# US 2003/0198312 A1 · Link adaptation in general packet radio service networks > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2003/0198312 A1 - Document ID: US20030198312A1 - Status: Published application - Kind: A1 - Application number: 10/124,298 - Filed: 2002-04-18 - Published: 2003-10-23 - Earliest claimed: 2002-04-18 - Assignees: Alcatel-Lucent USA Inc. - Inventors: Kenneth C. Budka; Arnab Das; Wei Luo - Web page: https://patentgrep.com/patent/US20030198312A1 ## CPC - H04L 1/0015: {characterised by the adaptation strategy} - H04L 1/0009: {by adapting the channel coding (H04L1/1812 takes precedence)} - H04L 1/0021: {in which the algorithm uses adaptive thresholds} - H04L 1/0026: {Transmission of channel quality indication} - H04L 1/20: using signal quality detector - H04L 1/16: in which the return channel carries supervisory signals, e.g. repetition request signals - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract In one embodiment of the method of adaptively selecting an airlink coding scheme in a telecommunications network, a coding scheme operating region is determined based on a currently used coding scheme and measurements representative of a block error rate. A block error coding scheme is determined based on the determined coding scheme operating region. In another embodiment of the method of adaptively selecting an airlink coding scheme in a telecommunications network, a first coding scheme is determined based on measurements representative of one or more conditional channel quality metrics, and a second coding scheme is determined based on measurements representative of a block error rate. One of the first and second coding schemes is selected as the coding scheme. ## Claims ### Claim 1 A method of adaptively selecting an airlink coding scheme in a telecommunications network, comprising: determining a coding scheme operating region based on a currently used coding scheme and measurements representative of a block error rate; and selecting a coding scheme based on the determined coding scheme operating region. ### Claim 2 (depends on 1) The method of claim 1, wherein each of the coding scheme operation regions are predefined operating regions. ### Claim 3 (depends on 1) The method of claim 1, wherein each coding scheme corresponds to a different coding scheme operating region; and the selecting step selects the coding scheme corresponding to the determined coding scheme operating region. ### Claim 4 (depends on 1) The method of claim 1, wherein the determining step comprises: estimating a block error rate for a predetermined one of the coding schemes in each coding scheme operating region based on the measurements; comparing the estimated block error rate to expected block error rates for the predetermined coding scheme in each coding scheme operating region; and determining the coding scheme operating region based on results of the comparing step. ### Claim 5 (depends on 1) The method of claim 1, wherein the determining step comprises: receiving the measurements from a mobile station; generating a region indicator for each coding scheme operating region based on the measurements; and determining a coding scheme operating region based on the generated region indicators. ### Claim 6 (depends on 5) The method of claim 5, wherein the measurements include a report of correctly and incorrectly received blocks of data. ### Claim 7 (depends on 5) The method of claim 5, wherein the determining step further comprises: calculating a number of block errors for a number of blocks sent using the current coding scheme based on the measurements; and wherein the generating step generates the region indicators based on results of the calculating step. ### Claim 8 (depends on 1) The method of claim 1, wherein the determining step comprises: making the measurements on a signal received from a mobile station; generating a region indicator for each coding scheme operating region based on the measurements; and determining a coding scheme operating region based on the generated region indicators. ### Claim 9 (depends on 8) The method of claim 8, wherein the measurements include a report of correctly and incorrectly received blocks of data and a measure of a number of bit errors observed in correctly received blocks. ### Claim 10 (depends on 1) The method of claim 1, wherein the determining step determines the coding scheme operating region based on the measurements, which are indicative of a probability that a number of block errors occurred for a number of blocks sent using the current coding scheme. ### Claim 11 (depends on 1) The method of claim 1, further comprising: selecting a set of coding scheme operating regions from multiple sets of coding scheme operating regions based on one of quality of service and type of service. ### Claim 12 (depends on 1) The method of claim 1, further comprising: determining a bit error coding scheme based on a bit error rate determined from the measurements; and selecting one of the bit error coding scheme and the block error coding scheme as the coding scheme. ### Claim 13 (depends on 12) The method of claim 12, wherein the selecting step selects one of the bit error coding scheme and the block error coding scheme having a lowest block error rate as the coding scheme. ### Claim 14 (depends on 12) The method of claim 12, wherein the determining a bit error coding scheme step reads the bit error coding scheme from a look-up table based on the measurements. ### Claim 15 (depends on 12) The method of claim 12, wherein the determining step comprises: estimating a block error rate for a predetermined one of the coding schemes in each coding scheme operating region based on the measurements; comparing the estimated block error rate to expected block error rates for the predetermined coding scheme in each coding scheme operating region; and determining the coding scheme operating region based on results of the comparing step. ### Claim 16 (depends on 12) The method of claim 12, wherein the determining step comprises: generating a region indicator for each coding scheme operating region based on the measurements; and determining a coding scheme operating region based on the generated region indicators. ### Claim 17 (depends on 1) The method of claim 1, further comprising: changing the selected coding scheme to a first stronger coding scheme when predetermined criteria regarding performance at a second stronger coding scheme have not been met, the first and second stronger coding schemes being one of same and different coding schemes. ### Claim 18 (depends on 1) The method of claim 1, further comprising: changing the selected coding scheme to a strongest coding scheme if an amount of data to be transmitted using the selected coding scheme is less than a threshold amount. ### Claim 19 (depends on 1) The method of claim 1, further comprising: changing the selected coding scheme to a coding scheme supported by a transmission time slot when the time slot to be used in transmitting data according to the selected coding scheme does not support the selected coding scheme. ### Claim 20 (depends on 1) The method of claim 1, further comprising: performing the method when performance using the current coding scheme falls below a predetermined performance threshold. ### Claim 21 (depends on 1) The method of claim 1, further comprising: caching, at an end of a first downlink communication flow with a mobile station, the selected coding scheme; retrieving the cached coding scheme when a second downlink communication flow is being established with the mobile station; and changing the retrieved coding scheme to a stronger coding scheme based on an amount of time between the end of the first downlink communication flow and the beginning of the second downlink communication flow. ### Claim 22 (depends on 1) The method of claim 1, further comprising: caching, at an end of a first uplink communication flow with a mobile station, the selected coding scheme; retrieving the cached coding scheme when a second uplink communication flow is being established with the mobile station; and changing the retrieved coding scheme to a stronger coding scheme based on an amount of time between the end of the first uplink communication flow and the beginning of the second uplink communication flow. ### Claim 23 (depends on 1) The method of claim 1, further comprising: changing the selected coding scheme based on power control being performed by a power control algorithm. ### Claim 24 A method of adaptively selecting an airlink coding scheme in a telecommunications network, comprising: estimating a block error rate for a predetermined one of the coding schemes in each coding scheme operating region based on measurements representative of block error rate; comparing the estimated block error rate to expected block error rates for the predetermined coding scheme in each coding scheme operating region; and determining a coding scheme based on results of the comparing step. ### Claim 25 (depends on 24) The method of claim 24, wherein the determining step determines the coding scheme associated with the coding scheme operating region having the estimated block error rate less than the expected block error rate as the determined coding scheme. ### Claim 26 (depends on 25) The method of claim 25, wherein the determining step determines the coding scheme associated with the coding scheme operating region having a smallest difference between estimated and expected block errors and having the estimated block error rate less than the expected block error rate as the determined coding scheme. ### Claim 27 A method of adaptively selecting an airlink coding scheme in a telecommunications network, comprising: generating a region indicator for each coding scheme operating region based on measurements representative of block error rate; and determining a coding scheme operating region based on the generated region indicators. ### Claim 28 (depends on 27) The method of claim 27, wherein the measurements include the measurements include a report of correctly and incorrectly received blocks of data. ### Claim 29 (depends on 27) The method of claim 27, further comprising: calculating a number of block errors for a number of blocks sent using the current coding scheme based on the measurements; and wherein the generating step generates the region indicators based on results of the calculating step. ### Claim 30 (depends on 27) The method of claim 27, wherein the region indicators are indicative of a probability that a number of block errors occurred for a number of blocks sent using the current coding scheme. ### Claim 31 A method of adaptively selecting an airlink coding scheme in a telecommunications network, comprising: determining a first coding scheme based on measurements representative of one or more conditional channel quality metrics; determining a second coding scheme based on measurements representative of a block error rate; and selecting one of the first and second coding schemes as the coding scheme. ### Claim 32 (depends on 31) The method of claim 31, wherein the selecting step selects a stronger one of the first and second coding schemes as the coding scheme. ### Claim 33 (depends on 31) The method of claim 31, wherein the conditional channel quality metric is bit error rate. ### Claim 34 (depends on 31) The method of claim 31, wherein the selecting step selects one of the first and second coding schemes based on a block error rate. ### Claim 35 An apparatus for adaptively selecting an airlink coding scheme in a telecommunications network, comprising: an advisor unit determining a coding scheme based on measurements representative of block error rate; and an override unit selectively changing the determined coding scheme based on at least one of an amount of data to be transmitted, a bandwidth of an interface in the telecommunications network, a time period since the measurements were one of made or received, a power control operation, and a desired quality of service.