Browse Prior Art Database

ANTENNA EXTENDER FOR WIDE AREA FALLBACK

IP.com Disclosure Number: IPCOM000006290D
Original Publication Date: 1991-Dec-01
Included in the Prior Art Database: 2001-Dec-20
Document File: 3 page(s) / 114K

Publishing Venue

Motorola

Related People

Andy Davis: AUTHOR [+3]

Abstract

Multisite two way radio systems typically use micro- wave links, fiber optic lines or phone lines to transmit voice and data from a central site to all of its remote sites. Failure of these links mean loss of wide area com- munications, which is not acceptable, especially if the users are city or government agencies. There are backup methods which allow limited communications for users to sites that have been isolated by a Iii f&lure. In this case two way communication is limited to subscriber radios within the geographic coverage area of the repeater station for the site. The communication then becomes local to the isolated site. The rest of the system operates in the conventional mode and has wide area coverage because its links are functional. The method described provides wide area communication capability when a remote site loses its link.

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MOTOROLA INC. Technical Developments Volume 14 December 1991

ANTENNA EXTENDER FOR WIDE AREA FALLBACK

by Andy Davis, Joe Lukose and Adrianna Petri

  Multisite two way radio systems typically use micro- wave links, fiber optic lines or phone lines to transmit voice and data from a central site to all of its remote sites. Failure of these links mean loss of wide area com- munications, which is not acceptable, especially if the users are city or government agencies. There are backup methods which allow limited communications for users to sites that have been isolated by a Iii f&lure. In this case two way communication is limited to subscriber radios within the geographic coverage area of the repeater station for the site. The communication then becomes local to the isolated site. The rest of the system operates in the conventional mode and has wide area coverage because its links are functional. The method described provides wide area communication capability when a remote site loses its link.

  Two antenna extenders along with control circuitry are placed in the overlap area of two sites. The antenna extenders will relay the information between the two sites. Refer to Figure 1. The extenders receive informa- tion from one site, then frequency translate and rebroad- cast the information to the other site. The control circuits prevent both extenders from keying up simultaneously. This prevents a feedback or echo condition from existing between sites. It also prevents subscriber radios in fringe areas from accessing the system because the transmit- ting extenders capture the receivers at the sites.

  The antenna extender controller monitors the radio communication system for SITE FS IND No. 1 and SITE FS IND No. 2 as shown in Figure 1. These are site failsot? indications 6om sites 1 and 2 respectively indicating a link

failure in both directions. If both of these signals become active, the controller allows the extenders to become operational. It then monitors VOICE DETECT No. 1 and VOICE DETECT No. 2 for...