# US 2014/0194135 A1 · System and method for calibration of a distributed amplifier system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0194135 A1 - Document ID: US20140194135A1 - Status: Published application - Kind: A1 - Application number: 14/149,824 - Filed: 2014-01-08 - Published: 2014-07-10 - Earliest claimed: 2013-01-08 - Assignees: Zone Access Technologies, Inc. - Applicants: Zone Access Technologies, Inc. - Inventors: Scott Terry - Web page: https://patentgrep.com/patent/US20140194135A1 ## CPC - H04W 52/245: {taking into account received signal strength} - H03G 3/20: Automatic control ({H03G3/005 takes precedence;} combined with volume compression or expansion H03G7/00) - H04B 1/16: Circuits - H04B 17/318: Received signal strength - H04W 16/26: Cell enhancers {or enhancement}, e.g. for tunnels, building shadow - H04W 24/02: Arrangements for optimising operational condition - H04W 24/08: Testing, {supervising or monitoring} using real traffic - H04W 24/10: Scheduling measurement reports {; Arrangements for measurement reports} - H04W 52/52: using AGC [Automatic Gain Control] circuits or amplifiers - H04W 88/085: {Access point devices with remote components} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H03G: CONTROL OF AMPLIFICATION - H04B: TRANSMISSION ## Abstract A system and method in a distributed amplifier system for correcting for RF losses between head end and coverage nodes by measuring RF losses in both directions; generating gains for amplifiers in both the head ends and coverage nodes; generating maximum output power limits; and adjusting the generated gains and output power limits based on downlink signal strength of cellular signals at a donor antenna. ## Claims ### Claim 1 A method, comprising: measuring RF losses at multiple frequencies in a first direction between a head end and a coverage node in a site by measuring output power from the head end and comparing that to input power on a plurality of coverage nodes as received from the coverage nodes for downlink loss; generating gains and output power limits for each amplifier in each coverage node and the head end based on the measured RF losses; and further adjusting the generated gains and output power limits based on downlink signal strength of cellular signals at a donor antenna. ### Claim 2 (depends on 1) The method of claim 1, further comprising: calculating RF loss from each amplifier to each antenna in the system based on antenna installation materials and antenna gain; and further adjusting the generated gains and output power limits for each coverage node based on the calculated RF losses. ### Claim 3 (depends on 1) The method of claim 1, further comprising: transmitting a test signal to determine over-the-air signal separation between the plurality of coverage nodes; and further adjusting the generated gains and output power based on the determination. ### Claim 4 (depends on 1) The method of claim 1, further comprising: monitoring the measured RF losses over time; and further adjusting the generated gains and output power based on the monitoring. ### Claim 5 (depends on 1) The method of claim 1, where the measuring includes measuring RF loss at both a donor antenna in the head end and coverage antennas in the coverage nodes. ### Claim 6 (depends on 1) The method of claim 1, further comprising: measuring RF losses at multiple frequencies in a second direction between a head end and a coverage node in a site by receiving measured output power from the nodes and comparing that to input power at a head end for uplink loss; generating gains and output power limits for each amplifier in each coverage node and the head end based on the measured RF losses; and further adjusting the generated gains and output power limits based on downlink signal strength of cellular signals at a donor antenna. ### Claim 7 A distributed amplifier system, comprising: a head end; and a plurality of coverage nodes distributed in a site and communicatively coupled to the head end; each coverage node including an amplifier and the head end including an amplifier,; wherein the head end amplifier is configured to measure RF losses at multiple frequencies in a first direction between the head end and the coverage nodes by measuring output power from the head end and comparing that to input power on a plurality of coverage nodes as received from the coverage nodes for downlink loss; generate gains and output power limits for each amplifier in each coverage node and the head end based on the measured RF losses; and further adjust the generated gains and output power limits based on downlink signal strength of cellular signals at a donor antenna. ### Claim 8 (depends on 7) The system of claim 7, wherein the head end amplifier is further configured to: calculate RF loss from each amplifier to each antenna in the system based on antenna installation materials and antenna gain; and further adjust the generated gains and output power limits for each coverage node based on the calculated RF losses. ### Claim 9 (depends on 7) The system of claim 7, further comprising a pilot Tx unit configured to: transmit a test signal to determine over-the-air signal separation between the plurality of coverage nodes; and wherein the amplifier is further configured to adjust the generated gains and output power based on the determination. ### Claim 10 (depends on 7) The system of claim 7, further comprising a characterization unit configured to monitor the measured RF losses over time and wherein the head end amplifier is further configured to adjust the generated gains and output power based on the monitoring. ### Claim 11 (depends on 7) The system of claim 7, where the measuring includes measuring RF loss at both a donor antenna in the head end and coverage antennas in the coverage nodes. ### Claim 12 A head end, comprising: a modem configured to communicatively couple to a plurality of nodes distributed in a site; and an amplifier; wherein each coverage node includes an amplifier; wherein the head end amplifier is configured to measure RF losses at multiple frequencies in a first direction between the head end and the coverage nodes by measuring output power from the head end and comparing that to input power on a plurality of coverage nodes as received from the coverage nodes via the modem for downlink loss; generate gains and output power limits for each amplifier in each coverage node and the head end based on the measured RF losses; and further adjust the generated gains and output power limits based on downlink signal strength of cellular signals at a donor antenna. ### Claim 13 (depends on 12) The head end of claim 12, wherein the head end amplifier is further configured to: calculate RF loss from each amplifier to each antenna in the system based on antenna installation materials and antenna gain; and further adjust the generated gains and output power limits for each coverage node based on the calculated RF losses. ### Claim 14 (depends on 12) The head end of claim 12, further comprising a pilot Tx unit configured to: transmit a test signal to determine over-the-air signal separation between the plurality of coverage nodes; and wherein the amplifier is further configured to adjust the generated gains and output power based on the determination. ### Claim 15 (depends on 12) The head end of claim 12, further comprising a characterization unit configured to monitor the measured RF losses over time and wherein the head end amplifier is further configured to adjust the generated gains and output power based on the monitoring. ### Claim 16 (depends on 12) The head end of claim 12, where the measuring includes measuring RF loss at both a donor antenna in the head end and coverage antennas in the coverage nodes.