# US 5,710,761 A · Error control negotiation based on modulation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,710,761 A - Document ID: US5710761A - Status: Granted - Kind: A - Application number: 08/458,048 - Filed: 1995-05-31 - Granted: 1998-01-20 - Earliest claimed: 1995-05-31 - Assignees: Paradyne Corporation - Inventors: Robert Earl Scott - Web page: https://patentgrep.com/patent/US5710761A ## CPC - H04L 5/1453: {of modulation type} - H04L 1/004: {by using forward error control (H04L1/0618 takes precedence; coding, decoding or code conversion, for error detection or correction H03M13/00)} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A modem dynamically selects the type of error-control negotiation sequence as a function of a negotiated parameter of the physical layer. In one embodiment of the invention, a modem selects between error-control negotiation sequences as a function of the type of modulation negotiated in the physical layer. In particular, the modem has at least two type of error-control negotiation sequences to select from: "LAPM or Disconnect," and "LAPM, MNP or Buffer." When the modem negotiates a V.32 or higher modulation, the modem uses the "LAPM or Disconnect" error control negotiation sequence. However, when the modem negotiates a V.22 bis or lower modulation, the modem uses the "LAPM, MNP or Buffer" error control sequence. ## Claims ### Claim 1 A method for use in data communications equipment, the method comprising the steps of: negotiating a physical layer of a data connection with a far-end data communications equipment to determine a set of parameters for the physical layer of the data connection with the far-end data communications equipment; and selecting one of a number of error control negotiation sequences as a function of a value of at least one parameter from the set of parameters for the physical layer. ### Claim 2 (depends on 1) The method of claim 1, further including the step of negotiating error control of the data connection with the far-end data communications equipment in accordance with the selected one of the number of error control negotiation sequences. ### Claim 3 (depends on 1) The method of claim 1, wherein the at least one parameter is the type of modulation negotiated with the far-end data communications equipment. ### Claim 4 (depends on 3) The method of claim 3, wherein the number of error control negotiation sequences include a Link Access Protocol Modem, Microcom Networking Protocol, or Buffer sequence and a Link Access Protocol Modem or Disconnect sequence. ### Claim 5 (depends on 4) The method of claim 4, wherein the Link Access Protocol Modem, Microcom Networking Protocol, or Buffer sequence is selected when the type of modulation negotiated is less than V.32, and wherein the Link Access Protocol Modem or Disconnect sequence is selected when the type of modulation negotiated is greater than or equal to V.32. ### Claim 6 (depends on 1) The method of claim 1, wherein the at least one parameter is the data rate negotiated with the far-end data communications equipment. ### Claim 7 (depends on 6) The method of claim 6, wherein the number of error control negotiation sequences include a Link Access Protocol Modem, Microcom Networking Protocol, or Buffer sequence and a Link Access Protocol Modem or Disconnect sequence. ### Claim 8 (depends on 7) The method of claim 7, wherein the Link Access Protocol Modem, Microcom Networking Protocol, or Buffer sequence is selected when the data rate is less than 4800 bits per second, and wherein the Link Access Protocol Modem or Disconnect sequence is selected the data rate is greater than or equal to 4800 bits per second. ### Claim 9 Data communications apparatus comprising: a memory that stores a number of error control negotiation sequences; and processor circuitry that negotiates a physical layer of a data connection with a far-end data communications equipment to determine a set of parameters for the physical layer of the data connection with the far-end data communications equipment, and then selects from memory one of a number of error control negotiation sequences as a function of a value of at least one parameter from the set of parameters for the physical layer. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the processor negotiates error control of the data connection with the far-end data communications equipment in accordance with the selected one of the number of error control negotiation sequences. ### Claim 11 (depends on 9) The apparatus of claim 9, wherein the at least one parameter is the type of modulation negotiated with the far-end data communications equipment. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein the number of error control negotiation sequences include a Link Access Protocol Modem, Microcom Networking Protocol, or Buffer sequence and a Link Access Protocol Modem or Disconnect sequence. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein the processor selects the Link Access Protocol Modem, Microcom Networking Protocol, or Buffer sequence when the type of modulation negotiated is less than V.32, and wherein the processor selects the Link Access Protocol Modem or Disconnect sequence when the type of modulation negotiated is greater than or equal to V.32. ### Claim 14 (depends on 9) The apparatus of claim 9, wherein the at least one parameter is data rate negotiated with the far-end data communications equipment. ### Claim 15 (depends on 9) The apparatus of claim 9, wherein the number of error control negotiation sequences include a Link Access Protocol Modem, Microcom Networking Protocol, or Buffer sequence and a Link Access Protocol Modem or Disconnect sequence. ### Claim 16 (depends on 15) The apparatus of claim 15, wherein the processor selects the Link Access Protocol Modem, Microcom Networking Protocol, or Buffer sequence when the data rate is less than 4800 bits per second, and wherein the processor selects the Link Access Protocol Modem or Disconnect sequence when the data rate is greater than or equal to 4800 bits per second.