Dynamic wireless link adaptation

• US 7,388,919 B2
• Filed: 09/20/2005
• Issued: 06/17/2008
• Est. Priority Date: 09/20/2000
• Status: Expired

• Current Assignee: Monument Bank of Intellectual Property, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Aperto Networks
• Inventors: Wong, Wendy Chiu Fai, Varma, Subir, Hakim, Joseph, Majidi-Ahy, Reza
• Primary Examiner(s): TSE, YOUNG TOI
• Application Number:
  US11/231,537
• Publication Number:
  US 20060098582A1
• Time in Patent Office: 1,001 Days
• Field of Search: 375/224, 375/225, 375/227, 375/259, 455/67.11, 455/67.13, 340/3.1, 714/708, 714/712, 714/721, 714/748, 714/749
• US Class Current: 375/259
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/002 Algorithms with memory of the previous states, e.g. Markovian models
• CPC Class Codes: H04L 1/0034 where the transmitter decides based on inferences, e.g. use of implicit signalling
• CPC Class Codes: H04L 1/16 in which the return channel carries supervisory signals, e.g. repetition request signals
• CPC Class Codes: H04L 1/1867 Arrangements specially adapted for the transmitter end
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A system that adapts wireless link parameters for a wireless communication link. A measure is determined of errors occurring in communication over a wireless link. In a case that the measure of errors corresponds to more errors than a first predetermined threshold, communication changes from a first set of wireless link parameters to a second set of wireless link parameters. The second set of wireless link parameters corresponds to higher error tolerance than the first set of wireless link parameters. In a case that the measure of errors corresponds to fewer errors than a second predetermined threshold, communication changes from the first set of wireless link parameters to a third set of wireless link parameters. The third set of wireless link parameters corresponds to lower error tolerance than the first set of wireless link parameters. Preferably, the measure of errors is determined by monitoring a number of NACK messages and a number of ACK messages that occur. It is determined that the measure of errors corresponds to more errors than the first predetermined threshold when more than a predetermined number of NACK messages occur in succession. It is determined that the measure of errors corresponds to fewer errors than the second predetermined threshold when more than a predetermined number of ACK messages occur in succession.

Claims

1. A method of dynamically adapting wireless link parameters, comprising:

determining a plurality of states, each state corresponding to a plurality of wireless link parameters;

determining a plurality of thresholds for transitioning from a current state to a next state of said plurality of states, said thresholds comprising a number of NACK messages or a number of ACK messages received using said wireless link parameters for said current state; and

transitioning among said plurality of states based on said thresholds, thereby dynamically adapting said wireless link parameters for a wireless link.

2. A method as in claim 1, wherein said wireless link parameters comprise a modulation scheme, a symbol rate, and an error correction scheme.

3. A method as in claim 1, wherein each of said plurality of states can only transition to and from one or two adjacent states.

4. A method as in claim 1, wherein said plurality of states are stored in a memory.

5. An apparatus that dynamically adapts wireless link parameters, comprising:

a wireless link interface to a wireless link;

a processor; and

a memory storing instructions executable by the processor to control communication over the wireless link interface, the instructions including the steps of;

determining a plurality of states, each state corresponding to a plurality of wireless link parameters;

determining a plurality of thresholds for transitioning from a current state to a next state of said plurality of states, said thresholds comprising a number of NACK messages or a number of ACK messages received using said wireless link parameters for said current state; and

transitioning among said plurality of states based on said thresholds, thereby dynamically adapting said wireless link parameters for the wireless link.