Interference Detection and Signature Matching Month Year doc.: IEEE 802.11-yy/xxxxr0 10 Nov 05 Interference Detection and Signature Matching Authors: Date: 2005-11-10 Notice: This document has been prepared to assist IEEE 802.11. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.11. Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures <http:// ieee802.org/guides/bylaws/sb-bylaws.pdf>, including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair <stuart.kerry@philips.com> as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.11 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at <patcom@ieee.org>. Roger Durand, AutoCell Labs John Doe, Some Company

Month Year doc.: IEEE 802.11-yy/xxxxr0 10 Nov 05 Abstract The interference detection techniques require a mechanism for quieting the channel and a mechanism for sampling energy in the channel relative to sample period and measurement duration. The interference results can be forwarded for signature mapping. The signature mapping techniques require a mechanism for matching the signature results to known sources of interference for identification – or catalogue. Once a source of interference is characterized and/or matched, appropriate responses or countermeasures may be taken to improve likelihood of successful transmissions. Roger Durand, AutoCell Labs John Doe, Some Company

Interference Detection 10 Nov 05 Interference Detection Signal Processor G BPF G LPF G A/D Valid assumptions, WLAN Radios all are able to… 1.) Sample energy in a short time interval = to determine the noise floor in an IFS (Availability of the channel) 2.) Convert the A/D voltages for time samples to an RF dBm value at the antenna connector (802.11k) 3.) Blocking higher firmware is usually the only concern… you want to do what? 4.) All known modern 802.11WLAN radios CAN employ this method without dedicated or additional hardware Valid Interference Detection Measurement set up… 1.) Quiet the Channel 2.) Sample energy in a repeating 10 microsecond window (or shorter) and repeat 2000 times for 20 milliseconds 3.) Other combinations are valid dependant on resolution results and or types of interference expected. 4.) Read the results, interpret and match the results to signature from catalog or add to catalog… Roger Durand, AutoCell Labs

Interference Detection & Signature Analysis 10 Nov 05 Interference Detection & Signature Analysis CW Interferer degrades noise floor 8 to 12 dB Example AP A/D Output of Interference Detection CW Interferer dBm 10 dB Elevated Noise Floor Time Roger Durand, AutoCell Labs

Interference Detection & Signature Analysis 10 Nov 05 Interference Detection & Signature Analysis Microwave Interferer degrades noise floor 3 to ~50 dB Example AP A/D Output of Interference Detection 16 msec/60Hz Microwave Interferer 6 msec dBm Time Roger Durand, AutoCell Labs

Interference Detection & Signature Analysis 10 Nov 05 Interference Detection & Signature Analysis FHSS Interferer degrades noise floor 4 to~35 dB Example AP A/D Output of Interference Detection FHSS Interferer 780 µsec 840 µsec 680 µsec 780 µsec dBm Time Roger Durand, AutoCell Labs

Why is this Important An important tool for the kit: 10 Nov 05 Why is this Important An important tool for the kit: A means to access the channel quality on channel selection Knowledge of the degradations that are happening in the channel Explain increasing errors and the dropping data rates Countermeasures are dependent on type of interference Increase Transmitter Power Increase Radio Sensitivity Threshold Fragment packets Enables synchronization methods Change operating channel (variant of channel switch command) Roger Durand, AutoCell Labs

10 Nov 05 Motion Motion:“The substantive text IEEE 802/11_05_ 1067r1 Interference Detection addresses objectives: degradations caused by contention or other issues, channel selection and dynamic channel selection, site survey mode, access point coordination, and neighbor learning process is worthy of inclusion in the base draft” Merge= No= Abstain= Roger Durand, AutoCell Labs