The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 15, 1994
Filed:
Jul. 02, 1993
Edward A Combs, Lynchburg, VA (US);
Dennis M Maddox, Rustburg, VA (US);
Wim A Imron, Forest, VA (US);
Ericsson GE Mobile Communications Inc., Lynchburg, VA (US);
Abstract
A distributed switching network (switch) routes audio and control signals throughout the switch from various audio sources to one or more audio destinations. Audio sources such as mobile/portable radio units (via RF repeater transmitters), dispatch consoles, and landline telephone subscribers (via the central telephone switching network) are preassigned and routed onto an audio channel (i.e. a time slot) on a time division multiplexed (TDM) audio bus through a corresponding node. Each microprocessor controlled node is connected to plural control message buses provided for transferring control messages between nodes. A first supervisory node is physically connected at one end of the message buses and an end node is connected at the other end. If the end node fails to respond to a polling message from the supervisory node within a predetermined time period, the supervisory node assumes that the current messaging bus is faulty and initiates a bus switching operation to an alternate messaging bus. The supervisory and end nodes thereafter coordinate switching of all nodes in the switch to the alternate control messaging bus to insure reliable trunked RF communications over the multisite network.