WO2015041580A1

WO2015041580A1 - Apparatus and method for crediting subscriber billing accounts

Info

Publication number: WO2015041580A1
Application number: PCT/SE2013/051106
Authority: WO
Inventors: Kollapalli GANESH; Vivek GIRIDHARAN; Ashwin DEVARAJAN; Ramana Shankar YENISHETTI; Saravanan Mohan
Original assignee: Telefonaktiebolaget L M Ericsson (Publ)
Priority date: 2013-09-23
Filing date: 2013-09-23
Publication date: 2015-03-26

Abstract

An interface unit (100) is provided for use in a telecommunications network, for enabling a billing account of a subscriber of a first (home) network to be credited using prepaid vouchers associated with one or more second (destination) networks. The interface unit (100) comprises a processing unit (101) configured to exchange messages (Msg1, Msg2, Msg3, Msg4) between a network element (300) of the first network and a network element (400) of the one or more second networks. The processing unit is adapted to receive a validation request message from the network element (300) of the first network for validating a prepaid voucher, liaise with the network element (400) of the second network to determine whether the prepaid voucher is authorized, and return an authorization message to the network element (300) of the first network.

Description

Apparatus and Method for Crediting Subscriber Billing Accounts

Technical Field

The present invention relates to an apparatus and method for crediting a billing account of a subscriber, and in particular to an apparatus and method for crediting the billing account of a subscriber associated with a first network, using prepaid vouchers relating to a different network.

Background

In many developing nations the users of mobile telecommunication networks still rely on the use of prepaid paper vouchers for day to day communication, and for crediting the billing accounts of subscribers, particularly in rural locations of such developing nations. Despite infrastructures being in place to distribute such prepaid paper vouchers, the voucher refill process requires a complex supply management chain to ensure that vouchers are distributed to different parts of the country. Since the system is established in such a way that customers are tightly coupled with particular service providers, this can be a h indrance if the vouchers of a particular service provider have a poor supply chain in certain parts of the country, or at certain times of the year.

In a developing country such as India, for example, according to the Telecom Regulatory Authority of India (TARI), the Telecom Subscription Data as on September 2012 indicate that there were about 906.62 million wireless subscribers in India, with a projected monthly growth rate of about 0.19%. Out of the 906.62 Million subscribers, the rural subscriber population is at 334.92 million which has a monthly growth rate of 0.51 %. As such, it can be seen that a large number of subscribers can be affected by a poor distribution network of prepaid paper vouchers.

P41052WO1 There are many other ways or methods to recharge a billing account of a mobile phone subscriber. For example, these include methods such as an Interactive Voice Response Systems (IVRS), Administrative systems (MINSAT), Home Location Registers (USSD), or internet recharges using applications provided by third parties (for example banks, private vendors or agents), or mobile money.

However, the solutions available today do not provide a way for end users to re- charge their accounts by using other service providers' paper vouchers or other administrative tools. This results in an unfavorable situation for the end user and the service provider when there is an unavailability of the end user's service provider vouchers in most of the rural places. An end user therefore has to wait until the arrival of vouchers to their area, or travel a long distance to purchase the voucher, even though the vouchers of another operator are available with nearby vendors.

Summary

It is an aim of the present invention to provide a method and apparatus which obviate or reduce at least one or more of the disadvantages mentioned above.

According to a first aspect of the present invention there is provided an interface unit for use in a telecommunications network, for enabling a billing account of a subscriber of a first network to be credited using prepaid vouchers associated with one or more second networks. The interface unit comprises a processing unit configured to exchange messages between a network element 300 of the first network and a network element 400 of the one or more second networks, wherein the processing unit is adapted to receive a validation request message from the network element 300 of the first network for validating a prepaid voucher, liaise with the network element 400 of the second network to determine whether the prepaid voucher is authorized, and return an

authorization message to the network element 300 of the first network.

The provision of such an interface unit has the benefit of enabling a billing account of a user associated with a first network (such as the user's home network) to be credited using a prepaid voucher of another network.

According to another aspect of the present invention there is provided a method in an interface unit of a telecommunications network, for enabling a billing account of a subscriber of a first network to be credited using prepaid vouchers associated with one or more second networks. The method comprises the steps of exchanging messages between a network element of the first network and a network element of the one or more second networks. The exchange of messages comprises the steps of receiving a validation request message from the network element of the first network for validating a prepaid voucher, liaising with the network element of the second network to determine whether the prepaid voucher is authorized, and returning an authorization message to the network element of the first network. The network element of the first network is then able to take steps to credit the billing account of the subscriber based on the authorization message it has received.

According to another aspect of the present invention, there is provided a network element for use in a first network, the first network being a network associated with a subscriber, and different to a second network associated with a prepaid voucher. The network element comprises a processing unit configured to receive a voucher identifier code relating to a prepaid voucher, and determine if the voucher identifier code is associated with the first network. If not, the processing unit is configured to send a first message to an interface unit, the first message comprising a voucher identifier code for identifying a particular prepaid voucher, a subscriber number for identifying the subscriber whose billing account is to be updated, a first network identifier for identifying the first network associated with the subscriber, a second network identifier for identifying the second network associated with the voucher identifier code, and a first transaction identifier for identifying the particular transaction being processed.

According to another aspect of the present invention, there is provided a method in a network element of a first network, the first network being a network associated with a subscriber, and different to a second network associated with a prepaid voucher. The method comprises the steps of receiving a voucher identifier code relating to a prepaid voucher, and determining if the voucher identifier code is linked to the home network. If not, the method comprises the step of sending a first message to an interface unit, the first message

comprising a voucher identifier code for identifying a particular prepaid voucher, a subscriber number for identifying the subscriber whose billing account is to be updated, a first network identifier for identifying the first network associated with the subscriber, a second network identifier for identifying the second network associated with the voucher identifier code, and a first transaction identifier for identifying the particular transaction being processed.

According to another aspect of the present invention, there is provided a network element for use in a second network, the second network being a network that is associated with a prepaid voucher, and different to a first network associated with a subscriber. The network element comprises a processing unit, the processing unit being configured to receive a second message, the second message comprising a voucher identifier code relating to the prepaid voucher, the second message further comprising a second transaction identifier. The processing unit is also configured to compare the voucher identifier code against a list of valid voucher identifier codes, and in response to a match send a third message, the third message comprising the second transaction identifier and a value number, the value number

representing a monetary value associated with the validated voucher identifier code.

According to another aspect of the present invention, there is provided a method in a network element of a second network, the second network being a network that is associated with a prepaid voucher, and different to a first network associated with a subscriber. The method comprises the steps of receiving a second message, the second message comprising a voucher identifier code relating to the prepaid voucher, the second message further comprising a second transaction identifier. The method further comprises the step of comparing the voucher identifier code against a list of valid voucher identifier codes, and in response to a match sending a third message, the third message comprising the second transaction identifier and a value number, the value number representing a monetary value associated with the validated voucher identifier code. According to another aspect of the present invention there is provided a billing apparatus for a telecommunications network, the billing apparatus comprising an interface unit as defined in the appended claims.

Brief description of the drawings

For a better understanding of examples of the present invention, and to show more clearly how the examples may be carried into effect, reference will now be made, by way of example only, to the following drawings in which:

Figure 1 shows an interface apparatus according to an embodiment of the present invention; Figure 2a shows a method according to an embodiment of the invention; Figure 2b shows a method according to an embodiment of the invention;

Figure 3a shows a network node associated with a first network, according to an embodiment of the invention;

Figure 3b shows a method performed at a network node of Figure 3a, according to an embodiment of the invention;

Figure 4a shows a network node associated with a second network, according to an embodiment of the invention; Figure 4b shows a method performed at a network node of Figure 4a, according to an embodiment of the invention;

Figure 5 shows a typical application of an embodiment of the invention; Figure 6 shows another example of a typical application of an embodiment of the invention; and

Figure 7 shows another example of a typical application of an embodiment of the invention.

Detailed description

The embodiments of the invention, as described in the examples below, enable end users or subscribers to credit their billing accounts with one service provider, using vouchers provided by other service providers, and using their own service provider's network. It is noted that references made herein to vouchers or paper vouchers or prepaid vouchers are intended to embrace any form of voucher which enable a prepaid monetary amount to be credited to the billing account of a user or subscriber.

Figure 1 shows an interface apparatus 100 for use in a telecommunications network, for enabling a billing account of a subscriber of a first network (for example a home network) to be credited using prepaid vouchers associated with one or more second networks (for example other networks to which the subscriber is not associated with). The interface unit 100 comprises a processing unit 101 configured to exchange messages (for example Msg1 , Msg2, Msg3, Msg4) between a network element 300 of the first network and a network element 400 of the one or more second networks. The processing unit is adapted to receive a validation request message from the network element 300 of the first network for validating a prepaid voucher, liaise with the network element 400 of the second network to determine whether the prepaid voucher is authorized, and return an authorization message to the network element 300 of the first network.

As will be described in greater detail below, the processing unit 101 is

configured to map the validation request message received from the network element 300 of the first network with an authorization message received from the network element 400 of the second network, using transaction identifiers communicated between the network element 300 of the first network and the network element 400 of the second network via the interface unit 100.

The interface unit can be configured to receive a first message Msg1 from the network element 300 of the first network. According to one example the first message comprises a voucher identifier code Vn for identifying a particular prepaid voucher, a subscriber number Sn for identifying the subscriber whose billing account is to be updated or credited, a first network identifier Hnld for identifying the first network (e.g. home network) associated with the subscriber, a second network identifier Onld for identifying the second network (e.g. other network) associated with the voucher identifier code, and a first transaction identifier InTx (also referred to herein as an "inward" transaction identifier) for identifying the particular transaction being processed.

It is noted that a voucher identifier code Vn can identify a particular voucher, including a particular service provider or network associated with that voucher.

The interface unit 100 can be configured to send a second message Msg2 to the network element 400 of the second network. According to one example the second message comprises the voucher identifier code Vn, the second network identifier Onld, and a second transaction identifier OutTx (also referred to herein as an "outward" transaction identifier) for identifying the particular transaction being processed.

The interface unit 100 may comprise a storage module (not shown), wherein the processing unit 101 is configured to store the voucher identifier code Vn, the subscriber number Sn, the first network identifier Hnld, the first transaction identifier InTx and the second transaction identifier OutTx in the storage module. The storage of the first transaction identifier InTx and the second transaction identifier OutTx enables the interface unit to map a message subsequently received from a second network (i.e. the network relating to the prepaid voucher) with an original request message, and hence to the home network and subscriber that originally sent the request (i.e. using the stored Sn and Hnld information). The interface unit 100 can be configured to receive a third message Msg3 from the network element 400 of the second network. The third message Msg3 corresponds to a message that is received after the second network has processed the second message Msg2 that has been previously sent to it.

According to one example the third message Msg3 comprises the second transaction identifier OutTx and a value number (Value), the value number representing a monetary value that is to be credited to the billing account of the subscriber. According to one embodiment the interface unit 100 comprises a mapping table, wherein the processing unit 101 is further configured to use the second transaction identifier OutTx to map the information contained in the third message Msg3 with the validation request that was previously received in the first message Msgl For example, the mapping table can store lists of

InTx/OutTx pairs or associations, such that a received second transaction identifier OutTX can be mapped with a first transaction identifier InTX, with the first transaction identifier InTx then pointing to the other relevant data that is needed to send the fourth message, i.e. pointing to the first (or home) network identifier Hnld and the respective subscriber number Sn.

From the above it can be seen that the first and second transaction identifiers can relate to two different transaction IDs for the two different networks, which can be used to differentiate between incoming and outgoing requests. It is noted, however, that the embodiments of the invention may also be adapted to use a single or the same identifier for a particular InTx/OutTx pair, i.e. whereby the same actual identifier is used to represent both InTx and OutTx. Although such an embodiment would not have the advantages mentioned earlier of being able to quickly differentiate between incoming and outgoing requests, there may be other advantages such as error-handling or other fault management issues, or with the mapping operation or with regard to storage requirements. The processing unit 101 can be configured, upon successful mapping, to send a fourth message Msg4 to the network element 300 of the first network. According to one example the fourth message comprises the subscriber number Sn, the value number (Value) representing the monetary value that is to be credited to the billing account of the subscriber, and the first transaction identifier InTx.

By sending this information the first network, or home network, is able to match the first transaction number, and update the billing account of the subscriber with the correct monetary value.

According to one embodiment the interface unit 100 forms part of a billing apparatus or processing module of a telecommunications network, the billing apparatus comprising an interface unit 100 as described herein. It is noted that the interface unit may also form a stand-alone unit, or form part of some other node or processing module of a telecommunications network.

Figure 2a shows the steps which are performed in an interface unit 100 of a telecommunications network, according to an embodiment of the invention, for enabling a billing account of a subscriber of a first network to be credited using prepaid vouchers associated with one or more second networks. The method comprises the steps of exchanging messages between a network element 300 of the first network and a network element 400 of the one or more second networks. The exchange of messages comprises the step of receiving a validation request message from the network element 300 of the first network for validating a prepaid voucher, step 201 . The method comprises the step of liaising with the network element 400 of the second network to determine whether the prepaid voucher is authorized, step 202, and returning an authorization message to the network element 300 of the first network, step 203. Figure 2b shows the steps performed by another embodiment of the invention, and shows in greater detail the messages that may be exchanged via the interface unit 100 according to such an embodiment.

In step 210 a first message Msg1 is received from a network element 300 of a first network. The first message Msg1 comprises a voucher identifier code Vn for identifying a particular prepaid voucher, a subscriber number Sn for identifying the subscriber whose billing account is to be updated, a first network identifier Hnld for identifying the first network associated with the subscriber, a second network identifier On Id for identifying the second network associated with the voucher identifier code, and a first transaction identifier InTx for identifying the particular transaction being processed. In step 212, the method comprises the step of sending a second message

Msg2 to the network element 400 of the second network. The second message comprises the voucher identifier code Vn, the second network identifier Onld, and a second transaction identifier OutTx for identifying the particular transaction being processed.

In step 214 the method comprises the step of receiving a third message Msg3 from the network element 400 of the second network. The third message comprises the second transaction identifier OutTx, and a value number (Value), the value number representing a monetary value that is to be credited to the billing account of the subscriber.

It is noted that the interface unit can perform the steps of storing the voucher identifier code Vn, the subscriber number Sn and the second transaction identifier OutTx in a storage module, for enabling transactions to be mapped or matched. For example, the method may comprise the steps of using the second transaction identifier OutTx received in the third message to map the

information contained in the third message Msg3 with the validation request previously received in the first message Msg1 . In step 216, the method comprises the steps of sending a fourth message Msg4 to the network element 300 of the first network. According to one example the fourth message Msg4 comprises the subscriber number Sn, the value number (Value) representing the monetary value that is to be credited to the billing account of the subscriber, and the first transaction identifier Inld.

Figure 3a shows a network element 300 for use in a first network, the first network being a network associated with a subscriber, and different to a second network associated with a prepaid voucher. For example, the first network may comprise a home network to which the subscriber is affiliated with and has a billing account or association, while the second network is another network to which the subscriber has no such affiliation, for example a network of another service provider having prepaid vouchers for that service provider.

The network element 300 comprises a processing unit 301 . The processing unit 301 is configured to receive a voucher identifier code Vn relating to a prepaid voucher, determine if the voucher identifier code is linked to the home network, and, if not send a first message (Msg1 ) to an interface unit 100. The first message comprises a voucher identifier code Vn for identifying a particular prepaid voucher, a subscriber number Sn for identifying the subscriber whose billing account is to be updated; a first network identifier Hnld for identifying the first network associated with the subscriber; a second network identifier Onld for identifying the second network associated with the voucher identifier code, and a first transaction identifier InTx for identifying the particular transaction being processed. In this way, if a prepaid voucher is not one that is not associated with the first network (or home network of the subscriber), the first message is sent to the interface unit, the first message comprising information for enabling the interface unit to liaise with the network associated with the prepaid voucher. The network element 300 may determine whether the voucher is associated with its own network, for example, by interfacing with a voucher server (VS). The voucher server may either form part of the network element 300, or be located elsewhere. The first network identifier Hnld (or home network ID) is used to identify the request from where it originated during the response. The second network identifier Onld (or other network ID) is used to identify the network of the destination service provider (i.e. whose prepaid voucher is being validated). The subscriber number Sn is used for the response which needs to be sent to the first (home) network Hnld, with Sn also enabling the first (home) network to identify the subscriber who initiated the recharge, and hence whose billing account should be credited. The voucher number Vn is used by a second (destination) network to determine if the prepaid voucher is valid. As such the destination network validates this num ber and sends a response back to interface unit 100. The first transaction identifier InTx is generated by the first (home) network, and this identifier will be used by the interface unit 100 to keep track of a particular transaction. The processing unit 301 will receive a fourth message Msg4, confirming whether or not the voucher has been authorized. If so, the processing unit 301 can be configured to credit the billing account of a user based on the information received in the fourth message Msg4.

Figure 3b shows the steps performed in a first network element 300 of a first network according to an embodiment of the invention, the first network being a network associated with a subscriber, and different to a second network associated with a prepaid voucher. The method comprises the steps of receiving a voucher identifier code Vn relating to a prepaid voucher, step 303. In step 305 it is determined if the voucher identifier code is associated with the first network. If not, a first message Msg1 is sent to an interface unit 100, step 307, the first message comprising a voucher identifier code Vn for identifying a particular prepaid voucher, a subscriber number Sn for identifying the

subscriber whose billing account is to be updated, a first network identifier Hnld for identifying the first network associated with the subscriber, a second network identifier Onld for identifying the second network associated with the voucher identifier code, and a first transaction identifier InTx for identifying the particular transaction being processed.

Figure 4a shows a network element 400 for use in a second network, the second network being a network that is associated with a prepaid voucher, and different to a first network associated with a subscriber. The network element comprises a processing unit 401 , the processing unit 401 being configured to receive a second message Msg2, the second message comprising a voucher identifier code Vn relating to the prepaid voucher, the second message further comprising a second transaction identifier OutTx. The processing unit 401 is further configured to compare the voucher identifier code Vn against a list of valid voucher identifier codes. In response to a match the processing unit 401 is configured to send a third message Msg3, the third message comprising the second transaction identifier OutTx and a value number Value, the value number representing a monetary value associated with the validated voucher identifier code Vn.

A voucher identifier code Vn may be validated at the network element by interfacing with a voucher server (VS), either located at the network element 400 or elsewhere. The third message Msg3 is sent to an interface unit from which the second message Msg2 was received, as identified by the home network identifier Hnld.

In the event that the network element 400 does not identify a valid voucher identifier code Vn, an error handling mechanism can be invoked, as will be described later in the application.

Figure 4b shows a method in a network element 400 of a second network, the second network being a network that is associated with a prepaid voucher, and different to a first network associated with a subscriber. The method comprises the steps of receiving a second message Msg2, step 403, the second message comprising a voucher identifier code Vn relating to the prepaid voucher, and a second transaction identifier OutTx. In step 405 the voucher identifier code Vn is compared against a list of valid voucher identifier codes. In response to a match a third message Msg3 is sent, step 407, the third message comprising the second transaction identifier OutTx and a value number (Value), the value number representing a monetary value associated with the validated voucher identifier code Vn. Reference will now be made to various error handling procedures, according to another aspect of the present invention. As mentioned above, when the network element 400 of the second network does not identify the voucher identifier code as being a valid voucher associated with its network, or there has been some transaction error, the network element 400 of the second network can be configured to respond with a error code.

In such a scenario the third message Msg3 sent by the network element 400 may comprise the second transaction identifier OutTx, the voucher identifier code Vn and an error code CODE_error (i e- OutTx +Vn + CODE_error)- In response to receiving a third message Msg3 of this type, the processing unit 101 of the interface apparatus 100 is configured to identify the error code, and send the error code with the fourth message Msg4 to the network element 300 of the first network. In such a scenario to the fourth message Msg4 may comprise the first transaction identifier InTx, the subscriber number Sn and the error code CODE_error (i e- InTx + Sn + CODE_error)-

The network element 300 of the first network can then send a message to the subscriber, intimating the failure of the transaction.

According to another aspect of the present invention, the processing unit 101 of the interface unit 100 can be configured to have a maximum network delay. If such a mode is activated, and the network element 400 of the second network does not respond within a particular time out period, the processing unit 101 of the interface unit 100 can be configured to send out a time out message to the network element 300 of the first network in the fourth message Msg4. The message format can comprise the first transaction identifier InTx, the subscriber number Sn and the time-out error code (i.e. InTx + Sn + CODE_error-time-out)- The network element 300 of the first network can then send a message to the subscriber intimating the failure of the transaction (i.e. due to timeout).

In the event that the network element 400 of the second network responds after the time out period (such that the processing unit 101 of the interface unit 100 will have sent the time out error to the network element 300 of the first network element), then the processing unit 101 of the interface unit 100 can be configured to reject the third message Msg3 received from the network element 400, and respond to the network element 400 of the second network with a fifth message Msg5 containing a transaction to rollback the prepaid voucher, i.e. to indicate that the particular prepaid voucher has not been credited to an account. The message format of the fifth message may comprise the voucher identifier code Vn, the second transaction identifier OutTx and the roll back error code

(i.e. Vn + OutTx + CODE_error-roll-back).

According to another aspect, in the event that the network element 300 of the first network does not receive the fourth message Msg4, the network element 300 of the first network can be configured to send out a message to the processing unit 101 of the interface unit 100, the message containing an error code that the subscriber details have not been updated, and that the processing unit 101 should send a rollback error code (CODE_error-roii-back) to the network element 400 of the second network.

The Message format from the network element 300 to the interface unit 100 may comprise the subscriber number Sn, the voucher identifier code Vn, the first transaction identifier Inld and a time out error code CODE_error-time-out (i e- Sn + Vn + Inld + CODE_error-time-out). The subsequent message from the interface unit 100 to the network element 400 of the second network may comprise the voucher number Vn, the second transaction identifier OutTx and the roll back error code CODE_error-roii-back (i.e. Vn + OutTx + CODE error-roll-back^-

Typical error codes may comprise the following examples, although it is noted that any form of code may be used: Voucher Not Found = 1000

Voucher Processing Error = 999

Voucher Rollback Error code = 1001

Time Out Error Code = 1002 Error codes may be provided for other faults or transactional errors that may be encountered.

From the above it can be seen that an universal voucher system is established, whereby an interface unit 100 (a form of universal recharge system) interfaces w ith a recharge application running in a home network and a recharge application running in a different network, such that one recharge application can determ ine whether a particular prepaid voucher is valid, while another recharge application can identify a subscriber account and credit the value to the appropriate subscriber.

Referring to Figure 5, according to one embodiment the network element 300 of the first network and the network element 400 of the second network comprise re-charge applications (APIs) operating on network nodes of the respective networks. In the example of Figure 5 the interface unit 100 and network element 300 of the home network (in the form of a universal recharge system and recharge application, respectively) are provided in one network node 500, while the network element 400 of the second network is provided as a recharge application on a network node of the second network.

The interface unit 100 (or universal recharge system) described above, upon receiving a request from a recharge application 300 of a home network, generates the second transaction identifier OutTx that will be used to liaise with the recharge application 400 of a destination or second network. The interface unit 100 stores the details from the incoming request from home network (i.e. received in the first message Msg 1 ), along with the generated second transaction identifier OutTx. The generated second transaction identifier OutTx is sent out along with the voucher identifier code Vn to the recharge application 400 of the destination network via the second message Msg2. The recharge application 400, on receiving the request from the universal recharge system 100, is configured to parse the request and obtain the voucher number Vn, and validate the voucher number Vn, for example against its own voucher database (for example stored in a voucher server). If the voucher has been found in the database of the destination network, a successful response is sent to the universal recharge system 100, indicating that the prepaid voucher is authorized. The response, in the form of a third message Msg3, contains the Value of the voucher along with the second transaction identifier OutTx. U pon receiving a successful response from the destination network, the universal recharge system 100 retrieves the transaction using the received second transaction identifier OutTx. On successfully obtaining the transaction the universal recharge system 100 may be adapted to store the value of the voucher in a local database, for example if this information is needed for future processing at the universal recharge system 1 00, such as future auditing purposes. Alternatively, the value may be simply forwarded to the home network if no future processing is envisaged or required.

The universal recharge system 100 is adapted to send out a response to the recharge application 300 of the home network, in a fourth message Msg4 which contains the subscriber number Sn and the voucher value (Value).

The recharge application 300 of the home network is then able, based on the subscriber number, to credit the billing account of the subscriber with the monetary value corresponding to the received value number (Value).

Figures 6 and 7 provide examples of how embodiments of the invention may be incorporated into billing systems of a communications network, or a communications system in general. For example, interface units (or universal recharge systems) 100 according to embodiments of the invention may form part of a node 500 which forms part of a charging system architecture. This has the advantage of enabling integration and design to be delivered as quickly as possible with legacy interfaces available in a charging system. For example in Figure 6 the universal recharge system 1 00 (the interface unit) can form part of a billing system 500 which interfaces with one or more of a voucher database 601 , an account database 603, and interactive voice response (IVR) module 605, an administration unit 607 and an account finder module 609, all of which will be described in further detail below with reference to the example of Figure 7.

The example of Figure 7 shows a charging system 700 in which an universal recharge system or interface unit 100 according to embodiments of the invention forms part of an account information refill (AIR) module 500 of the charging system 700. In this example the charging system 700 interfaces with a service network 703 and a core network 705, and a mediation unit 707.

The AIR module 500 is a module which handles all the type refill requests to the billing accounts of subscribers, and can be co-located with an account finder 609. The account finder (AF) 609 is a module that is used to find the billing account of a subscriber, using the received subscriber number Sn, and recharge the billing account with the monetary value "Value". The account finder can provide location information for subscriber accounts in the system. It stores a service data point identifier (SDP ID) and a related IP address for each mobile station international subscriber directory number (MSISDN) in the network.

The voucher server (VS) 601 is a server which has a database of all the vouchers for the home network, and is a network element that handles the administration of the vouchers and the voucher database, which includes all relevant information about the vouchers. It is noted that a voucher may comprise a plurality of different voucher states. Examples of the different voucher states are provided below: ■ Unavailable

■ Available

■ Used

■ Stolen or Missing

■ Damaged

The voucher server (VS) 601 can be co-located with the AIR module 500.

The interactive voice response (IVR) system 605 is an input system that enables an end subscriber to make modifications to his account and to also make refills to his/her account. It is also the source for recharging a billing account of a mobile phone subscriber.

The administration unit (ADMIN) 607 is a module typically used by customer care agents to view or make a modification to the billing accounts of subscribers.

The service data point (SDP) 61 1 is a network element that is used to safely store and handle large quantities of subscriber data. The SDP network element 61 1 contains the database with subscribers and account information. It can provide rating of calls and events as well as post-processing of Charging Data Records (CDRs). The SDP 61 1 can control the life cycle of the subscriber accounts and manages real time charging of any service. The SDP 61 1 can also be responsible for sending notifications through Unstructured

Supplementary Service Data (USSD) messages, Short Message Service (SMS) messages, or files. Furthermore, the SDP 61 1 can be adapted to take and return policy decisions. An SDP network element 61 1 may consist of two servers in one cluster. A charging system 700 can have one or many of such SDP network elements 61 1 . The charging system 700 may also comprise a charging control node (CCN) or online charging control (OCC) network element 613, which comprises business logic to route and charge the calls for a subscriber, and provide online charging support based on data calls in the case of OCC. A Charging data Reporting System (CRS) 617 may be provided to collect, enrich and correlate charging information from multiple network elements and process such information into reports. For example, reports may be related to:

- Usage and account history

- Subscriber provisioning and lifecycle

- Basic and Enriched

The CRS 617 may be focused on charging related information from the charging system 700, and may form a pre-integrated charging data point with enriched and harmonized data. For example, the CRS 617 may be configured to provide the following information:

■ Usage and Account History protocol

■ Data export to other systems

■ Data Dumps to other systems

■ Data Warehouse specific purpose, case, or situation (ad-hoc) reporting

The charging system may also comprise a charging system network

management toolkit (CS-NMT) network element 615 which can perform, for example, automated upgrades in the charging system nodes shown in Figure 7, from one version to another. The embodiments of the invention described above have the advantage of enabling various service providers to establish presence in regions where they have a very low local paper voucher supply chain mechanisms. This can ultimately enable the end users to use prepaid vouchers irrespective of the service providers.

The end users are therefore able to recharge their billing accounts by using any available prepaid paper vouchers that are available in the marketplace, and not be restricted by having to purchase vouchers from their home network or service provider. As such, service providers do not need to worry about the unavailability of supply chains in remote areas where their presence is low.

The em bodiments of the invention also enable newly emerging service providers to enter a highly competitive segment and slowly penetrate that segment.

The embodiments also enable service provides to identify which region has a large number of this universal recharge request and improve their supply chain to that region, thereby increasing their presence as an optimal solution to this problem. Also it improves their supply chain management to an optimal way and aids the service provider to offer better services to their customers.

The embodiments described above can be particularly advantageous for service providers that offer charging and billing in one (CBIO).

The embodiments of the invention avoid any unnecessary processing of vouchers associated with unrelated service providers, and thus avoid any revenue lost by such unnecessary processing. The embodiments of the invention have the advantage of enabling vouchers of one service provider to be used with another, thus enabling a service provider to save revenues in a supply chain for distributing vouchers, together with the cost associated with printing the vouchers. The embodiments can stand alone, or form part of a charging system of a service provider, so that the account update mechanism can be easily integrated into a billing solution provided by a service provider.

The embodiments of the invention have the advantage of relaxing the closely coupled "paper based" recharging mechanisms of service providers, and allow the end users to decouple the paper based vouchers recharges from the recharging mechanisms of a current service provider.

Since a mobile subscriber is able to recharge an existing account associated with a current service provider using a voucher associated with a different service provider, the subscriber remains loyal to the current service provider, thereby avoiding a churn behavior in which subscribers jump from one service provider to another, and thereby reduce the impact caused by the Mobile Number Portability (MNP) system (i.e. the MNP system provided by law for allowing subscribers to move to other networks for any reason, one of which may be the unavailability of paper vouchers, such that the same mobile number can be used irrespective of the telecommunications service provider).

The various messages described above may comprise any form of messages transm itted in a com m un ications network, for example unstructured supplementary service data (USSD) messages or html based messages.

It is noted that although some of the embodiments refer to the first message Msg1 containing the other network identifier Onld (on the assumption that the network element 300 of the first network will have determ ined which other network is associated with the prepaid voucher, it is noted that th is determination may be performed at another node, for example in the interface unit 100, such that the Onld information is not received in the first message Msgl

It is also noted that although some embodiments of the invention refer to the first message Msg l and fourth message Msg4 containing the subscriber number Sn associated with the subscriber whose billing account is to be credited, such information can be omitted from these messages and retained in the network element 300 of the first network instead, for example if the network element 300 of the first network stores a link between the subscriber number Sn and the first transaction identifier InTx. In this way only the first transaction number InTx is sent to the interface unit for validating a particular prepaid voucher, with the value number (Value) and the first transaction identifier InTx received in the further message Msg then being used to determ ine which subscriber number Sn was associated with that first transaction identifier InTx.

It is noted that references made above to a network are intended to embrace a network provided by a service provider, with other networks being networks provided by other service providers. It is also noted that two separate networks may have entirely different physical or software resources, or may share some or all of their physical and software resources, for example where two different service providers share a common operating platform, or common hardware such as base stations.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. The word "comprising" does not exclude the presence of elements or steps other than those listed in a claim, "a" or "an" does not exclude a plurality, and a single processor or other unit may fulfil the functions of several units recited in the claims. Any reference signs in the claims shall not be construed so as to limit their scope.

Claims

1 . An interface unit (100) for use in a telecommunications network, for enabling a billing account of a subscriber of a first network to be credited using prepaid vouchers associated with one or more second networks, the interface unit (100) comprising:

a processing unit (101 ) configured to exchange messages (Msg1 , Msg2, Msg3, Msg4) between a network element (300) of the first network and a network element (400) of the one or more second networks, wherein the processing unit is adapted to receive a validation request message from the network element (300) of the first network for validating a prepaid voucher, liaise with the network element (400) of the second network to determine whether the prepaid voucher is authorized, and return an authorization message to the network element (300) of the first network.

2. An interface unit (100) as claimed in claim 1 , wherein the processing unit (101 ) is configured to map the validation request message received from the network element (300) of the first network with an authorisation message received from the network element (400) of the second network, using transaction identifiers communicated between the network element (300) of the first network and a network element (400) of the second network via the interface unit (100).

3. An interface unit (100) as claimed in claim 1 or 2, wherein the interface unit is configured to receive a first message (Msg1 ) from the network element (300) of the first network, the first message comprising:

a voucher identifier code (Vn) for identifying a particular prepaid voucher; a subscriber number (Sn) for identifying the subscriber whose billing account is to be updated;

a first network identifier (Hnld) for identifying the first network associated with the subscriber;

a second network identifier (On Id) for identifying the second network associated with the voucher identifier code; and

a first transaction identifier (InTx) for identifying the particular transaction being processed.

4. An interface unit (100) as claimed in claim 3, wherein the interface unit (100) is configured to send a second message (2) to the network element (400) of the second network, wherein the second message comprises:

the voucher identifier code (Vn);

the second network identifier (Onld); and

a second transaction identifier (OutTx) for identifying the particular transaction being processed.

5. An interface unit as claimed in claim 3 or 4, further comprising a storage module, and wherein the processing unit (101 ) is configured to store the voucher identifier code (Vn) , the subscriber number (Sn) and the second transaction identifier (OutTx) in the storage module.

6. An interface unit (100) as claimed in any one of claims 3 to 5, wherein the interface unit is configured to receive a third message (3) from the network element (400) of the second network, wherein the third message comprises:

the second transaction identifier (OutTx); and

a value number (Value), the value number representing a monetary value that is to be credited to the billing account of the subscriber.

7. An interface unit (100) as claimed in claim 6, further comprising a mapping table, and wherein the processing unit (101 ) is further configured to use the second transaction identifier (OutTx) to map the information contained in the third message (Msg3) with the validation request received in the first message (Msg1 ).

8. An interface unit (100) as claimed in claim 7, wherein the processing unit (101 ) is configured, upon successful mapping, to send a fourth message (Msg4) to the network element (300) of the first network, wherein the fourth message comprises:

the subscriber number (Sn);

the value number (value) representing the monetary value that is to be credited to the billing account of the subscriber; and the first transaction identifier (InTx).

9. A method in an interface unit (100) of a telecommunications network, for enabling a billing account of a subscriber of a first network to be credited using prepaid vouchers associated with one or more second networks, the method comprising the steps of:

exchanging messages between a network element (300) of the first network and a network element (400) of the one or more second networks, wherein the step of exchanging messages comprises:

receiving a validation request message from the network element (300) of the first network for validating a prepaid voucher; liaising with the network element (400) of the second network to determine whether the prepaid voucher is authorized; and returning an authorization message to the network element

10. A method as claimed in claim 9, wherein the validation request message comprises a first message (Msg1 ) comprising:

a voucher identifier code (Vn) for identifying a particular prepaid voucher;

a subscriber number (Sn) for identifying the subscriber whose billing account is to be updated;

1 1 . A method as claimed in claim 10, further comprising the step of sending a second message (Msg2) to the network element (400) of the second network, wherein the second message comprises:

the voucher identifier code (Vn);

the second network identifier (Onld); and

12. A method as claimed in claim 1 1 , further comprising the step of receiving a third message (Msg3) from the network element (400) of the second network, wherein the third message comprises:

the second transaction identifier (OutTx); and

13. A method as claimed in claim 12, further comprising the steps of sending a fourth message (Msg4) to the network element (300) of the first network, wherein the fourth message comprises:

the subscriber number (Sn);

the value number (Value) representing the monetary value that is to be credited to the billing account of the subscriber; and the first transaction identifier (Inld).

14. A network element (300) for use in a first network, the first network being a network associated with a subscriber, and different to a second network associated with a prepaid voucher, wherein the network element (300) comprises a processing unit (301 ), the processing unit (301 ) being configured to:

receive a voucher identifier code (Vn) relating to a prepaid voucher;

determine if the voucher identifier code is associated with the first network, and, if not:

send a first message to an interface unit (100), the first message comprising a voucher identifier code (Vn) for identifying a particular prepaid voucher, a subscriber number (Sn) for identifying the subscriber whose billing account is to be updated; a first network identifier (Hnld) for identifying the first network associated with the subscriber; a second network identifier (Onld) for identifying the second network associated with the voucher identifier code, and a first transaction identifier (InTx) for identifying the particular transaction being processed.

15. A method in a network element (300) of a first network, the first network being a network associated with a subscriber, and different to a second network associated with a prepaid voucher, the method comprising the steps of: receiving a voucher identifier code (Vn) relating to a prepaid voucher;

determining if the voucher identifier code is linked to the home network, and, if not:

sending a first message to an interface unit (100), the first message comprising a voucher identifier code (Vn) for identifying a particular prepaid voucher, a subscriber number (Sn) for identifying the subscriber whose billing account is to be updated; a first network identifier (Hnld) for identifying the first network associated with the subscriber; a second network identifier (Onld) for identifying the second network associated with the voucher identifier code, and a first transaction identifier (InTx) for identifying the particular transaction being processed.

16. A network element (400) for use in a second network, the second network being a network that is associated with a prepaid voucher, and different to a first network associated with a subscriber, wherein the network element comprises a processing unit (401 ), the processing unit (401 ) being configured to:

receive a second message (Msg2), the second message comprising a voucher identifier code (Vn) relating to the prepaid voucher, the second message further comprising a second transaction identifier (OutTx);

compare the voucher identifier code (Vn) against a list of valid voucher identifier codes, and in response to a match;

send a third message (Msg3), the third message comprising the second transaction identifier (OutTx) and a value number (value), the value number representing a monetary value associated with the validated voucher identifier code (Vn).

17. A method in a network element (400) of a second network, the second network being a network that is associated with a prepaid voucher, and different to a first network associated with a subscriber, the method comprising the steps of:

receiving a second message (Msg2), the second message comprising a voucher identifier code (Vn) relating to the prepaid voucher, the second message further comprising a second transaction identifier (OutTx);

comparing the voucher identifier code (Vn) against a list of valid voucher identifier codes, and in response to a match;

sending a third message (Msg3), the third message comprising the second transaction identifier (OutTx) and a value number (value), the value number representing a monetary value associated with the validated voucher identifier code (Vn).

18. A billing apparatus for a telecommunications network, the billing apparatus comprising an interface unit (100) as claimed in any one of claims 1 to 8.