WO2004110089A1

WO2004110089A1 - Use of sim cards in different networks

Info

Publication number: WO2004110089A1
Application number: PCT/IB2004/001765
Authority: WO
Inventors: Ari Kahn
Original assignee: Ari Kahn
Priority date: 2003-06-04
Filing date: 2004-05-28
Publication date: 2004-12-16

Abstract

A method of operating a telephony service is disclosed. According to the method, a unique network identity is allocated to each of a plurality of network users, so that each network user has a unique network telephone number. At least two networks, a home network to which the network identities are linked and a visited network, are configured to recognise the network identities. A database associated with the visited network contains data corresponding to users whose network identities are usable on the visited network, and the users are issued with one or more subscriber identity modules usable in telephones connected to the home network and the visited network, so that such users can access telephony services on both the home network and the visited network, using the same network identity.

Description

Telephony Service with Portable Network Identity

BACKGROUND OF THE INVENTION

THIS invention relates to a method of operating a telephony service in which users of a telephone network are issued with one or more subscriber identity modules.

Conventionally, a subscriber to a cellular telephone network is issued with a subscriber identity module (SIM) or SIM card usable in a mobile telephone, the SIM card defining a network identity for the subscriber and containing subscriber data, security related information and operational algorithms. In particular, the SIM card defines a mobile subscriber integrated services digital network (MSISDN) number or primary number which is effectively the network telephone directory number of the subscriber. The SIM card contains a processor and memory and is operable to store a PIN code selected by the subscriber for use when powering on the mobile telephone, to prevent use by unauthorised persons.

It may happen that a subscriber to a cellular network needs to access telephony services in an area not serviced by his/her network, that reception in a particular area is poor, or that ambient conditions such as noise hamper the use of a mobile telephone. In such a situation, it might be preferable for such a subscriber to make use of an alternative infrastructure. SUMMARY OF THE INVENTION

According to the invention there is provided a method of operating a telephony service, the method comprising:

allocating a network identity to each of a plurality of network users, so that each network user has a unique network telephone number;

configuring at least two different networks to recognize the network identities; and

issuing at least one subscriber identity module to each user, said at least one subscriber identity module being usable in telephones connected to a home network and telephones connected to one or more other networks, so that respective users can access telephony services on the home network and said one or more other networks using the same network identity.

The method may comprise issuing at least first and second different subscriber identity modules to users.

For example, a user may be issued with a miniature subscriber identity module usable in a mobile telephone connected to a cellular network, and a credit card sized subscriber identity module usable in a card reader of a public telephone connected to a fixed line network.

Alternatively, the method may comprise issuing miniature subscriber identity modules to users, with an adapter operable to receive a miniature subscriber identity module and to be received by a card reader of a public telephone or the like, to connect the miniature subscriber identity module to the card reader. In any case, the home network and said one or more other networks are preferably configured to bill a user account associated with the network identity, irrespective of which network is used by a user.

Preferably, calls from a user are presented to call recipients as originating from a telephone number associated with the network identity, irrespective of which network is used to originate the call.

Further, according to the invention there is provided a telephony system comprising:

a first, home network having a plurality of users, each user having a user identity linked to the home network;

a second, visited network, both the home network and the visited network being configured to recognise the network identities of the users; and

a database associated with the visited network and containing data corresponding to users whose network identities are usable on the visited network, so that such users can access telephony services on both the home network and the visited network using the same network identity.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a pictorial view of a subscriber identity module and a related smart card issued to users of a telephony service according to the invention;

Figure 2 is a pictorial view of an adapter for converting a miniature subscriber identity module for use in a conventional smart card reader; and Figure 3 is a highly simplified schematic diagram illustrating a telephony network of the invention.

DESCRIPTION OF EMBODIMENTS

Several telephony service operators operate both fixed line and cellular mobile networks. One such operator is British Telecom (BT) in the United Kingdom. In other cases, a fixed line network operator may have equity in a cellular network or vice versa. However, it is generally not possible for a subscriber of one network to make use of the infrastructure of a related network in a convenient manner, let alone the infrastructure of a non- related network.

The present invention addresses this situation by configuring networks to recognise a network identity allocated to a network user or subscriber, irrespective of the actual network infrastructure used by the subscriber to make a call or access other networks.

The following examples illustrate how this is achieved.

In a first example, a subscriber to a cellular mobile network is issued with a subscriber identity module (SIM) or SIM card 10 (see Figure 1) which he/she uses in a mobile telephone to access communication services on the network. The SIM card defines a mobile subscriber integrated services digital network (MSISDN) number or network telephone number which effectively defines the subscriber network identity. The SIM card is essentially a smart card comprising a microprocessor with associated memory mounted on a flat plastics substrate, and is normally a miniature SIM card which can be received in a suitable card slot in a mobile telephone. The operation of such SIM cards is well known to those skilled in the art and need not be described in further detail. With the SIM card inserted into the mobile telephone, the subscriber can access the network to make and receive calls, send and receive messages and access other network services. The network recognises the MSISDN of the SIM card and presents the user's network telephone number to call recipients using caller line identity (CLI) technology.

For various reasons, it may from time to time be necessary or desirable for the subscriber to make calls or otherwise access telephony services from a different telephone than his/her mobile telephone. For example, in noisy environments, environments where reception is poor or there is no network coverage, where broader band services are available to service data connectivity requirements, or where the battery of the subscriber's mobile telephone is discharged, the subscriber may need to use a public telephone. Alternatively, if the subscriber is in a foreign country, he/she may find the cost of roaming on a local cellular network prohibitive, and prefer to use a local public telephone. Conventionally, this would require the subscriber to have coins or a prepaid telephone card for use in the public telephone. Generally, a subscriber is unlikely to have large amounts of coins or a prepaid card with a large credit value on it, effectively limiting the cost of calls which can be made in this way. In addition, the functionality available to the subscriber is limited compared with that available via the subscriber's home network.

The invention therefore proposes that the public switched telephone network (PSTN) or other network supporting public telephone terminals be configured to recognise the network identity of a subscriber to a different network, typically the Public Land Mobile Network (PLMN), and that the subscriber be issued with a SIM card or other smart card readable by such telephone terminals so that the subscriber can utilise the visited network and use it as if accessing his/her own home network in what may be termed a micro roaming capacity.

By way of example, and with reference again to Figure 1 , a subscriber to a mobile network can be provided with a duplicate credit card-sized SIM card 12 for use in public telephones or other telephone terminals, in addition to the usual miniature SIM card 10 usable in a mobile telephone. Alternatively, as shown in Figure 2, the subscriber can be provided with one or more miniature SIM cards 10 and an adapter 14 which receives the miniature SIM card and has a front portion 16 shaped to be received in a conventional smart card reader, with a conventionally shaped and oriented contact pad 18. Towards a rear portion 20 of the adapter, a shallow cavity 22 is formed, which is sized to receive the miniature SIM card. A sliding clip 24 is provided to retain the SIM card 10 in position, and miniature flexible electrical contacts 26 within the cavity 22 engage respective contacts on a contact pad 28 of the SIM card. Fine electrical conductors 30 buried in the substrate of the adapter 14 connect the contacts 26 to respective contacts on the contact pad 18, thus enabling the miniature SIM card 10 to be connected to the contacts of the card reader when the adapter 14 is inserted into the card reader in a conventional manner.

The adapter 14 can be substantially the same size as the conventional credit card-sized SIM card 12, and the front portion 16 thereof need be no thicker than the conventional card, allowing it be received in conventional card readers.

In either case where the subscriber is issued with a SIM card which can be read by conventional smart card readers in existing public telephones, the PSTN can be configured to read the MSISDN from the smart card, to compare the MSISDN with a database of authorised users and, if the MSISDN read from the smart card corresponds with an authorised number, to allow the subscriber access to the visited network, with the cost of services accessed by the subscriber being debited to the subscriber's account with his/her home network.

Figure 3 shows, in a highly simplified schematic form, an arrangement in which a first, home network 32 is connected to a second, visited network 34. In the illustrated example, the subscriber's home network is a mobile network, while the visited network 34 is a fixed line network. A database 36 contains data identifying registered users whose network identities may be used on the visited network 34, and can be accessed when such a subscriber utilizes his/her network identity to originate a call from the visited network 34. For example, the subscriber may use a public telephone 38 connected to the visited network 34, inserting the credit card-sized SIM card 12 (or the miniature SIM card 10 in an adapter 14) into a card reader 40 to identity him/herself to the visited network 34.

Preferably, the PSTN is configured to allow the subscriber's MSISDN to be presented to call recipients (rather than the number of the public telephone being used). Optionally, the subscriber can be required to enter a PIN or other security code when utilising a public telephone in this way, analogously to entering a PIN code when powering up his/her mobile telephone. This PIN may correspond to the PIN used by the user with his/her mobile telephone.

The described arrangement permits a network subscriber who is unable to use his/her mobile telephone, or who prefers for some reason to use a public telephone, or an alternate network service, to make and receive calls, send and receive messages and otherwise transact as if he/she were accessing his/her own home network. The basic functionality to enable this is readily available in modern communication networks and any enhanced functionality would be elementary to those skilled in Intelligent Network management. Thus the invention requires relatively minor configuration changes to an existing network.

It will be appreciated that the logistics of the described arrangement are easier in the case of a network operator that operates both networks in question. However, suitable commercial service sharing arrangements already exist in the Interconnect Agreements (ICAs) common to all network operators who transmit and carry traffic between a home network and foreign network, and such an ICA may easily be modified to cater for the method of the invention. Effectively, the described arrangement allows a subscriber of a mobile network to "roam" virtually on a fixed network while maintaining all or most of the functionality of the mobile network

Apart from the obvious convenience benefits of the invention, there are potential commercial benefits as well. For example, in South Africa the operator of the existing fixed line network would pay a mobile network operator R 1.23 per minute for a call originating on the fixed line network and terminated on the mobile network. If a visiting subscriber from the mobile network is allowed to roam on the fixed line network, with a revenue sharing scheme in place between the fixed line and mobile network operators, the mobile network operator may share the interconnect fee, earned when the visiting subscriber terminates a call on the mobile network, with the fixed line network operator. Assuming that the visiting subscriber is charged a premium above the applicable interconnect fee, so that the discount received from the mobile network plus the premium charged to the visiting subscriber together exceed the net interconnect cost to the fixed line network operator, the latter makes a profit. At the same time, the mobile network operator earns an interconnect fee, albeit reduced, which it otherwise would not have earned.

When the visitor terminates a call on the visited fixed line network, the fixed line network operator charges a fee which is not necessarily shared with the mobile network operator. However, due to the fact that the visiting subscriber's home network identity is presented, the mobile network operator should earn future revenue from returned or new calls.

In a second scenario, a user of telephony services may not have access to a mobile network, due to economic or other factors. Nonetheless, such a user can be allocated a network identity as described above, with a network telephone number on which calls can be made and received. Such an arrangement is described in International patent application no. PCT/IB2004/000965 of the present applicant, the contents of which are incorporated herein by reference. According to the present invention, a smart card allocated to such a network user may have an IMSI and MSISDN recorded on an associated duplicate miniature SIM card which can be used in a mobile telephone, thus enabling such a network user, who may initially be limited to use of public telephones, to upgrade to his/her own mobile telephone usable on a mobile network, while retaining the same network identity. It is envisaged that such a scenario will have economic benefits to network operators offering both fixed network and mobile network services, due to expected customer loyalty arising out of a desire to retain one's network identity when upgrading to a mobile network.

It will be appreciated that the advantages of number portability and unified billing are beneficial to both types of network user described above, while at the same time presenting an opportunity for network operators to increase revenues from their existing subscriber base.

In a scenario where there are multiple fixed line and mobile networks, a user's SIM card should ideally be recognised by all networks, with suitable commercial arrangements being made by the network operators to compensate one another, if required, for user "roaming". Alternatively, an existing or modified interconnect fee structure can be utilised in terms of which networks from which calls are originated pay interconnect fees to networks on which calls are terminated.

The above described invention is useful in the method and system described in International patent application no. PCT/IB2004/000216 of the present applicant, the contents of which are incorporated herein by reference. In the referenced patent application, a network subscriber defines groups of approved or associated callers who may make reverse charge calls to the subscriber. According to the present invention, where such a member of an approved group of callers makes a call to the subscriber, the calling group member's network telephone number is presented irrespective of whether the call is made on the group member's home (mobile) network, a fixed line network or another visited network, enabling the group member to make an automatic reverse charge call from a telephone and even a network other than the group member's normal personal telephone and network.

Claims

1. A method of operating a telephony service, the method comprising:

2. A method according to claim 1 comprising issuing at least first and second different subscriber identity modules to each user.

3. A method according to claim 2 comprising issuing a user with a miniature subscriber identity module usable in a mobile telephone connected to a cellular network, and a credit card sized subscriber identity module usable in a card reader of a public telephone connected to a fixed line network.

4. A method according to claim 1 comprising issuing at least one miniature subscriber identity modules to each user, with an adapter operable to receive a miniature subscriber identity module and to be received by a card reader of a public telephone or the like, to connect the miniature subscriber identity module to the card reader.

5. A method according to any one of claims 1 to 4 wherein the home network and said one or more other networks are configured to bill a user account associated with the network identity, irrespective of which network is used by a user.

6. A method according to any one of claims 1 to 5 wherein calls from a user are presented to call recipients as originating from a telephone number associated with the network identity, irrespective of which network is used to originate the call.

7. A telephony system comprising:

a second, visited network, both the home network and the visited network being configured to recognise the. network identities of the users; and