# US 2014/0192851 A1 · Adjusting physical layer transmission properties > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0192851 A1 - Document ID: US20140192851A1 - Status: Published application - Kind: A1 - Application number: 13/738,594 - Filed: 2013-01-10 - Published: 2014-07-10 - Earliest claimed: 2013-01-10 - Assignees: QUALCOMM Incorporated - Applicants: Qualcomm Incorporated - Inventors: Ehab Tahir; Nikolai Kroupetski; John Fraser Chappel; Brian James Langlais; Joubin Karimi; Richard D. Roze; Son Binh Cam - Web page: https://patentgrep.com/patent/US20140192851A1 ## CPC - H04L 1/0001: {Systems modifying transmission characteristics according to link quality, e.g. power backoff (adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04)} - H04L 25/02: Details {; arrangements for supplying electrical power along data transmission lines (systems for transmitting signals via power distribution lines H04B3/54)} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A transmitting device may determine a physical layer transmission properties based upon an amount of data to transmit via a communications channel. The physical layer transmission properties may comprise a derated tone map that has a lower physical layer transmission throughput capability than an original tone map. An indication regarding the derated tone map may be included in a first message, a portion of a physical layer framing protocol, a physical layer control transmission (such as a frame control symbol), or other transmissions such that the receiving device can derive the derated tone map without significant added overhead. ## Claims ### Claim 1 A method comprising: receiving, at a first device, at least a first tone map for use over a communications channel between the first device and a second device, the first tone map including transmission properties for each of a set of frequencies; determining, at the first device, a derated tone map different from first tone map, the derated tone map determined based, at least in part, upon an amount of data to transmit over the communications channel; and transmitting the data using the derated tone map. ### Claim 2 (depends on 1) The method of claim 1, wherein the first tone map is received from the second device based upon a channel estimation process. ### Claim 3 (depends on 1) The method of claim 1, wherein said determining the derated tone map is further based upon the first tone map and a protocol minimum transmission unit. ### Claim 4 (depends on 1) The method of claim 1, further comprising, prior to determining the derated tone map: determining, at the first device, the amount of data associated with a scheduled transmission; determining that the amount of data is less than a minimum transmission unit associated with the first tone map; and and in response to determining the amount of data is less than the minimum transmission unit, determining to generate a derated tone map different from the first tone map. ### Claim 5 (depends on 1) The method of claim 1, wherein said determining comprises: calculating a first physical layer transmission rate based upon the first tone map and a protocol minimum transmission unit; calculating a second physical layer transmission rate associated with the amount of data and the protocol minimum transmission unit; and comparing the first calculated physical layer transmission rate with the second calculated physical layer transmission rate to determine a derating factor. ### Claim 6 (depends on 1) The method of claim 1, wherein the derated tone map utilizes a smaller modulation scheme for at least one frequency included in the first tone map. ### Claim 7 (depends on 1) The method of claim 1, further comprising: communicating, to the second device, a signal indicative of a derating factor or derating algorithm used to generate the derated tone map from the first tone map. ### Claim 8 (depends on 7) The method of claim 7, wherein the signal is communicated in a frame control portion of a physical layer transmission unit. ### Claim 9 (depends on 1) The method of claim 1, wherein, in the first tone map, said transmission properties for each of the set of frequencies include one or more of a modulation scheme, forward error correction scheme, coding rate, or guard interval; and wherein the derated tone map adjusts one or more of the modulation scheme, the forward error correction scheme, the coding rate, or the guard interval for at least one frequency in the set of frequencies. ### Claim 10 (depends on 9) The method of claim 9, wherein the derated tone map adjusts one or more of the modulation scheme, the forward error correction scheme, the coding rate, or the guard interval for all frequencies in the set of frequencies as a derating factor applied to the transmission properties in the first tone map. ### Claim 11 A first device comprising: a physical layer controller configured to receive at least a first tone map including transmission properties for each of a set of frequencies used on a communications channel between the first device and a second device; determine a derated tone map different from first tone map, the derated tone map determined based at least in part upon an amount of data to transmit from the first device to the second device over the communications channel; and a network interface configured to transmit said data using the derated tone map. ### Claim 12 (depends on 11) The first device of claim 11, wherein the first tone map is received from the second device based upon a channel estimation process. ### Claim 13 (depends on 11) The first device of claim 11, wherein said physical layer controller is configured to determine the derated tone map based upon the first tone map and a protocol minimum transmission unit. ### Claim 14 (depends on 11) The first device of claim 11, wherein said physical layer controller is further configured to: determine, at the first device, the amount of data associated with a scheduled transmission; determine that the amount of data is less than a minimum transmission unit associated with the first tone map; and and in response to determining the amount of data is less than the minimum transmission unit, determine to generate a derated tone map different from the first tone map ### Claim 15 (depends on 11) The first device of claim 11, wherein said physical layer controller is further configured to: calculate a first physical layer transmission rate based upon the first tone map and a protocol minimum transmission unit; calculate a second physical layer transmission rate associated with the amount of data and the protocol minimum transmission unit; and compare the first calculated physical layer transmission rate with the second calculated physical layer transmission rate to determine a derating factor. ### Claim 16 (depends on 11) The first device of claim 11, wherein the derated tone map utilizes a smaller modulation scheme for at least one frequency included in the first tone map. ### Claim 17 (depends on 11) The first device of claim 11, wherein said physical layer controller is further configured to: communicate a signal indicative of a derating factor or derating algorithm used to generate the derated tone map from the first tone map. ### Claim 18 (depends on 17) The first device of claim 17, wherein the signal is communicated in a frame control portion of a physical layer transmission unit. ### Claim 19 (depends on 11) The first device of claim 11, wherein, in the first tone map, said transmission properties for each of the set of frequencies include one or more of a modulation scheme, forward error correction scheme, coding rate, or guard interval; and wherein the derated tone map adjusts one or more of the modulation scheme, the forward error correction scheme, the coding rate, or the guard interval for at least one frequency in the set of frequencies. ### Claim 20 (depends on 19) The first device of claim 19, wherein the derated tone map adjusts one or more of the modulation scheme, the forward error correction scheme, the coding rate, or the guard interval for all frequencies in the set of frequencies as a derating factor applied to the transmission properties in the first tone map. ### Claim 21 A method comprising: determining, at a first device, at least a first tone map for use over a communications channel between the first device and a second device, the first tone map including transmission properties for each of a set of frequencies; receiving, at the first device, an indication regarding a derated tone map different from first tone map; and receiving data from the second device using the derated tone map. ### Claim 22 (depends on 21) The method of claim 21, wherein the indication is included in a frame control symbol of a physical layer transmission unit. ### Claim 23 (depends on 21) The method of claim 21, wherein the indication is a derating factor, and the method further comprises: determining, at the first device, the derated tone map based upon the derating factor and the first tone map. ### Claim 24 A non-transitory computer readable medium storing computer program code, the computer program code comprising instructions which when executed by a processor of a hybrid device cause the hybrid device to: receive, at a first device, at least a first tone map for use over a communications channel between the first device and a second device, the first tone map including transmission properties for each of a set of frequencies; determine, at the first device, a derated tone map different from first tone map, the derated tone map determined based, at least in part, upon an amount of data to transmit over the communications channel; and transmit the data using the derated tone map. ### Claim 25 (depends on 24) The non-transitory computer readable medium of claim 24, wherein the first tone map is received from the second device based upon a channel estimation process. ### Claim 26 (depends on 24) The non-transitory computer readable medium of claim 24, wherein the derated tone map is further based upon the first tone map and a protocol minimum transmission unit. ### Claim 27 (depends on 24) The non-transitory computer readable medium of claim 24, wherein the computer program code further comprises instructions which when executed by the processor of the hybrid device cause the hybrid device to, prior to determining the derated tone map: determine, at the first device, the amount of data associated with a scheduled transmission; determine that the amount of data is less than a minimum transmission unit associated with the first tone map; and and in response to determining the amount of data is less than the minimum transmission unit, determine to generate the derated tone map different from the first tone map. ### Claim 28 (depends on 24) The non-transitory computer readable medium of claim 24, wherein the computer program code further comprises instructions which when executed by the processor of the hybrid device cause the hybrid device to: calculate a first physical layer transmission rate based upon the first tone map and a protocol minimum transmission unit; calculate a second physical layer transmission rate associated with the amount of data and the protocol minimum transmission unit; and compare the first calculated physical layer transmission rate with the second calculated physical layer transmission rate to determine a derating factor. ### Claim 29 A communication system comprising: a receiving device coupled to a communications channel between the receiving device and a transmitting device, the receiving device configured to determine a first set of physical layer transmission properties for use over the communications channel based upon a channel estimation process, and send the first set of physical layer transmission properties to the transmitting device; and the transmitting device coupled to the communications channel, the transmitting device configured to receive at least the first set of physical layer transmission properties, determine a second set of physical layer transmission properties different from first set of physical layer transmission properties, the second set of physical layer transmission properties determined based at least in part upon an amount of data to transmit from the transmitting device to the receiving device over the communications channel, and transmit said data using the second set of physical layer transmission properties. ### Claim 30 (depends on 29) The communication system of claim 29, wherein the transmitting device is further configured to communicate, to the receiving device, a signal indicative of a derating factor or derating algorithm used to generate the second set of physical layer transmission properties from the first set of physical layer transmission properties; and wherein the receiving device is further configured to receive the signal indicative of the derating factor or derating algorithm, and derive the second set of physical layer transmission properties based upon the first set of physical layer transmission properties and the derating factor or derating algorithm. ### Claim 31 (depends on 29) The communication system of claim 29, wherein the communications channel includes a powerline communications channel and the first set of physical layer transmission properties comprises a first tone map including transmission properties for each of a set of frequencies.