WO2005125163A1

WO2005125163A1 - Long distance carrier selection within a public land mobile network

Info

Publication number: WO2005125163A1
Application number: PCT/GB2005/002368
Authority: WO
Inventors: James Etheridge Barnes; Sanjeev Kumar; Gray Murray
Original assignee: Primus Telecommunications Limited
Priority date: 2004-06-18
Filing date: 2005-06-17
Publication date: 2005-12-29

Abstract

A method (l 00) of establishing a specific routing of a telecommunications call from a first mobile telecommunications device (16) having a first telecommunications address and being registered with a first mobile telecommunications network (12), to a second telecommunications device (13) having a second telecommunications address via a second telecommunications network (38), is described. The method comprises: specifying the second telecommunications address at the first device (16) and, upon subsequently receiving a single key press of a dedicated key (34) on a keypad (30) of the first device (16): retrieving an access number specific to the current country telecommunications network; establishing a telecommunications connection between the first device (16) and a remote server (28) using the retrieved access number; and transmitting the second telecommunications address from the first device (16) to the remote server (28) so as to enable the call to be routed to the second device (13) via the second telecommunications network (38). Apparatus (16, 28) for carrying out the method are also described.

Description

LONG DISTANCE CARRIER SELECTION WITHIN A PUBLIC LAND MOBILE NETWORK

Technical Field

The present invention concerns improvements relating to mobile telecommunications, and more particularly to least-cost routing of international phone calls made from mobile (or cell) phones. Background Art

The relatively recent rise in the number of mobile telephones has lead to a revolution in the area of personal communications. According to the UK Office of Communications (Ofcom), the time spent on mobile phone calls almost tripled between 1999 and 2003, and the number of text messages sent during this period increased fifteen-fold to an average of 15 text messages per user per week. UK phone users are also spending an increasing amount of money on fixed and Internet communications services in addition to mobile services - residential customers alone spending £1.3 billion in 2003 on all such services. Furthermore, total consumer spending on mobile services (phone and text) has exceeded the total consumer spending on fixed-line phone calls for the first time, with 21% of customers now using their mobile phone as the main device for making and receiving calls.

However, despite the decrease in the cost of making mobile phone calls in recent years, making international calls from a mobile phone can be prohibitively expensive for some users: calls can cost as much as £1.49 a minute to certain parts of the world on some price plans. These high costs have lead to the provision of services specifically for mobile phone customers which enable them to use other, cheaper networks for making international calls. To achieve savings in this way, the mobile user usually needs to carry out a two-stage call. This two-stage call may involve dialling an access number to gain access to a third party provider of cheaper international calls, listening to prompts and announcements, and entering PIN numbers etc before dialling the actual telephone number the user requires. The user may also be required to dial a different access number when moving from country to country, or even to insert a local SLM card in their mobile phone. Making such two-stage calls is often inconvenient and difficult to understand for some mobile phone users, which results in a low take-up of such services. Another disadvantage of the two-stage call is that the user may press the "call" or "send" button on their mobile phone at the end of dialling the international number they require, as a user naturally would do. However, if the user does this, the two-stage call is actually put on hold, and a second call using the more expensive mobile phone network is generated. So, instead of saving money, a user actually pays more than by just using the mobile network alone to make the international call because the user has effectively made two calls each using a different network.

An object of the present invention is therefore to provide a method of routing an international phone call via a low-cost carrier network (known as least-cost routing) which overcomes the aforementioned disadvantages.

Summary ofthe Invention

According to a first aspect of the present invention there is provided a method of establishing a specific routing of a telecommunications call from a first mobile telecommunications device having a first telecommunications address and being registered with a first mobile telecommunications network, to a second telecommunications device having a second telecommunications address via a second telecommunications network, the method comprising: specifying the second telecommunications address at the first device and, upon subsequently receiving a single key press of a dedicated key on a keypad of the first device: retrieving an access number specific to the current country telecommunications network; establishing a telecommunications connection between the first device and a remote server using the retrieved access number; and transmitting the second telecommunications address from the first device to the remote server so as to enable the telecommunications call to be routed to the second device via the second telecommunications network. Preferably the second telecommunications address is an international telephone number, and the second telecommunications network is a low-cost carrier network. Additionally, the retrieving step may comprise manually entering the access number into the first mobile telecommunications device.

The present invention provides a least-cost routing functionality for a mobile phone, thereby allowing outbound international calls from a home mobile network to be redirected to a low-cost carrier network via a national call rate or freephone access number which is stored on phone's SIM card. By the use of a dedicated key (referred to hereinafter as the "Primus P-key"), the user does not have to use PIN codes or directly use access numbers to connect to the low-cost carrier network to obtain cheaper international calls: he or she simply has to dial the international number followed by a single press of the Primus P-key. This avoids the risk of the user pressing the send key after entering the international number on a two-stage call-around service.

As an added precaution to the user accidentally pressing the send key after dialling their required international number, the user may request that they are barred from making international calls using the mobile network with which they are registered.

The Primus P-key may have a second functionality, such as enabling a connection to be established between the mobile phone and the Internet using the Wireless Application Protocol (WAP). However, such functionality is mode dependent. Within a given general operating mode, the P-key always has a dedicated function.

The method may further comprise the step of determining which country telecommunications network the first device is using.

Preferably the determining step comprises receiving a first country code from the first telecommunications network, retrieving a second country code from the first device, comparing the first country code and the second country code and, if they match, enabling the first device to be used for establishing the specific routing of the telecommunications call. The second country code may be a code which is stored on the SIM card of the first device when the first device is registered with the first mobile telecommunications network.

On the other hand, if the first country code and the second country code do not match, the first mobile device is not being used in the network with which it is registered, and the international call is thus not routed via the low-cost carrier network. Additionally, if a local S M card is not inserted in the mobile phone, the international call is not routed via the low-cost carrier network, as the first and second country codes will not match. This protects the user from unforeseen roaming charges if they use call around services (e.g. two step services such as calling cards) while roaming.

Preferably the retrieving step comprises comparing the second country code with at least one country code provided in a lookup table on the first device and, if there is a match, reading from the lookup table the access number associated with the matching second country code.

If necessary, the retrieving step may comprise manually entering the access number into the first mobile telecommunications device. This advantageously allows the user to enter the access number if it is not possible to retrieve the access number as described above. Preferably the retrieving step may further comprise storing the access number in a temporary data store to which further information can be added.

The lookup table may comprise a single country code and associated access number(s), or a plurality of country codes and associated access numbers. The provision of a lookup table having a plurality of country codes enables a single type of SLM card to be produced for use in mobile phones which may be used to carry out least-cost routing in a respective plurality of different countries. For example, the lookup table may comprise different country codes for countries A and B, together with associated different access numbers. A single type of SIM card could then be inserted in mobiles phones to enable least-cost routing of international calls made from countries A and B. An example of such a card is known as the "dual SIM card" which may be registered with mobile telecommunications networks in two different countries. The provision of a lookup table containing access numbers of different countries advantageously provides a cost significant cost saving to mobile phone manufacturers and vendors, and increased ease of user for the mobile user.

Preferably the step of reading an access number from the lookup table further comprises storing the access number in a temporary data store to which further information may be added.

Preferably the retrieving step further comprises storing the access number in a temporary data store (36) to which further information can be added.

Preferably the specifying step further comprises storing the second telecommunications address in the temporary data store.

The temporary data store may include a temporary number, in which case, the access number may be stored in a first portion of the temporary number, and the second telecommunications address may be stored in a second portion of the temporary number. The temporary data store may be provided on the SLM card or on the mobile device itself.

The step of retrieving an access number may comprise reading the access number from the temporary data store and, if the temporary data store includes a temporary number, from the first portion thereof.

The method may further comprise reading the second telecommunications address from the temporary data store prior to carrying out the transmitting step. If the temporary data store includes a temporary number, the reading step may comprise reading the second telecommunications address from the second portion thereof.

Preferably the method further comprises reading from the lookup table a pause variable associated with the second country code, and storing the pause variable in a third portion of the temporary number. Preferably a pause variable (p) is manually entered into the first telecommunications device, and the pause variable is stored in a third portion of the temporary number. Preferably the establishing step further comprises reading the access number from the first portion of the temporary number, and the method further comprises reading the pause variable from the third portion of the temporary number, waiting for a time period specified by the pause variable, and reading the second telecommunications address from the second portion of the temporary number prior to carrying out the transmitting step. The pause variable is used to accommodate access numbers with post-dial delay. It may be necessary to manually enter the pause variable into the first telecommunications device, the pause variable being stored in a third portion of the temporary number, if their is no pause variable associated with the access number.

The transmitting step may further comprise transmitting the first telecommunications address from the first device to the remote server prior to transmitting the second telecommunications address thereto, so as to enable the remote server to carry out an authentication process via caller line identification.

The transmitting step may carried out via a further telecommunications network, such as Public Switched Telephone Network (PSTN), a mobile telecommunications network, or any other suitable network, wireless or otherwise.

The method of establishing a specific routing of a telecommunications call may further comprise receiving a unique prepayment identifier and on subsequent actuation of a dedicated single actuator; retrieving a predetermined telephone number of the telecommunications service computer; establishing a telephone call with the telecommunications service computer; and transmitting the unique prepayment identifier to the telecommunications service computer to register the same.

Preferably the predetermined telephone number is the access number specific to the current country telecommunications network. The method may further comprise reading the value of a prepayment identifier store and if the value is a default value, overwriting the default value with the unique identifier. Preferably the transmitting step further comprises retrieving the stored unique prepayment identifier and transmitting the same from the first device to the remote server.

According to another aspect of the present invention there is provided a method of maintaining an up-to-date means for accessing a second telecommunications network, the method comprising receiving an instruction for updating a lookup table comprising at least one access number for accessing the second telecommunications network, and executing the instruction to update the lookup table. Preferably the executing step comprises removing, adding and/or amending data in the lookup table. In this manner, country codes, access numbers and pause variables may be amended automatically, without any user intervention. The purpose of this is to enable the remote server to ensure that any changes to access numbers are communicated to each mobile phone such that the access numbers are always up to date, thereby improving the reliability of the least-cost routing service to the user. Problems such as a country changing its dialling code format, for example, may be overcome by this aspect ofthe present invention.

Preferably the method further comprises generating a confirmation message upon successful execution ofthe instruction.

The updating instruction may be encapsulated in an SMS message. The confirmation message may also comprise an SMS message. Alternatively, the updating instruction may be encapsulated in an EMS (Enhanced Messaging Service) message, an MMS (Multimedia Messaging Service) message, or any other suitable type of message that can be received by a mobile phone.

According to a further aspect of the present invention there is provided an apparatus for routing a call from a first mobile telecommunications device having a first telecommunications address and being registered with a first mobile telecommunications network, to a second telecommunications device having a second telecommunications address, via a second telecommunications network, the apparatus comprising: specifying means arranged to specify the second telecommunications address from the first device and to initiate routing of the call upon receiving a subsequent single key press of a dedicated key on a keypad of the first device; retrieving means for retrieving an access number specific to the current country telecommunications network; connecting means arranged to establish, in use, a connection between the first device and a remote server using the retrieved access number; and transmitting means for transmitting the second telecommunications address from the first device to the remote server so as to enable the call to be routed, in use, to the second device via the second telecommunications network.

The apparatus preferably further comprises determining means for determining which country telecommunications network the first device is using. The determining means may comprise receiving means for receiving a first country code from the first network, country code retrieving means for retrieving a second country code from the first device, and first compare means for comparing the first and second country codes and for indicating that the phone is being used in the home country if the first and second country codes match.

The retrieving means preferably comprises second compare means for comparing the second country code with at least one country code provided in a lookup table, and reading means for reading from the lookup table the access number associated with a matching second country code. The reading means may be further arranged to write the access number to a data store, and wherein the retrieving means is further arranged to read the access number from the data store.

The receiving means is advantageously further arranged to write the second telecommunications address to a data store, and the connecting means is further arranged to read the second telecommunications address from the data store, and to send the second telecommunications address to the transmitting means.

The second compare means may be further arranged to read from the lookup table a pause variable associated with the matching second country code, and the transmitting means is further arranged to wait for a time period specified by the pause variable prior to transmitting the second telecommunications address to the remote server. Preferably the transmitting means is further arranged to transmit the first telecommunications address from the first device to the remote server prior to transmitting the second telecommunications address thereto, so as to enable, in use, the remote server to carry out an authentication process via caller line identification.

The apparatus may further comprise notification means for notifying a user that the call cannot be routed via the second telecommunications network if the authentication process is unsuccessful.

The apparatus may also further comprise receiving means arranged to receive an instruction from the remote server to update the lookup table data, and updating means for executing the updating instructions. The updating means is preferably further arranged to generate a confirmation message upon successful updating of the lookup table data, and wherein the transmitting means is further arranged to transmit the confirmation message to the remote server.

The instruction to update the lookup table data may be encapsulated in a message, such as an SMS message, an EMS message, or an MMS message.

Preferably the transmitting means is arranged to transmit a unique prepayment identifier in a predetermined format.

According to a yet further aspect of the present invention there is provided a server computer arranged to route a call from a first telecommunications device having a first telecommunications address and being registered with a first mobile telecommunications network, to a second telecommunications device having a second telecommunications address, via a second telecommunications network, the server computer comprising: a routing engine arranged to receive a second telecommunications number from the first device, to establish a connection from the server computer to the second device via the second telecommunications network, and to receive the first telecommunications address and to carry out an authentication process using that address; and a messaging engine arranged to generate instructions for updating a lookup table comprising at least one access number for establishing a connection between the first device and the server computer.

Preferably the messaging engine is further arranged to encapsulate the instructions in a message, and to send the message to the first telecommunications device.

Preferably the server computer comprises receiving means arranged to receive a unique prepayment identifier in a predetermined format and to identify the unique prepayment identifier from its predetermined position within the format.

Preferably the server computer may further comprise storing means for storing account details of the first telecommunications device; and validating means arranged to validate the unique prepayment identifier and to look up the account details of the first telecommunications device in an index of prepayment identifiers.

According to a further aspect of the present invention there is provided a mobile telecommunications device comprising the apparatus described above, and further comprising a keypad including a dedicated key for initiating the routing of the call via the second (low-cost) telecommunications network.

The dedicated key may be further arranged to establish a connection between the mobile device and the Internet using the Wireless Application Protocol (WAP). Such a connection may be established when this dedicated key is activated without an International phone number (i.e. a second telecommunications address) being entered manually or from the phonebook etc., the P-key may perform another function such as launching a WAP/Internet service. This dual functionality is unique and advantageous in that without the provision of a new, additional key, a single key press can be used to activate the least-cost routing functionality. Also, the use of a single, readily locatable P- key on a mobile phone makes the keypad less cluttered and potentially less confusing. According to a further aspect of the present invention there is provided a data carrier comprising a computer program arranged to configure a mobile telecommunications device to implement the method described above.

Brief Description of Drawings

Presently preferred embodiments of the present invention will be described, by way example only, with reference to the following drawings, in which: -

Figure 1 is a schematic representation of a system suitable for implementing preferred embodiments ofthe present invention;

Figure 2 is a schematic representation of the protocol layers of a mobile phone for use with the present invention;

Figure 3 is a flow diagram showing an overview of a method of low-cost routing of a phone call according to a first embodiment ofthe present invention;

Figure 4 is a flow diagram showing in more detail the method steps of Figure 3;

Figure 5 is a schematic representation part ofthe system shown in Figure 1 together with a further system component, for implementing a second embodiment of the present invention;

Figure 6 is a flow diagram showing the method steps for updating a lookup table, according to the second embodiment ofthe present invention;

Figure 7 is a flow diagram showing the method steps taken for using a prepaid voucher in a further embodiment ofthe invention, from the user's perspective;

Figure 8 is a flow diagram showing the method steps for setting up a prepayment account on the Primus platform; Figure 9 is a flow diagram showing the method steps for topping up a prepaid account in a further embodiment ofthe invention, from the user's perspective; and

Figure 10 is a flow diagram showing the method steps for topping up a prepaid account on the Primus platform.

Detailed Description ofthe Preferred Embodiments

Referring to Figure 1, there is shown a system 10 which is suitable for implementing presently preferred embodiments ofthe present invention.

The system 10 comprises a GSM telecommunications network 12 and a public switched telephone network (PSTN) 14. A mobile telephone communications device 16, such as a mobile (or "cell") phone is connectable to the GSM network 12 via a base station 18 which includes an antenna, and a base station controller 19. The base station controller 19 communicates with a mobile switching centre (MSC) 20. The MSC 20 is an integral part of the GSM network: it not only handles all the tasks of a conventional phone network (such as establishing a connection between the mobile phone 12 and the PSTN 14) but also provides all the functions needed for mobile communication such as authentication and verification, etc.

The MSC 20 is connected to a visited location register (VLR) 22 and a home location register (HLR) 24, which both comprise databases. The HLR 24 contains administrative information about the subscribers to a particular mobile network, and also keeps track of the location of each subscriber within the network 12. The HLR 24 also stores the unique international mobile equipment identity number of each mobile phone 12. The VLR 22 contains temporary information about the subscriber's location within the network 12 which is communicated to the HLR 24 when required. An Equipment Identity Register (EIR) (not shown) may also be connected to the MSC 20 for requesting the mobile phone 12 to broadcast its international mobile equipment identity (IMEI) number.

The MSC 20 may also be connected to a short messaging service centre (SMSC) 26. The SMSC 26 primarily acts to route SMS messages to and from mobile telecommunications devices. The SMSC 26 acts as a store and forward service for SMS messages, thereby enabling SMS messages to be delivered to a recipient if their phone 12 is not switched on, or if they are out of network coverage at the time the message was sent.

Connected to the PSTN 14 is a remote server computer 28, referred to hereinafter as the "Primus platform". The Primus platform 28 is connectable to a fixed telecommunications device (or another suitable type of device) 13 via a further network 38 which may be a public or private network. The Primus platform 28 comprises a routing engine 56 for routing a call to the fixed device 13 via the further network 38, and an SMS engine 58 for creating, sending and receiving SMS messages 68.

The mobile phone 16 has a keypad 30 and a graphics display screen 32. The keypad 30 includes a plurality of keys which include a dedicated Primus P-key 34 (the purpose of which will be described later) and a send key 35 that is generally pressed when a user 40 wishes to make a call. A subscriber identity module (SIM) card 36 is also provided in the phone 12. The SIM card 36 is arranged to store a unique identifier (the LMEI), the phone number of the subscriber 40 (known as the A-number), a telephone directory, and SMS messages. A lookup table 54 (shown in Figure 2) for storing a plurality of access numbers may also be provided on the SLM card 36.

When a subscriber makes use of their mobile phone 12, some of the information contained on the SLM card 36 is transmitted to the HLR database, which recognises the subscriber. More particularly, when the mobile phone 12 is switched on, it locks onto the network cell in which it is currently located and is sent the local area identity (LAI) code from the cell's base station 18. The LAI code is comprised of three codes: a mobile country code (MCC), a mobile network code (MNC) and a location area code (LAC) which together make up the global identity of the area. The mobile phone 12 then contacts the MSC 20 and reports its position using information from the LAI. This information is then stored in the VLR 22. The MSC 20 then sends a signal to the HLR 24 reporting that the mobile phone 12 is active in its service area. The mobile phone 12 is then sent an acknowledgement which terminates the registration process.

Referring now to Figure 2, the mobile phone 16 also includes a microprocessor 42. The microprocessor 42 includes an application layer 44, a protocol layer 46, a hardware driver 48, an operating system 50 for running software, and a hardware layer 52, as shown in Figure 2.

The application layer 44 provides services for application programs running on the mobile phone 16, and is arranged to receive a keypad event (e.g. an event relating to the pressing ofthe Primus P-key 34 by a user 40) and to communicate with the SLM 36. The operating system 50 is a program that manages all the other application programs running on the mobile phone 12, such as an application 60 for performing least-cost routing. The protocol layer 46 comprises a set of rules and conventions which govern how the mobile phone communicates with the mobile network 12. The hardware layer 52 enables the operating system 50 to communicate with the phone's hardware (namely the screen, microphone, speaker, power supply, telecommunications transmitter and receiver, etc) via the hardware driver 48 which provides a direct interface to the hardware.

A first embodiment of the present invention, wherein an international phone call is routed via a low-cost telecommunications network, is now described.

With reference to Figure 3 of the drawings, there is shown an overview of a method 100 for implementing the first embodiment of the present invention, according to the user's perspective.

The method 100 commences with a user 40 entering at Step 102 the desired international phone number (also known as a B-number) that they wish to be connected to. This may be done by the user 40 directly entering the number using the keypad 30 on their mobile phone 16, indirectly from the phone's phonebook, from a list of recently dialled phone numbers, or from an SMS message. The user 40 then presses at Step 104 the dedicated Primus P-key 34 provided on the mobile phone 16. Next, the mobile phone identifies at Step 106 whether it is being used in the home country (i.e. the country in which the HLR 24 is located), or whether the phone 16 is being used abroad.

If the phone is being used in the home country, a connection is made at Step 108 automatically and without any further user intervention to the low-cost carrier network 38, and the international call is then made at Step 110 to the B-number via the low-cost carrier network 38. If, on the other hand, the mobile phone 16 is not being used in the home country (i.e., it is "roaming"), the user 40 is informed at Step 112 that connection to the low-cost carrier network 38 is not permissible.

A more detailed description of the first embodiment of the present invention is now given with reference to the flow diagram of Figure 4. This flow diagram illustrates the steps that are carried out by the software application 60 running on the mobile phone 16.

As a result ofthe user 40 pressing the P-key at Step 104, the application 60 stores at Step 120 the B-number as a temporary number 62 on the SLM card 36. The application 60 then determines whether or not the mobile phone 16 is being used in its home country

(Step 106) by interrogating the phone's SLM card 36 and getting the unique code assigned to the SLM card 36 which is known as the International Mobile Subscriber

Identity (LMSI). The MSI which contains a five digit code, the first three digits of which denote the country in which the SIM card 36 is registered (i.e. the home country), and the last two digits of which specify the mobile network with which the mobile is registered.

The application 60 reads at Step 122 the first three digits of this code which indicates the country that the SLM card 36 is registered in. The application 60 then gets at Step 124 the

MCC from the HLR 24, and compares at Step 126 the MCC with the SIM's country code. If the MCC and the SIM's country code match, the mobile phone 16 is currently being used in its home country, and if these codes do not match, the mobile phone 16 is not currently being used in its home country. Consider now that the mobile phone 16 is being used in its home country. The lookup table 54 stored on the SLM card 36 comprises a plurality of access numbers for connecting to the Primus platform 28 from different countries. More particularly, the lookup table 54 comprises the following information: a line number, a home network code for each country, an associated access number for connecting to the Primus platform 28 from each country, and an associated pause variable (p). Note that the lookup table 54 may include further data, such as a second access number for each country, and an SMS gateway access number or an indication of which SMS gateway should be used for a particular country. The application 60 then compares at Step 128 the SIM's country code with each country code in the lookup table 54. If there is a matching country code, the application 60 gets at Step 130 the relevant access number and its associated pause variable. The temporary number 62 is then updated at Step 132 by appending the retrieved access number to the front of the B-number, and inserting the pause between the access number and the B-number (the length of the pause being determined by the value associated with the pause variable).

The application 60 then uses the access number stored as the temporary number 62 to call at Step 134 the Primus platform 28 over the mobile network 12 and the PSTN 14. The A-number ofthe mobile phone 16 may also be sent to the Primus platform 28 at this point, so that an authentication process can be performed via caller line identification.

The application 60 waits for a period of time specified by the pause, and then sends at

Step 136 the B-number portion of the temporary number 62 to the Primus platform 28.

Provided that the user 40 is authorised with the Primus platform 28 and has enough credit, the Primus platform 28 the connects at Step 138 the international B-number to the telephone 13 via the low-cost carrier network 38.

An example ofthe utilisation ofthe method 100 of the first embodiment of the invention is now described.

A user 40 has a mobile phone 16 with a SLM card 36 that is registered in Country A. The user 40 is using her phone in Country A (i.e. the home country), and she wishes to make an international call. She therefore enters the desired international B-number (00113455678912345) into her mobile phone 16 via the keypad 30. Rather than pressing the send key 35 to access the mobile network 12 (as a user 40 would normally do to make a phone call), she presses the Primus P-key 34 to push the international call through the Primus platform 28. This has the effect of storing the international B-number to the temporary number 62.

The access numbers for connecting to the Primus platform 28 are stored in a lookup table 54 such as that shown below. The table 54 includes two access numbers for each country. The access numbers given in the third column (CI) of the table 54 are used as the default access numbers. The access numbers given in the fourth column (C2) of the table 54 are only used if the first access number is not in service. The table 54 may also contain a further column (C3) which denotes an SMS gateway access number or which SMS gateway should be used for a particular country.

From the lookup table 54 shown above, it can be seen that the default access number for connecting to the Primus platform 28 from Country A is 0207 1234567. Upon pressing the Primus P-key 34, the mobile phone 16 establishes that it is being used in Country A (in accordance with the method steps 122 to 126 described above), and therefore retrieves the default access number 0207 1234567 and the associated pause variable p. This access number is inserted before the international B-number in the temporary number 62, followed by the pause variable p.

However, if required, it is possible for the user 40 of the mobile phone 16 to manually enter the access number; for example, to take advantage of a cheaper access number for the exclusive use of the service provider's employees, say. This can be done by selecting a corresponding menu option on the mobile phone that enables this service. The manually entered access number is then inserted before the international B-number in the temporary number 62, followed by a pause variable p which can be a default pause variable, or one specified by the user 40.

A hash (#) is then inserted at the end ofthe temporary number 62. For example:

1. User is in Country A (345) 2. Dials 00113455678912345 3. Access number 02071234567 inserted 4. Pause inserted 5. Temporary number = 02071234567p00113455678912345#.

Here the pause is one second in length as the p variable has a value of one. However, due to the variable nature of access number operation in different countries, the pause variable may take other values. For example, in Country C, access numbers may take two seconds to connect. Therefore the pause (p) coded against the Country C access number in the table is two seconds.

The access number 0207 1234567 is then retrieved from the temporary number 62 and dialled so that a connection is made from the mobile phone 16 to the Primus platform 28. The user's mobile phone number (the A-number) is also sent to the Primus platform 28 to enable the call to be registered and authenticated via caller line identification. This may be carried out by the routing engine 56 provided on the Primus platform 28. While the A-number is being registered and authenticated, the international B-number 00113455678912345 is retrieved from the temporary number 62 and sent to the Primus platform 28.

Note that the last dialled number stored in the SIM card 36 does not include the access number. Also note that the leading zero digits of the international dialling code are not removed from the number string.

A second embodiment ofthe present invention, wherein the list of access numbers stored in the lookup table 54 is updated via SMS messaging, is now described with reference to Figures 5 and 6 of the drawings. It is to be appreciated that the lookup table 54 is typically provided with all handsets regardless of the country of use and is a table which is designed, if required, to be changed remotely by the Primus platform 28 and not by the mobile phone user.

Referring firstly to Figure 5, there is shown an SMS platform 64 which is required for implementing the second embodiment of the present invention. The SMS platform 64 is connected to the Primus platform 28 via the PSTN 14, and to the SMSC 26 via the Internet 66 (i.e. via TCP/IP). The SMS platform 64 will typically comprise a server computer including an SMS gateway interface for connecting to a telecommunications network. The SMS platform 64 will typically be part of the mobile network 12. Data between the Primus platform 28 and the SMS platform 64 may also be sent via the Internet.

Referring now to Figure 6, there is shown a method 200 for updating the lookup table 54 via SMS messaging according to the second embodiment ofthe present invention.

The method 200 commences with the SMS engine 58 of the Primus platform 28 generating at Step 202 an SMS message 68 to instruct the amendment of an entry in the lookup table 54 stored in the SLM card 36 of the mobile phone 16. The SMS message 68 may contain a change command, together with data which represents a new access number which is to be written to a specific part of the lookup table 54. Alternatively, the SMS message 68 may contain an instruction to remove an entry in the lookup table 54. The SMS message 68 is then sent at Step 204 to an SMS platform 64 via the PSTN 14. Next, the SMS message 68 is sent at Step 206 to the SMSC 26 for forwarding to the mobile phone 16. The SMSC 26 provides a store and forward service which stores messages and forwards them to a user 40 when their mobile phone 16 is switched on and connected to the mobile network 12. If the mobile phone 16 is switched on, the SMS message 68 is sent at Step 208 from the SMSC 26 to the mobile phone 16. The SMS message 68 is then used by the application 60 installed on the mobile phone 16 to update at Step 210 the lookup table 54.

A confirmatory SMS message 70 (see Figure 1) may then be sent at Step 212 from the mobile phone 16 to the SMS engine 58 of the Primus platform 28 via the SMSC 26 and the SMS platform 64. The confirmatory SMS message 70 may contain an indication of whether or not the requested change to the lookup table 54 was successful, along with the user's mobile phone number. The confirmatory SMS message 70 may be encoded in a suitable format (if required) at the SMS platform 64 for subsequent delivery to the SMS engine 58.

An example of an SMS message 68 for instructing the application 60 to amend an access number stored in the lookup table 54 is given below.

To change an existing lookup table entry the following SMS message format may be used: GCSSet*line number*Cl or C2*old home network code*old access number*new home network code*new access number*new home network code confirmed*new access number confirmed#.

For example, to change the first Country A access number from 0207 1234567 to 0207 1234555, the following SMS message 68 would be created by the Primus platform's SMS engine 58 and sent to the user's mobile phone 16 at Step 210 ofthe method 200: GCSSet*!* CI or C2*345*02071234567*345*02071234555*345*02071234555#, where line number=l, old home network code=345, old access number=02071234567, new home network code=345, new access number=02071234555, new home network code confirmed=345, new access number confirmed=02071234555.

To amend the first line of the lookup table 54 to change the home network code and the access number, the following SMS message 68 would be created by the Primus platform's SMS engine 58 and sent to the mobile phone 16: GCSSet*l* CI or C2*345*02071234567*001*00113455678901*001* 00112345678901#, where line number=l, old home network code=345, old access number=02071234567, new home network code=001, new access number=00113455678901, new home network code confirmed=001, new access number confirmed=00113455678901.

To delete an entry from the lookup table 54 the following SMS message format may be used: GCSDel*line number*Cl or C2*home network code*old access number#.

For example, to remove Country A and its associated access numbers from the lookup table 54, the following SMS message 68 would be created by the Primus platform's SMS engine 58 and sent to the mobile phone 16 in Step 210: GCSDel*l*Cl or C2*345*02071234567#, where line number=l, home network code=345,old access number=02071234567. Once successfully removed, the home network code is set at 000 and the access number as 00000000000000 such that the first line ofthe lookup table 54 would appear as follows:

The above change to the lookup table 54 would have the effect of the user 40 no longer being able to connect to the Primus platform 28 (and therefore being unable to use the least-cost routing function) from Country A. Any of the above SMS messages may include further commands for amending or deleting lookup table data. For example, if the lookup table 54 contains an additional column (C3) comprising SMS gateway data, the following SMS message format may be used: GCSSet*line number*Cl or C2 or C3*old home network code*old access number*new home network code*new access number*new home network code confirmed*new access number confirmed#.

Upon successful amendment of the lookup table 54, the application 60 creates and sends a confirmation SMS message 70 from the user's mobile phone 16 to the SMS engine 58 ofthe Primus platform 28 which could have the following format: GSCOk*new home network code*new access number#. For example, if the instruction to change the first Country A access number from 0207 1234567 to 0207 1234555 was successful, the following confirmation SMS message 70 would be sent: GSCOk*345*02071234555#. Upon a successful deletion of an entry from the lookup table, the confirmation SMS message 70 GSCOk*# could be sent to the SMS engine 58.

In order to identify whether an instructed amendment of a lookup table entry (or the deletion of such an entry) is successful, the following confirmation SMS message 70 would be created by the application 60 and sent to the SMS engine 58: GCSFal*#.

Looking again at the flow diagram shown in Figure 6, if the mobile phone 16 is not switched on (or is switched on, but not within the range of the network 12), the SMS message 68 instructing the amendment/deletion of a lookup table entry is stored at Step 214 at the SMSC 26 to be sent to the mobile phone 16 when it is connected to the network 12. When the mobile phone 16 is connected to the network 12, Steps 208 to 212 above are then carried out to update the lookup table 54 and to generate and send a confirmation SMS message 70. If the SMS message 68 cannot be delivered to the mobile phone 16, the user 40 is contacted at Step 216 directly by customer services and asked to switch on their mobile phone 16 to connect at Step 218 to the network 12. The SMS message 68 is thus sent at Step 208 from the SMSC 26 to the mobile phone 16, and Steps 210 and 212 above are then carried so that the SMS message 68 can be used to update the lookup table 54.

Two different methods can be used to ascertain whether or not the SMS message 68 has been delivered to the mobile phone 16. The first method entails the use of an expiration time which may be attached to the SMS message 68. If a message expiration is used, the SMSC 26 stores and re-attempts delivery of the message 68 for unavailable users 40 until either the delivery of the message is successful, or the expiration time is reached. Such an expiration time may be set on a per-message basis, or on a platform-wide basis. In a second method, upon receipt of the SMS message 68, the application 60 generates an SMS confirmation message 70, as described above. If a confirmatory SMS message 70 is not received by the SMS engine 58 by a predetermined time, customer services are informed that the SMS message 68 has not been received, so that the user 40 may be contacted directly and asked to switch on their phone (as in Steps 216 and 218 described above).

The embodiments of the present invention described above can each be varied to incorporate different features. For example, in the present embodiments of the invention the connection between the mobile network 12 and the Primus platform has been described as being made using a PSTN. However, in practice, any other suitable type of telecommunications network may be used. Also, the present invention has been described in relation to making a phone call between a mobile phone and a fixed telephone. In practice, the present invention could be used to make mobile to mobile calls, or to make calls to (or from) other types of devices such as PDAs (personal digital assistants).

Although the above embodiments of the present invention have been described in relation to a dedicated Primus P-key, the send key (or any other suitable key) of a mobile phone could be programmed to initiate least-cost routing. For example, upon the user entering an international B-number and pressing the send key, the application running on the user's mobile phone could automatically recognise that the B-number is an international number, and so carry out the steps to connect to the Primus platform. In order for this to occur, the user ofthe mobile phone would have to positively activate the application on the mobile phone, though this can be done is a multitude of different ways. When in such a mode and under the specified conditions (international number recognised), the single key used in the present invention is considered to have a 'dedicated' function.

Least-cost routing according to the above described embodiments of the present invention may be provided using a prepaid voucher-based service. Figure 7 of the drawings shows an overview of a method 180 for implementing this embodiment of the present invention at the Primus phone, according to the user's perspective.

Referring now to Figure 7, the user 40 purchases, or is provided with, at Step 182 a prepaid voucher. The voucher contains a ten-digit activation number, referred to hereinafter as the GCS Key (GCSK). The user inputs at Step 184 the GCSK with a leading digit, for example * 1234567890 (where * is associated with the star button ofthe mobile phone 16). The leading digit enables the mobile phone to distinguish the number from other numbers entered into it, such as standard telephone numbers.

The user presses at Step 186 the Primus P-key. At this point the Primus phone automatically stores the GCSK, preferably in a dedicated submenu in the Primus phone's Call Options menu. However, the GCSK can only be stored in the Primus phone if the default factory set GCSK field (0000000000) is present. Therefore, the Primus phone checks at Step 188 to see if the GCSK value stored within it is 0000000000. If this is not the case, an error message is displayed to the user. On the other hand, if the GCSK value stored in the Primus phone is 0000000000, the GCSK overwrites at Step 190 the default value. This prevents the user from having their GCSK inadvertently overwritten and thus losing access to their account which will be created by the Primus platform. The Primus phone then initiates at Step 192 a telephone call with the Primus platform during which the GCSK including the leading digit is then sent to the Primus platform via DTMF tones.

Referring now to Figure 8, an overview of a method 300 for implementing this embodiment of the present invention, according to the Primus platform's perspective, is now described. After receiving at Step 302 the activation GCSK via DTMF tones, the

Primus platform then searches at Step 304 its GCSK database for the received GCSK.

The Primus platform then validates at Step 306 the GCSK. If it is found to be invalid, a message is sent at Step 309 informing the user. However, if the GCSK is found to be valid, the Primus platform creates and opens at Step 308 an account for the user utilising the GCSK as the account identification (ID). It is possible, if required, to also register the user's Calling Line Identifier (CLI) against that account ID.

Once the account has been set-up, the user can then use the prepay service by entering their desired international B-number (00113455678912345) into the Primus phone and pressing the Primus P-key, as described previously. The appropriate access number (0207 1234567) and pause variable p, which are obtained from the lookup table 54, again as described previously, are added to the temporary number 62. In this embodiment, the pause variable allows the Primus platform 28 to differentiate the access number from the GCSK which is added to the temporary number 62. A further pause variable p is added to the temporary number 62, after which the desired international B- number (00113455678912345) is stored in the temporary number 62. A hash (#) is then inserted at the end ofthe temporary number 62. For example, in this embodiment: Temporary number = 02071234567p*1234567890p00113455678912345#.

The access number 0207 1234567 is then retrieved from the temporary number 62 and dialled so that a connection is made from the mobile phone 16 to the Primus platform 28. The GCSK is retrieved from the temporary number 62 and sent to the Primus platform 28. After the required pause the international B-number 00113455678912345 is retrieved from the temporary number 62 and also sent to the Primus platform 28. The Primus platform 28 is thus able to debit the account associated with the GCSK. A method 220 for topping up an account by a user on their mobile phone which can be implemented with the current embodiment of the invention is now described with reference to Figure 9. When the user 40 uses all of the credit available in the GCSK account, they can purchase a top up voucher to obtain more credit. The voucher contains a top up GCSK which is stored in the GCSK database of the Primus platform together with the associated credit that the voucher entitles the user to. The user inputs at Step 222 the top up GCSK, for example *2345678901, where * is associated with the star button of the mobile phone. Again, this enables the mobile phone to distinguish the number from other numbers entered into the mobile phone, such as standard telephone numbers.

The user then presses at Step 224 the Primus P-key. The mobile phone checks at Step 226 to see if a GCSK has been stored previously. If a GCSK has not been stored previously, i.e. the GCSK stored in the mobile phone is the default GCSK (0000000000), then a message is sent at Step 227 to the user informing them that the GCSK is invalid as they do not have a GCSK account to top up. In this example, a GCSK has been stored previously.

Subsequently, the mobile phone obtains the appropriate access number (0207 1234567) and pause variable p for the country that they are in (i.e. Country A) from the lookup table 54. These are then added to the temporary number 62. The pause variable allows the Primus platform 28 to differentiate the access number from the top up GCSK which is added to the temporary number 62. A hash (#) is then inserted at the end of the temporary number 62. For example:

Temporary number = 02071234567p*1234567890p00113455678912345#.

The access number 0207 1234567 is then retrieved from the temporary number 62 and dialled so that a connection is made from the mobile phone 16 to the Primus platform 28.

After the required pause the GCSK is retrieved from the temporary number 62 and sent to the Primus platform 28. After the second pause the international B-number 00113455678912345 is retrieved from the temporary number 62 and also sent to the Primus platform 28. The Primus platform 28 is thus able to debit the account associated with the GCSK.

Referring now to Figure 10, an overview of a method 240 for topping up an account according to a further embodiment of the present invention, from the perspective of the Primus platform, is shown. The method 240 commences at Step 242 with the Primus platform receiving the top up GCSK. The Primus platform then searches at Step 244 its GCSK database for the received top up GCSK. The Primus platform checks at Step 246 to see if the top up GCSK is valid. If so, the Primus platform adds at Step 248 the credit associated with the top up GCSK to the account associated with the activation GCSK contained in the header of the SMS message. If the top up GCSK is not valid, for example if the top up GCSK has been used or does not exist, an appropriate error message is sent at Step 247 to the user.

Upon successful completion of top up of the account associated with the activation GCSK, the Primus platform sends at Step 250 a confirmation message to the user verifying that the account has been topped up.

The use of a prepaid card service is advantageous because it provides further security and a degree of anonymity for the user. In particular, the user does not have to provide their personal details nor their preferred payment method in order to obtain a callback service. Many users of mobile services prefer to use prepaid voucher systems as it also gives the user greater control of the amount of money they spend on mobile communications.

In this further embodiment, the GCSK (activation) is effectively used as a unique identifier of the mobile telecommunications device, therefore it is possible to use this unique voucher identifier once it has been registered at the Primus platform as the unique identifier of the mobile telecommunications device. If by chance the home network country is not in the access table, then the application running on the mobile phone could initiate a different method of establishing a least-cost routing service. An example of the type of service which could be provided is an SMS Callback service, whereby an SMS message can be constructed and sent to the Primus platform. On receipt, the Primus platform could establish a call to a desired destination specified in the SMS message after a least-cost route and call the mobile phone back to connect it to the call. An example of such a service has been described in our co-pending UK patent application no. 0506825.9, the contents of which are incorporated herein by reference.

Having described particular preferred embodiments of the present invention, it is to be appreciated that the embodiments in question are exemplary only, and that variations and modifications, such as those that will occur to those possessed of the appropriate knowledge and skills, may be made without departure from the spirit and scope of the invention as set forth in the appended claims. For example, it will be readily apparent to those skilled in the art that the above prepaid system could utilise SMS messaging or the use of a call centre to register for, and top up, GCSK services.

Furthermore, line 1 in the access number table can be changed to have a 'wild card' function. More specifically, if a customer is using a SIM card with an MNC that is not in the table, the service provided can default to an SMS Call Request (see co-pending UK patent application no. 0506825.9 - the contents of which have been disclosed) and the access number would default to the number provided in column C3 (not shown) in line 1 (Country A SMS Call Request access number). By adding this function, there is advantageously now no restriction on where Call Request may be used (beyond the ability to send an International SMS).

Claims

1. A method (100) of establishing a specific routing of a telecommunications call from a first mobile telecommunications device (16) having a first telecommunications address and being registered with a first mobile telecommunications network (12), to a second telecommunications device (13) having a second telecommunications address via a second telecommunications network (38), the method comprising: specifying the second telecommunications address at the first device (16) and, upon subsequently receiving a single key press of a dedicated key (34) on a keypad (30) of the first device (16): retrieving an access number specific to the current country telecommunications network; establishing a telecommunications connection between the first device (16) and a remote server (28) using the retrieved access number; and transmitting the second telecommunications address from the first device (16) to the remote server (28) so as to enable the telecommunications call to be routed to the second device (13) via the second telecommunications network (38).

2. A method (100) according to Claim 1, further comprising the step of determining which country telecommunications network the first device (16) is using.

3. A method (100) according to Claim 1 or Claim 2, wherein the retrieving step comprises manually entering the access number into the first mobile telecommunications device 16.

4. A method (100) according to any of Claims 1 to 3, wherein the second telecommunications address is an international telephone number, and the second telecommunications network (38) is a low-cost carrier network.

5. A method (100) according to Claim 2 or Claim 4 as dependent on Claim 2, wherein the determining step comprises receiving a first country code (MCC) from the first network (12), retrieving a second country code (LMSI) from the first device (16), comparing the first country code (MCC) and the second country code (LMSI) and, if they match, enabling the first device (16) to be used for establishing the specific routing of the telecommunications call.

6. A method (100) according to Claim 5, wherein the retrieving step comprises comparing the second country code (LMSI) with at least one country code provided in a lookup table (54) and, if there is a match, reading from the lookup table (54) the access number associated with the matching second country code (LMSI).

7. A method (100) according to Claim 6, wherein the step of reading an access number from the lookup table (54) further comprises storing the access number in a temporary data store (36) to which further information can be added, and the retrieving step comprises reading the access number from the temporary data store (36).

8. A method (100) according to Claim 3, wherein the retrieving step further comprises storing the access number in a temporary data store (36) to which further information can be added.

9. A method (100) according to any preceding claim, wherein the specifying step further comprises storing the second telecommunications address in the temporary data store (36) to which further information can be added, and wherein the method further comprises reading the second telecommunications address from the temporary data store (36) prior to carrying out the transmitting step.

10. A method (100) according to Claim 8 or Claim 9 as dependent on Claim 7, wherein the data store (36) comprises a temporary number (62), and the step of storing the access number comprises storing the access number in a first portion of the temporary number (62), and the step of storing the second telecommunications address comprises storing the second telecommunications address in a second portion of the temporary number (62).

11. A method (100) according to Claim 10, further comprising reading from the lookup table a pause variable (p) associated with the second country code (IMSI), and storing the pause variable in a third portion ofthe temporary number (62).

12. A method (100) according to Claim 10 as dependent on Claim 8, wherein a pause variable (p) is manually entered into the first telecommunications device, and the pause variable is stored in a third portion ofthe temporary number (62).

13. A method (100) according to Claim 11 or Claim 12, wherein the establishing step further comprises reading the access number from the first portion of the temporary number, and the method further comprises reading the pause variable (p) from the third portion of the temporary number, waiting for a time period specified by the pause variable, and reading the second telecommunications address from the second portion of the temporary number prior to carrying out the transmitting step.

14. A method (100) according to any preceding claim, wherein the transmitting step further comprises transmitting the first telecommunications address from the first device (16) to the remote server (28) prior to transmitting the second telecommunications address thereto, so as to enable the remote server (28) to carry out an authentication process via caller line identification.

15. A method (100) according to any preceding claim, wherein the step of transmitting the second telecommunications address is carried out via a further telecommunications network (14).

16. A method (100) according to any preceding claim, further comprising: receiving a unique prepayment identifier; and on subsequent actuation of a dedicated single actuator: retrieving a predetermined telephone number of the telecommunications service computer; establishing a telephone call with the telecommunications service computer; and transmitting the unique prepayment identifier to the telecommunications service computer to register the same.

17. A method (100) according to Claim 16, wherein the predetermined telephone number is the access number specific to the current country telecommunications network.

18. A method (100) according to Claim 16 or Claim 17, further comprising reading the value of a prepayment identifier store and if the value is a default value, overwriting the default value with the unique identifier.

19. A method (100) according to any of Claims 16 to 18, wherein the transmitting step further comprises retrieving the stored unique prepayment identifier and transmitting the same from the first device (16) to the remote server (28).

20. A method (200) of maintaining an up-to-date means for accessing a second telecommunications network, the method comprising: receiving an instruction (68) for updating a lookup table (54) comprising at least one access number for accessing the second telecommunications network, and executing the instruction to update the lookup table (54).

21. A method (100) according to Claim 20, further comprising generating a confirmation message upon successful execution ofthe instruction (68).

22. A method (100) according to Claim 20 or Claim 21, wherein the executing step comprises removing, adding and/or amending data in the lookup table (54).

23. Apparatus (60) for routing a call from a first mobile telecommunications device (16) having a first telecommunications address and being registered with a first mobile telecommunications network (12), to a second telecommunications device (13) having a second telecommunications address, via a second telecommunications network (38), the apparatus comprising: specifying means arranged to specify the second telecommunications address from the first device (16) and to initiate routing of the call upon receiving a subsequent single key press ofa dedicated key (34) on a keypad (30) ofthe first device (16); retrieving means for retrieving an access number specific to the current country telecommunications network; connecting means arranged to establish, in use, a connection between the first device (16) and a remote server (28) using the retrieved access number; and transmitting means for transmitting the second telecommunications address from the first device (16) to the remote server (28) so as to enable the call to be routed, in use, to the second device (13) via the second telecommunications network (38).

24. Apparatus (60) according to Claim 23, further comprising determining means for determining which country telecommunications network the first device (16) is using.

25. Apparatus (60) according to Claim 24, wherein the determining means comprises receiving means for receiving a first country code from the first network (12), country code retrieving means for retrieving a second country code from the first device (16), and first compare means for comparing the first and second country codes and for indicating that the phone is being used in the home country if the first and second country codes match.

26. Apparatus (60) according to Claim 25, wherein the retrieving means comprises second compare means for comparing the second country code with at least one country code provided in a lookup table (54), and reading means for reading from the lookup table (54) the access number associated with a matching second country code.

27. Apparatus (60) according to Claim 26, wherein the reading means is further arranged to write the access number to a data store (36), and wherein the retrieving means is further arranged to read the access number from the data store (36).

28. Apparatus (60) according to any of Claims 23 to 27, wherein the receiving means is further arranged to write the second telecommunications address to a data store (36), and the connecting means is further arranged to read the second telecommunications address from the data store (36), and to send the second telecommunications address to the transmitting means.

29. Apparatus (60) according to Claim 26, 27, or 28 as dependent on Claim 26 or 27, wherein the second compare means is further arranged to read from the lookup table (54) a pause variable (p) associated with the matching second country code, and the transmitting means is further arranged to wait for a time period specified by the pause variable prior to transmitting the second telecommunications address to the remote server (28).

30. Apparatus (60) according to any of Claims 23 to 29, wherein the transmitting means is further arranged to transmit the first telecommunications address from the first device (16) to the remote server (28) prior to transmitting the second telecommunications address thereto, so as to enable, in use, the remote server (28) to carry out an authentication process via caller line identification.

31. Apparatus (60) according to Claim 30, further comprising notification means for notifying a user (40) that the call cannot be routed via the second telecommunications network (38) if the authentication process is unsuccessful.

32. Apparatus (60) according to any of Claims 23 to 31, further comprising receiving means arranged to receive an instruction from the remote server (28) to update the lookup table data, and updating means for executing the updating instructions.

33. Apparatus (60) according to Claim 32, wherein the updating means is further arranged to generate a confirmation message upon successful updating of the lookup table (54) data, and wherein the transmitting means is further arranged to transmit the confirmation message (70) to the remote server (28).

34. Apparatus (60) according to Claim 32, wherein the instruction is encapsulated in a message (68).

35. Apparatus (60) according to Claim 33 or Claim 34, wherein the message (68,70) comprises one of the group of an SMS message, an EMS message, and an MMS message.

36. Apparatus (60) according to any of Claims 23 to 35, wherein the transmitting means is arranged to transmit a unique prepayment identifier in a predetermined format.

37. A server computer (28) arranged to route a call from a first telecommunications device (16) having a first telecommunications address and being registered with a first mobile telecommunications network (12), to a second telecommunications device (13) having a second telecommunications address, via a second telecommunications network

(38), the server computer (28) comprising: a routing engine (56) arranged to receive a second telecommunications number from the first device (16), to establish a connection from the server computer to the second device (13) via the second telecommunications network (38), and to receive the first telecommunications address and to carry out an authentication process using that address; and a messaging engine (58) arranged to generate instructions for updating a lookup table comprising at least one access number for establishing a connection between the first device (16) and the server computer (28).

38. A server computer (28) according to Claim 37, wherein the messaging engine (58) is further arranged to encapsulate the instructions in a message, and to send the message to the first telecommunications device.

39. A server computer (28) according to Claim 37 or Claim 38, comprising receiving means arranged to receive a unique prepayment identifier in a predetermined format and to identify the unique prepayment identifier from its predetermined position within the format.

40. A server computer (28) according to any of Claims 37 to 39, comprising storing means for storing account details of the first telecommunications device; and validating means arranged to validate the unique prepayment identifier and to look up the account details ofthe first telecommunications device in an index of prepayment identifiers.

41. A mobile telecommunications device (16) comprising the apparatus claimed in any of Claims 23 to 36, and further comprising a keypad (30) including a dedicated key (34) for initiating the routing ofthe call via the second telecommunications network.

42. A mobile telecommunications device (16) according to Claim 41, wherein the dedicated key (34) is further arranged to establish a connection between the device and the Internet using the Wireless Application Protocol (WAP).

43. A data carrier comprising a computer program arranged to configure a mobile telecommunications device (16) to implement the method according to any one of Claims 1 to 22.