discourage a user from calling an IVR, the apparatus according to the invention must be fast enough so that the user does not experience annoying delays.

According to one embodiment, at call termination, a Service Logic Program (SLP) processing calls in a Service Control Point (SCP) sends the credit information (e.g., via a LAN connection) to a program running on a separate processor or workstation WS. This program then reformats it and passes the information (e.g., over another LAN) to a Short Message Service Center (SMSC) which sends the actual short message to the mobile station. The LAN connection may be a standard TCP/IP connection. The protocol between the SCP and the workstation may be a special protocol used through an Application Programming Interface (API). The protocol used between WS and SMSC such as Nokia is called the computer interface for message distribution 2 (CIMD-2). Programs running on a workstation are typically written in C + +. To use the API, a programmer would have to insert statements in the business logic program (SLP) and write a separate C + + program for receiving this information. CIMD-2 is a simple character based protocol where a client operation makes a request to a server and the server responds.

The basic idea behind the solution is to use the interfaces mentioned above for a direct connection from the SCP to the SMSC, thereby reducing the delay from call termination over the time the information is sent as an SMS. This short time is a major advantage of this solution and experiments performed by the inventors on a test platform have shown that the mobile station can receive the short message within 1 to 5 seconds from call termination.

Alternatively, disconnection of the call will be deferred so that a separate paging message is not necessary to transmit the message according to the present invention.

Preferably, this information is extracted from the SCP, since no problems due to propagation delays will occur. The SLP (service logic program that handles the call) executing on the SCP provides functionality for communicating with an external operation through a gateway between the service running within the Service Logic Execution Environment (SLEE) and the external application. More particularly, the SLP may send messages to an external operation through a socket. The external operation runs on a separate computer or workstation so it does not affect the performance of the SCP. The SLP processing the prepaid call runs throughout the call because it controls credit updates. This means that it will know when the call has ended. It is possible to transmit information required for an external operation by adding some SLP codes at the end of the SLP paid in advance.

Yet another solution is to use an SS7 network for sending information between the SCP and the SMSC. This solution obviously requires the use of the MAP protocol. As an advantage, no new elements (network connections, procedures) will be introduced.

According to one aspect of the present invention there is provided a method for transmitting credit/charging information to a mobile station in a cellular telecommunications system, the method comprising the steps of: a) maintaining deposit/charging information associated with a subscriber of said mobile station in an intelligent network node; b) detecting a call setup request, said call setup request indicating that a call is billed by said subscriber of said mobile station but does not include said credit/billing information; c) determining the deposit/charging information maintained in the intelligent network node according to the call establishment request; d) establishing a call; characterized in that the method further comprises the following steps: e) detecting termination of the call in response to the detecting; f) updating the credit/charging information maintained in the intelligent network node; and g) upon detecting termination of the call, sending the credit/billing information to the mobile station as a connectionless message.

According to another aspect of the present invention there is provided an apparatus for sending credit/charging information to a mobile station in a mobile telecommunications network, the apparatus comprising: a business logic execution environment, comprising: a first service logic element for detecting the termination of a call for which a user of said mobile station is charged; and a second service logic element, responsive to said first service logic element, for sending said credit/charging information to said mobile station as a connectionless message.

Description of the drawings:

the invention will be described in more detail by means of preferred embodiments and with reference to the accompanying drawings.

Fig. 1 is a block diagram of a mobile communication network equipped with a device according to a preferred embodiment of the present invention;

FIG. 2 is a signal diagram illustrating one embodiment of the present invention; and

fig. 3 depicts a mobile station after receiving and displaying a short message in accordance with the present invention.

The specific implementation mode is as follows:

fig. 1 is a block diagram of a mobile communication network equipped with a device according to a preferred embodiment of the invention. This embodiment uses intelligent network technology. An Intelligent Network (IN) is capable of providing a plurality of services to users of a telecommunications network, such as a wired network or a mobile telephone network. These services include a Virtual Personal Network (VPN) which allows the use of short numbers between subscribers belonging to a local area network, and personal numbers, wherein the intelligent network reroutes directed calls to a personal number controlled in a manner by the subscriber. An example of such an intelligent network is described in the ITU-TQ-1200 series of recommendations, wherein Q-1210 to Q-1219 define a set of features known as CS-1 (performance group 1), and Q-1220 to Q-1229, respectively, define a set of features CS-2. The invention and its background will be described by the term corelnap suggesting ETS 300374-1, but the invention may also be used in intelligent networks implemented according to other intelligent network standards.

The Basic Call State Mode (BCSM) defined with respect to an intelligent network describes different levels of call control and defines the points at which call control can be interrupted in order to start an intelligent network service. It identifies points in the call and connection process where the service logic entities of the intelligent network may have an interactive relationship with the basic call and connection management features.

In conventional call set-up, which occurs without the assistance of an intelligent network, the telephone exchange makes all the deductions about the routing of calls independently. One or more Service Control Functions (SCF) are associated with the intelligent network architecture. The device or network element performing the tasks determined by the SCF is called a Service Control Point (SCP). In the present invention, SCF and SCP are equal and will be referred to as SCP hereinafter. The SCP gives call setup instructions to the switch, or the switch may query for call setup instructions from the SCP. If the interface of user B is found to be busy with certain levels of call setup, for example, the call may be directed to a selectable number. The service data function SDF and the service data point SDP form a database comprising subscriber-specific and/or service-specific information.

The Service Switching Function (SSF) is the interface between the call control function CCF and the service control function SCF. The network element that performs SSF is called a Service Switching Point (SSP). An intelligent network service is generated by a service switching point SSP interrogating instructions from a service control point SCP, by means of a message transmitted via the SSP/SCP interface immediately after encountering a detection point associated with the service. These messages are called operations in intelligent network terminology. In connection with intelligent network services, a service program is started at a service control point SCP, the operation of which program determines the calculations to be transmitted by the SCP to the SSP at each level of the call.

Fig. 2 is a signal diagram illustrating a preferred embodiment of the present invention. The scheme shown in fig. 2 begins at step 2-0, in which the MS sends a call setup signal to the MSC. IN this example it will be assumed that call set-up takes place under IN control, but this is not essential to the invention. Another assumption made here is that IN is also responsible for keeping track of the available credit for the pre-paid SIM card. In step 2-2, the MSC sends an Initial Detection Point (IDP) message to the SCP, whose parameters include a service key Skey1 and calling and called party numbers a # and B #. The service key Skey1 identifies the IN service IN question. In step 2-4, the SCP MSC sends a request report BCSM event message indicating which detection points the MSC must report to the SCP. One such detection point of interest is a point that involves call termination. In step 2-6, the SCP sends a continue message to the MSC, which directs the MSC to route the call normally. (alternatively, the SCP may send a connect message indicating an alternative number, but such a change is irrelevant for understanding the actual invention.) steps 2-8 include all steps necessary for establishing a call to called party B. For the sake of clarity, these conventional steps are not separately shown. In step 2-10, the MS terminates the call by sending a disconnect message. In step 2-12, the MSC sends an event report BCSM message to the SCP indicating a disconnection from the originating side. In step 2-14, the SCP returns a complete charging information message to the MSC. In response to the continue message in step 2-16, the MSC releases the resources allocated to the call in step 2-18. Again these conventional steps are not separately shown.

According to one embodiment of the invention, in step 2-20, the MSC sends a second IDP message to the SCP, which has as its parameters the second service key (Skey2) and the calling party number a #. The service key Skey2 identifies additional services representing the available credit of the user paid in advance. The next two steps use a separate workstation WS, although these steps can also be implemented depending on the operations performed in the SCP. Next, in step 2-22, the SCP sends a message to the WS requesting the WS to format a short message representing the deposit information. Preferably, the credit information includes the duration and price of the last call, the amount of available credit and the age. In step 2-24, the WS sends this information to the short message service center SMSC, which sends the information to the MS in the form of a suitably formatted short message in step 2-26.

Fig. 3 shows the mobile station MS after having received and displayed the short message of step 2-24. In a bilingual language like finland or switzerland or in countries using multiple languages, the workstation SW may use the user's language (stored in the HLR) and format the message accordingly.

Based on the above examples, some variations will be apparent to a skilled reader. For example, assume that the SCP considers both call handling and keeping track of the available credit to the prepaid SIM card, and that the SCP stores the available credit IN an IN database called a service data point (SDP, not separately shown). This is why the available credit does not have to be transferred to the SCP at the start of the call. Of course, keeping track of the available credit may occur IN the MSC, so IN call control (steps 2-2 to 2-6 and 2-12 to 2-16) is not necessary. Alternatively, the SCP may perform call control but the MSC may keep track of the prepaid credit. In this case, only steps 2-14 are not necessary.

Alternatively, however, IN call control and credit reporting may be combined such that sending the continue message to the MSC IN step 2-16 will simultaneously trigger sending the formatted short message to the WS IN step 2-22, IN accordance with the present invention. In other words, the message in step 2-20 is not necessary. However, for compatibility with different implementation options, in the example shown in fig. 2, the SCP reports the deposit information to the MSC in step 2-14, and the MSC returns the deposit information to the SCP in step 2-20. In this way, the deposit reporting service (steps 2-20 to 2-26) according to the present invention is consistent with all combinations of call control and deposit tracking under the MSC or SCP.

Although it is considered optimal to send the credit information as a short message, other transmission channels may be used. One possible selective transmission method is the use of USSD (unstructured supplementary service data), which is defined in reference 2 to. However, the introduced network USSD is only possible with phase 2 mobile stations. Short message transmissions and USSD transmissions can generally be classified as connectionless transmissions because the information is only transmitted to the recipient and no end-to-end connection has to be established.

The present invention may be used to transmit any kind of credit/billing information, the transmission of which is triggered in response to the end of a call. Preferably, the credit/billing information includes the current credit status, the duration of the last call, the price of the last call and the expiration date of the SIM card. Although the invention has been described in relation to a prepaid subscription, it is not strictly required that the subscription be prepaid. Alternatively, the user may wish to set an upper limit for monthly telephone bills. Thus, even if the mobile phone is stolen, the loss total may be limited to a predefined upper limit, and parents may set an upper limit on the monthly phone bill for their children. The invention is equally suitable for transmitting the available cost limit (predefined upper limit minus cumulative, but not invoiced, cost).

Reference:

1, GSM 02.90: european digital cellular telecommunications system (phase 2); description of level 1 Unstructured Supplementary Service Data (USSD)

GSM 03.90: digital cellular telecommunications system (phase 2) Unstructured Supplementary Service Data (USSD) -level 2

GSM 04.90: european digital cellular telecommunications system (phase 2); unstructured Supplementary Service Data (USSD) stage 3 is herein incorporated by reference for all purposes.

Claims (11)

1. A method for sending credit/billing information to a mobile station, the method comprising the steps of:

maintaining deposit/charging information associated with a subscriber of said mobile station in an intelligent network node;

-detecting a termination of a call paid for by said user of said mobile station (2-10);

in response to said detection;

updating the credit/charging information maintained in the intelligent network node;

sending said credit/charging information to said mobile station as a connectionless message (2-26); and

-disconnecting said call (2-18) with sufficient delay for sending said connectionless message without having to page the mobile station otherwise, after detecting said termination (2-10) of said call.

2. The method of claim 1, further comprising the steps of:

defining an upper limit for the cumulative price of the telephone call;

monitoring a cumulative price of the telephone calls;

a new call is only allowed if the cumulative price of telephone calls is below said upper limit.

3. Method according to any of the preceding claims, characterized in that said connectionless message is a short message.

4. A method according to claim 1 or 2, characterised in that said connectionless message is a USSD message.

5. A method according to claim 1 or 2, characterized in that said connectionless message may be not only a USSD message but also a short message.

6. The method of claim 1, wherein the intelligent network node:

requesting a mobile services switching centre to report said termination of the call (2-4); and

-initiating said sending (2-16, 2-22) of said credit/billing information in response to said report (2-12).

7. The method of claim 6, wherein the intelligent network node is a service control point.

8. The method according to claim 6 or 7,

triggering the sending of the deposit/charging information by a service logic program executed in a service logic execution environment in a service control point;

the service logic program providing functionality for communicating with an external operation through a gateway between a service running within the service logic execution environment and an external application; and

the deposit/billing information is sent by the gateway to the external application, which sends the information to the mobile station.

9. An apparatus for sending credit/billing information to a mobile station in a mobile telecommunications network, the apparatus comprising:

a first service logic means for detecting the termination of a call for which a user of said mobile station is charged; and

a second service logic means responsive to the detection by said first service logic means and for sending credit/charging information to said mobile station as a connectionless message;

wherein the first and second business logic devices form a business logic execution environment;

and wherein, after detecting said termination (2-10) of said call, said call (2-18) is disconnected with sufficient delay for sending said connectionless message without having to page the mobile station otherwise.

10. The apparatus of claim 9, further comprising: a service control point of an intelligent network for requesting a mobile communications services switching centre to report said termination (2-4) of a call; and initiating said sending (2-16, 2-22) of said credit/billing information in response to said report (2-12).

11. The apparatus of claim 10, further comprising: a separate processor for formatting the credit/billing information.