Abstract:
A virtual network has an identity distinct from an existing network identity. A user of the virtual network, without being charged, generates a request, over an existing telephony network, for a first communication between a first communication device and a second communication device. Without allowing the first communication to connect completely to the second communication device, a notification is transmitted to the second communication device and the request is automatically disconnected. The notification includes information sufficient to allow a user of the second communication device to request a second communication connection with the first communication device. The user of the second communication device to request the second communication after the request for the first communication is disconnected.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from and is a continuation-in-part of U.S. application Ser. No. 10/558,644, filed Oct. 18, 2006, which is a national stage entry of PCT/IB04/01718, filed on May 26, 2004, which itself claims priority from South African Application 2003/4248, filed May 30, 2003. 
     
    
     BACKGROUND 
       [0002]    This invention relates to a method of operating a telephony service and to a telephony network configured to implement the method. 
         [0003]    Various factors limit the access of the sectors of the population to telephony services. In South Africa, for example, a substantial portion of the population cannot afford the cost of a telephone service and the cost of calls. 
       SUMMARY 
       [0004]    According to the invention there is provided a method of operating a telephony service, the method comprising allocating a network identity comprising a unique network telephone number to each of a plurality of network users; and configuring the network to permit each network user to receive calls and/or messages from callers calling a respective network telephone number of the network user, and to give network access to said network user for outgoing calls, irrespective of the status of an account of said network user. Thus, such a network user may receive calls and/or messages without having prepaid airtime or a credit account in good standing, outgoing calls made from a telephone of a network user without credit or airtime being disconnected after a predetermined number of rings, thereby creating a missed call notification for the intended call recipient. 
         [0005]    The method may include providing each user with a mobile telephone in which the network identity can be used. 
         [0006]    The mobile telephones may be locked to a telephony network associated with the unique network number. 
         [0007]    The mobile telephones may also be locked to a subscriber identity module defining the network identity. 
         [0008]    Alternatively, the mobile telephones may have a built-in subscriber identity module defining the network identity. 
         [0009]    The mobile telephones may be provided free of charge, or at a nominal charge, to the network users. 
         [0010]    The network is preferably configured to cause outgoing calls made from a telephone of a network user without credit or airtime to be disconnected after one ring. 
         [0011]    The network may be configured to generate a notification to the intended call recipient of an attempted call from a network user if the call recipient&#39;s telephone is off, engaged or out of coverage. For example, the notification may be a text message or a recorded announcement. 
         [0012]    The network identity allocated to each network user may be allocated on a virtual network hosted at least partially by an existing network, the virtual network having a network prefix distinct from that of existing networks. 
         [0013]    Further according to the invention there is provided a system for providing telephony access to a plurality of network users, the system comprising: 
         [0014]    a telephony network; and 
         [0015]    a plurality of network identities issued to respective users of the telephony network, each network identity defining a unique network telephone number and being usable in at least one telephone, the network being configured to permit telephones of the users to receive calls and/or messages from callers calling respective network telephone numbers of the users, and to give network access to said network user for outgoing calls, irrespective of the status of accounts of the users, so that users may receive calls and/or messages without having prepaid airtime or a credit account in good standing, outgoing calls made from a telephone of a network user without credit or airtime being disconnected after a predetermined number of rings, thereby creating a missed call notification for the intended call recipient. 
         [0016]    The telephony network may be configured to define voice and/or message mailboxes for each user, thereby to store voicemail and/or text messages from callers to the respective users. 
         [0017]    The telephony network may be a virtual mobile telephony network hosted at least partially by an existing mobile telephony network and having a unique network identifier code. 
         [0018]    The network identities are preferably defined by subscriber identity modules (SIMs) issued to the users, the subscriber identity modules each being usable in a telephone of a user. 
         [0019]    Each subscriber identity module may be built into a respective telephone. 
         [0020]    Alternatively, each subscriber identity module may be a miniature SIM usable in a mobile telephone and be locked to a particular mobile telephone. 
         [0021]    Further alternatively, each subscriber identity module may be a credit card sized SIM usable in public telephones and/or other telephone terminals. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    The single drawing is a simplified diagrammatic illustration of a telephony network which can be configured to implement the method and system of the invention. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0023]    Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a sufficient understanding of the subject matter presented herein. But it will be apparent to one of ordinary skill in the art that the subject matter may be practiced without these specific details. Moreover, the particular embodiments described herein are provided by way of example and should not be used to limit the scope of the invention to these particular embodiments. In other instances, well-known timing protocols, operations, procedures, and components in a telephony network have not been described in detail so as not to unnecessarily obscure aspects of the embodiments of the invention. 
         [0024]    The present embodiments of the invention(s) is premised on the idea that offering free telephones and access to a telephony network, although seemingly unprofitable on the face of it, can in fact lead to increased revenue for a network operator implementing such a method and system. 
         [0025]    The embodiments of the invention(s) proposes that free or low cost mobile telephones be provided which are network-locked to a new network. Each mobile telephone is provided with a subscriber identity module (SIM card) which is locked to the respective telephone, so that each telephone effectively is usable only on the new network and with the SIM card provided. The telephone may have a built-in SIM card, for example, as opposed to conventional removable SIM cards. The SIM card determines a network telephone number for the telephone which is unique. 
         [0026]    The mobile telephones are offered to prospective users free of charge or at a nominal charge (below cost), and the mobile telephones are preferably basic, low cost “entry level” units. 
         [0027]    The new network is preferably a virtual mobile network hosted by an existing mobile telephony network. As usage of the virtual network expands beyond the capacity of the existing network to support it, additional network infrastructure to support the new network can be provided. However, the new network could also have new network infrastructure of its own, at least in part. 
         [0028]    The virtual network preferably has a network prefix distinct from that of existing networks. However, as it is based on an existing mobile network, it can have the functionality of that network. For maximum functionality, the host network should be an intelligent network (IN). 
         [0029]    The host network is configured to permit the mobile telephones which are issued to receive calls, and is also configured to provide a voice mailbox and/or message mailbox for each network user, able to receive and store voicemail and/or text messages which can be accessed by the network users. These services are offered free of charge. This means that users do not need to have prepaid airtime or a credit account in good standing in order to use the network. 
         [0030]    The drawing shows, in a highly simplified schematic form, the architecture of a portion of a modem GSM mobile telephone network. The diagram does not purport to, be comprehensive but merely illustrative. The network will typically embody intelligent network (IN) functionality. 
         [0031]    In the illustrated network, which serves as a host network to the above mentioned virtual mobile network, a mobile telephone  10  of a caller communicates with a first base station  12  which in turn communicates with a mobile switching center (MSC)  14 . The base station  12  comprises a base station controller (BSC) and a base transceiver station (BTS) with associated antenna (not shown). Associated with the mobile switching center  14  is a visited location register (VLR)  16 . 
         [0032]    A call recipient has a mobile telephone  18  which communicates with a second base station  20 . The base station  20  is connected to a further mobile switching center (MSC)  22  with its own associated visited location register  24 . (In some cases, the two base stations could be connected to the same MSC.) The respective mobile switching centers  14  and  22  and the respective visited location registers  16  and  24  are interconnected as shown. The visited location registers are also connected to a home location register (HLR)  26  and to a billing center  28 . The MSCs  14  and  22  are also connected to the billing center. The HLR is a central database containing data relating to the account status and predetermined network settings of subscribers. The VLRs are decentralized databases which are updated with data from the HLR relating to a particular subscriber when that subscriber&#39;s telephone connects to the MSC in question. 
         [0033]    A Short Message Service Center (SMSC)  30  is connected to the MSC  22 . Network users can be offered prepaid airtime or have credit accounts with the network operator in a conventional manner. However, it is envisaged that many or most of the network users will not be able to afford to purchase airtime to a significant value, or at all. Therefore, the network is configured to facilitate the generation of notifications to called parties, in the same network or other networks, that a call attempt from a user of the virtual network has been made, without actually connecting the call. 
         [0034]    For example, assume first that such a user of the new virtual network wishes to talk to a person who is a subscriber of the same network. The user (the caller using the mobile telephone  10  in the drawing) dials the number of the call recipient&#39;s telephone  18 . The call is routed via the base station  12  and the mobile switching center  14 , which can determine from its associated visited location register  16  that the caller is a user without either prepaid airtime or a credit account in good standing. The MSC  14  modifies the call setup characteristics accordingly, and forwards the call to the MSC  22  handling the base station  20  and the call recipient&#39;s mobile telephone  18 . The network allows the mobile telephone  18  to ring once and then disconnects the call without allowing it to connect (terminate) completely. 
         [0035]    Assuming that the mobile telephone  18  of the call recipient is on and in coverage, this generates a missed call message for the call recipient, notifying the call recipient of the caller&#39;s attempt to contact him/her. The call recipient can then return the call at his/her discretion. 
         [0036]    If the mobile telephone  18  of the call recipient is off or out of network coverage, the network generates a notification to the call recipient of the call attempt, preferably in the form of an SMS text message. The SMSC  30  generates a message which can have the following form, for example: “Please ring me on (caller&#39;s number)”. Alternatively, the network can generate a synthesized voicemail message. Such a message could have the form, for example: “Please return a call received from (caller&#39;s number).” 
         [0037]    In the case where the caller, being a user of the new virtual network, wishes to talk to a person who is a subscriber on a different network, a similar procedure is followed, but there are further implications in respect of interconnect fees payable by the network originating the call to the network on which the call is terminated. If the call recipient receives a missed call notification arising out of a “ring once and disconnect” call, or receives an SMS or voicemail message, as described above, and then returns the call to the original caller, the network of the original call recipient (who is now calling back) pays the operator of the new virtual network an interconnect fee (as determined by SATRA in South Africa) which is typically R1.23 per minute during business hours. This means that the operator of the new virtual network receives revenue from calls made to its users, while the “scotch call” made by the virtual network user does not attract the same cost levied by the other network, as the call is not terminated. (It may well be that an interconnect fee will be levied for the routing of the “scotch call”, and for the sending of voicemail and SMS messages, but these fees should be less than for the termination of normal calls.) 
         [0038]    In a development of the various embodiments of the invention(s), users can be allowed to roam on other networks, including fixed line networks (particularly where the users are issued with full size SIM cards usable in public telephones). In such a case, the primary network of which the user is a subscriber and the visited network can share interconnect fees earned due to calls terminated on the visited network, in a predetermined ratio or according to a predetermined scheme. This can avoid a scenario in which other network operators are prejudiced by a one-way outflow of interconnect fees to the new network. The advantage to the users is that they can choose which network to use in given situations, based on coverage or other factors. 
         [0039]    In combination with the method and system described in International patent application no. PCT/IB2004/000216, the contents of which are incorporated herein by reference, the method and system of the various embodiments of the invention(s) can allow a user of the above described new virtual network to make calls to subscribers of a network who have included the telephone number of the user in a group of designated approved callers, who can thus make automatic reverse charge calls to that subscriber. For example, in a family scenario, one or more parents might be subscribers of a first network and have prepaid airtime or a credit account with that network. The children of the family could be users of the new virtual network, with their telephone numbers being included in a group of approved reverse charge callers, so that calls made by the children to the parent(s) are connected automatically and billed to the account(s) of the parent(s). 
         [0040]    If one of the children wishes to contact a friend, but does not have airtime to do so, the child can telephone the parent as described above, and request the parent to connect him/her to the friend. The parent may do this at his/her discretion and can then transfer the call and drop out of the conversation, using existing network functionality. In this case, both the call from the child and the call to the friend are billed to the parent&#39;s account. This arrangement gives the parent control over calls made by the child. In a variation of this arrangement, the child might be allocated a predetermined amount of airtime on a regular basis, but will have to make calls via the parent if this airtime has been used up. 
         [0041]    It will be appreciated that variations of the above scenario can be applied to the business world, where employees wishing to make business calls can contact a designated operator at their office, who will connect them to called parties according to predetermined guidelines. 
         [0042]    The above described method and system can be implemented using an existing intelligent mobile network, and it is envisaged that operating such a method and system would generate substantial revenue for the virtual network operator, due to the generation of a substantial volume of interconnect fees arising from calls made to users of the new network from users of other networks. 
         [0043]    Although an example of the embodiments of the invention(s) has been described in which users of the network are issued with free or low cost mobile telephones, it will be appreciated that the principles of the embodiments of the invention(s) can be applied irrespective of the means of issuing a network identity to a user, whether or not the user has his/her own telephone. Thus, by merely issuing the user with a SIM card defining a network identity, the SIM card being usable in a mobile telephone, other telephone terminal, or even a public telephone, the full functionality of the various embodiments of the invention(s) can be provided by configuring the host network appropriately. 
         [0044]    For example, the SIM card could be a mini SIM card of the kind used in mobile telephones, which can be provided with a holder/adapter that effectively converts the mini SIM card to a full sized (credit card sized) SIM card usable in other telephones or terminals, such as public telephones with built in smart card readers. 
         [0045]    It is envisaged that the above described embodiments of the invention(s) will enable millions of potential network users, previously excluded from access to personal telephony services, to gain useful access to such services. 
         [0046]    The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the various embodiments of the invention(s) to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention(s) and its practical applications, to thereby enable others skilled in the art to best utilize the invention(s) and various embodiments with various modifications as are suited to the particular use contemplated.