Patent Abstract:
A call setup process ( 28 ) in a telecommunication device ( 10 ) is controlled, wherein the telecommunication device ( 10 ) receives a user command ( 22 ) to set up a call, initiates the call setup process ( 28 ), determines that the call is likely to reach a voicemail system ( 14 ), and, in response to the determination that the call is likely to reach the voicemail system ( 14 ), automatically terminates the call setup process ( 28 ). A telecommunication device ( 10 ) comprises related features. A telecommunication network ( 12 ) is adapted to support or implement a determination whether or not an incoming call is forwarded to the voicemail system ( 14 ). The invention improves the user experience if a called party does not personally answer a telephone call.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of International Application No. PCT/EP 2007/057212, filed on Jul. 12, 2007, entitled “Controlling a Call Setup Process,” commonly assigned with this application and incorporated herein by reference. 
     TECHNICAL FIELD 
     The invention generally relates to the technical field of telecommunications. In particular, the invention relates to the field of controlling a call setup process in a telecommunication device and/or a telecommunication network. 
     BACKGROUND 
     Voicemail systems have become ubiquitous in modern telecommunication networks. For example, U.S. Pat. No. 4,371,752 shows an early voicemail system that evolved into the systems of today. 
     As common daily experience shows, many users do not wish to leave a message when they reach a voicemail system. Some people never leave messages at all as a matter of principle. Other people feel insecure in having their massage recorded and therefore hang up unless there is a very pressing matter. Even people who are generally comfortable with the use of voicemail systems may wish to avoid leaving messages in certain situations. 
     Calls that reach a voicemail system are generally charged even if the caller does not leave any message. There is often a minimum fee that is incurred as soon as the call is connected, even if the caller hangs up after a few seconds when realizing that a voicemail system answered the call. Furthermore, there is often a greeting message which the owner of a mailbox has recorded in his or her own voice. It may take some time for the caller to listen to this greeting message and realize that only the voicemail system has answered. The caller pays for this time. This may annoy the caller and may lower the attractiveness of using certain telecommunication services and networks. 
     There is therefore a need for providing a better user experience with respect to voicemail systems. 
     SUMMARY 
     It is an object of the present invention to provide a technique that avoids at least some of the problems of the prior art and provides a better user experience if a called party does not personally answer a telephone call. 
     Certain embodiments of the invention provide a method for controlling a call setup process in a telecommunication device, wherein the telecommunication device is a user device, the method comprising: (1) receiving a user command to set up a call, (2) initiating the call setup process, (3) determining that the call is likely to reach a voicemail system, wherein the telecommunication device determines that the call is likely to reach a voicemail system if the telecommunication device receives a call forwarding notification and (4) in response to the determination that the call is likely to reach the voicemail system, terminating the call setup process. 
     Certain embodiments of the invention provide a method for controlling a call setup process in a telecommunication device, wherein the telecommunication device is a user device, the method comprising: (1) receiving a user command to set up a call, (2) initiating the call setup process, (3) determining that the call is likely to reach a voicemail system, wherein the telecommunication device determines that the call is likely to reach a voicemail system if the telecommunication device receives a call forwarding notification that passes at least one test performed by the telecommunication device and (4) in response to the determination that the call is likely to reach the voicemail system, automatically terminating the call setup process. 
     Certain embodiments of the invention provide a telecommunication device that is adapted for performing any of the above methods. 
     The present invention is based on the insight that a caller often knows in advance that he or she will not leave a message in a voicemail system if a called person is not available. The invention therefore teaches to control a call setup process in a way that, if it is determined that the call is likely to reach a voicemail system, the call setup process will be automatically terminated. Preferably, this termination takes place before any connection is established, thus avoiding any unnecessary connection of the call to the voicemail system. Even in cases where the automatic termination of the call is too late to avoid establishing a connection, the call is still terminated as soon as possible, thus reducing the connection time. The calling party thereby saves various kinds of communication costs, i.e., not only connection charges, but also battery power (if calling from a mobile device) and time. 
     All in all, the present invention considerably improves the user experience of a caller because the invention avoids unnecessary and wasteful call connections. Furthermore, it is expected that any initial loss of fees at the side of the network operators will be more than made up by the increased attractiveness of the service. 
     In some embodiments of the invention, the telecommunication device determines whether or not the call is likely to reach a voicemail system. It is understood that this determination may not always be accurate. Therefore the wording “is likely” is intended to mean that a predefined criterion or more than one predefined criteria is/are fulfilled, the criterion/criteria being typical for calls that reach a voicemail system. 
     As mentioned above, an exact determination whether or not the call will reach a voicemail system is often impossible, at least if this determination is to be made at the side of the telecommunication device. Little harm is done in case of a “false negative” determination, i.e., if the call unexpectedly reaches a voicemail system. The user then simply terminates the call. The user will need to pay the connection costs, but he or she will be no worse off than without using the present invention. A “false positive” determination is less desirable because it means that a call is automatically terminated even if the call would in fact have reached the called subscriber. In embodiments where a false positive determination may occur with more than negligible probability, the user should not employ the method of the present invention for important calls. 
     In some embodiments, the criterion for determining that the call is likely to reach a voicemail system is that the telecommunication device receives any kind of call forwarding notification from the network. Of course, use of this criterion is only practicable if the network issues call forwarding notifications to calling devices in at least some circumstances. As an alternative in some embodiments, the criterion may simply be a timeout event, i.e., that the call is not connected within a predetermined time interval. 
     In order to reduce the number of “false positive” determinations, some embodiments provide for at least one further test that is performed in response to receiving the call forwarding notification. The further test may comprise checking a call forwarding type stated in the call forwarding notification and/or analyzing a call forwarding target number contained in the call forwarding notification. In embodiments where a call forwarding target number is analyzed, the analyzing may comprise checking whether the call forwarding target number or a part thereof corresponds to a voicemail system number and/or the number of the called subscriber and/or a part of the number of the called subscriber. 
     In many embodiments, the telecommunication device is a mobile device having a wireless telecommunication function like, for example, a GSM telecommunication function and/or a UMTS telecommunication function. 
     The present invention also comprises a telecommunication device that may, in some embodiments, offer a standard call setup command and a modified call setup command, the latter initiating the call setup process of the present invention. 
     Another aspect of the present invention is a telecommunication network that supports or implements a determination whether or not an incoming call is forwarded to a voicemail system. If such a determination is made, the telecommunication network may notify the calling telecommunication device and/or automatically terminate the call before any connection is established. This embodiment has the advantage that the telecommunication network is usually in a position to determine the target of any call redirection with a high degree of reliability. 
    
    
     
       BRIEF DESCRIPTION 
       Reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  (the single drawing FIGURE) shows a sample sequence diagram of a call setup process in accordance with an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a telecommunication device  10  that is adapted to communicate with a telecommunication network  12 . In the embodiment of  FIG. 1 , the telecommunication device  10  is a mobile device like, for example, a mobile telephone or a mobile organizer having a wireless telecommunication function. The telecommunication device  10  communicates with the network  12  via an air interface. For example, the telecommunication device  10  and the network  12  may use the well-known GSM or UMTS standards or other wireless communication standards. 
     The network  12  comprises a voicemail system  14 , which maintains at least one mailbox for each subscriber. In other embodiments, the voicemail system  14  may be external to, but accessible via, the network  12 . A subscriber may activate his or her mailbox by registering and activating a call forwarding service of the network  12 . The call forwarding service causes incoming calls that are directed to the subscriber&#39;s number to be forwarded to the subscriber&#39;s mailbox. The subscriber may choose one of a number of different types of call forwarding services, e.g., call forwarding unconditional (CFU), call forwarding on mobile subscriber busy (CFB), call forwarding on no reply (CFNRy), and call forwarding on mobile subscriber not reachable (CFNRc). 
     The call forwarding services described above and their use for directing incoming calls to a mailbox are well known. For example, the standard document 3GPP TS 24.082 (“Call Forwarding Supplementary Service”), Version 6.0.0, available from the European Telecommunication Standards Institute, Sophia Antipolis, France, specifies call forwarding operations in the context of GSM Phase 2+ and UMTS systems. This document also specifies that a user (served subscriber) can request that a calling subscriber whose call has been forwarded receives a corresponding notification. In GSM and UMTS systems, this notification is transmitted to the calling subscriber in the form of a NotifySS operation containing the type of the call forwarding service. 
     The process shown in  FIG. 1  starts when a user of the telecommunication device  10  initiates a call to a subscriber. In the following description, it is assumed that the called subscriber has registered and activated a call forwarding service to his or her mailbox in the voicemail system  14 . Furthermore, it is assumed that the network  12  is set up so that calling subscribers will be notified of any redirection of an outgoing call. As mentioned in the previous paragraph, this functionality is specified in the GSM/UMTS standard. There may also be other protocol layers or other features of the network  12  that allow the telecommunication device  10  to detect any call forwarding, and these layers or features may be used in some embodiments. 
     In order to initiate the call, the user first enters the telephone number of the called subscriber at a keypad  16  of the telecommunication device  10 . Alternatively, the user may select a telephone number from a contacts list stored in the telecommunication device  10 . The telecommunication device  10  then shows, on a display  18 , the entered or selected telephone number and a menu with a plurality of possible user commands  20 ,  22 ,  24 . These user commands include a standard call setup command  20 , a modified call setup command  22 , and a save number command  24 . 
     The save number command  24  is used to store the displayed telephone number in the contacts list. The standard call setup command  20  dials the displayed number in the usual manner and establishes a connection either to the called subscriber or to his or her mailbox. This is the usual calling command customary in the prior art. The modified call setup command  22 , however, is particular to the invention. In a manner that will be described in more detail below, the modified call setup command  22  initiates the call setup process, but terminates the process immediately—before any connection is established—if there is some indication that the call is likely to reach a voicemail system. 
     The embodiment shown in  FIG. 1  and described above uses a menu with menu items that correspond to the available user commands  20 ,  22 ,  24 . However, in some embodiments other or additional means for entering commands—in particular the modified call setup command  22 —may be provided. For example, the user interface of the telecommunication device  10  may provide soft keys, i.e., variable function keys of the keypad  16  whose current function is shown in a section of the display  18  adjacent to the soft keys. In such embodiments, the modified call setup command  22  may be assigned to one of these soft keys at least temporarily. In other embodiments, the soft keys may also be implemented on a touch-sensitive display. Alternatively or additionally, the telecommunication device  10  may be equipped with a voice command recognition functionality that is known as such. The voice command recognition functionality recognizes certain words spoken by the user as commands, for example, as the modified call setup command  22 . 
     Step  26  shown in  FIG. 1  signifies that the user gives the modified call setup command  22  by a menu selection or by any of the other command entry means discussed above. The telecommunication device  10  then initiates a call setup process  28 . The call setup process  28  begins by an exchange of various call setup communications  30  between the telecommunication device  10  and the network  12 . This part of the call setup process  28  is customary in the prior art and is defined in the applicable standards, e.g., the GSM/UMTS standards. 
     As stated above, the sample sequence of  FIG. 1  assumes that the called subscriber has activated a call forwarding service to his or her mailbox, and that the network  12  has been set up to send a call forwarding notification to the calling device whenever a call is forwarded. Therefore, the network  12  now forwards the user&#39;s call to the voicemail system  14  and sends the corresponding call forwarding notification  32  to the telecommunication device  10 . 
     Upon receipt of the call forwarding notification  32 , the telecommunication device  10  performs at least one test  34  in order to determine whether the call forwarding notification  32  signifies that the call will likely be forwarded to a mailbox—and not to another fixed line or mobile number of the called subscriber. In different embodiments, various different kinds of tests  34  can be performed, depending on the information contained in the call forwarding notification  32  and on other circumstances. Some of the possibilities will be described in detail below. 
     If the test  34  results in the finding that the call forwarding target is probably a mailbox of the voicemail system  14 —this is assumed to be case in the sample sequence of FIG.  1 —, then the telecommunication device  10  terminates the call setup process  28  and sends a corresponding call termination message  36  to the network  12 . In other words, the telecommunication device  10  immediately “hangs up.” This is done preferably before any connection is made, so that connection charges are avoided. However, the invention has benefits even if the call forwarding notification  32  is received late and the call is only terminated after it has been connected to the mailbox since, in this case, the chargeable connection time will be very short. 
     After terminating the call setup process  28 , the telecommunication device  10  notifies the user in step  38 . This user notification may comprise a suitable message shown on the display  18 . The user then knows that the call was judged as likely to reach a mailbox so that the user can call again later. 
     As mentioned above, there are various possibilities for determining whether or not the call will likely reach the voicemail system  14 . In a very simple embodiment, receipt of any call forwarding notification  32  from the network  12  will cause the telecommunication device  10  to terminate the call setup process  28 . In other words, no additional test  34  is performed. This embodiment may cause “false positive” results, but it may still be useful in systems in which the call forwarding notification  32  comprises no or no significant additional information. 
     If the call forwarding notification  32  contains an indication of the type of the invoked call forwarding service, then this indication may be used in the test  34 . For example, it may be judged that only the types call forwarding on mobile subscriber busy (CFB), call forwarding on no reply (CFNRy), and call forwarding on mobile subscriber not reachable (CFNRc) indicate that the call will likely reach the voicemail system  14 . The telecommunication device  10  therefore terminates the call setup process  28  only if the received call forwarding notification  32  signifies one of these call forwarding types. If the notification  32  indicates a call forwarding unconditional (CFU) service, then it can be assumed that the call is forwarded to another fixed line or mobile number of the called subscriber, and the call setup process  28  will not be terminated. 
     It is also possible in some systems that the call forwarding notification  32  indicates the call forwarding target number, i.e., the number to which the forwarded call is directed. The telecommunication device  10  can then analyze in test  34  whether or not the call forwarding target number signifies a mailbox in the voicemail system  14 . The details may depend on the particular network operator or service provider, and different tests  34  may be performed for different network operators or service providers. 
     For example, in some networks  14  a mailbox number may comprise a network operator prefix, a voicemail system number, and the number of the called subscriber. Taking the called number +49-177-12345678 shown in  FIG. 1  as an example, the corresponding mailbox number may read +49-177-99-12345678. The telecommunication device  10  can then check in test  34  whether the call forwarding target number contains the voicemail system number  99 , and/or whether the trailing portion of the call forwarding target number is identical to the trailing portion of the called number. 
     In further embodiments, the test  34  may comprise a check whether or not the call forwarding target number contains (or consists of) a certain voicemail system number. As this number may be specific to the individual network operators or service providers, the telecommunication device  10  may contain a lookup table associating, for example, each network operator prefix with the corresponding voicemail system number. In the above example, the lookup table may indicate that the operator prefix  177  corresponds to the voicemail system number  99 . The telecommunication device  10  then extracts the operator prefix from the called number, determines one or more associated voicemail system number(s), and tests whether the call forwarding target number stated in a received call forwarding notification  32  contains or consists of (one of) the operator&#39;s voicemail system number(s). 
     It is also possible that the network  12  does not or not reliably issue any call forwarding notifications even if call forwarding takes place. In embodiments that are adapted to such networks  12 , the test  34  can be a simple timeout check that is performed even if no call forwarding notification  32  is received. The telecommunication device  10  will then terminate the call setup process  28  if no connection has been established within a certain time interval. 
     While the previous paragraph envisaged a non-cooperating network  12 , it is also possible that a network  12  is specifically adapted to support or even implement the functionality of the invention. Such a network  12  will automatically determine whether or not an incoming call is forwarded to the voicemail system  14 . If a call forwarding to the voicemail system  14  is detected, the network  12  will notify the telecommunication device  10  accordingly. Since the network has full access to its internals, any “call forwarded to mailbox” notification issued by the network  12  will usually be reliable, and the telecommunication device  10  can immediately terminate the call without performing any additional tests. In further embodiments, the network  12  may be configured to automatically terminate any calls forwarded to a mailbox, provided that the network  12  was informed during the call setup communications  30  that the user selected the modified call setup command  22 . 
     The applicability and merits of the various embodiments described above depend on the type and functionality of the network  12 , in particular on the setting of the network  12  with respect to the issuing of call forwarding notifications. It is therefore also envisaged in some embodiments to equip the telecommunication device  10  with a number of different strategies for determining whether or not an outgoing call is likely to reach the voicemail system  14 . The particular strategy or strategies to be used can then be selected automatically—depending on the type of the network  14  and/or the network operator and/or the service provider—or manually by the user. 
     Those skilled in the art to which this application relates will appreciate that other and further additions, deletions, substitutions and modifications may be made to the described embodiments.

Technology Classification (CPC): 7