WO2017067562A1

WO2017067562A1 - System and method for routing calls between mobile devices

Info

Publication number: WO2017067562A1
Application number: PCT/DK2016/050339
Authority: WO
Inventors: Runi HAMMER
Original assignee: Voxtream A/S
Priority date: 2015-10-23
Filing date: 2016-10-20
Publication date: 2017-04-27

Abstract

The present invention relates to a system and method for routing calls between mobile devices, wherein the system comprises a plurality of gateway units that are linked together via a routing table stored in each of the gateway units. Each of the gateway units is adapted to the type of telecommunications network and telecommunications standard at that location. The gateway unit is thus able to connect any type of telecommunications network and communicate with mobile devices as well as stationary devices using any telecommunications standard. An application on the mobile devices is used to detect when a call is made to another user of the system. The call is rerouted from the calling party to a first gateway unit via a first network. The call is then routed to a second gateway unit which further routes the call to the receiving party.

Description

System and method for routing calls between mobile devices

Field of the Invention

The present invention relates to a system and method for routing calls between mobile devices using one or more internal networks to which the mobile devices are connected. The internal networks are linked together to route calls from the calling party to the receiving party.

Background of the Invention

An increasing amount of calls between parties today are conducted by using mobile devices connected to a mobile telecommunications network. The user of a mobile device can select between numerous different service agreements offered by multiple telecommunications providers. Some providers have their own mobile telecommunications network while other providers may have a license agreement with an owner of a mobile telecommunications network to use their telecommunications network. The user can conduct or receive calls via a subscriber identity module (SIM) in the mobile device which contains a unique number, e.g. an international mobile subscriber identity (IMSI) number, used to identify the mobile device and, thus, the user on the telecommunications network of that provider. The user is limited to the services specified in the selected service agreement with that provider.

Different mobile telecommunications networks as well as different telecommunications standards exist throughout the world. The mobile device may thus not function on a visiting network if the communications module of the mobile device is not con- figured to connect with that visiting network. The user is therefore limited to the service agreements between providers of the different telecommunications networks and the user is thus billed at a higher rate than the normal network rates, particularly in a roaming situation. It is a well-known that the roaming rate for an incoming call is typically lower than the roaming rate for an outgoing call.

International companies with local divisions in different countries and local companies with employees travelling to other countries often spend a lot of money on mobile telephony, mainly due lo internal call rates and roaming rates. It is therefore more desirable for the companies that a roaming employee receives calls rather than makes calls. It may also be desirable for the companies to route international calls through a third-party telecommunications network to lower the calling rates.

Today, some telecommunications operators provide a solution to users that are roaming and want to make a call. In this solution the user is provided with a special SIM card which is configured to intercept the outgoing call and reverse the call so that the user is charged with a lower rate. The user is required to enter country code as well as the telephone number. This solution is a pure software solution and restricts the user to the service agreements between that provider and providers in other countries. Any changes or cancellations of service agreements may affect the roaming rales, or even prevent the user from roaming in certain countries. An alternative solution is to conduct the call using Internet protocol (IP) telephony wherein the call is routed via a third-party network. This Voice-over-IP service requires that the mobile devices have an Internet module or are connected to an adapter unit having an Internet module. A known problem with this solution is that the quali- ty-of-service depends on the stability of the current Internet connection, and thus the sound quality may vary during the conversation as well as the call may be terminated unintentionally due to a disconnection of the Internet connection.

Another solution is to use more than one SIM card, such as dual SIM mobile devices, wherein a local SIM card is used when roaming. The user may manually replace the SIM card located in the mobile device with another SIM card or the mobile device may be configured to automatically switch between the respective SIM cards located in the mobile device. This solution requires the user to keep track of multiple SIM cards and multiple service agreements. However, the user is still restricted to the service agreements between the different providers.

Thus, there is a need for a method and system that combine the effects of the hardware and software solutions without limiting the user to the service agreements between different telecommunications providers. WO 2012/064990 discloses smart dealer method and system for mobile communication facilitated by a gateway that routes a subscribers MO call to a called party through a local number. The subscriber may be present in either a home country or a roaming country, and the called party may be present in same or different country from the subscriber. The gateway stores the local number in either subscriber's mobile device or the gateway or both.

Object of the Invention

An object of this invention is to provide a system that is capable of routing calls be- tween mobile devices independent of the service agreements between different telecommunications providers.

An object of this invention is to provide a system that is capable of selecting a desired routing of calls so that the calling costs are reduced to a minimum.

An object of this invention is to provide a system that is capable of operating in different telecommunications networks with different communications standards.

An object of this invention is to provide a method that routes calls between mobile devices independent of the service agreements between different telecommunications providers.

An object of this invention is to provide a method that switches between outgoing and ingoing calls when roaming.

Description of the Invention

In the description below and, unless otherwise specified, the term "entering a telephone number" include any means of physically or verbally entering a telephone number or retrieving a telephone number from a list of contacts. In the description below, unless otherwise specified, the term "roaming" means any type of roaming between different networks, including roaming during calls and data roaming. An object of the invention is achieved by a system for routing calls between mobile devices, comprising:

- a first mobile device comprising a communications module for connecting to a first network,

- at least a second mobile device,

- at least a first gateway unit comprising a communications module configured to connect with at least one of the first and second mobile devices via the first network, wherein

- at least the first mobile device comprises an application configured to run on the first mobile device, wherein the application is configured to detect an entered telephone number of a receiving party, and wherein the controller of the gateway unit may be configured to determine the geographic location of at least the first mobile device and, thus, the calling party. The controller may be configured to exchange data with the application in the mobile device for determining the location of the mobile device.

This provides a routing management system that establishes one or more internal networks in one or more countries or regions via a plurality of gateway units and allows calls to be routed through these internal networks. Conventional software solutions attempt to create a virtual network across existing telecommunications networks using service/roaming agreements between the different telecommunications providers. This configuration allows international calls as well as calls during roaming to be conducted over the internal networks at local rates which in turn reduce the total costs. This configuration also allows the mobile devices to exchange mobile data over the internal networks and, thus, allows the data services to be billed at local rates. This system is particularly suited for companies having different divisions or subsidiaries in different countries or regions as well as companies having employees that often travel to other countries or regions. This system is also suitable for telecommunications providers as they can reduce their costs to third-party telecommunications providers. At least one of the first and second networks, preferably both, may be a telecommunications network, such as a GSM, a LTE, a CDMA, a UMTS network or another suitable telecommunications network. The first and second networks may be the same network or different networks and/or the same type of network or different types of networks, e.g. a GSM network and a UMTS or a CDMA network. The application may be configured to communicate with a gateway unit, e.g. a gateway box, located in that country or region using the communications module of the mobile device. The mobile device may be a mobile phone, a smartphone, a personal digital assistant (PDA), a phablet or another suitable mobile device. The gateway unit may comprise a communications module configured to communicate with the mobile device via the respective network. The gateway unit may further comprise a controller connected to that communications module wherein the controller is configured to control at least the operation of the gateway unit. According to one embodiment, the system further comprises at least a second gateway unit that is connected to the second mobile device via the second network, wherein the second gateway unit is linked to the first gateway unit via a predetermined routing table. Two or more gateway units may be linked together via a routing table stored in the system. The routing table may define one or more routing paths between the first and second gateway units. The routing table may be stored in each of the gateway units. The gateway units may comprise another communications module configured to another gateway unit via a different telecommunications network, e.g. a PSTN network, an ISDN network, or an Internet network. The routing path may be selected based on one or more criteria, such as the most cost-effective routing path or a routing path having the best quality of service. The routing path may also define a routing path between different types of communications devices, such as between a mobile device and a stationary device. This allows the users of the system to select the most attrac- tive service agreement amongst the different telecommunications providers independent of mat provider's service agreements with other telecommunications providers.

The first gateway unit may be configured to communicate with me first mobile device using a first communications standard, while the second gateway unit may be config- ured to communicate with the second mobile device using a second communications standard. The first and second communications standards may be the same communication standard or different communications standards. The communications standard may be any type of an IP, an ISDN, or a session initiation protocol (SIP) standard, or another suitable communication standard. In example, the first and/or second commu- nications standard may be G.711 PCM, G.726 ADPCM, G.729 Annex A, VN2-VN6, ITR6, BAKOM, INS64, INS 1500, or any other suitable communications standard. This allows the gateway units to be adapted to the type of network and communication standard used in that country or region. This also allows the gateway units to the in- ternal communications standard used within the respective company.

Conventional hardware solutions are specifically designed for stationary devices, such as IP-telephones or integrated services for digital network (ISDN)-telephones. The present system enables mobile devices as well as stationary devices to be connected to the respective gateway unit using any type of network or communications standard.

According to a special embodiment, the routing table is further configured to link the first and second gateway units to at least a third gateway unit. The first gateway unit may be linked to the second gateway unit via one or more third gateway units. The routing path between the first, second and third gateway units may be stored in the routing table described above. In some situations, it is cheaper to route the call via a third country or region to the final destination, i.e. the second gateway unit. The routing paths may also be determined based on the service agreements be- tween the respective telecommunications providers.

According to one embodiment, the system is further configured to determine a geographic location of at least one of the first and second mobile devices, wherein the system is configured to select a routing path, e.g. an Internet line, based on the geo- graphic location.

The controller of the gateway unit may be configured to determine the geographic location of at least the first mobile device and, thus, the calling party. The controller may be configured to exchange data with the application in the mobile device for de- termining the location of the mobile device. The controller may determine the location of the calling party based on a global positioning system (GPS)-signal of the mobile device or of the mobile station to which the mobile device is connected. Alternatively, the controller may determine the geographic location by multi- or trilateration using signals from at least three radio or WiFi-antennas. Alternatively, the controller may determine the geographic location using a signal of a location-based service, such as an unstructured supplementary service data (USSD) signal. Other location techniques may be used. In a similar manner, the controller in the first gateway unit or another controller in the second gateway unit may determine the geographic location of the second mobile device and, thus, the receiving party. The controller, e.g. the controller in the first gateway unit, is further configured to select the routing path based on the determined locations of the calling party and the receiving party.

The locations of the first and/or second mobile devices may alternatively be determined based on an external location signal received from the provider of the first and/or second networks. Optionally, this step of determining the locations of the mobile devices may be implemented in the application on the respective mobile devices.

According to a special embodiment, the system is configured to detect if at least the first mobile device of the calling party is roaming, wherein the system is configured to disconnect an outgoing call from that mobile device and establish an incoming call to that mobile device from the respective gateway unit.

The controller may be configured to determine whether at least one of the calling party and the receiving party is roaming or not based on the determined locations of the respective mobile devices.

If the calling party is determined to be roaming, the controller may be configured to activate a callback function. In this callback mode, the controller may be configured to disconnect the outgoing call from the first mobile device to the first gateway unit and instead send a call request to the first mobile device from the first gateway unit. The first gateway unit may be configured to further route the call from the calling party to the receiving party according to the routing table described above. If both parties accept the call requests, the system may then establish the call between the calling party and the receiving party. This callback function may be implemented as an automatic function or a semi-manual function wherein the calling party may activate or deactivate this function. This reduces the calling costs for the roaming calling party as the user is only charged with local rates instead of the higher roaming rate. This also reduces the calling costs for the receiving party, roaming or not, as the user is only charged with the local or roaming rate of receiving the call.

If the calling party is determined not to be roaming, the controller may be configured to activate a callthrough function. In this callthrough mode, the controller may be configured to route the call from the calling party to the receiving party, e.g. via a third gateway unit, using a selected routing path of the routing table as described above. If the receiving party accepts the call request, the system may then establish the call between the calling party and the receiving party.

If both the calling party and the receiving parly are located within the same country or region, they may be connected to the same gateway unit and, thus, the call may be routed through that gateway unit even if one or both parties are roaming. In convention software solutions, the call would normally be routed via the home country or region of the calling party and/or the receiving party. This configuration allows for a more direct routing of the call.

Optionally, this step of switching between the callback mode and the callthrough mode may be implemented in the application on the respective mobile devices.

According to one embodiment, the system is configured to generate at least one first telephone number based on the entered telephone number, wherein the at least one first telephone number comprises at least a unique identification number of one of the gateway units and a unique identification number of the receiving party.

The application is configured to detect an entered telephone number of the selected receiving party. The application is further configured to reroute the outgoing call, e.g. the call request, to the first gateway unit. The controller is then configured to select a routing path based on the determined location of at least the calling party, preferably of both parties, as described above. The controller is further configured to reroute this call request to the gateway unit to which the receiving party is connected. This allows companies to conduct internal calls between local divisions or subsidiaries via internal networks defined by first and second networks instead of having to pay excessive international fees or roaming fees. The system may be configured to initially perform an authorisation process of a calling party prior to establishing the call. This allows the system to identity the calling party and to verify that the party is authorised to route calls through the system and, thus, via the gateway units. In example, the application may be configured to generate an initial first telephone number based on a unique identification number, e.g. a tele- phone number, of the first gateway unit. This initial first telephone number may further comprise at least a unique identification number, e.g. a telephone number, of the calling party. This initial call request may act as an authorisation request which may be forwarded to the first gateway unit. The controller in the first gateway unit may be configured to receive this authorisation request and compare the telephone number of the calling party to a plurality of users stored in the system, where each of which is associated with at least one telephone number. If the telephone number matches a stored telephone number, the controller is configured to send a confirmation signal back to the application indicating that the calling party is known by the system. The confirmation signal may be a dial-tone, a digital signal or another suitable type of con- firmation signal. The application may be configured to further generate a subsequent first telephone number based on the unique identification number of the first gateway unit. This subsequent first telephone number may further comprise at least a unique identification number, e.g. a telephone number, of the receiving party. The controller is further configured to receive this subsequent call request and reroute the call request to the gateway unit to which the calling party is connected. This allows the system to identify the users of the system and manage which calls are rerouted through the system. Alternatively, the unique identification number of the receiving party may be incorporated in the initial first telephone number so that the controller receives only one call request from the application. This call request may thus act as both an author- isation request as well as a request for establishing a call.

The controller of the first gateway unit may be configured to further reroute the call request received from the first mobile device to at least one third gateway unit which is configured to further reroute the call request to the second gateway unit. In exam- pie, this may be done by changing the unique identification number of the respective gateway unit according to the selected routing path. Other routing techniques may be used to reroute the call request between the individual gateway units. If no match is found, the controller is then configured to send a confirmation signal back to the application indicating that the first mobile device and, thus, the calling party is unknown by the system. The application does not continue to generate the first telephone number and the call request is routed directly to the receiving party using the telecommunications networks of the respective parties in a conventional manner. This allows calls to be established using a normal routing path defined by the telecommunications providers. Alternatively, the application may be configured to reroute the call request to a predefined telephone number, e.g. a call answering service or a front desk of the company. Optionally, this step of comparing the telephone number with the stored telephone numbers and/or the step of selecting the routing path may be implemented in the application on the respective mobile device. The list of known users of the system may thus be stored in the respective gateway unit or, optionally, in the application. The call may be routed from the first mobile device of the calling party via a private branch exchange (PBX)-unit connected to the first gateway unit. The PBX unit may be an IP-PBX unit or another switching system for connecting a plurality of mobile devices and/or stationary devices to the respective gateway unit. The call may further be routed from the second gateway unit to the mobile device of the receiving party via another PBX unit connected to the second gateway unit. The PBX units may have the same or different configurations.

According to a special embodiment, the system is further configured to generate a second telephone number based on the at least one first telephone number, wherein the second telephone number comprises at least the unique identification number of the receiving party.

The controller of the second gateway unit may be configured to receive the call request from the first gateway unit via the selected routing path. This controller may be further configured lo remove the unique identification number of the respective gateway unit from the first telephone number and to generate a second telephone number for finally rerouting the call request to the receiving party. The first and second telephone numbers may further comprise the unique identification number of the calling party.

Each of the gateway units may comprise a backend or web-based interface module configured to provide access to the settings stored in the system. The interface module may comprise an authorisation sub-module for identifying the user or operator of the system. The interface module may further comprise a diagnostic sub-module for performing a diagnostic process on the system. The user interface of this interface module may be configured to enable the user or operator to update or alter the routing table, the stored users, callback/callthrough functions and other settings of the system. According to another special embodiment, at least one of the gateway units is a session initiation protocol-unit comprising at least one user account associated with at least one of the parties, wherein at least one of the first and second networks is a session initiation protocol-network. The first, second, or third gateway unit may be a gateway box prepared for installation in that country or region as described above. The first, second, or third gateway unit may also be a session initiation protocol (SIP) unit comprising one or more SIP accounts. In example, the SIP unit may be a server unit, a session border controller (SBC) unit, or a PBX unit. Each of these SIP accounts may be associated with one or more of the users of the system. The SIP unit may comprise a communications module configured to communicate with a matching communications module in the first or second mobile device via a SIP network. The SIP network acts as the first and/or second network. This allows the users to connect with the system in regions or countries where no gateway box is installed. The users may generate a new SIP account or be assigned to an existing SIP account, e.g. a SIP account belonging lo the company of the employee. Information about the local telephone number associated with the SIP account, e.g. the ENUM, and other relevant information about the SIP account may be stored in the system, e.g. in the other gateway units or in the SIP unit. The SIP unit may further be linked to the other gateway units via the routing table. A dedicated SIM may be used together with the application in the mobile device described above to communicate with the SIP unit. Alternatively, the dedicated SIM and the application may be inte- grated into a single application implemented into the mobile device. This allows the system to be operated in a callthrough mode. This also allows the user to use data services at local rates instead of roaming rates.

According to yet another special embodiment, the system is further configured to switch between a home telephone number associated with the first or second mobile device and at least a local telephone number associated with that mobile device.

The present solution may also be combined with the use of a multi-SIM or the use of a local SIM of a selected country or region. In this configuration, the SIM located in the first and/or second mobile device may be a multi-SIM comprising a home telephone number of the user's home country or region and at least one local telephone number of a selected country or region. In example, the local telephone number may be a virtual telephone number. The application described above or the multi-SIM may be configured to switch between the home and local telephone numbers, e.g. automatically or upon request by the user or operator. The home telephone number and/or the local telephone number may be stored in the system, e.g. in the gateway units, using the application or the backend or web-based interface module of the gateway unit.

Alternatively, the SIM located in the first and/or second mobile device may be re- placed with a local SIM of a selected country or region. The local SIM comprises a local telephone number of that country or region. The local telephone number may be stored in the system, e.g. in the gateway units, using the application or the backend or web-based interface module of the gateway unit. In this configuration, the system can be operated in a callthrough mode where calls are established between the parties using the local telephone number selected by the user. Also, this configuration allows data services to be billed at local rates instead of roaming rates. An object of the invention is achieved by a method for routing calls between mobile devices, comprising:

- associating a first mobile device with a calling party, wherein the mobile device is connected to a first network,

- associating at least a second mobile device with at least a receiving party, - providing at least a first gateway unit connected with at least one of the first and second mobile devices via the first network, wherein

- detecting a telephone number of the receiving party entered on the first mobile device,

This provides a method for routing calls via one or more internal networks in one or more countries or regions. The users of the system are then able to connect a gateway unit in that country or region via the first network so that calls between users of the systems are routed through the internal networks and, thus, only charged at local rates. Also, the users are able to exchange mobile data using the local networks so that the use of data services is charged at local rates instead of roaming rates. An application installed on at least the mobile device of the calling party detects when that party wants to call a receiving party and if the calling party is known by the system, the call is then rerouted through at least one gateway unit to the receiving party. No special SIM cards or additional SIM cards are required. Also, the users of the system are independent of the service agreements between different telecommunications providers.

Conventional software based solutions attempt to solve the roaming problem by establishing multiple service agreements between telecommunications providers in differ- ent countries, thereby creating a virtual network across existing telecommunication networks. However such a solution is sensitive to the changing politics of the respective telecommunications providers.

The SIM may either be implemented onto an Integrated Circuit (IC) card that can be inserted into a slot in the mobile device or be implemented directly into the mobile device as a virtual SIM. The mobile device may comprise a dedicated operating system such as Windows, iOS, Android, or another suitable operating system. The application is configured to operate with the respective operating system of that mobile device and to optionally use the functionality of that mobile device, such as the GPS module and the communications module. The application may be configured to continuously run on the mobile device and to detect when the user wants to make a call using the call function of that mobile device. This allows calls to be automatically rerouted through the system. Alternatively, the user may manually activate the appli- cation and then enter the telephone number of the receiving party directly into the application.

According to one embodiment, the first gateway unit is linked to at least a second gateway unit, wherein the call is routed from the first gateway unit to the at least sec- ond gateway unit and further to the second mobile device via the second network.

When the calling party and the receiving party are located in different countries or regions, the call is rerouted via a first gateway unit located in a first country or region to a second gateway unit located in a second country or region using a routing table as described earlier. In a preferred embodiment, the gateway units may be linked together via an Internet connection to further reduce the calling costs. This significantly reduces the total costs of the call compared to the normal routing path where the parties would be directly connected via the respective telecommunications networks. The present solution provides a combined hardware and software solution that can be adapted to the type of telecommunications network and telecommunications standards used in any country or region. The settings of the gateway units may be adapted according to the type of telecommunications network and telecommunications standard of that country or region. Furthermore, the respective gateway units may be connected to a PBX unit and adapted according to the telecommunications standard used within the environment in which the PBX unit is situated. This allows companies to establish an internal network across its different divisions or subsidiaries without being dependent of the service agreements between the different telecommunications providers in the respective countries or regions.

In a special embodiment, the call is further routed from the first gateway unit to a third gateway unit and further to the second gateway unit. In some situations, it is advantageous to further reroute the call over at least a third gateway unit in at least a third country or region to obtain the most effective routing path. This routing path may be stored in the routing table. This enables the total costs of the international calls or roaming calls to be further reduced.

According to one embodiment, the method further comprises the steps of:

- determining a geographic location of at least one of the first and second mobile devices,

- selecting a routing path based on the geographic location using a routing table.

The application on the first mobile device may then send location data to the controller in the first gateway unit, e.g. upon request from the controller, which then determines the geographic location of that mobile device and, thus, the calling party as described earlier. The controller may use a GPS or USSD signal received from the first mobile device to determine the location. Alternatively, the application may send the signals received from at least three radio or WiFi antennas to the controller which in turn uses an algorithm to estimate the location based on these signals. Optionally, this step may be performed by the application in the first mobile device to reduce the data traffic on the first network.

The application or controller may then send a request to the second gateway unit to which the second mobile device of the receiving party is connected. The application in that mobile device or the controller in the second gateway unit may then determine the location of the receiving party in a similar manner as described above. The location of the second mobile device and, thus, the receiving party may then be forwarded to the controller in the first gateway unit and, optionally, further to the application in the first mobile device.

Alternatively, the respective gateway unit may comprise a list indicating which gate- way unit each of the mobile devices is connected to. This list may then be used to determine the location of the user. This list may be updated each time a mobile device of one of the parties is switched on or changes connection to another gateway unit.

According to a special embodiment, the method further comprises the steps of: - determining whether the calling party is roaming or not,

- disconnecting an outgoing call if the calling party is roaming, and establishing an incoming call to the calling party from the respective gateway unit connected the first mobile device.

The application or controller may further use the locations of the first and second mobile devices to determine if one or both parties are roaming. The list of users of the system may further indicate a home telecommunication network, a home country or region, a home gateway unit or any combinations thereof. Any techniques may be used to determine if the calling or receiving party is roaming.

If the calling parly is not roaming, then the application in the first mobile device or the controller in the first gateway unit may activate a callthrough function as described above. In this callthrough mode, the gateway units route the call from the calling party to the receiving party according to the routing table. This allows the call to be routed more efficiently to the country or region in which the receiving party is located, even if that party is roaming.

If the calling party is roaming, then the application in the first mobile device or the controller in the first gateway unit may activate a callback function as described above. In this callback mode, the first gateway unit may disconnect the outgoing call received from the calling party and may instead establish an incoming call to the calling parly. At the same time, the gateway units further route the call from the calling party to the receiving party according to the routing table. This allows a roaming call- er to only be charged at a lower roaming rate.

If both parties are roaming, the callback function may be activated and the call may be routed more efficiently to the countries or regions in which the parties are located using a gateway unit in each of the countries or regions. If the parties are roaming in the same country or region, then the call may be routed through a single gateway unit located in that country or region. According to another special embodiment, the method further comprises the step of assigning a local telephone number to at least one of the calling party and the receiving parly, and forwarding the call to the local telephone number when roaming. As described above, the first, second, or third gateway unit may be a SIP unit and the calling and/or receiving party may be associated with a SIP account. The user or operator is able to add, edit, or delete information about the SIP account in the system via the backend or web-based interface module. The mobile device may then connect to the SIP unit via the SIP network using the dedicated SIM. Mobile data services and outgoing calls can thus be conducted at local rales which in turn reduces the roaming costs.

The system may automatically switch between the home telephone number and the local telephone number depending on the geographical location of the mobile device or depending on the gateway/SIP unit to which the mobile device is connected. Alternatively, the party may send a request to the respective gateway unit using the application on the mobile device which may comprise a local telephone number entered by the party. The gateway unit may, upon receiving this request, switch the home telephone number to the local telephone number indicated in the request. The gateway unit may then indicate in the system that the party is roaming and that incoming and outgoing calls are forwarded to that party using the local telephone number. The gateway unit may optionally send a confirmation signal back to the mobile device indicating that this switch has been registered in the system. Calls between the calling party and the receiving party can thus be established in a callthrough mode. Also, the mobile device of that party then acts as a local mobile device instead of a roaming mobile device.

The party may alternatively use a multi-SIM located in the mobile device to select a desired local telephone number or country/region, e.g. via the application. The party may instead insert a local SIM card or switch to a local SIM located in the mobile device when connected to the first or second network. The selected local telephone number of the multi-SIM or local SIM may then be stored in the system, e.g. in the gateway units, thus indicating that the party is roaming and that incoming and outgoing calls are forwarded to that party using that local telephone number. Calls be- tween the calling party and the receiving party can thus be established in a callthrough mode.

The SIP account, multi-SIM and local SIM all provide an anti-roaming function of the system which reduces the costs of roaming and data-roaming. The calling party simply enters the home telephone number of the receiving party and the call is routed through the gateway units and optional SIP units via the routing table to the receiving party. Also mobile data traffic when roaming is billed at cheap local rates and not at high roaming rates.

According to one embodiment, the method further comprises the steps of:

- generating at least one first telephone number based on the entered telephone number, wherein the at least one first telephone number comprises at least a unique identification number of one of the gateway units and a unique identification number of the receiving party,

- generating a second telephone number based on the at least one first telephone number, wherein the second telephone number comprises at least the unique identification number of the receiving party. The application may generate at least one first telephone number that includes the unique identification numbers of the first gateway unit and of at least one of the calling and receiving parties as described earlier. The entered telephone number (unique identification number) of the receiving party may be inserted into to a predetermined slot in the first telephone number. The telephone number (unique identification num- ber) of the calling party may be inserted into to another predetermined slot in the first telephone number. Alternatively, the telephone number of the calling party may be inserted into an initial first telephone number while the telephone number of the receiving party may be inserted into a subsequent first telephone number. The system may initially perform an authorisation step to identify the calling party as described earlier. The call request is initially sent to the first gateway unit via the first network, wherein the controller determines if the calling party is known by the system or not. If the calling party is known by the system, then the controller determines the location of the first mobile device and optionally also of the second mobile device and, thus, the respective parties. The controller afterwards selects a routing path in the routing table according to one or more criteria and routes the call request to the second gateway unit using the selected routing path. If the calling party is an unknown user, then the call is not routed through the system and, thus, the call is established using a normal routing path between the first and second mobile devices.

When the second gateway unit receives the call request from the first gateway unit, the controller then removes the unique identification number of the respective gateway unit and generates a second telephone number based on the received first telephone number. The second gateway unit then finally sends the call request to the receiving party via the second network to establish the call. The second mobile device, e.g. an application in the second mobile device, may be configured to display the unique identification number of the calling party on the second mobile device as if it was an ordinary call. Preferably, the displayed unique identification number is the home telephone number which makes it easier for the receiving party to recognise the receiving party. According to one embodiment, the method further comprises the steps of:

- sending a first call request to the receiving party after a predetermined time period has lapsed or when the receiving party is determined to be available,

- if a call accept signal is returned, sending a second call request to the calling party,

- if a call accept signal is returned, establishing a call between the calling party and the receiving party.

If the second gateway unit receives a signal from the second mobile device, e.g. from the application, indicating that the receiving party is busy or the call cannot be established, then the second gateway unit may send a busy signal back to the first mobile device and the calling party.

The second gateway unit or the calling party may then activate an automatic callback function. In this automatic callback mode, the second gateway unit may temporarily store the call and monitor the signal received from the second mobile device. The sec- ond gateway unit may then wail for a predetermined time period before sending a call request to the receiving party. Alternatively, the second gateway unit may wait until the above-mentioned condition is removed and then send the call request. If the second gateway unit receives a call accept signal from the receiving party, then it may further send a call request to the first mobile device via the first gateway unit using the routing table. The calling party may then send a call accept signal back to the second gateway unit which then establishes the call between the parties. As described earlier, the gateway units may comprise an interface module. The user, e.g. an administrator, or the operator of the system may access the system via the user interface of mis interface module. This allows the user or operator to add, remove, or edit the user profiles stored in the system. The user or operator may also update the software version of the system, e.g. push updates to the application implemented on the mobile devices. This user interface may also be used to adapt the gateway unit to type of telecommunication network and telecommunications standard used at that location. Likewise, the interface module allows the user or operator to add, delete or edit the routing paths specified in the routing table, the SIP account, and/or the local telephone numbers associated with the respective user.

The application may be downloaded to the respective mobile device via the interface module. The interface module may also be used to perform other tasks, such as diagnostics or extract statistical data for establishing a billing service. The dedicated SIM may optionally be downloaded via the SIP unit.

The system can be configured to compare a telephone number of a calling party to a plurality of telephone numbers stored in the system and, if the telephone number matches a stored telephone number, to reroute a call between the first and second mobile devices through the at least first gateway unit.

Description of the Drawing

The invention is described by example only and with reference to the drawings, wherein: Fig. 1 shows a conventional callthrough solution between mobile devices;

Fig. 2 shows a first embodiment of the system according to the invention;

Fig. 3 shows a second embodiment of the system according to the invention;

Fig. 4 shows a third embodiment of the system according to the invention; and

Fig. S shows a flowchart of the calling process according to the invention.

In the following text, the figures will be described one by one and the different parts and positions seen in the figures will be numbered with the same numbers in the different figures. Not all parts and positions indicated in a specific figure will necessarily be discussed together with that figure.

Reference list

1 First mobile device

2 Second mobile device

3 First gateway unit

4 First network

5 Second gateway unit

6 Second network

7 First PBX unit

8 Second PBX unit

9 Internet network

10 SIP unit

11 SIP network

12 Entering

13 Comparing

14 Roaming

15 Callback mode

16 Callthrough mode

17 Rerouting

18 Routing

19 Establishing Detailed Description of the Invention

Fig. 1 shows a conventional routing path between a first mobile device 1 of a calling party and a second mobile device 2 of a receiving party. The first mobile device 1 is connected to a home telecommunications network (marked by HOME) and the second mobile device 2 is connected to a local telecommunications network (marked by LOCAL). The connection between me two telecommunications networks are limited by the service agreement between the respective telecommunications providers.

Fig. 2 shows a first embodiment of the system configured as a routing management system capable of rerouting calls between at least one calling party and at least one receiving party.

The first mobile device 1 is connected to a first gateway unit 3 via a first network 4. A communications module in the first gateway unit 3 is configured to communicate, e.g. exchange mobile data and/or call data, with a communications module in the first mobile device 1 using a selected communications standard. The second mobile device 2 is connected to a second gateway unit 5 via a second network 6. A first PBX unit 7 and a second PBX unit 8 are optionally connected to the respective gateway units 3, 5 for connecting the mobile devices 1, 2 to the gateway units 3, 5. A communications module in the second gateway unit S is configured to communicate, e.g. exchange mobile data and/or call data, with a communications module in the second mobile device 2 using a selected communications standard. The first and second networks 4, 6 are mobile telecommunications networks of the same or different telecommunications providers. This enables the users of the system to communicate with the gateway units 3, 6 using any type of telecommunications network of any telecommunications provider.

The first and second gateway units 3, 5 are linked together via a routing table stored in the gateway units 3, 5. The routing table defines one or more routing paths between the respective gateway units 3, S using one or more dedicated networks, such as an Internet network 7, an ISDN network, or a VoIP network. The first and second gateway units 3, 5 may be linked via an optional third gateway unit (not shown) via a dedicated network. This enables the call to be routed between individual gateway units 3, 5 using the most effective routing path which may be selected based on one or more predetermined criteria.

A controller in the first gateway unit 3 selects a routing path in the routing table upon receiving an outgoing call from the calling party. The controller then establishes a connection between the first and second gateway units 3, S and routes the call request to the second gateway unit S. Another controller in the second gateway unit S further sends the call request to the receiving party. If the receiving party accepts the call request, then a call between the parties is established. This provides a combined hard- ware and software solution for routing calls independent of the service or roaming agreements between the respective telecommunications providers.

According to the invention, an application implemented on at least the mobile device 1 of the calling party is configured to communicate with the controller of the respec- tive gateway unit 3. The application detects a telephone number of the receiving party which is then compared to a list of users of the system. If the receiving party is known by the system, the outgoing call is rerouted to the gateway unit 5 as described in reference to fig. 5. If the calling party is not roaming, then the system is operated in a callthrough mode (indicated by solid arrows) where the outgoing call is routed from the first mobile device 3 to the second mobile device 2 through the respective gateway units 3, 5.

If the controller in the first gateway unit 3 detects that the calling party is roaming based on the geographic location of the first mobile device 1, the system is then operated in a callback mode. The controller then disconnects the outgoing call between the calling party and the first gateway unit 3. The controller of the first gateway unit 3 afterwards sends another call request (indicated by dotted arrow) back to the calling party via the first network 4. This reverses the call direction and, thus, reduces the roaming rate for the roaming calling party.

As the same time, the controller of the first gateway unit 3 further establishes a connection to the second gateway unit 5 based on the routing table as described in refer- ence to fig. 1. If both the calling party and the receiving party accept the respective call requests, then the call between the parties is established.

The application is optionally configured to connect the mobile device 1, 2 with a pre- determined gateway unit 3, 5 in that country or region where the respective party is situated, thus allowing the respective party to connect with a local gateway unit when roaming. This is advantageous if both parties are roaming or at least the calling party is roaming. In this configuration, the second mobile device is connected to the first gateway unit 3 via the first network 4 or the second network 6, thus the second gate- way unit 2 may be omitted. This enables the call to be routed through only the first gateway unit 3. This allows for a more direct and effective routing of the call which in turn may further reduce the costs for conducting a call between the respective parties.

Fig. 3 shows a second embodiment of the system wherein the first mobile device 1 comprises a multi-SIM comprising at least two telephone numbers used to connect to different networks. In example, the respective party uses a home telephone number (indicated by A) of the multi-SIM to connect to me first network 4. The party then uses the application in the first mobile device 1 to select a local telephone number of the second network 6. When the party is roaming, the first mobile device 1 is connect- ed to the second network 6 and thus the second gateway unit 5 is using the selected local telephone number (indicated by B). This allows the party to conduct calls at local rates instead of paying the roaming fees. This also enables the roaming party, e.g. the calling party, to use various data services at local rates, thus further reducing the roaming costs.

The party may use a local SIM instead of a multi-SIM wherein the local SIM comprises the local telephone number as mentioned above. The party may then replace the current SIM comprising the home telephone number with me local SIM or switch between the SIMs if the first mobile device 1 has more than one slot.

The local and home telephone numbers are stored in the system, e.g. in the gateway unit 3. The local telephone number is used by the gateway units 3, 5 to select the routing path between the respective parties. When a calling party enter the home or local telephone number of the roaming party, the first gateway unit 3 uses the local telephone number to redirect the call to the receiving party via the second gateway unit 5.

Fig. 4 shows a third embodiment of the system wherein the second gateway unit 5 is replaced by a SIP unit 10, e.g. a SIP-server. The SIP unit 10 is connected to the second mobile device 2 via a dedicated SIP network 11. A SIP account associated with the party of the second mobile device 2 is stored in the SIP unit, wherein the SIP account comprises a local telephone number for connecting to the SIP network 11. Similar to that of fig. 3, this local telephone number is stored along with the home tele- phone number of this party.

When the calling party enters the home or local telephone number of the receiving party, the first gateway unit 3 routes the call request to the SIP unit 10. The SIP unit 10 further routes the call request to the second mobile device 2 of the receiving party via the SIP network 11. If the receiving party accepts the call request, then the call between the parties is established using a callthrough mode (indicated by solid arrows).

Fig. 5 shows an exemplary flowchart of the method for routing calls between the call- ing party and the receiving party.

In an initial step, the user, i.e. the calling party, enters 12 a telephone number of another user, i.e. the receiving party, on the first mobile device 1. The telephone number may be entered directly in the application or the application may monitor the call function of the first mobile device 1 to detect when the telephone number is entered.

The application then sends the entered telephone number of the receiving party and the telephone number of the calling party to the first gateway unit 3, e.g. in the same request. The controller of the first gateway unit 3 compares 13 the telephone number of the calling party with a list of users stored in the system. If the telephone number matches a stored user, then the calling party is known and the controller sends a confirmation signal back to the application indicating that the calling parly is a known user. If the calling party is not known by the system, then the call is routed to the second mobile device using the normal routing path, i.e. via the first and second networks 3, 6, as shown in fig. 1. The geographical location of the calling party is afterwards determined 14, e.g. using the GPS module in the first mobile device 1 or based on the received signals from a plurality of radio or WiFi antennas. Similarly, the geographic location of the receiving party is determined, e.g. using the GPS module in the second mobile device 2 or based on the received signals from a plurality of radio or WiFi antennas. The geographic locations of the mobile devices 1, 2 are then used to determine if the respective parties are roaming or not.

If the calling party is not roaming, then the application generates a first telephone number for rerouting 17 the outgoing call to the first gateway unit 3. The call is routed between the first and second gateway units 3, S using a selected routing path as mentioned earlier.

If the calling party is roaming, the first gateway unit 3 enters either a callback mode IS or a callthrough mode 16. In the callback mode the outgoing call is disconnected and a call request is sent back to the calling party via the first network 4. The calling party may then accept this call request to establish the call. In the callthrough mode the first gateway unit 3 uses the local telephone number of the receiving party instead of the entered telephone number to route the call to the receiving party. The call is then further routed 18 to the receiving party via the controller in the second gateway unit 5. Upon receipt of the call from the first gateway unit 3, the controller then generates a second telephone number for sending another call request to the second mobile device 2 via the second network 6. The receiving parly may then accept this call request and the system finally establishes 19 the call between the parties. The invention is nol limited to the respective embodiments described herein, and the features of the described embodiments may be combined or modified without departing from the scope of the present invention.

Claims

1. A system for routing calls between mobile devices (1,2) comprising:

- a first mobile device (1) comprising a first communications module for con- necting to a first network, (4)

- at least a second mobile device (2)

- at least a first gateway unit (3) comprising a communications module configured to connect with at least one of the first (1) and second (2) mobile devices via the first (4) network,

- characterised in that at least the first mobile device (1) comprises an application configured to run on the first mobile device (1), wherein the application is configured to detect an entered telephone number (12) of a receiving party and where in

the system is configured to determine a geographic location of at least one of the first (1) and second mobile devices (2), wherein the system is configured to select a routing path, e.g. an Internet line, based on the geographic location.

2. A system according to claim 1, characterised in that the system further comprises at least a second gateway unit (5) that is connected to the second mobile device (2) via the second network (6), wherein the second gateway unit (5) is linked to the first gateway unit (3) via a predetermined routing table.

3. A system according to claim 2, characterised in that the routing table is further configured to link the first and second gateway units to at least a third gateway unit.

4. A system according to claim 3, characterised in that the system is configured to detect if at least the first mobile device of the calling party is roaming, wherein the system is configured to disconnect an outgoing call from that mobile device and establish an incoming call to that mobile device from the respective gateway unit.

5. A system according to any one of claims I to 4, characterised in that the system is configured to generate at least one first telephone number based on the entered telephone number, wherein the at least one first telephone number comprises at least tele- phone number of one of the gateway units and a telephone number of the receiving party.

6. A system according to claim 5, characterised in that the system is further config- ured to generate a second telephone number based on the at least one first telephone number, wherein the second telephone number comprises at least the unique identification number of the receiving party.

7. A system according to any one of claims 1 to 6, characterised in that at least one of the gateway units is a session initiation protocol-unit comprising at least one user account associated with at least one of the parties, wherein at least one of the first and second networks is a session initiation protocol-network.

8. A system according to any one of claims 1 to 7, characterised in that the system is further configured to switch between a home telephone number associated with the first or second mobile device and at least a local telephone number associated with the first or second mobile device.

9. A method for routing calls between mobile devices, comprising:

- associating at least a second mobile device with at least a receiving party,

- providing at least a first gateway unit connected with at least one of the first and second mobile devices via the first network, characterised in that

- activate an application configured to run on the first mobile device (1), wherein the application is configured to detect an entered telephone number (12) of a receiving party,

- selecting a routing path based on the geographic location using a routing table

- detecting a telephone number of the receiving party entered on the first mobile device.

10. A method according to claim 9, characterised in that the first gateway unit is linked to at least a second gateway unit, wherein the call is routed from the first gateway unit to the at least second gateway unit and further to the second mobile via the second network.

11. A method according to claim 10, characterised in that the method further comprises the steps of:

- determining whether the calling party is roaming or not,

12. A method according to any one of claims 9 to 11, characterised in that the method further comprises the step of assigning a local telephone number to at least one of the calling party and the receiving party, and forwarding the call to the local telephone number when roaming.

13. A method according to any one of claims 9 to 12, characterised in that the method further comprises the steps of:

- generating at least one first telephone number based on the entered telephone number, wherein the at least one first telephone number comprises at least a telephone number of one of the gateway units and a telephone number of the receiving party,

- generating a second telephone number based on the at least one first telephone number, wherein the second telephone number comprises at least the unique identification number of the receiving party.