Telecommunications – Transmitter and receiver at same station – Radiotelephone equipment detail
Reexamination Certificate
1997-03-27
2001-02-06
Maung, Nay (Department: 2744)
Telecommunications
Transmitter and receiver at same station
Radiotelephone equipment detail
C455S551000, C455S575100, C379S357040
Reexamination Certificate
active
06185436
ABSTRACT:
TECHNICAL FIELD
This invention relates generally to wireless communication systems and more particularly to personal communication systems and cellular telephone systems adapted to operate in different geographical locations.
BACKGROUND OF THE INVENTION
As is known in the art, current cellular telephone use has expanded rapidly over the past few years. While typically a user subscribes to only one service provider and is assigned a single telephone number, many subscribers have cellular phones adapted to operate with two different telephone numbers. Thus, when the subscriber operates in one geographical location he/she manually selects one of two Number Assignment Modules (NAMs) provided within his/her cellular telephone. In this way, if the subscriber generally travels to, and works in, two geographical locations he/she can select the NAM associated with a local service provider thereby reducing long distance telephone costs and inter-network roaming charges. Thus, these users are able to obtain two subscriptions from two service providers in two different geographical locations for the same handset. In other words, dual subscription is achieved by having the same handset programmed with different telephone numbers of subscription information in different Number Assignment Modules (NAMs); one for each of the two different geographical locations of the local service provider. This arrangement allows a roaming subscriber to save roaming fees and long distance charges, which can be very expensive if the user frequently travels between two locations and merely uses the same subscribed local service provider when on travel. However, as noted above, the user must manually select the NAM to be used and the NAMs are not removable by the user.
As is also known in the art, certain cellular telephones are adapted to receive a credit-card sized Subscriber Identity Module (SIM). Each SIM is associated with a unique service provider and has stored therein different subscriber information. This information is transmitted to a receiving radio base station cell to obtain network access. Thus, in one example, one SIM may be associated with a subscriber's business telephone number and another with his/her home telephone number. In this case, each SIM may be for the same or different providers in the same Public Land Mobile Network (PLMN), or for the same or different providers in different PLMNs. Thus, if a subscriber is on travel to a different geographical location from his/her home office, he/she needs only to remove the SIM from his/her handset, slips it into his/her wallet, rents a handset at the other location where the radio frequency coverage is different from his/her own handset (i.e, where the user travels from the United States to Europe) and merely inserts the SIM into the rented handset. During operation, the subscriber's information is transmitted from the SIM to the local base station cell to obtain authorization from the home PLMN.
In a PCS 1900 network, multiple subscriber number service for voice application is not possible with a single Subscriber Identity Module (SIM) in the handset since it can only be provided with one Mobile Subscriber Integrated Service Digital Network (MSISDN) number for voice service per Global System for Mobile (GSM) standards. In GSM communication, standards allow for two SIMs in a handset. One of the SIMs must be the plug-in type. The plug-in type SIM is very small (i.e., chip size) and, if removed from the handset, may be easily lost. For the GSM handset, there can only be one full size, i.e., credit-card like SIM.
It is noted that both NAM and SIM refer to modules which provide subscriber identification information and are both sometimes referred to hereinafter as subscriber identity modules.
SUMMARY OF THE INVENTION
In accordance with the present invention, a personal communication system handset is provided. The handset has a plurality of slots provided therein. Each one of the slots is adapted to store a corresponding one of a plurality of removable/insertable subscriber identity modules. The subscriber identity modules have stored therein different subscriber information.
With such arrangement, a user is able to subscribe to two, or more, different providers and is able to remove at least one of the modules for use in another handset. Further, the modules are credit-card size and are therefore less likely to be lost, or misplaced, than a chip sized module.
In accordance with another feature of the invention, an electronic switch is disposed in the handset for electrically coupling one of the modules to a transceiver in the handset selectively in accordance with a program stored in the handset based on a signal received by the transceiver from a base station cell. The selected module provides the base station cell with the stored subscriber information.
With such an arrangement, the handset can automatically select the proper module based on the stored program.
In accordance with another feature of the invention, an automatic subscriber identification module control system is provided. The system includes a handset having a plurality of subscriber identity modules. A transceiver is disposed in the handset for receiving and transmitting signals from and to a base station cell. A memory is also disposed in the handset, such memory storing an executable program. A processor in the handset is responsive to the signals received by the transceiver and adapted to execute the stored program to producing a control signal in accordance with the received signals and the executed program. A electronic switch, disposed in the handset, is provided for coupling one of the plurality of subscriber identity modules to the processor selectively in response to the control signal. The subscriber identity modules have stored therein different subscriber information and the module selected by the control signal provides, via the transceiver, the subscriber information stored therein to the base station cell.
With such an arrangement, a user may travel to a different PLMN and the handset automatically select a module associated with a nearby home network thereby saving long distance and roaming charges.
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patent: 5418837 (1995-05-01), Johansson et al.
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patent: 5465401 (1995-11-01), Thompson
patent: 5604787 (1997-02-01), Kotzin et al.
patent: 5875404 (1999-02-01), Messiet
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patent: 2269512 (1994-09-01), None
Codispoti Joseph S.
Maung Nay
Siemens Information and Communication Networks Inc.
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