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Method of Providing Range Extension Through Data Proxy

IP.com Disclosure Number: IPCOM000034018D
Original Publication Date: 2005-Jan-12
Included in the Prior Art Database: 2005-Jan-12
Document File: 5 page(s) / 505K

Publishing Venue

Motorola

Related People

David Wiatrowski: AUTHOR

Abstract

In typical land-mobile wireless communications systems, conventional (non-trunked) subscriber units (SU) typically transmit signals on an uplink frequency that is monitored by a repeater and receive signals on a downlink frequency that is sourced by a repeater. Referring to the communications system 100 shown in Figure 1, vehicles 104, 106, 110, 112, 114 each contain a subscriber unit (SU) and are located within the nominal RF coverage contour of the system. While within the RF coverage contour of the communication system 100, these subscriber units may intercommunicate by way of a repeater 101 using wireless communication links 151, 153, 155, 157, 159. When a subscriber unit roams out of system coverage (e.g., away from the repeater, or into a building), the subscriber unit user typically manually switches to "talkaround" or "direct" mode, whereby the subscriber unit continues to receive signals on the repeater's downlink frequency, but transmits signals on the downlink frequency instead of the uplink frequency. This allows out-of-range subscriber unit users to communicate with nearby users that may or may not be within system coverage. Again referring to the communications system 100 shown in Figure 1, vehicles 108, 116, 118 are geographically located beyond the nominal RF coverage contour of the communication system 100. Additionally, vehicle 102, while located within the outer boundaries of the nominal RF coverage contour, is positioned in an RF "hole" (e.g., an RF "shadow" cast by a large building or a mountain) and is not able to be served directly by repeater 101. When not able to be served by repeater 101, subscriber units 102, 108, 116, 118 may use wireless communication links 161, 163, 165, 167, 169, 171, 173, 175 to communicate with their respective neighboring subscriber units.

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In typical land-mobile wireless communications systems, conventional (non-trunked) subscriber units (SU) typically transmit signals on an uplink frequency that is monitored by a repeater and receive signals on a downlink frequency that is sourced by a repeater.  Referring to the communications system 100 shown in Figure 1, vehicles 104, 106, 110, 112, 114 each contain a subscriber unit (SU) and are located within the nominal RF coverage contour of the system.  While within the RF coverage contour of the communication system 100, these subscriber units may intercommunicate by way of a repeater 101 using wireless communication links 151, 153, 155, 157, 159.  When a subscriber unit roams out of system coverage (e.g., away from the repeater, or into a building), the subscriber unit user typically manually switches to “talkaround” or “direct” mode, whereby the subscriber unit continues to receive signals on the repeater’s downlink frequency, but transmits signals on the downlink frequency instead of the uplink frequency.  This allows out-of-range subscriber unit users to communicate with nearby users that may or may not be within system coverage.  Again referring to the communications system 100 shown in Figure 1, vehicles 108, 116, 118 are geographically located beyond the nominal RF coverage contour of the communication system 100.  Additionally, vehicle 102, while located within the outer boundaries of the nominal RF coverage contour, is positioned in an RF “hole” (e.g., an RF “shadow” cast by a large building or a mountain) and is not able to be served directly by repeater 101.  When not able to be served by repeater 101, subscriber units 102, 108, 116, 118 may use wireless communication links 161, 163, 165, 167, 169, 171, 173, 175 to communicate with their respective neighboring subscriber units.

Subscriber units may transmit and receive conventional control messages, such as Emergency Alarm, Call Alert, Selective Radio Inhibit (and Uninhibit), Message, Status, Status Poll, and Remote Monitor.  In APCO Project 25 systems, these messages are normally transmitted between subscriber units and wireline console operator position 130, attached to a repeater 101.  Some messages, e.g., Call Alert, may also be exchanged between two subscriber units (with or without the assistance of a repeater).  Additionally, short data messages, such as subscriber unit location updates, are transmitted from the subscriber unit to a dispatch operator 130 or server 132 within the Fixed Network Equipment (FNE).  In communication system 100, the wireline operator position 130, server 132, wireline communication links 150, 152 and the repeater 101 comprise the FNE.  The dispatch operator station is typically connected to the repeater 101 by way of wireline communication link 150 while the server is typically connected to the repeater 101 by way of wireline communication link 152.

As subscriber units roam towards the fringe of system coverage...