Mobile Telephony Services

Technical Field

The present invention relates to methods and systems for enabling communications services to be offered to customers. In particular, this invention relates to methods and systems for providing one or additional numbers for voice or messaging telephony services in a mobile network for a user of a mobile telephony device.

Background to the Invention

There are certain situations and occasions in which a phone user may wish to reveal their phone number to one or more people they do not know, or to the general public, in order that such people are able to contact them. Examples include the advertising of goods for sale or of accommodation to let. In such circumstances, there may be a need to contact or to be contactable for a certain period of time, but phone users often do not want to reveal their "permanent" phone number to unknown parties. Such concerns are often particularly acute in relation to mobile phone users' numbers, due for example to the possibility of the number then being used for the sending of "spam" or "junk" text messages, or for the more general concern users have of their number being used for intrusive "cold-calling" at inconvenient or unwanted times of day or night.

Some users may have a different but related concern about revealing their permanent number in relation to a particular event or activity. They may not wish for people who do know them and would recognise their permanent number to associate them with the event or activity in question. One example of such a situation is when an employee wishes to publicise their desire to be contacted by potential future employees without wanting to alert acquaintances or colleagues at their present place of employment who may know- and by chance recognise their permanent number.

For the reasons given above and others, it will be understood that a phone user may wish to have the use of a second number for incoming and/or outgoing calls for a certain period of time (a few days, weeks or months, for example), possibly with at least some option of a level of anonymity.

At this point it should be pointed out that use of the term "permanent" in the present specification in relation to telephone numbers does not necessarily imply "for all time".

While a strict definition may not be possible or appropriate, it will be understood that a user's "permanent" number is generally a number that he or she intends to use for a significant amount of time, perhaps several years, perhaps as their principal general, business or personal number. Corresponding to this, a user's "permanent identity" may be thought of as their identity from the point of view of people (friends, business contacts etc.) who contact the user or are contacted by the user by virtue of a number thought of as "permanent" in the manner explained above. A user may of course change from one "permanent" number to another sometimes, perhaps on account of a wish to "leave behind" a number that has become known to unwanted callers who are abusing the number, or simply on account of a wish to use a mobile phone number associated with an account with a different mobile phone provider in the same or a different country, although it is generally possible for users to keep the same mobile number when transferring their account from one mobile phone services provider to another, so it is in fact common for a user's mobile phone number to be "more permanent" than that user's contractual relationship with any particular service provider. In a similar sense, a landline number may be thought of as a permanent number, but users are often forced to change their landline number as a result of a move to a new residential address in a different region, even in the same country. In view of the above, it will be appreciated that it is common for people to have three or more "permanent" numbers at any time, such as a "work" number, a "home" number, and a mobile number.

It is of course possible for a user who already has a "permanent" mobile phone number and an associated mobile phone handset to obtain an additional mobile phone number using normal services already available, and operate it only for a set period, in the following manner. The user may obtain a second number by obtaining a second

"Subscriber Identity Module" (normally referred to as a SIM card) and use it in the same or an additional handset. For a user with only one handset, it is usually possible for the user to switch regularly between the two SIM cards, but this results in one of the phone numbers being "out of action" at any one time, and may be considered inconvenient.

An option available to a user with only one handset would be to use a Dual SIM Card Slot, or Dual SIM Card Holder, a representation of which is shown in Figures 1 (a) and 1 (b). With a dual SIM card holder 1 , the user can have two SIM cards 3 in their mobile phone 2 via a dummy SIM card 4 which fits in the housing normally used for a single SIM card, enabling the user to select between two different networks or two different accounts. After,

inserting two SIM cards 3 into the holder 1 , and inserting the holder 1 into the handset 2, the user may change between SIM cards by turning the phone off and on (hardware control), or appropriate software may allow the user to select the SIM card they prefer to use at any time (software control). Dual SIM card holders allow the user to operate two lines and two numbers (for example a business number and a personal number), and it appears that a triple SIM card holder may be available at the time of filing this application, but at this time the applicant is not aware of any such device that enables the number of SIM cards to be greater than three, let alone unlimited. Space considerations in particular provide a physical limit as to the number of SIM cards that could be held within a handset. Further to this, the procedure for obtaining an additional SIM card is as complex if the SIM card is to be used only for a short period as it is if the SIM card is to be used for the user's permanent number. The user not only needs to obtain the dual SIM card holder hardware item initially, but then needs to obtain the SIM card hardware itself each time use of an additional number is required. More information about dual SIM card holders can be found at http://www.fonefunshop.co.uk/dualsim/dualsimcovers.htm

Referring to prior patent publications, the possibility of allocating two different identities to one SIM card, predominantly for the purpose of enabling a user to keep a separate private and business account for billing purposes, has been disclosed in International patent application WO 92/19078 ("Comvik GSM"). This discloses a technique in which the SIM card can be inserted in two different positions, one corresponding to each identity, the circuitry for which are at respective ends of the card. It will thus be noted that the SIM card hardware is specifically designed for the purpose of holding two separate identities, and does not enable the addition of further numbers or identities beyond those for which it carries the necessary hardware.

Two other related patent applications, US 6,738,622 ("Stadelmann") and WO 98/10614 ("Generaldirektion PTT") relate to manners in which mobile phones may be used during international roaming. The first of these discloses a method in which the user has a first IMSI ("International Mobile Subscriber Identity") from his home network and is then assigned a second IMSI from a different network in which he is roaming. In this document, a common call number (MSISDN) is assigned to the two IMSI numbers. In the second of these documents, there is disclosed an earlier version in which each IMSI number is assigned a different call number.

In a similar field to the above, United States application US 2004/0176092 relates to the field of mobile radio telephony, and in particular to roaming. It refers to a communication method for logging a subscriber into a visited partner communication network, in particular a mobile radio network, an identification module, in which a subscriber identification outside the number range of the visited partner communication network is stored, being connected to communication terminal of the subscriber.

Also in the field of mobile telephony, US 5,933,785 discloses a method for concurrent registration of two identification numbers using a multi-number SIM card, involving use of a specially re-configured SIM card.

European patent application EP 1 528 827 also relates to the field of mobile telephony, and discloses a method for making subscriber information module (SIM) toolkit proactive commands available to applications running on a virtual operating system on a mobile telephony device. It explains that the mobile phone includes two virtual environments, which may be two separate Java environments, one of which is a J2ME virtual operating system running on the handset itself. While maintaining that it is possible to customise the J2ME virtual operating system so that it is able to operate the hardware of the specific model, it is acknowledged that such customisation is difficult.

In the field of fixed-line telephones, US 6,327,353 discloses a method for permitting temporary use of a "virtual" telephone number, involving directing calls made to the virtual telephone number to the same land-line as calls made to the normal number of that land- line.

Another situation in which a second "number" may be assigned to the same SIM card occurs when a customer wishes to send or receive faxes using their mobile phone. To enable this, their mobile service provider may assign an additional number to the same SIM card, in order to ensure that faxes reach the correct customer, but may be treated differently by that customer's handset to normal voice calls, and in a manner appropriate to what is being sent. This will be briefly explained with reference to Figure 2, which illustrates a part of a Home Location Register (HLR) relating to a particular SIM card.

The Home Location Register or "HLR" can be thought of as a central database that contains details relating to mobile phone subscribers that are authorised to use the mobile

network. The HLR stores details of every SIM card issued by a particular mobile phone operator. Each SIM card has a unique identifier called an International Mobile Subscriber Identity or "IMSI", which is one of the primary keys to each HLR record.

Other important items of data associated with the SIM are the numbers used to make calls from and receive calls to the mobile phone, known as Mobile Station Integrated Services Digital Network or "MSISDN" numbers. The main MSISDN is the number used for making and receiving voice calls and Short Message Service ("SMS") messages, but it is possible for a SIM to have other secondary MSISDNs associated with it for fax and data calls. Each MSISDN is also a primary key to the HLR record.

Also shown is the Temporary Mobile Subscriber Identity ("TMSI"). This is the identity most commonly sent between a mobile and the network. It is a randomly allocated number given to a mobile the first time it is switched on. The TMSI is local to a location area so must be updated every time the mobile does a location update procedure. The network can also force the mobile to accept a new TMSI at any time. These procedures make it difficult to trace which mobile is which except briefly, the first time a mobile is switched on or when the data in a mobile becomes invalid for some reason. At that point the global IMSI must be sent to the network. A key use of the TMSI is in paging of the mobile.

Examples of other data that may be stored in the HLR in a SIM record are:

- A list GSM services that the subscriber has requested or been given;

- General Packet Radio Services ("GPRS") settings to allow the subscriber to access packet services; - The current location of the subscriber (the Visitors Location Register or "VLR", and the Serving GPRS Support Node or "SGSN");

- Call divert settings applicable for each associated MSISDN.

The HLR data is generally stored for as long as a subscriber remains with a particular mobile phone operator. Further information on this is available from the following site, for example: http://en.wikipedia.org/wiki/GSM core network

None of the above technologies provide a simple manner in which a user may obtain a second number for an agreed temporary period that may be used for voice calls or messaging in a mobile network without the need for specific hardware to be obtained and

used or installed, and without the need for the user to reveal their permanent number to potential callers or message senders, or to compromise their anonymity.

Summary of the Invention

According to the present invention, there is provided a method in a mobile network of associating an additional number for voice or messaging telephony services with an existing identity module, said identity module being removably associated with a mobile telephony device and already having associated therewith a first number for voice or messaging telephony services, said method comprising the steps of: receiving from a user a request for an additional number to be associated with said existing identity module; in response to receipt of such a request for an additional number to be associated with said existing identity module, associating an additional number with the identity module, and sending a notification to said user, said notification including an indication of said additional number; in the event of a subsequent attempt to make a voice call to or send a message to said user by virtue of said additional number during an agreed period of time, arranging for said call or said message to be directed to the mobile telephony device with which said identity module is associated.

Also according to the present invention, there is provided a system arranged to provide an additional number service in a mobile network in accordance with the above method for users having a mobile telephony device, an existing identity module removably associated therewith, and a first number for voice or messaging telephony services.

According to preferred embodiments of the invention, a mobile phone service provider is able to provide a service that allows a mobile phone services customer having existing use of a permanent mobile phone number by means of a SIM card and an associated mobile phone handset temporarily to have concurrent use of one or more additional numbers without the need for an additional SIM card, an additional account or an additional mobile phone handset, while preserving the option of not revealing the permanent mobile phone number to potential calling or called parties.

According to preferred embodiments, in order for such a service to operate, the customer may apply for a temporary mobile number by sending an SMS message to their existing

service provider, possibly stating the duration the temporary number is required. The service provider may then respond with a reverse-charge SMS message, sending the customer an indication of a temporary number valid for an agreed duration. The customer can then advertise or use the temporary number for any required and/or permitted purpose. The customer (or user) may apply for more than one such temporary number, and theoretically an unlimited amount of such temporary numbers in this manner, for periods that may correspond or overlap.

When a caller, such as someone responding to an advertisement placed by the user, calls using a temporary number, the call is redirected to the user's handset containing the SIM card associated with the user's actual or permanent number. A notification on the user's mobile phone may indicate that the call was in fact made to their temporary number. If the user currently has more than one temporary number, such a notification may indicate to which of the temporary numbers the call was in fact made. The caller's number or identification may also be displayed, or may be stored.

If the customer wishes to make a call using a temporary number, he may launch an application on his phone that shows him the active temporary numbers. The customer may scroll to the desired one and select it to make his outgoing call. This allows anonymity to be kept for both incoming and outgoing calls.

The customer may be charged by his existing service provider for each temporary number according to the duration for which it is active, or according to the amount of use made of it, or according to a combination of these and possibly other factors.

Before a temporary number is due to expire, the customer may be sent an SMS message asking if the customer wishes to extend the period for which the temporary number is active.

It will be noted that while preferred embodiments of the invention may assist a customer in maintaining anonymity and avoiding the risk of his permanent number being abused later following disclosure thereof to strangers, some preferred embodiments of the invention may in fact allow a customer to abuse the use of a temporary number and subject others to unwanted anonymous calls. Telephone Service Providers may not wish to offer a service that allows such abuse, or use in certain other contexts, such as using a

temporary number when buying mobile content, or when conducting mobile financial transactions such as "m-Banking". Thus a further preferred embodiment of the invention may be offered in such a way as to prevent such problems, which will be referred to as the "One-directional Callback Model".

According to the "One-directional Callback Model", customers subscribing to a temporary number service are restricted in their use of their temporary number such that they cannot make direct outgoing calls or perhaps cannot send SMS messages directly to any recipient. Thus, "spamming" using the service is prevented or at least hindered. It will be of course be appreciated that with some embodiments of the invention, no such restrictions need be or will be imposed.

It will be noted that with the preferred embodiments of the invention described below, the Permanent Number is generally a user's existing, permanent, actual mobile number, and thus that any temporary numbers will make use of the functionality of the mobile phone handset containing the SIM card associated with the user's existing, permanent mobile number.

Brief Description of the Drawings

Preferred embodiments of the present invention will now be described with reference to the appended drawings, in which:

Figure 1 (a) shows a Dual SIM Card Holder next to a mobile phone with the rear cover removed;

Figure 1 (b) shows a Dual SIM Card Holder installed in a mobile phone with the rear cover open; Figure 2 shows indicates the types of information that may be stored in a Home Location

Register according to the prior art;

Figure 3 shows the steps that may be taken when a user applies for a temporary number according to a preferred embodiment of the present invention;

Figure 4 shows illustrates a Home Location Register storing information relating to two temporary numbers provided according to an embodiment of the present invention;

Figure 5 shows the steps that may be taken when a user makes a Callback Request according to an embodiment of the present invention;

Figure 6 shows the steps that may be taken when a user receives a call to a temporary number provided according to an embodiment of the present invention;

Figure 7 shows the steps that may be taken when a user sends an SMS message from a temporary number provided according to an embodiment of the present invention.

Description of the Embodiments

Preferred embodiments of the invention will now be described in detail with reference to Figures 3 to 7.

Requesting or Applying for a Temporary Number

Referring to Figure 3, the steps that may be taken when a user applies for a temporary number according to a preferred embodiment of the present invention will be explained.

In Step 1 , the user (Subscriber) writes an SMS message requesting a new Temporary Number. The SMS message may appear as follows: "BUY TEMPNO 01234567890" indicating that the user wishes to have the use of additional number "01234567890" as a temporary number. Alternatively, the user may simply request any additional number and accept whatever number may be offered. This is then sent to the service provider, possibly using a dedicated SMS Short-Code having five digits, e.g. 39000.

The SMS is be routed to a Subscription Server via a Short Message Service Centre (SMSC). The Short Message Service Centre may be installed at the network operator's premises or at a Base Station (BS). It acts as an SMS application server. The functions of the SMSC may include:

1. Processing incoming SMS messages ("MO" - see below).

2. Communicating with an "Unstructured Supplementary Services Data" (USSD) server (see later) to verify and register a new Temporary Number.

3. Responding to the subscriber's request by sending a Premium Charge SMS message ("MT" - see below).

4. Hosting a J2ME Application for download (see later).

5. Sending the J2ME Application to the subscriber's mobile phone (using "WAP-push", for example)

In items 1 and 3 above, "MO" stands for "Mobile Originated", and refers to messages sent from a mobile phone, such as requests. Similarly, "MT" stands for "Mobile Terminated", and refers to replies received by the mobile in response to such requests, for example.

In Step 2, the Subscription Server captures the following information for processing:

1. The Originating Number (i.e. the sender's Mobile Number)

2. The SMS content: "BUY TEMPNO 01234567890"

The Subscription Server communicates with the USSD server according to the Short Message Peer to Peer (SMPP) protocol. The SMPP is an open, industry standard protocol designed to provide a flexible data communications interface for transfer of short message data between a Message Centre, such as a Short Message Service Centre (SMSC) and a GSM USSD server. Thus, using this, a new request for a Temporary Number or application is sent to the USSD.

In Step 3, the USSD server validates the Originating Number and the requested Temporary Number. If the Temporary Number has not already been taken, it is inserted into the HLR database under the Originating Number's IMSI node. Alternatively, if the user has not requested a particular number, the USSD server simply selects a number that has not already been taken and inserts this into the HLR database under the Originating Number's IMSI node.

In Step 4, once the Temporary Number request has been successful, the Subscription Server sends a Premium Charged SMS (MT) to the subscriber as an acknowledgement. This may be used by the Service Provider in order to ensure that the customer pays for the setting up of a new number before being able to use it. Further to this, a J2ME Application, which may be referred to as the "Mini Client" may be forwarded to the subscriber, particularly if this is the first time he/she uses the service. This may be used to provide appropriate software on the user's mobile handset enabling the user to select between the permanent number and a temporary number when making outgoing voice calls or sending SMS messages, for example, thus avoiding the need for any hardware modifications to be made to the handset. Alternatively or additionally, this may enable the handset to indicate, for incoming calls, which number (permanent or temporary) the caller dialled, or intended to contact. This will be explained in more detail later. Briefly, however, J2ME, which stands for "Java 2 Platform, Micro Edition" and is also known as "Java ME",

is a collection of Java application programming interfaces (APIs) targeting embedded consumer products such as PDAs, mobile phones and other consumer appliances. More information on them is available from http://iava.sun.com/i2me/ for example.

Thus, after carrying out Steps 1 to 4 in Figure 3, a new temporary number will have been chosen and allocated to the user, and information, at least, relating to the temporary number will have been sent to the user and inserted into the HLR database under the user's IMSI node. During the initial setting-up, a period of use for the temporary number may be set up as a predetermined period (three months, for example) for a predetermined cost. Alternatively or additionally, a set period (one month, for example) may be initially offered and paid for, with the user perhaps having the option of "renewing" the period towards or at the end of the initial period, and so in until the user decides that the number should be allowed to lapse.

With reference to Figure 4, there is illustrated a representation of a Home Location Register (HLR) following allocation of two temporary numbers to a user in accordance with an embodiment of the invention.

The user may now make use of the temporary number to make or receive voice calls, or to send or receive SMS messages, for example.

Making a Callback Request

With reference to Figure 5, this shows the steps that may be taken when a user makes a Callback Request. In order to enable this, the J2ME Client may use Short Message Peer to Peer (SMPP) protocol interacting with the USSD server.

To use the Temporary Number, the subscriber runs the J2ME client on the mobile phone. At the client application start up, it communicates with the USSD server to request the Temporary Number List for the user. It will be noted that if a user is currently holding more than one temporary number with the service provider in question, this list contains all of the user's currently operational Temporary Numbers. The above functions are shown as Steps 1 and 2 of Figure 5.

In Step 3, the USSD server queries the HLR Database. In Step 4, the Temporary Number List is returned to the J2ME Client.

In Step 5, once a start-up process is complete, the user may see a list of numbers displayed on his mobile phone display, according to a function enabled by the J2ME client. The user may then: 1. Choose a Temporary Number, and

2. Key in the Recipient Number

Alternatively, the user's permanent number may appear in the displayed list, in which case Option 1 above may be set out as "Choose from Temporary Number(s) and Permanent Number", or more simply, "Choose from Available Numbers".

The use is then given the option to select one from the possible "Actions" below:

1. Make Callback Request

2. Send SMS

3. Call Recipient Number (if use of temporary number is not restricted in such a way as to prevent this, or if the Permanent Number was in fact the number selected).

In order to make a Callback Request to a recipient, the subscriber selects "Make Callback Request" (see Step 6), and the request is forwarded to the USSD server. In Step 7, the USSD server generates a Callback Request and sends it to the Recipient. The Callback request can be in the form of:

1. An SMS message;

2. An Interactive Voice Response (IVR) call; or in another appropriate form. (Further information on IVR telephony may be found at: http://www.webopedia.eom/TERM/l/IVR.html )

The recipient may then call the user, using the user's temporary number, thus removing the need for the user to disclose their permanent number to the recipient.

Receiving a Call

When a caller makes an Incoming Call to a subscriber using a temporary number of that subscriber, it is translated back to the IMSI at the HLR, thus enabling the call to be delivered to the subscriber's mobile phone. Once the MSISDN (mobile phone number) has been used to identify the IMSI, the HLR verifies the subscription records to ensure that the call can be delivered to the last known location of the subscriber.

Referring to Figure 6, steps that may be taken when a user receives a call to a temporary number are explained. Since the caller may have received information relating to the temporary number from a text message from the subscriber as set out earlier, or may have received an advertisement placed by the subscriber giving the temporary number in some form, we will refer to the calling user as the "recipient" for the sake of consistency, although it will be noted that the calling user may simply have received an indication of the temporary number, and is not in fact the recipient in relation to the call made.

In Step 1 , a recipient/caller calls the Temporary Number (for example seen in an advert, given in an SMS, or by giving an appropriate answer interpreted as "Yes" to an IVR call, causing the call to be diverted to the subscriber).

In Step 2, a Mobile Switching Centre (MSC) (not shown) interfacing with the HLR consults the HLR to find the Actual Mobile Number to route the call to. The Temporary Number is used to search for the IMSI root. Once the IMSI root is found, the Actual Mobile Number can be obtained.

Once the HLR has located the Actual Number, a call is directed to the subscriber (Step 3), and the subscriber may answer the call (Step 4). The system may be set up to show the subscriber the number from which the calling user is making the call, and/or an indication of the number (temporary or permanent) that the calling user believed the call was being made to. This may be of particular importance if the subscriber has more than one temporary numbers relating to different activities or events, and wishes to know which of these any particular incoming call relates to before answering the call. ^■

Sending an SMS Message

With reference to Figure 7, the steps that may be taken when a user sends an SMS message from a temporary number will now be explained.

To use the Temporary Number, the Subscriber first runs the J2ME client on the mobile phone. If the Temporary Number List is outdated, it can be updated at this stage. This is shown as Step 1. As shown in Step 2, at the client application start up, it will communicate with the USSD server to request for the Temporary Number List. This list contains the user's current and complete list of Temporary Numbers.

In Step 3, the USSD server queries the HLR Database. The Temporary Number List is returned to the J2ME Client in Step 4.

In Step 5, once the start up process is completed, the subscriber may see a list of numbers displayed by virtue of the J2ME client. The user can then:

1. Choose a Temporary Number;

2. Key in a Recipient Number; and

3. Key in text for an SMS message. By default, the J2ME Client may auto- insert a line of text at the end of the SMS message: "XXXXX XXXXX XXX XXXXX x xxxx xxxxxx xxxxx

XXX XXXX XX XXXXX.

Please reply to this Number:

01234 567890"

As before, the user's permanent number may also appear in the displayed list of numbers, in which case Option 1 above may be set out as "Choose from Temporary Number(s) and Permanent Number", or more simply, "Choose from Available Numbers".

The user may then select one of the Actions below:

1. Make Callback Request

2. Send SMS

3. Call Recipient Number (if use of temporary number is not restricted in such a way as to prevent this, or if the Permanent Number was in fact the number selected).

In Step 6, the subscriber selects "Send SMS" as a request. The complete formed SMS message together with the recipient number is then forwarded to the USSD server, which extracts the recipient number and forwards the SMS message to the Recipient.

In Step 7, the Recipient receives the SMS from what may appear as a dedicated short- code number (e.g. 32001) rather than from the subscriber's temporary number or actual/permanent number.

Further Information

Unstructured Supplementary Services Data (USSD)

USSD is a session oriented protocol, which is not a store and forward Service. USSD requests are processed instantaneously in contrast to SMPP (like SMS) requests which are stored for transmission on the SMSC.

The USSD Broadcast Centre may be built on an open platform providing industry standard connectivity to mobile applications. It can be easily integrated by using SMPP, Karinel HTTP, XML and WAP/WML application.

USSD is Roaming Supported - because messages are exchanged with the mobile subscriber's HLR, services are available even while on roaming.

Some existing familiar USSD applications in the market are: * Air-time balance checks

* Prepaid top-up

* Missed calls alerts Callback

* Interactive Menu Driven functions

Some network operators offer "Pre-paid Roaming Call Back". With this service, a mobile user can send a notification to another user asking to be called back when the prepaid customer is out of credit.

The request is simply sent by a USSD code including the phone number of the other party, for instance: < #11 *123456789# >. The receiving party receives an SMS message with a message "Please call me back on 987654321". Optionally, each user can enter a personalised message from a USSD menu, e.g. "Hi, it's Sophie. Could you please call me back on 987654321. Thanks in advance! ; - ) "

The USSD short/service code may be very short and simple, such as #11 , #123, #100.

J2ME Mobile Applications

In order to provide the subscribers to a Temporary Numbers service with a user-friendly tool to manage their subscribed temporary numbers, a J2ME Mobile Application (Mini Client) may be used. The Mini Client may provide the following three functionalities, and possibly others:

1. To allow viewing of the Number List :- The user can view a list of subscribed temporary numbers. Alternatively this list may also include the user's permanent number.

2. To send a Callback Request :- The user may select an appropriate number from the list which he wants to use, and send the callback request to the recipient using USSD.

3. To send an anonymous SMS message (or where appropriate and applicable, a voice call) :- The user selects a temporary number from the list, and sends an SMS message (or makes a call) to the recipient. The recipient will receive an SMS message (or call) from a dedicated short-code number, instead of the user's mobile number.