Abstract:
Currently existing web applications for calculation of routes from an origin to a destination do not take into account traffic jams, road/rail reparations, accidents, or other temporary incidents. To overcome this drawback, the present specification provides for new network entities and method of providing a subscriber of an IP Multimedia Subsystem “IMS” network with a route to a destination, wherein this method comprises a step of receiving at an application server “AS” associated with the IMS network dynamic parameters from a plurality of transport media indicating respective incidental information, and a step of processing at the AS these dynamic parameters along with other input criteria to determine a number of routes from the origin to the destination.

Description:
TECHNICAL FIELD 
       [0001]    The present invention generally relates to mobile positioning and route calculation services. More specifically, the present invention relates to services for route calculations offered by an IP Multimedia Subsystem. 
       BACKGROUND 
       [0002]    Nowadays, Global Positioning System (hereinafter GPS) receptors have become a quite popular tool used by millions of people all over the world, whereby a GPS user may accurately know at any time his or her geo-position. The GPS receptor was originally introduced as a newer and powerful navigational instrument in aircrafts and ships whilst, now, it has been incorporated in most of the vehicles as well as in sport activities where knowing the geo-position is, at least, helpful. 
         [0003]    In addition and complementary to GPS receptors, plotter systems provided with a worldwide-coverage cartography have launched into the market; firstly, as isolated products connectable with GPS receptors; and, more recently, integrated with the GPS receptor as a compact GPS+Plotter unit (hereinafter GPS unit), whereby the user does not have to worry about interfaces compatibility between GPS and Plotter. 
         [0004]    Regarding the cartography required by any Plotter unit or GPS unit, and as introducing higher and higher granularity and details, there is a need to split such cartography in smaller portions on regional and national basis. This split implies that users of GPS units have to likely buy more than one cartography set to fulfill their needs, especially where such users travel across regions and nations and want to make use of their GPS units at any time and place. 
         [0005]    Cartography sets are generally available in the market in the form of individual Map cartridges to be introduced in the Plotter unit, or in the integrated GPS unit, and to be replaced by another Map cartridge as the user moves from a region or nation coverage area to another. This is somewhat disappointing for people who travel very often between national borders or between different coverage areas. 
         [0006]    Regarding prices, the high penetration of GPS units in the market, especially in terrestrial vehicles, has considerably lowered the price of any commercial GPS unit, as well as the price of those Map cartridges available worldwide. Moreover, newer cars already incorporate a GPS unit and a Map cartridge appropriate to the nation or region where the car is sold. 
         [0007]    Nevertheless, and especially in the terrestrial environment, Map cartridges have to be updated or replaced quite often as new roads appear, or as existing roads are modified, so that the most suitable facilities offered by commercial GPS units, such as guiding you from an origin to a destination following a number of highways, precisely indicating exits from one to another, and remaining distance to such exits, are still valid for use without risking the user to be lost. In this scenario, and even if Map cartridges are not that expensive as before, the continuous replacement of Map cartridges and the costs are not insignificant. 
         [0008]    Aware of the high penetration of GPS units in the market, most of the suppliers of mobile phones, and more sophisticated mobile terminals, have provided some models with a GPS receptor and some additional facilities. However, even if a user can thus know his or her geo-location at any time and almost any place, such user cannot enjoy all the service features as provided by a complete GPS unit with integrated plotter and removable Map cartridges. In this respect, and since the size of newer mobile phones and terminals is smaller than predecessors, said newer mobile phones and terminals cannot be easily provided with a Map cartridge reader for conventional Map cartridges available in the market. 
         [0009]    Nevertheless, this drawback may be somewhat saved thanks to several well known applications, known and used all over the world such as Google Earth®, especially adapted for use in modern mobile terminals with access to Internet, and whereby a user can get a sort of simplified map illustrating a route from an origin position towards a destination position. 
         [0010]    Apart from that, there are quite a few web applications accessible through Internet, which calculate a best route from an origin to a destination, including the selection and combination of different transport media such as underground, bus and train, and which allow users the establishment of some input criteria, such as the fastest route, lower number of different transport media, or the shortest distance. 
         [0011]    However, these well known web applications cannot be expected to be updated as often as new roads appear, or as existing roads are modified, worldwide or even on national or regional basis. Even if some of these web applications, at least those on national basis, are more frequently updated, users cannot always be sure to what extent any of them is up to date, so that the information provided by said well known web applications cannot always be fully trusted, or might make the users to check more than one before deciding which one to trust and which route to choose. 
         [0012]    On the other hand, the currently existing applications may be adapted to calculate a best route based on the position of a user and, in some cases, some fix parameters collected from the transport media, and selection criteria received from the users. 
         [0013]    However, the currently existing applications do not take into account any dynamic data, such as traffic jams, road/rail reparations, accidents, or other temporary and occasionally incidents that might occur and that can hardly be spread through web applications in charge of route calculation services all over the world. 
       SUMMARY 
       [0014]    The present invention is aimed to at least minimize the above drawbacks and provides for a new route calculation service provided by an IP Multimedia Subsystem (hereinafter IMS) of a telecommunication network for subscribers of the IMS. 
         [0015]    In accordance with a first aspect of the present invention, there is provided a method of providing a subscriber of an IP Multimedia Subsystem “IMS” network with a route to a destination. 
         [0016]    This method comprises a step of configuring an application server (hereinafter AS), which is associated with the IMS network, with fix parameters to determine as first input criteria for calculations at least one criterion selected from: available transport media, transport routes, transport time-tables and combinations thereof; a step of receiving at the AS dynamic parameters from a plurality of transport media indicating respective incidental information, other than the one derivable from the fix parameters, to determine second input criteria for the calculations; a step of invoking from a user equipment (hereinafter UE), the UE being in use by a subscriber of the IMS, activation of a route calculation service towards the AS; a step of indicating from the UE to the AS a location of the subscriber and at least one given destination of the subscriber to determine third input criteria for calculations; a step of processing at the AS the first, second and third input criteria to determine a number of routes from the location of the subscriber towards the at least one given destination; and a step of submitting from the AS towards the UE the processed number of routes. 
         [0017]    In particular, the location of the subscriber may be a geo-location and, more particularly, said geo-location might be expressed in terms of latitude and longitude, or in other 2-dimension (hereinafter 2D) or 3-dimension (hereinafter 3D) coordinates. 
         [0018]    Generally speaking for this method, the dynamic parameters may include information preventing the fulfilment of the first input criteria. More particularly and in order to provide a more accurate result in terms of presently valid routes, the dynamic parameters received from each transport medium may include information related to events such as, amongst others, traffic jams, accidents, road reparations, rail reparations, transport medium unavailability, expectable delays, and combinations thereof. 
         [0019]    Even though several implementations are possible, the step in this method of receiving at the AS the dynamic parameters may include a step of collecting at a transport media server from each transport medium the respective incidental information, and a step of submitting from the transport media server the respective incidental information towards the AS. In this way, the transport media server, which may be a centralized server on national or regional basis, does not need to be permanently checking possible updates but simply awaiting notification from events. More particularly, this centralized transport media server may be connected with a hierarchical network of companies and servers in charge of, and receiving such information from, each different transport medium. 
         [0020]    Regarding the step of indicating from the UE to the AS, in particular, the geo-location of the subscriber, this step may include a step of obtaining said geo-location from a Global Positioning System (hereinafter GPS) associated with the UE, that is connected with or integrated in the UE. Alternatively or complementary, the step of indicating from the UE to the AS the location of the subscriber may include a step of obtaining at the AS said location as provided from a General Packet Radio System (hereinafter GPRS) network where the UE accesses the IMS through. 
         [0021]    Moreover, where the geo-location of the subscriber can be determined, the step of indicating from the UE to the AS the geo-location of the subscriber may include a step of calculating at the UE a speed vector including a speed modulo and direction of the UE, and a step of indicating said speed vector to the AS. In this way, the AS may more accurately select the number of still possible routes, discarding those which appear to be close to the subscriber but in an opposite direction, or currently inaccessible, to the direction followed by the subscriber. 
         [0022]    Regarding the invocation or activation of a route calculation service towards the AS, and especially useful in the IMS environment, the step of invoking the best route calculation service may include a step of identifying said route calculation service by a public service identifier (hereinafter PSI), and a step of interrogating an entity of the IMS network about the AS in charge of said route calculation service. In particular, this entity to be interrogated may be a Home Subscriber Server (hereinafter HSS) of the IMS holding subscription data for the subscriber. 
         [0023]    This method may further be enhanced where the AS in charge of the route calculation service is connected with one or more navigational and meteorological information systems. Where this is the case, this method may further comprise a step of receiving at the AS from at least one of said navigational and meteorological information systems notifications of incidents on earth, air and oceans, accompanied by respective geo-locations of said incidents, to determine fourth input criteria for calculations; and a step of further processing at the AS the fourth input criteria with the first, second and third input criteria to determine the number of routes from, in particular, the geo-location of the subscriber towards the at least one given destination. 
         [0024]    On the other hand, and quite advantageously depending on the current location of the subscriber, the destination, and the time expected to arrive therein, this method may further comprise a step of indicating from the UE to the AS a number of transport media selected from: terrestrial transportation media (such as bus, taxi, private car, underground, tramp, train, etc), aerial transportation media (such as air lines, private aircraft, etc), marine transportation media (such as sea lines, rent or private ships or boats, etc), animal-powered media (such as elephants, camels, horses, etc), and combinations thereof, to determine fifth input criteria for calculations; and a step of processing at the AS the fifth input criteria with the first, second and third input criteria to determine the number of routes from the, in particular, geo-location of the subscriber towards the at least one given destination. 
         [0025]    In order to complement this IMS service with plotting features this method may further comprise a step of configuring the AS with cartography; a step of selecting an appropriate map in the cartography to plot the geo-location of the subscriber and the at least one given destination; and a step of submitting from the AS towards the UE the appropriate map with information to plot the geo-location of the subscriber, the at least one given destination, applicable input criteria and corresponding routes on said map. In particular, appropriate new symbols are included to display any occasional incidents in the cartography that justify discarding other routes. 
         [0026]    In accordance with a second aspect of the present invention, and in order to contributory carry out steps of the above method, there is provided an AS associated with the IMS network, the AS having: a first input unit for configuring the AS with fix parameters to determine as first input criteria at least one criterion selected from: available transport media, transport routes, transport time-tables and combinations thereof; a second input unit for receiving at the AS dynamic parameters from a plurality of transport media indicating respective incidental information, other than the one derivable from the fix parameters, to determine second input criteria for calculations; a third input unit for receiving from a UE, which is in use by a subscriber of the IMS, a message invoking activation of a route calculation service towards the AS, a location of the subscriber, and at least one given destination of the subscriber to determine third input criteria for calculations; a processing unit for processing the first, second and third input criteria to determine a number of routes from the location of the subscriber towards the at least one given destination; and an output unit for submitting from the AS towards the UE the processed number of routes. 
         [0027]    Aligned with the above method, the location of the subscriber may, in particular, be a geo-location expressed in terms of 2D or 3D coordinates. In this AS, the third input unit may be arranged for receiving a speed vector from the UE in terms of speed modulo and speed direction, whilst the processing unit may be arranged for processing said speed vector along with the input criteria to determine the number of routes from the geo-location of the subscriber towards the at least one given destination. 
         [0028]    Also in this AS, the second input unit may be adapted for receiving dynamic parameters with information related to events selected from: traffic jams, accidents, road reparations, rail reparations, transport medium unavailability, expectable delays, and combinations thereof; and the processing unit is adapted to determine whether or not these dynamic parameters prevent the fulfilment of the first input criteria. 
         [0029]    In order to obtain useful information from one or more navigational or meteorological information systems, this AS may further comprise a fourth input unit for receiving from at least one of said navigational and meteorological information systems notifications of incidents on earth, air and oceans, accompanied by respective geo-locations of said incidents, to determine fourth input criteria for calculations; and the processing unit of the AS may be arranged for processing the fourth input criteria with the first, second and third input criteria to determine the number of routes from the geo-location of the subscriber towards the at least one given destination. 
         [0030]    Advantageously aligned with the above method, the third input unit of the AS may be arranged for receiving from the UE a number of transport media selected from: terrestrial transportation media (such as bus, taxi, private car, underground, tramp, train, etc), aerial transportation media (such as air lines, private aircraft, etc), marine transportation media (such as sea lines, rent or private ships or boats, etc), animal-powered media (such as elephants, camels, horses, etc), and combinations thereof, to determine fifth input criteria for calculations; and wherein the processing unit of the AS may be arranged for processing these fifth input criteria with the first, second and third input criteria to determine the number of routes from the, in particular, geo-location of the subscriber towards the at least one given destination. 
         [0031]    Moreover, in order to complement this IMS service with plotting features, the AS may include a fifth input unit for configuring the AS with cartography; whereas the processing unit of the AS may be arranged for selecting an appropriate map in the cartography to plot the geo-location of the subscriber and the at least one given destination; and the output unit of the AS may be arranged for submitting towards the UE the appropriate map with information to plot the geo-location of the subscriber, the at least one given destination, applicable input criteria and corresponding routes on said map. 
         [0032]    In accordance with a third aspect of the present invention, there is provided a UE enabled to access an IMS network and to operate services thereof, the UE having: a first output unit for registering a subscriber of the IMS in the IMS network; a first input unit for receiving a confirmation that the subscriber is registered in the IMS network; a location unit arranged for determining a location of the subscriber, which in particular may be a geo-location expressed in terms of 2D or 3D coordinates, and for setting at least one given destination wanted by the subscriber; a second output unit for invoking activation of a route calculation service towards an AS associated with the IMS network, and for indicating the location of the subscriber and the at least one given destination of the subscriber as input criteria to the AS; and a second input unit for receiving from the AS a number of routes from the location of the subscriber towards the at least one given destination. 
         [0033]    In particular, the location unit may include, or may be associated with, a Global Positioning System “GPS” for obtaining the geo-location of the subscriber. Alternatively or complementary, the location unit may be arranged for obtaining the location of the subscriber from a General Packet Radio System “GPRS” network where the UE accesses the IMS through. 
         [0034]    Aligned with advantageous corresponding features in the above method and AS, and especially useful where the location is a geo-location, the UE may further comprise a processing unit for calculating a speed vector, which includes a speed modulo and direction representing the movement of the UE; whereas the second output unit is arranged for submitting said speed vector to the AS. 
         [0035]    As advantageously as for the above method and AS, the UE may further comprise a third input unit for receiving from the subscriber notification of a number of transport media selected from: terrestrial transportation media, aerial transportation media, marine transportation media, animal-powered media, and combinations thereof; and the second output unit of the UE may be arranged for submitting towards the AS the selected transport media to determine further input criteria for calculations. 
         [0036]    In order to complement the service with plotting features, the second input unit of the UE may be arranged for receiving from the AS a map with information to plot the geo-location of the subscriber, the at least one given destination, applicable input criteria and corresponding routes on said map; and the UE may further comprise a third output unit for presenting to the subscriber the map with the information plotted therein. 
         [0037]    On the other hand, the invention may be practised by a computer program, in accordance with a fourth aspect of the invention, the computer program being loadable into an internal memory of a computer with input and output units as well as with a processing unit, and comprising executable code adapted to carry out the above method steps. In particular, this executable code may be recorded in a carrier readable in the computer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0038]    The features, objects and advantages of the invention will become apparent by reading this description in conjunction with the accompanying drawings, in which: 
           [0039]      FIG. 1A  and  FIG. 1B  illustrate alternative embodiments of the sequence of actions to be followed by an AS to respectively obtain fix parameters from a Transport Media Centre either directly or indirectly through a Home Subscriber Server and to be used for the route calculation service. 
           [0040]      FIG. 2  shows a simplified view of an exemplary sequence of actions to be followed for an AS to obtain dynamic parameters from an Incidence Centre and to be used for the route calculation service. 
           [0041]      FIG. 3  shows a simplified view of an exemplary sequence of actions to be followed for a user to activate the route calculation service in an AS in charge of said route calculation service. 
           [0042]      FIG. 4  shows a simplified view of an exemplary sequence of actions to be followed for a user to indicate the location of the user, a destination, and other input criteria to an AS in charge of the route calculation service. 
           [0043]      FIG. 5  illustrates an exemplary implementation of structural components that an AS may include for providing a route calculation service. 
           [0044]      FIG. 6  illustrates an exemplary implementation of structural components that a UE may include for using a route calculation service. 
           [0045]      FIG. 7  shows a simplified view of an exemplary sequence of actions to be followed for a user to register in the IMS network. 
           [0046]      FIG. 8  shows a simplified view of another exemplary sequence of actions to be followed for a user to activate the route calculation service in an AS in charge of said route calculation service. 
       
    
    
     DETAILED DESCRIPTION 
       [0047]    The following describes currently preferred embodiments of means and method for a route calculation service provided by an IMS network for IMS subscribers. 
         [0048]    In accordance with the invention, there is provided a method of providing a subscriber of an IMS network with a route to a destination. This method includes a step of configuring an AS  1  associated with the IMS network with fix parameters to determine as first input criteria for calculations at least one criterion selected from: available transport media, transport routes, transport time-tables and combinations thereof.  FIGS. 1A and 1B  respectively illustrate a first and second exemplary embodiment of a configuration of the AS with said fix parameters. 
         [0049]    As illustrated in  FIG. 1A , these fix parameters selectable from transport media (terrestrial, aerial or marine transport media), transport routes (Line 6 of Metro at Madrid-Spain, train ‘Talgo’ from Madrid-Spain to Paris-France), car renting, etc), transport time-tables (14:00-18:00, 22:00, night, a.m., etc) and combinations thereof may be submitted during a step S- 110  from a Transport Media Centre  6  directly to the AS  1 . In particular, the Transport Media Centre  6  may submit this information with a http PUT message of a so-called ‘Ut’ interface as specified in 3GPP TS 33.220 and TS 33.222. 
         [0050]    Still with reference to  FIG. 1A , the AS receiving these fix parameters, namely static parameters, which may be modified at any time but which are supposed to be stable and non-incidental or occasional, stores these fix or static parameters during a step S- 120  to determine first input criteria for route calculations requested by any IMS subscriber. 
         [0051]    Alternatively or complementary to the embodiment of  FIG. 1A , especially where not every Transport Media Centre is directly connectable to the AS, the invention also provides for the embodiment of  FIG. 1B  whereby a Transport Media Centre  6  may keep updated a HSS of the IMS network with the static parameters explained above. As  FIG. 1B  illustrates, the Transport Media Centre  6  may submit during a step S- 105  the static parameters towards a HSS  5  of the IMS to be stored therein and provided to the AS upon request. In particular, where both HSS and Transport Media Centre support the so-called “Lightweight Directory Access Protocol” (hereinafter LDAP) as specified in RFC 4511, the Transport Media Centre  6  might submit this information with an LDAP ‘Create’ or LDAP ‘Modify’ message towards the HSS  5 . 
         [0052]    Still with reference to  FIG. 1B , the AS  1  in charge of route calculation may request during a step S- 115  from the HSS  5  such static parameters, for a first time or in order to be refreshed with up-to-date information, and the HSS may provide the requested static parameters during a step S- 125 . Upon receipt of the static parameters at the AS  1 , said static parameters are stored in the AS during a step S- 135  to determine first input criteria for route calculations requested by any IMS subscriber. In particular, the AS  1  may request this information with a so-called PULL Request message, and the HSS may provide the static parameters with a corresponding PULL Response message of a so-called ‘Sh’ interface as specified in 3GPP TS 29.328. 
         [0053]    This method of providing a subscriber of an IMS network with a route to a destination also includes a step of receiving at the AS dynamic parameters from a plurality of transport media indicating respective incidental information, other than the one derivable from the fix parameters, to determine second input criteria for calculations. 
         [0054]    As illustrated in  FIG. 2 , the invention provides for an Incidence Centre  4 , so called in the instant specification, which is arranged for submitting during a step S- 205  towards a so-called Authentication Proxy  3  said dynamic parameters from a plurality of transport media indicating respective incidental information. 
         [0055]    In particular, this Authentication Proxy (hereinafter AP) is enabled to handle security relations with the UE and may thus relieve the AS from this task. The AP may also be used to authenticate the UE with help of a Generic Bootstrapping Architecture, as specified in 3GPP TS 33.220 and 3GPP TS 33.222, though the mechanism for this authentication is not relevant for the purpose of the present invention. This AP is conventionally enabled to distribute the UE queries towards a dedicated AS based on the service invoked by the UE, namely, based on a so-called ‘AUID’. 
         [0056]    For the purpose of the present invention, said dynamic parameters are submitted from the Incidence Centre  4  along with an AUID value indicating Route Calculation Service, so that the AP  3  can unambiguously determine the AS  1  in charge of such service. The AP  3  thus forwards during a step S- 210  the received message towards the AS  1 . In particular, and following current trends in accordance with applicable technical specifications, such messages between the Incidence Centre  4  and the AP  3 , as well as between the AP  3  and the AS  1 , could be the so-called ‘http PUT’ messages, and may include additional indications identifying a particular transport medium, likely with a transport-ID, a particular geo-position where an incident has occurred, likely with 2D or 3D coordinates, a particular Incident type and/or Incident severity, others, and combinations thereof. 
         [0057]    Upon receipt of the dynamic parameters at the AS  1 , the dynamic parameters are stored in the AS during a step S- 315  to determine second input criteria for route calculations requested by any IMS subscriber, and a successful response is returned to the AP  3  during a step S- 220  and forwarded during a step S- 225  from the latter to the Incidence Centre  4 . 
         [0058]    This method of providing a subscriber of an IMS network with a route to a destination also includes a step of invoking from a UE, the UE being in use by a subscriber of the IMS, activation of a route calculation service towards the AS. 
         [0059]    To this end, the present invention provides two alternative or complementary embodiments respectively illustrated in  FIG. 3  and  FIG. 8 . The former makes use of a direct interface, the so-called ‘Ut’ interface, between the UE and the AS already commented above; whereas the latter makes use of a conventional procedure carried out through the IMS network whereby a Serving Call Session Control Function (hereinafter S-CSCF) server, which is assigned during the registration of the user with a UE for serving the user, submits the invocation of the service requested from the UE towards a dedicated AS known to the S-CSCF server. 
         [0060]    Prior to discussing these two embodiments for the activation of the route calculation service at the AS, the registration of a user with a UE  2  is discussed in the following with reference to  FIG. 7 . 
         [0061]    As  FIG. 7  shows, a user with a UE  2  can register one or more pairs of IMS public user identity (hereinafter IMPU) and IMS private user identity (hereinafter IMPI) for identification purposes into the IMS network where the user holds a subscription with a ‘Register’ message submitted during a step S- 705  from the UE to a Proxy Call Session Control Function (hereinafter P-CSCF) server  7 , which is an entry point to the IMS network. 
         [0062]    This P-CSCF server forwards during a step S- 710  the ‘Register’ message received from the UE  2  towards an Interrogating Call Session Control Function (hereinafter I-CSCF) server  8 , which is in charge of selecting a S-CSCF server having the capabilities required for serving the user in the IMS. 
         [0063]    This I-CSCF server queries during a step S- 715  a HSS  5 , which holds subscription data for the user in the IMS network, about a S-CSCF server already assigned for serving the user or about the capabilities that a selectable S-CSCF server should have for serving said user. 
         [0064]    The HSS  5  returns during a step S- 720  a response towards the I-CSCF  8  indicating either a S-CSCF server previously assigned for serving the user, if a previous registration of one or more IMPI/IMPU pairs had taken place, or the capabilities required for a S-CSCF server to be selected. 
         [0065]    The I-CSCF  8 , depending on the information received from the HSS  5 , determines a suitable S-CSCF server  9  for serving the user, and forwards during a step S- 725  the ‘Register’ message received from the P-CSCF  7  towards the S-CSCF  9 . 
         [0066]    The S-CSCF server  9  receiving the registration of the user with UE  2  informs during a step S- 730  to the HSS  5  of having been assigned for serving the user, and the HSS submits as response during a step S- 735  a user profile with data necessary for serving the user at the S-CSCF server. Then, the S-CSCF server returns back during a step S- 740  to the I-CSCF server  8  a successful result code, the I-CSCF server submits during a step S- 745  such successful result code to the P-CSCF server  7 , and the latter forwards during a step S- 750  the successful result code to the UE  2 . 
         [0067]    After having discussed above the registration of the user with reference to  FIG. 7 , the exemplary embodiments illustrated with reference to  FIG. 3  and  FIG. 8  for activation of the route calculation service are discussed in the following. 
         [0068]      FIG. 3  illustrates a first exemplary embodiment of a user with a UE  2  invoking the activation of the route calculation service though the so-called ‘Ut’ interface towards the AS  1  in charge of such service. To this end, and in accordance with general procedures specified in 3GPP TS 33.222 V8.0.0, the UE submits towards the Authentication Proxy  3  an http PUT message to invoke a particular service. This AP  3 , which operates as a HTTP Proxy, distributes the UE queries towards the concerned AS based on the service invoked by the UE. For the purpose of the present invention, this PUT message is submitted during a step S- 305  and includes a user identifier, such as and IMPU, and a new AUID indicating ‘Route Calculation Service’ so that the AP  3  can determine an AS  1  in charge of this service. The AP forwards during a step S- 310  the received PUT message to the AS  1  with the AUID and the user identifier. 
         [0069]    Still with reference to  FIG. 3 , the AS  1  activates during a step S- 315  the route calculation service for the indicated user, identified by the given user identifier, and returns during a step S- 320  an activation result back to the AP, which in turn, forwards during a step S- 325  the activation result to the UE  2 . In particular, and depending on security requirements that the AS and the AP might have been configured with, the AS, the AP, or both may check whether the user had already been registered in the IMS network and the AP may carry out a particular authentication of the user following the teaching in the above 3GPP TS 33.222 V8.0.0. 
         [0070]      FIG. 8  illustrates a second exemplary embodiment of a user with a UE  2  invoking the activation of the route calculation service though the IMS network where the user holds a subscription, and where the user has been registered following the procedure described above with reference to  FIG. 7 . As illustrated in  FIG. 8 , the UE  2  submits during a step S- 805  an ‘Invite’ message towards the S-CSCF  9  assigned for serving the user during the registration procedure. For the purpose of the present invention, this ‘Invite’ message includes an identifier of the user, such as the IMPU, and an identifier of the service to be invoked, such as the above AUID indicating ‘Route Calculation Service’. In order to identify the service to be invoked, the invention also provides for making use of the so-called Public Service Identity (hereinafter PSI), which is generally available to identify a service in the IMS, by registering such new PSI so that the S-CSCF may unambiguously determine the AS in charge of the service identified by said PSI. 
         [0071]    Still with reference to  FIG. 8 , the S-CSCF  9  receiving such message determines the AS  1  in charge of the service and forwards during a step S- 810  the ‘Invite’ message to said AS  1 . The AS  1  activates during a step S- 815  the route calculation service for the indicated user, identified by the given user identifier, and returns during a step S- 820  the activation result back to the S-CSCF  9 , result which in particular may be a so-called ‘200-OK’ message, and the S-CSCF forwards during a step S- 825  this activation result to the UE  2 . 
         [0072]    This method of providing a subscriber of an IMS network with a route to a destination also includes a step of indicating to the AS a location of the subscriber and at least one given destination of the subscriber to determine third input criteria for calculations. In particular, the location of the subscriber may be obtained from a GPS associated with the UE  2 , or may be obtained from network infrastructure such as a GPRS location. More particularly, for instance where the location is obtained from a GPS associated with the UE, this location may be indicated as a geo-location in 2D coordinates, such as latitude and longitude, or in 3D coordinates as a conventional GPS is enabled to provide. 
         [0073]    To this end, the present invention also provides two alternative or complementary embodiments as those already described above with reference to  FIG. 3  and  FIG. 8 . As in the previous case, a first embodiment illustrated in  FIG. 4  makes use of the direct ‘Ut’ interface between the UE and the AS already commented above; whereas the second embodiment, which is not illustrated in any drawing, makes use of a conventional procedure carried out through the IMS network whereby a Serving Call Session Control Function (hereinafter S-CSCF) server, which is assigned during the registration of the user with a UE for serving the user, submits the submissions from the UE towards a dedicated AS known to the S-CSCF server. It is believed that the skilled person will not have any difficulty on applying the teaching described below for the first embodiment with reference to  FIG. 4  to develop an equivalent procedure for the second embodiment in view of the comparison between  FIGS. 3 ,  4  and  8 . 
         [0074]    As illustrated in  FIG. 4 , the UE  2  submits to the AP  3  during a step S- 405  a GET message including and identifier of the user, particularly an IMPU, an identifier of the route calculation service, which in particular may be a PSI or an AUID, a location of the subscriber and at least one given destination for which the subscriber desires to find one or more possible routes. The AP  3  receiving the GET message forwards it during a step S- 410  towards the AS  1 . 
         [0075]    Alternatively, for the second embodiment where the conventional procedure through the IMS network applies, an ‘Invite’ message with equivalent contents as the GET message may be sent from the UE  2  to the S-CSCF  9  and forwarded from the latter to the AS  1 . 
         [0076]    The method of providing a subscriber of an IMS network with a route to a destination continues with a step of processing at the AS the first, second and third input criteria to determine a number of routes from the location of the subscriber towards the at least one given destination. To this end and still with reference to  FIG. 4 , the AS  1  determines during a step S- 415  a number of routes from the origin position, namely the subscriber location, to the at least one given destination. 
         [0077]    Once the number of routes has been determined, the method includes a step of submitting from the AS towards the UE the processed number of routes. To this end and still with reference to  FIG. 4  the AS  1  submits during a step S- 420  a successful result towards the AP  3  including the number of routes calculated from the origin to the destination, likely including additional relevant information such as time-tables of the different transport media involved in each route to facilitate the user choice. The AP  3  receiving the successful result with number of routes and additional information forwards during a step S- 425  such message and the included information towards the UE  2 . Likewise, where the second embodiment not illustrated in any drawing applies, the successful result is submitted to the S-CSCF  9  and forwarded from the latter to the UE  2 . 
         [0078]    In order to carry out the above method, there is provided an AS  1  associated with an IMS network and basically illustrated in  FIG. 5 . 
         [0079]    As  FIG. 5  illustrates, this AS includes a first input unit  31  for configuring the AS with fix parameters to determine as first input criteria at least one criterion selected from: available transport media, transport routes, transport time-tables and combinations thereof. In particular, this first input unit is connectable with a Transport Media Centre  6  adapted for submitting to the AS the fix or static parameters. 
         [0080]    Still with reference to  FIG. 5 , this AS also includes a second input unit  32  for receiving at the AS dynamic parameters from a plurality of transport media indicating respective incidental information, other than the one derivable from the fix parameters, to determine second input criteria for calculations. The incidental information may be collected from at least one centralized Incidence Centre  4 , processed therein to obtain the dynamic parameters and submitted towards the AS wherein they are received in the second output unit  32 . 
         [0081]    Still with reference to  FIG. 5 , this AS also includes a third input unit  33  for receiving from a UE, the UE being in use by a subscriber of the IMS, a message invoking activation of a route calculation service towards the AS, a location of the subscriber, and at least one given destination of the subscriber to determine third input criteria for calculations. In particular, the third input unit  33  is adapted for receiving the location of the subscriber as a geo-location expressed as 2D coordinates, such as latitude and longitude, or as 3D coordinates, as a conventional GPS is enabled to provide. 
         [0082]    Still with reference to  FIG. 5 , this AS also includes a processing unit  20  for processing the first, second and third input criteria to determine a number of routes from the location of the subscriber towards the at least one given destination. If required, and especially where the time required to arrive at the destination is long enough to justify that the subscriber might be periodically notified of any changes, the input criteria may be temporary saved in an internal memory  10 , or database. This processing unit is connected with the first, second and third input units to respectively receive data received therein. In particular, said first, second and third input units may be provided as separate modules or as an integral input unit connectable with the Transport Media Centre  6 , the Incidence Centre  4  and the UE  2 . 
         [0083]    Still with reference to  FIG. 5 , this AS also includes an output unit  40  for submitting from the AS  1  towards the UE  2  the processed number of routes. This output unit is connected with the processing unit  20  and receives the number of routes determined therein. In particular, this output unit  40  may be adapted to periodically notify the UE  2  with updates and additional information processed by, and received from, the processing unit  20 . 
         [0084]    Cooperating with the above AS and in order to carry out the above method, there is provided a UE  2  enabled to access an IMS network and to operate services thereof. 
         [0085]    As illustrated in  FIG. 6 , this UE includes a first output unit  81  for registering a subscriber of the IMS in the IMS network and a first input unit  91  for receiving a confirmation that the subscriber is registered in the IMS network. In this respect, where the subscriber of the IMS invokes the route calculation service following a conventional procedure for invoking services through the IMS network, that is, carrying out a registration of a subscriber IMPI/IMPU pair, being assigned a S-CSCF for serving the subscriber, invoking the service towards the S-CSCF, and the latter assigning a dedicated AS and forwarding the invocation towards said AS, the subscriber has previously been registered into the IMS network. This assumption is not necessarily required where the subscriber carries out the invocation through the ‘Ut’ interface as explained above. 
         [0086]    Still with reference to  FIG. 6 , the UE  2  also includes a location unit  70  arranged for determining a location of the subscriber and for setting at least one given destination wanted by the subscriber. In particular, the location unit  70  may be adapted for determining the location of the subscriber as a geo-location expressed as 2D coordinates, such as latitude and longitude, or as 3D coordinates, as a conventional GPS is enabled to provide. More particularly, the location unit  70  may include, or be associated with, a GPS for obtaining the geo-location of the subscriber. Alternatively or complementary, the location unit  70  may be arranged for obtaining the location of the subscriber from a GPRS network where the UE has accessed the IMS through. 
         [0087]    Still with reference to  FIG. 6 , the UE  2  also includes a second output unit  82  for invoking activation of a route calculation service towards an AS  1  associated with the IMS network, and for indicating the location of the subscriber and the at least one given destination of the subscriber as input criteria to the AS; and a second input unit  92  for receiving from the AS a number of routes from the location of the subscriber towards the at least one given destination. 
         [0088]    In this respect, the second output unit  82  and second input unit  92  may be provided as integral output unit and input unit with the first output unit  81  and first input unit  91 , where the subscriber of the IMS invokes the route calculation service following a conventional procedure for invoking services through the IMS network; and the second output unit  82  and second input unit  92  may be separate from the first output unit  81  and first input unit  91 , where the invocation of the route calculation service is carried out with the ‘Ut’ interface directly or through the AP  3 , as exemplary illustrated in  FIG. 3 . Even if the communications between the UE  2  and the AS  1  are carried out through the AP  3  where the ‘Ut’ interface is used, the AP  3  has been omitted in  FIG. 6  for the sake of simplicity. 
         [0089]    Back to the above method of providing a subscriber of an IMS network with a route to a destination, the dynamic parameters received during a step S- 205 , and collected from each transport medium, may include information related to events selected from: traffic jams, accidents, road reparations, rail reparations, transport medium unavailability, expectable delays, and combinations thereof. Particularly in this method, the step of receiving at the AS the dynamic parameters may thus include a step of collecting at an Incidence Centre  4  from each transport medium the respective incidental information, and a step of submitting from the Incidence Centre  4  the respective incidental information towards the AS. To this end, the second input unit  32  of the AS  1  is adapted for receiving from the Incidence Centre  4  dynamic parameters including information related to events selected from: traffic jams, accidents, road reparations, rail reparations, transport medium unavailability, expectable delays, and combinations thereof. Moreover, the processing unit  20  of the AS  1  may advantageously be adapted to determine whether or not these dynamic parameters prevent the fulfilment of the first input criteria. 
         [0090]    Aligned with capabilities of the above UE  2 , the step of indicating from the UE to the AS the location of the subscriber may include a step of obtaining said location from a GPRS network where the subscriber has accessed the IMS network through, or as a geo-location expressed as 2D or 3D coordinates and obtained from a GPS associated with the UE  2 . 
         [0091]    Advantageously in this method, in order to determine whether all candidate routes are still valid and especially where many possibilities are possible in the area where the subscriber is located, the step of indicating from the UE to the AS the geo-location of the subscriber, likely in terms of 2D or 3D coordinates, may include a step of calculating at the UE a speed vector including a speed modulo and direction of the UE, and a step of indicating said speed vector to the AS. In particular, this speed vector may be submitted during steps S- 405  and S- 410  from the UE towards the AS, along with other input criteria such as update notifications in the case of long distance trips. To this end, the third input unit  33  of the AS  1  may be arranged for receiving the speed vector from the UE in terms of speed modulo and speed direction, and the processing unit  20  may be arranged for processing said speed vector along with the input criteria to determine the number of routes from the geo-location of the subscriber towards the at least one given destination. Also to this end, the UE  2  may further comprise a processing unit  60  for calculating the speed vector, which includes a speed modulo and direction representing the movement of the UE; and the second output unit  82  of the UE  2  may be arranged for submitting said speed vector to the AS  1 . 
         [0092]    Apart from the above features, the method may be enhanced with an additional step, not illustrated in any drawing, of receiving at the AS  1  from at least one of navigational and meteorological information systems notifications of incidents on earth, air and oceans, accompanied by respective geo-locations of said incidents, to determine fourth input criteria for calculations; and a step of further processing at the AS the fourth input criteria with the first, second and third input criteria to determine the number of routes from the geo-location of the subscriber towards the at least one given destination. To this end, the AS  1  may further comprise a fourth input unit  34  for receiving from at least one of navigational and meteorological information systems  7  notifications of incidents on earth, air and oceans, accompanied by respective geo-locations of said incidents, to determine fourth input criteria for calculations; and the processing unit  20  of the AS, which is connected with said fourth input unit  34 , may be arranged for processing the fourth input criteria with the first, second and third input criteria to determine the number of routes from the geo-location of the subscriber towards the at least one given destination. 
         [0093]    In order to offer the IMS subscriber the possibility to customize this service, for example, the selection of one or more transport media to consider for route calculations, or to avoid for route calculations, the method may further include a step of indicating from the UE  2  to the AS  1  a number of transport media selected from: terrestrial transportation media, aerial transportation media, marine transportation media, animal-powered media, and combinations thereof, to determine fifth input criteria for calculations; and a step of processing at the AS  1  these fifth input criteria with the first, second and third input criteria to determine the number of routes from the geo-location of the subscriber towards the at least one given destination. Of course, the step of processing the fifth input criteria may include the above optional fourth input criteria as well, since both fourth and fifth input criteria may be complementary to each other. To this end, the third input unit  33  of the AS  1  may be arranged for receiving from the UE  2  a number of transport media selected from: terrestrial transportation media, aerial transportation media, marine transportation media, animal-powered media, and combinations thereof, to determine fifth input criteria for calculations; and the processing unit  20  of the AS  1  may be arranged for processing the fifth input criteria with the first, second and third input criteria, as well as with the fourth input criteria, if available, to determine the number of routes from the location of the subscriber towards the at least one given destination. Also to this end, the UE  2  may further comprise a third input unit not illustrated in any drawing, which in particular may be implemented with key buttons or menus, for receiving from the subscriber notification of a number of transport media selected from: terrestrial transportation media, aerial transportation media, marine transportation media, animal-powered media, and combinations thereof; and the second output unit  82  of the UE  2  may be arranged for submitting towards the AS  1  the selected transport media to determine further input criteria for calculations. Advantageously, the UE  2  may also include an internal memory  50 , connected with the processing unit  60  wherein the selected transport media, amongst other data, can be saved at least whilst the service is active. 
         [0094]    Moreover, in order to provide users of this service with comparable plotting facilities as other dedicated GPS units available in the market, the method of providing a subscriber of an IMS network with a route to a destination may further comprise a step of configuring the AS  1  with cartography; a step of selecting an appropriate map in the cartography to plot the location of the subscriber and the at least one given destination; and a step of submitting from the AS towards the UE the appropriate map with information to plot the location of the subscriber, the at least one given destination, applicable input criteria and corresponding routes on said map. To this end, the AS  1  may further comprise a fifth input unit  35 , as illustrated in  FIG. 5 , for configuring the AS with cartography  11 , which may be configured for reading conventional Map cartridges as well as other dedicated maps; the processing unit  20  of the AS  1  may be arranged for selecting an appropriate map in the cartography to plot the geo-location of the subscriber and the at least one given destination; and the output unit  40  of the AS  1  may be arranged for submitting towards the UE  2  the appropriate map with information to plot the geo-location of the subscriber, the at least one given destination, applicable input criteria and corresponding routes on said map. Also to this end, the second input unit  92  of the UE  2  may be arranged for receiving from the AS  1  a map with information to plot the geo-location of the subscriber, the at least one given destination, applicable input criteria and corresponding routes on said map; and the UE  2  may further comprise a third output unit not illustrated in any drawing, which in particular may be a scrollable display, for presenting to the subscriber the map with the information plotted therein. 
         [0095]    The invention may also be practised by a computer program, loadable into an internal memory of a computer with input and output units as well as with a processing unit. This computer program comprises to this end executable code adapted to carry out the above method steps when running in the computer. In particular, the executable code may be recorded in a carrier readable means in a computer. 
         [0096]    The invention is described above in connection with various embodiments that are intended to be illustrative and non-restrictive. It is expected that those of ordinary skill in this art may modify these embodiments. The scope of the invention is defined by the claims in conjunction with the description and drawings, and all modifications that fall within the scope of the claims are intended to be included therein.