Apparatus and a method of allowing private cellular operation within an existing public cellular system

• US 5,448,619 A
• Filed: 04/14/1992
• Issued: 09/05/1995
• Est. Priority Date: 04/14/1992
• Status: Expired due to Term

• Current Assignee: Allen Telecom LLC (CommScope Holding Company, Inc.)
• Original Assignee: Orion Industries Incorporated
• Inventors: Leslie, Samuel A., Evans, Michael W.
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Shankar, Vijay
• Application Number:
  US07/868,472
• Time in Patent Office: 1,239 Days
• Field of Search: 379/58, 379/59, 379/60, 455/33.1, 455/33.2, 455/54.1
• US Class Current: 455/426.1
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 84/00 Network topologies
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user
• CPC Class Codes: H04W 88/181 Transcoding devices; Rate adaptation devices

Abstract

An apparatus and method which can provide a private cellular system within an area already served by a public cellular system include a receiver for receiving RF control signals from the public system. The public system control signals are converted to saturation level control signals from the private system. Subscriber units to be serviced by the public system are directed thereto. Those associated with the private system can be serviced directly.

Claims

1. A private radio telephone system with a set of subscribers, having a first coverage area which overlaps at least in part, a second coverage area of a second, different radio telephone system with a different set of subscribers, wherein each of the systems can communicate with one or more associated movable, subscriber units located in a respective coverage region and wherein each of the systems has a respective set of control channels, each of which can be used to establish communication with a respective movable unit, the private system being associated with a telephone switch, the private system comprising:

a controller with an input/output port for receiving communication signals thereto, and circuitry for transmitting radio frequency signals into the first coverage area; and

a receiver coupled to said controller, for receiving the selected set of control channels for the second system and including further circuitry for retransmitting selected representations thereof on one of its respective control channels whereupon a movable subscriber unit in the first coverage area being called on the second system will initiate communication herewith.

2. A private system as in claim 1 including storage for maintaining a list of movable units eligible for service in the private system.

3. A private system as in claim 2 including circuitry for directing a movable unit not identified in said list to the second system for service.

4. A private system as in claim 1 including an amplifier for amplifying selected control channel signals to be transmitted into the first coverage area at a higher power level than corresponding control channel signals associated with the second system.

5. A private system as in claim 1 which includes a translation table wherein a communication signal associated with a first telephone number and received from the switch can be directed to a predetermined movable unit in the first coverage area.

6. A method of providing service to a movable unit by a first radio telephone system in a first coverage area simultaneously with providing service by a second different radio telephone system in a second coverage area wherein the first coverage area can overlap the second, the method comprising:

transmitting into the first coverage area a control signal of a selected intensity from the second system;

transmitting into the first coverage area a control signal from the first system at a higher intensity than that of the control signal from the second system, such that subscriber units in the first coverage area will initially respond to that control signal;

detecting for use in the first coverage region the control signal from the second system, and retransmitting a processed representation of same as part of the control signal from the first system, thereby causing a selected subscriber unit which is to be serviced by the second system, and which is in the first coverage area to then respond to the control signal for the second system; and

responding to a subscriber unit in the first coverage area, determining if it is to be serviced by the first system, and in response thereto providing service thereto.

7. An apparatus for providing service to movable subscriber units by first or second radio telephone systems, wherein the first and second system need not have the same subscribers and wherein a coverage region of the first system is included, at least in part, in a coverage region of the second system, and wherein the subscriber units are usable in either radio telephone system, the apparatus comprising:

circuitry, located in the first coverage region, for receiving radiant signals from the second system;

control circuitry, coupled to said receiving circuitry, for detecting received signals from the second system and in response thereto, for radiating a command signal to a predetermined subscriber unit in the first coverage region, thereby directing that unit, if present in the first coverage region, to communicate with the second system and wherein another subscriber unit is capable of communicating with the first system while in said first coverage region and is capable of communicating with the second system when outside of said first region.

8. An apparatus as in claim 7 wherein said control circuitry includes circuitry for storing a plurality of identifiers of subscriber units eligible to receive service from said first system.