Radiotelephone system in the form of a private branch exchange

• US 5,133,001 A
• Filed: 12/19/1989
• Issued: 07/21/1992
• Est. Priority Date: 12/23/1988
• Status: Expired due to Term

• Current Assignee: Standard Elektrik Lorenz AG
• Original Assignee: Standard Elektrik Lorenz AG
• Inventors: Bohm, Manfred
• Primary Examiner(s): Dwyer, James L.051315646
• Assistant Examiner(s): Cumming, William D.
• Application Number:
  US07/453,818
• Time in Patent Office: 945 Days
• Field of Search: 379/57, 379/58, 379/59, 379/60, 379/62, 379/66, 379/61, 379/63, 379/64, 455/33, 455/56, 455/6, 455/17, 455/18, 455/31, 455/7, 370/69.1
• US Class Current: 455/464
• CPC Class Codes: H04W 16/26 Cell enhancers or enhancement, e.g. for tunnels, building shadow
• CPC Class Codes: H04W 84/14 WLL [Wireless Local Loop]; RLL [Radio Local Loop]
• CPC Class Codes: H04W 84/16 WPBX [Wireless Private Branch Exchange]

Abstract

A radiotelelphone system in the form of a private branch exchange (12) within and/or outside one or more buildings is equipped with a plurality of mobile subscriber units (28), a plurality of transmitter/receiver units (27) capable of communicating with the subscriber units (28) by radio, and a central unit (26) cooperating with the transmitter/receiver units (27). In order that such a radiotelephone system not only permits mobile telephoning within and/or outside buildings but also can be installed later and adapted to changing requirements in a simple manner, the transmitter/receiver units (27) are arranged and designed to form not only a radio link to at least one of the subscriber units (28) but also, via respective adjacent transmitter/receiver units (27), a radio-link chain (radio bus) to the central unit (26), which has a separate transmitter/receiver unit.

Claims

1. A radiotelephone system, particularly in the form of a private branch exchange, including a plurality of mobile subscriber units, a plurality of transmitter/receiver units coupled with the subscriber units by radio links, and a central unit cooperating with the transmitter/receiver units, characterized in that the transmitter/receiver units are arranged and designed to form not only a radio link to at least one of the subscriber units, but also, via respective adjacent transmitter/receiver units, a radio-link chain to the central unit which has a separate transmitter/receiver unit, said transmitter/receiver units each operating with three carrier frequency pairs, a first of which is used for duplex communication with the respective subscriber unit, while the other two are used for duplex communication with two adjacent transmitter/receiver units of the radio-link chain.

2. A radiotelephone system as claimed in claim 1, characterized in that the transmitter/receiver unit and the subscriber unit operate in a TDMA mode.

3. A radiotelephone system as claimed in claim 2, characterized in that the subscriber unit operates with a single carrier-frequency pair.

4. A radiotelephone system as claimed in claim 3, characterized in that the transmitter/receiver unit is provided with a power supply for connection to an element of the electric building wiring system.

5. A radiotelephone system as claimed in claim 4, characterized in that the power supply is provided with a base for a conventional lamp socket.

6. A radiotelephone system as claimed in claim 5, characterized in that the transmitter/receiver units of the radio-bus are used in a quasi-optical, line-of-sight path.

7. A radiotelephone system as claimed in claim 2, characterized in that the transmitter receiver unit is provided with a power supply for connection to an element of the electric building wiring system.

8. A radiotelephone system as claimed in claim 7, characterized in that the transmitter/receiver units of the radio-bus are used in a quasi-optical, line-of-sight path.

9. A radiotelephone system as claimed in claim 1, characterized in that the transmitter/receiver unit is provided with a power supply for connection to an element of the electric building wiring system.

10. A radiotelephone system as claimed in claim 9, characterized in that the power supply is provided with a base for a conventional lamp socket.

11. A radiotelephone system as claimed in claim 10, characterized in that the transmitter/receiver units of the radio-bus (27) are used in a quasi-optical, line-of-sight path.

12. A radiotelephone system as claimed in claim 1, characterized in that the transmitter/receiver units of the radio-bus (27) are used in a quasi-optical, line-of-sight path.