WO2014104875A1

WO2014104875A1 - Method of communicating messages between a first and a second telephony device over a telephony network

Info

Publication number: WO2014104875A1
Application number: PCT/NL2013/050931
Authority: WO
Inventors: Igo TRAMPE
Original assignee: Ringlabs B.V.
Priority date: 2012-12-28
Filing date: 2013-12-20
Publication date: 2014-07-03
Also published as: NL2010068C2

Abstract

A method of communicating messages between a first and a second telephony device over a telephony network. The first telephony device maps a message selected by a first operator and an indication of the second telephony device to an outgoing telephone number and initiates a call to this number. A server receives the call to the outgoing telephone number, and determines from the outgoing telephone number an incoming phone number associated with the second telephony device and the message, and causes the second telephony device to receive a call from the determined incoming phone number. The second telephony device receives the missed call from the incoming telephone number, maps the incoming phone number to the message and presents the message to a second operator. The call to the outgoing telephone number and/or the call from the incoming telephone number is a missed call.

Description

Method of communicating messages between a first and a second telephony device over a telephony network

FIELD OF THE INVENTION

The invention relates to an improved method of communicating messages between a first and a second telephony device over a telephony network. The invention further relates to telephony devices and servers for use in such a method, as well as computer program products for causing computers to operate as such devices or servers.

BACKGROUND OF THE INVENTION

Telephony, in particular mobile telephony, is one of the most popular methods of communication. Message-based communication has exploded in popularity ever since SMS was introduced. Messages may comprise

alphanumerical content and are typically enriched with emoticons or other symbols to enhance or clarify the meaning of the content. The move from old- fashioned phones to more complex devices such as smartphones and telephony applications on tablets and other computers only contributed to this effect. (We will use "telephony device" to indicate the full range of devices capable of making and/or receiving telephone calls, from a simple dedicated phone to a tablet or smartphone with an app or special-purpose hardware, with or without the ability to transmit data, images, messages and so on.) The costs of telephone communication has dropped significantly in the past years, but is still felt to be relatively high, especially in developing countries.

Various technologies are available to reduce the cost of communication by phone. A currently popular tool is the WhatsApp service that allows the sending of messages over a data connection from one mobile phone to another. Because the costs for data transmissions are often lower than for SMS messages, WhatsApp has gained enormous popularity. But still, there is a cost - and that cost is likely to increase as the demand for (mobile) data communication grows.

A simple trick popular in particular in developing nations is to use the "missed call" feature of all telephony networks. A missed call does not cost the originator any money (unless it is transferred to voicemail). One can use a missed call to provide a signal to the recipient, for example "If you get a missed call from me at 15:00 tomorrow I will have landed safely on Heathrow Airport,

London". As long as the parties can agree beforehand on the intended interpretation and have only one message to exchange, this works fine. But even the slightest change, e.g. a delay in flight time, makes the message impossible to send with this trick.

EP2398216A1 proposes an improved technique that uses the duration of a missed call, preferably expressed as the number of rings before the originator ends the call, to provide additional information. In the example above, one ring could be agreed upon to mean a landing at the intended time and place, two rings could mean a diversion to Stansted Airport and three rings could mean the flight was delayed. A disadvantage of this technique is that the number of rings may differ between originator and recipient: the recipient may miss one of the rings and misinterpret the message. Further, typically only a limited number of rings is available before a call is diverted to voicemail, limiting the amount of information that can be sent. Although this is often

reconfigurable by the user it is still a drawback.

EP2039176A1 proposes to encode additional information in the data packets that make up the call. This requires a voice-over- IP connection, which implies a data connection with associated costs. Moreover, a telephony provider or network operator can block this technique by filtering out the additional information.

There is a need for an improved method of communicating messages between a first and a second telephony device over a telephony network.

SUMMARY OF THE INVENTION

The invention provides a method of communicating messages between a first and a second telephony device over a telephony network, in which the first telephony device maps a message selected by a first operator and an indication of the second telephony device to an outgoing telephone number and initiates a call to this number, a server receives the call to the outgoing telephone number, and determines from the outgoing telephone number an incoming phone number associated with the second telephony device and the message, and causes the second telephony device to receive a missed call from the determined incoming phone number, the second telephony device receives the missed call from the incoming telephone number, maps the incoming phone number to the message and presents the message to a second operator, where the call to the outgoing telephone number and/or the call from the incoming telephone number is a missed call.. The invention employs the method of the missed call, i.e. a call that is signaled to a recipient but which is not accepted or established for voice or data communication, to communicate a selected message to the second telephony device.

In essence, the invention relies on the insight that you can rely on a missed call to or from a predetermined number to convey information. The invention advantageously employs a mapping mechanism that provides more flexibility than the prior art discussed above. The message and intended recipient (e.g. phone number of the second telephony device) are mapped to a particular outgoing telephone number. A call to this number, which preferably is a missed call but could be an accepted call, arrives at the server,where it provides the trigger for the server to make its own determination: given this call from the outgoing telephone number, now use this outgoing telephone number and make a call to the second telephony device. At the second telephony device the call from the server, again which preferably is a missed call but could be an accepted call, provides a trigger. The second telephony device takes the call's number and maps it to the originally-intended message, preferably together with an indication of the first telephony device (e.g. its phone number, a name taken from the phone book associated with that phone number or a custom name configured by an operator). This indication can be construed by taking the incoming phone number and mapping it to the name in the address book associated with that phone number.The method allows for plural different messages to be exchanged, because for each message (and recipient) different respective outgoing and incoming telephone numbers can be determined. By using the mechanism of a missed call, a financial charge and/or technical overhead for accepting a call is avoided.

US 2009/0274284 proposes to modify the calling line identification (CLID) of an outgoing call. This way, one could place a call from a privately- owned mobile phone and have the recipient see the office landline number, for example. However nothing in this document discloses or suggests that the number shown can be used to convey messages.

The invention has many advantageous applications. For example, one may use the invention to update ones location as known at another person's phone or inform the other person of a current activity, by having messages correspond to common activities such as "driving car" or "at school". One may use the invention to indicate presence or absence at an event, e.g. sports practice or a meeting. One number could be assigned to the message "present" and another to the message "absent", preferably with additional messages to indicate possible delayed arrival times.

An employee assigned with maintenance duties could benefit from the invention by receiving messages indicating areas or objects that need maintenance. For example a janitor could receive messages indicating toilets to clean or floors to sweep after a spill. Visitors can send messages using the invention to numbers indicated on or near the floors or toilets etc. in question to notify the janitor free of charge. A delivery company can benefit from the invention by having its drivers send messages to update on the delivery process of various packages or mail items.

In an embodiment the first telephony device and the second telephony device from time to time obtain respective mapping tables providing a plurality of mappings between messages and outgoing and incoming phone numbers, respectively. These mapping tables thus are exchanged before the actual message-based communication takes place. Distributing such tables beforehand can be done efficiently and cheaply, for example when a cheap or free internet connection is available, or when the phone is connected to a computer or laptop and this computer's internet connection can be used. SMS messages, which may or may not be free of charge, or a mobile data connection can also be used.

The two phones may use a direct connection (e.g. Bluetooth,) to exchange mapping information, although this requires a later exchange with the server to also inform the server about the exchanged mapping.

In another embodiment the first telephony device upon selection of the message and the indication of the second telephony device makes a mapping request to the server, the server upon receipt of the mapping request associates the outgoing telephone number with the first phone and the incoming telephone number with the second telephony device, and communicates the respective associations to the respective telephony devices. In this embodiment the mapping is done at the level of an individual message and recipient, instead of at the level of a table with plural messages. Thereby individual messages can be added or changes, rather than a whole table at once. If only some messages change at a time, it is more efficient to only update the changed messages.

In both embodiments a particular mapping may be declared invalid if no calls were initiated to the outgoing number part of the mapping within a predetermined period of time. This period can be any period, in practice one month is preferred. This variation conserves phone numbers, because when a mapping is declared invalid the incoming and/or outgoing phone numbers associated with them can be reused for other messages and/or recipients.

In a further embodiment instead of a mapping from message to one outgoing telephone number, the message and the indication of the second telephony device are mapped to a sequence of outgoing telephone numbers, and the first phone initiates respective calls (preferably missed calls) to each of the numbers in the sequence. The server receives these calls, determines a sequence of incoming phone numbers associated with the second telephony device and the message, and causes the second telephony device to receive a sequence of missed phone calls from the determined incoming phone number sequence. The second telephony device receives the sequence of missed calls from the incoming telephone numbers, maps the incoming phone numbers to the message and presents the message to the second operator.

Using a sequence of numbers has the advantage that more messages can be sent with a select number of numbers than when using a one-to-one mapping. For example, already with two numbers (say, A and B) four sequences are possible (AA, AB, BA, BB) and thus four messages can be communicated by making missed calls in the appropriate sequence.

The invention further provides for a phone suitable as the first and/or the second telephony device in the method of the invention, and a computer suitable as the server in the method of the invention.

The invention further provides for a computer-readable storage medium comprising executable code for causing a computer to operate as the first or the second telephony device of the invention, and for a computer-readable storage medium comprising executable code for causing a computer to operate as the server of the invention. The storage media may be provided in a server connected to the Internet, allowing a download of the executable code to the phone or computer. BRIEF DESCRIPTION OF THE FIGURES

The invention will now be explained in more detail with reference to the figures, in which:

Fig. 1 schematically illustrates a telephone communication network to which are connected a first telephony device, a second telephony device and a server;

Fig. 2 schematically illustrates the method of the invention in general;

Fig. 3 schematically shows a mapping table for use in the invention that employs a one-to-one mapping;

Fig. 4 schematically shows another mapping table for use in the invention that employs a sequence-based mapping;

Fig. 5 schematically illustrates a telephony device comprising means for executing the method of the invention; and

Fig. 6 schematically illustrates a computer comprising means for operating as the server of the invention.

In the figures, same reference numbers indicate same or similar features. In cases where plural identical features, objects or items are shown, reference numerals are provided only for a representative sample so as to not affect clarity of the figures.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

Fig. 1 schematically illustrates a telephone communication network 300 to which are connected a first telephony device 100, a second telephony device 900 and a server 700 with database 800.

The first telephony device 100 is shown as a smartphone, a mobile phone built on a mobile operating system, with more advanced computing capability and connectivity than a classic phone. The second telephony device 900 is shown as a tablet computer. These are intended as illustrative examples only; nothing in the invention limits application to smartphones and/or tablets. The telephony devices 100, 900 communicate wirelessly with the network 300, while the server is shown to have a landline connection. Again this is for illustrative purposes only. The network 300 can be any existing or future network suitable for placing calls, e.g. a POTS networks, a GSM or 3G network, a TCP/IP network or any successor, replacement or alternative thereof. The technology used for the calls is not important; what matters is that calls can be made (and missed).

Fig. 2 schematically illustrates the method of the invention in general. The three apparatus involved, telephony devices 100, 900 and server 700 are shown to illustrate which of the actors performs which step.

In step 201, the first device 100 receives a selection of a message, denoted as M, and an indication, denoted as B, of the second device 900, both of which are made by a first operator (not shown) of the first device 100. In a first embodiment this is achieved by providing a user interface to the operator allowing him to select the message from a list or table or similar means. The second device can similarly be selected from a list or table. Inspiration may be drawn from SMS sending applications or software applications like WhatsApp, where e.g. emoticons or predefined messages can be selected from lists, menus or tables.

The messages can be prescribed by an operator of the service, or composed by the operator(s) of the device 100 and/or device 900. For example, in a consumer environment it may be attractive to have users choose messages they want to exchange among each other. They could compose these messages on a computer, after which the message table with allocated telephone numbers is sent to both users' phones.

Preferably each user/user combination may have their own table, meaning that if users A and B communicate they have a different set of messages to choose from than users A and C or B and D. But alternatively all users could have the same message set to choose from. This makes allocating numbers easier, reduces the amount of storage needed for the mappings and gives the operator more control over the messages.

In a business environment the business owner may dictate the set of messages and have this installed on all phones used by employees. For example a parcel delivery service could use the invention to provide status updates on the progress of delivery. The messages could be "package received at front desk", "package to local sorting center", "package in airplane", "package in delivery truck", and so on. Each employee involved in sorting and/or delivery now can send any of these messages to update colleagues or a computerized information system for customers. In step 202, the first device 100 maps this selection to an outgoing telephone number denoted as C. The mapping is preferably done using the tables of Fig. 3 or Fig. 4, although other mapping mechanisms are also possible.

The devices 100, 900 in an embodiment obtain from time to time new or updated versions of these mappings. Updates can be provided by replacement tables or by an indication of changes, additions and/or removals to individual entries in a table.

In an embodiment the first device 100 after step 201 makes a mapping request to the server 700 prior to step 202. This mapping request comprises the message and the intended recipient. In response the server 700 creates a mapping that is communicated to both devices 100, 900. The first telephony device receives an outgoing telephone number which it associates with the message and the intended recipient. The second telephony device receives an incoming telephone number which it associates with the message and the sender.

This embodiment can be used if the message is not a common message or if communication frequency is low. An advantage is that no potentially large tables with all possible message/recipient combinations need to be retained, but a disadvantage is that the actual sending of the message must wait until the mapping request has been completed and both devices have received the mapping information. This may take a while, especially if it is desired to perform the mapping protocol over a free-of-charge communication channel because then one may have to wait until this channel is available.

A particular mapping in an embodiment is declared invalid if no calls were initiated to the outgoing number part of the mapping within a predetermined period of time, for example one month.

In step 203 the first device 100 initiates a call to the outgoing telephone number

C. This call is communicated over the network 300 to the server 700. In one

embodiment the number C instead is a sequence of numbers, as per Fig. 4.

In step 213 the server 700 receives the call to C from the device 100. Depending on configuration the server 700 may take the call, refuse the call or let the call ring until the device 100 terminates the call. The call may be a free-of-charge number to avoid charges to the operator of device 100, or the refusal or termination options can be used to avoid such charges.

In step 214 the server 700 determines from the number C an incoming phone number, denoted as D, which is associated with the second device 900 and the message M. This determination is preferably made using the tables of Fig. 3 or Fig. 4, although alternative determinations are also possible.

In one alternative embodiment the number D instead is a sequence of numbers, as per Fig. 4. This does not materially change the invention but requires the device 900 to wait until all calls are received before step 225 can be performed.

In step 215 the server 700 causes the second telephony device 900 to receive a missed call from the determined incoming phone number D. The call may originate from the server 700 itself but could also be placed from another server if network design, interconnection or other considerations make this preferable.

In step 225 the call from D is missed at the device 900. This can be achieved by having the originator of the call terminate the call after a certain number of rings, or by having the device 900 itself refuse or terminate the call.

In step 226 the device 900 maps the incoming phone number D to the message M. In an embodiment the device 900 maps the incoming phone number D to a combination of the message M and an indication of the first telephony device 100.

The indication of the first device 100 may be derived from the table of

Fig. 3 or Fig. 4. Alternatively, the indication of the first device 100 may be transmitted as part of the call, preferably using the feature of a forwarded calling line indicator that can be added to calls in some telephony protocols. With this feature device 900 receives both the incoming phone number D and the original number of device 100 as part of the calling line identification. We will call this feature forwarded CLI for short.

In step 227 the device 900 presents the message M to a second operator of the device 900, optionally together with the indication of the first device 100. A great many presentation options are available; again inspiration may be drawn from SMS messaging systems or WhatsApp, or from display of system messages. In an embodiment the device 900 presents the combination of the message M and indication of the first telephony device 100 to the second operator. In a further embodiment the server 700 may validate the calling line

identification or other identifier of device 100. As discussed above, any call to number C will result in a call from number D to device 900, causing the device 900 to display message M . If any one other than device 100 makes this call to C, the message M is still displayed, and in some embodiments including this device 100 as its originator. Should this be undesirable, then it is necessary to validate the call to C and only cause the call from number D to device 900 to be made if the call originated with device 100. In embodiments where the number of device 100 is needed to map C to the right D, this feature is an automatic benefit. If

In a further embodiment one or more numbers is reserved for system messages, for example "service temporarily unavailable" or "mapping outdated". Such system messages are initiated by server 700 and roughly follow steps 214, 215, 225, 226 and 227. However, here the server 700 determines the system message by its own internal means (or as specified by a system operator) and causes a call to D to be made which is associated with the system message rather than with any message from device 100. Further, the message is preferably presented in a format that makes it easily

recognizable as a system message, to avoid confusion.

The above-mentioned feature of forwarded CLI can also or instead be used to more easily deliver system messages. The number D is then mapped to "system message" instead of another telephony device, and in the forwarded CLI an indication of the exact message to be delivered is provided.

Fig. 3 schematically shows a first mapping scheme for use in the invention that employs a one-to-one mapping. In this scheme, device 100 is provided with table 301, device 900 is provided with table 309 and server 700 is provided with table 307.

Table 301 provides a one-to-one mapping of message and recipient to outgoing phone number. Column 301A provides an overview of messages, in this case simple one- word textual messages but they can of course be any content, for example picture messages, a combination of image and text, or even video and/or audio content. Column 301B provides an indication of intended recipients, here indicated simply as B or C but in practice this will typically be the phone number of the recipient, and/or a user- programmed (alpha-)numerical indication of a person. A photo, e-mail address or other indication could also be used. Column 301C finally provides the outgoing phone number to be used if message from column 301A is to be provided to the recipient of column 301B. That is, if message 'Lorem' is to be provided to recipient 'B', the call should be made to number 1122 but if the same message is to be provided to recipient 'C then the call should be made to number 3344.

Table 309 provides a similar mapping as table 301, but uses the incoming phone number as the key. In column 309 A incoming phone numbers are listed, corresponding to calls caused by the server 700. Column 309B indicates the originator of the message and column 309C the message itself. The meaning of table 309 is that if an incoming call is from number 6677, then message 'Lorem' was sent by 'A' and if the call instead is from number 9900 then message 'Ipse' was sent by 'C.

In table 307 the outgoing phone numbers of column 301C are listed in column 307 A and mapped to the incoming phone numbers of column 309A, listed in column 307B. Column 307C provides an indication of the intended recipients of the calls to be made from the incoming phone numbers.

For example, if a call is received from number 1122, then a call to B is to be made using number 6677 as the incoming number - the telephony device B will receive a call from number 6677. As per table 309 in that device, the call from 6677 is translated to the message 'Lorem' from sender A. If instead a call from 3434 is received, then a call to B is caused to be made using number 8899 as the incoming number. This will result in device B showing message 'Ipse' from sender C, as per table 309.

Phone numbers can be allocated in this scheme in a variety of ways. A straightforward first way is to exclusively use one number for one sender A and one message M to one recipient B. In other words, if anyone other than A calls this number, the server will refrain from causing a call to B that would result in message M. This however requires a very large number of phone numbers.

A second way is to reuse phone numbers for multiple senders, that is both A and B have outgoing phone number 1122 in their versions of tables 301 but for A this number may cause message 'Lorem' to be presented to B and for B this number may cause message 'Ipse' to be presented to C. This way of working requires some form of identification of the sender at the server 700, preferably using the calling line identification (CLI). This CLI would then be present as a fourth column in table 307. For the incoming phone numbers at the server 700 the preferred way of working is to use one outgoing number per message, but to share outgoing numbers over devices. That is, each device has only one meaning for say incoming number 6677 but the meaning, the message, may differ between devices.

If it is possible to accompany the call with the outgoing number by an indication of the original sender, then reuse of numbers in one device is possible. One could then map incoming number 6677 to message 'Lorem' if the sender is A, and to 'Ipse' if the sender is B. The server 700 may be able to use the forwarded CLI for this purpose. This technique can also be used for system messages.

Fig. 4 schematically shows a second mapping scheme for use in the invention that employs a sequence-based mapping. Device 100 is provided with table 401, device 900 is provided with table 409 and server 700 is provided with table 407.

Table 401 corresponds roughly with table 301, except that the outgoing number of 301C now provides a sequence of outgoing numbers in 401C. That is, if message 'Lorem' is to be delivered to recipient 'B' now calls to 1122 and 2233 are to be made. If instead this message is to be delivered to 'C then calls to 1122 and 3434 are to be made. Both these calls will be received by server 700. Of course sequences may comprise more than two numbers.

Similarly, in table 309 a sequence of incoming numbers is provided in column 409A. Each sequence maps to a message, for example if calls from 1122 and 2233 are received, then this maps to message 'Lorem' from sender 'Α'.

In table 307 the sequences of incoming numbers in colunn 407A are translated to corresponding sequences of outgoing numbers in column 407B. Column 407C has the same meaning as column 307C.

In the tables shown, the order of the sequence is important. A call from 1122 followed by a call from 2233 means something different from a call from 2233 followed by a call from 1122. In some situations this may not be desirable, and then an unordered sequence can of course be used.

In a variation of this embodiment, the sequence of outgoing phone numbers actually represents a set of numbers, each number of which is called separately as per Fig. 3. This way group messaging is obtained: A makes a call to say number 1122, and the server 700 causes missed calls are caused to be made to three recipients. Each of the three recipients sees an incoming phone number that represents the same group message. Preferably this number is the same for all three recipients, but this does not have to be the case. The server 700 would preferably store in a table similar to 407 or 307 the number or numbers of the group message and the numbers of the members of the group. Alternative ways of coupling numbers to groups of recipients are also possible.

Fig. 5 schematically illustrates a telephony device comprising means for executing the method of the invention. The device 500 can operate as either the first device 100 or the second device 900, and preferably can operate as both. Means commonly used in telephony devices are not illustrated.

To handle outgoing messages, the device 500 comprises message selection module 501 for allowing an operator to make the selection of message M and the indication of the second device B. This selection is provided to mapping module 502, which uses a mapping mechanism to map M and B to number C, preferably using mapping table 301 or 401 stored in storage means 550. Updating module 551 can be added to update the table in the storage 550 as discussed earlier. This module 551 can be extended with functionality to make the mapping request discussed earlier, or this functionality can replace the mapping table.

The device 500 further comprises call initiation module 503 that is configured to cause a call to be initiated to the outgoing number C. While initiating calls as such is standard functionality for a phone, indicated as calling module 590, the manner in which calls are used in the invention makes the module 503 useful. The module 503 preferably is configured to terminate the call after a predetermined number of rings, for example three rings, or hangs up as soon as server 700 has received the call. The module 503 may also be configured to monitor usage of the device 500 and delay the call until the outgoing line is free or another suitable moment is found for the call.

To handle incoming messages, the device 500 comprises call monitoring module 511 that is configured to monitor incoming calls, as ordinarily handled by module 590. If the number of an incoming call is matched against a mapping, e.g. using the table in storage 550, then module 511 is configured to override the ordinary procedure for handling incoming calls, preferably also the common procedure of informing the operator that a call is incoming, and cause the call to be missed. Further, module 511 is configured to provide a signal to mapping module 512 which is configured to map the incoming phone number to the message M, optionally together with the indication of the first telephony device 100.

Presentation module 513 is configured to present the message M to a second operator of the device 900, optionally together with the indication of the first device 100.

Fig. 6 schematically illustrates a computer comprising means for operating as the server of the invention. The call reception module 601 is configured to receive calls from devices such as the first device 100. Mapping module 602 is configured to determine from the number C the incoming phone number, denoted as D, which is associated with the second device 900 and the message M. Storage module 650 can be used, for example to store the tables from Fig. 3 or Fig. 4. Calling module is configured to cause the second telephony device 900 to receive a missed call from the determined incoming phone number D.

CLOSING NOTES

The above provides a description of several useful embodiments that serve to illustrate and describe the invention. The description is not intended to be an exhaustive description of all possible ways in which the invention can be implemented or used. The skilled person will be able to think of many modifications and variations that still rely on the essential features of the invention as presented in the claims. In addition, well- known methods, procedures, components, and circuits have not been described in detail.

Some or all aspects of the invention may be implemented in a computer program product, i.e. a collection of computer program instructions stored on a computer readable storage device for execution by a computer. The instructions of the present invention may be in any interpretable or executable code mechanism, including but not limited to scripts, interpretable programs, dynamic link libraries (DLLs) or Java classes. The instructions can be provided as complete executable programs, as modifications to existing programs or extensions ("plugins") for existing programs. Moreover, parts of the processing of the present invention may be distributed over multiple computers or processors for better performance, reliability, and/or cost.

Storage devices suitable for storing computer program instructions include all forms of non- volatile memory, including by way of example semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices, magnetic disks such as the internal and external hard disk drives and removable disks, magneto- optical disks and CD-ROM disks. The computer program product can be distributed on such a storage device, or may be offered for download through HTTP, FTP or similar mechanism using a server connected to a network such as the Internet. Transmission of the computer program product by e-mail is of course also possible.

When constructing or interpreting the claims, any mention of reference signs shall not be regarded as a limitation of the claimed feature to the referenced feature or embodiment. The use of the word "comprising" in the claims does not exclude the presence of other features than claimed in a system, product or method implementing the invention. Any reference to a claim feature in the singular shall not exclude the presence of a plurality of this feature. The word "means" in a claim can refer to a single means or to plural means for providing the indicated function.

Claims

1. A method of communicating messages between a first and a second telephony device over a telephony network, in which the first telephony device maps a message selected by a first operator and an indication of the second telephony device to an outgoing telephone number and initiates a call to this number, a server receives the call to the outgoing telephone number, and determines from the outgoing telephone number an incoming phone number associated with the second telephony device and the message, and causes the second telephony device to receive a missed call from the determined incoming phone number, the second telephony device receives the missed call from the incoming telephone number, maps the incoming phone number to the message and presents the message to a second operator, where the call to the outgoing telephone number and/or the call from the incoming telephone number is a missed call.

2. The method of claim 1, in which the first telephony device and the second telephony device from time to time obtain respective mapping tables providing a plurality of mappings between messages and outgoing and incoming phone numbers, respectively.

3. The method of claim 1, in which the first telephony device upon selection of the message and the indication of the second telephony device makes a mapping request to the server, the server upon receipt of the mapping request associates the outgoing telephone number with the first phone and the incoming telephone number with the second telephony device, and communicates the respective associations to the respective telephony devices.

4. The method of 2 or 3, in which a particular mapping is declared invalid if no calls were initiated to the outgoing number part of the mapping within a

predetermined period of time.

5. The method of claim 1, in which the second telephony device maps the incoming phone number to a combination of the message and an indication of of the first telephony device, and presents the message together with the indication to the second operator.

6. The method of claim 1, in which the message and the indication of the second telephony device are mapped to a sequence of outgoing telephone numbers, the first phone initiates respective calls to each of the numbers in the sequence, the server receives these calls, determines a sequence of incoming phone numbers associated with the second telephony device and the message, and causes the second telephony device to receive a sequence of missed phone calls from the determined incoming phone number sequence, the second telephony device receives the sequence of missed calls from the incoming telephone numbers, maps the incoming phone numbers to the message and presents the message to the second operator.

7. A phone suitable as the first and/or the second telephony device in the method claim 1

8. A computer suitable as the server in the method of claim 1.

9. A computer-readable storage medium comprising executable code for causing a computer to operate as the first or the second telephony device of claim 7.

10. A computer-readable storage medium comprising executable code for causing a computer to operate as the server of claim 8.