Annex D Or Other As Deemed Appropriate by the TGT Editor

March 2007 doc.: IEEE 802.11-07/0255r11

IEEE P802.11 Wireless LANs

Proposal for resolution of comments P802.11.2 – CID 21, 22, 27

Date: 2007-03-13

Author(s): Name Company Address Phone email 27200 Haggerty Rd dward@siriusradio. Dennis Ward Sirius Satellite Radio Suite B-3 +1-248-699-0442 com Farmington Hills, MI 48331 Mark 190 Mathilda Place Broadcom +1-408-543-3318 [email protected] Kobayashi Sunnyvale, CA 94086 m 190 Mathilda Place Dalton Victor Broadcom +1-408-922-5824 dvictor@broadcom. Sunnyvale, CA 94086 com

Abstract This document proposes text to resolve Comment ID’s (CID) 21, 22, and 27 from the TGT Internal Comment resolution process.

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 , 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 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 Submissionquestions, contact the IEEE Patent Committee Administratorpage at1 . Ward, Sirius Satellite Radio March 2007 doc.: IEEE 802.11-07/0255r11

Add the following text as an informative Annex in the P802.11.2 draft to resolve CIDs 21 and 22:

Annex D or other as deemed appropriate by the TGT Editor

Recommendation to insure adequate shielding effectiveness within the COAT, Conducted, and OTA Shielded Enclosure environments.

D.1 Introduction

This Annex describes methods to insure adequate RF enclosure shielding effectiveness for the environments and measurements that dictate the need for shielded enclosures. Vendor certification of shielding effectiveness is also acceptable.

D.2 Shielded environments with linear dimensions equal to or greater than 2.0 Meters

D.2.1 - IEEE Std. 299-1997, Standard Method for Measuring Shielded Effectiveness of Electromagnetic Shielded Enclosures provides uniform procedures and techniques for measuring the shielding effectiveness of electromagnetic enclosures. Clause 1.3 defines the minimum 2.0 Meter linear dimension, and suggests future inclusion for those enclosures whose linear dimensions are less than 2.0 Meters. It is recommended that these procedures and techniques be used to verify isolation requirements for the environments and measurements that use enclosures having a linear dimension equal to or greater than 2.0 Meters.

D.3 Shielded environments with linear dimensions less than 2.0 Meters, preferred method

D.3.1 –Recommended Equipment (preferred method):

 Shielded enclosure to be tested, with at least one RF bulkhead connector. Any additional bulkhead connectors must be terminated on the exterior to a 50 ohm load.  Signal Generator capable of producting a Continous Wave output in the band of interest  Amplifier capable of providing at least 30dBm from the signal generator source. The tester should insure that the signal generator output remains 3dB or more below the 1dB compression point to provide the desired output  Power Meter  Horn antenna – preferred or other directional antenna whose gain and directivity are known to a high degree. Vendor data sheets should be independently verified.  Receive antenna, or DUT with attached antenna modified to remove antenna input from DUT radio. The gain and directivity should be known to a high degree. Vendor data sheets should be independently verified.  Spectrum Analyzer with sufficient dynamic range and sensitivity to measure expected CW signals at the DUT antenna  Network Analyzer

Submission page 2 Dennis Ward, Sirius Satellite Radio March 2007 doc.: IEEE 802.11-07/0255r11

D.3.2 – Test Set up

The figure below depicts the recommended test set up

Enclosure

Signal Amplifier Generator

Power Meter 10 l

Spectrum Analyzer

D.3.3 – Recommended Verification Procedure (preferred method)

 Prepare the test set up as shown in D.3.2. The shaded area depicts an RF safety zone. No person or part thereof should enter this area anytime the amplifier is active and transmitting.  Measure and record cable losses with the Network Analyzer: Amplifier to Antenna, Receive Antenna to Spectrum Analyzer including bulkhead if possible, and cables / attenuators used from amplifier to power meter  Set the Signal Generator to a mid-band frequency for 2.4 GHz, or sequence through a set of frequencies spaced no more than 250 MHz apart across the 5 GHz band and run a measurement for each of these frequencies until the band is spanned, and disable the output.  Connect the power meter, and add any characterized attenuation required to measure the power within the dynamic range of the power meter.  Enable the signal generator output insuring the signal generator is driving the amplifier at least 3dB below the 1dB compression point.  Record the output power in dBm for each measurement and disable the signal generator output.  Place the receive antenna/ DUT in the center of the enclosure, and connect the Spectrum Anlayzer to the receive antenna / DUT Antenna. Configure the spectrum analyzer for a narrow RBW and VBW at the desired frequency.  Insure the transmit and receive antennas are co-polarized  Enable the signal generator and configure as noted in the 3rd bullet above.  Measure and record the corresponding received signal in dBm with the spectrum analyzer for each frequency being measured  Calculate the Antenna EiRP output: o EiRP (dBm) = Amplifier Output (dBm) – Cable Loss (dB) + Antenna Gain (dBi)  Calculate the Shielding Effectiveness: o SE (dB) = EiRP (dBm) – 20log(4/) - DUT Antenna Gain (dBi) + Spectrum Analyzer Cable Loss (dB) – min(Spectrum Analyzer Signal level (dBm)) o Where: . min() calculates the minimum measured power

D.4 Shielded environments with linear dimensions less than 2.0 Meters, alternate method

D.4.1 –Recommended Equipment (alternate method):

 Shielded enclosure to be tested, with at least one RF bulkhead connector. Any additional bulkhead connectors must be terminated.  WLCP.  Amplifier capable of providing at least 30dBm from the WLCP source. The tester should insure that the WLCP output remains 3dB or more below the 1dB compression point of the amplifier.  Power Meter  Horn antenna – preferred or other directional antenna whose gain and directivity are known to a high degree. Vendor data sheets should be independently verified.  Receive antenna, or DUT with attached antenna modified to remove antenna input from DUT radio. The gain and directivity should be known to a high degree. Vendor data sheets should be independently verified.  Spectrum Analyzer with sufficient dynamic range and sensitivity to measure expected CW signals at the DUT antenna  Network Analyzer

Enclosure

WLCP Amplifier

Power Meter 10 l

Spectrum Analyzer

D.4.3 – Recommended Verification Procedure (alternate method)

 Prepare the test set up as shown in D.4.2. The shaded area depicts an RF safety zone. No person or part thereof should enter this area anytime the amplifier is active and transmitting.  Measure and record cable losses with the Network Analyzer: Amplifier to Antenna, Receive Antenna to Spectrum Analyzer including bulkhead if possible, and cables / attenuators used from amplifier to power meter  Set the WLCP to a mid-band channel for 2.4 GHz, ot to a channel or channels with a maximum channel separation of 250 MHz for the 5 GHz band of interest, and disable the output  Connect the power meter to the amplifier output, and add any characterized attenuation required to measure the power within the dynamic range of the power meter.  Measure and record the average output power in dBm.  Place the receive antenna/ DUT in the center of the enclosure, and connect the Spectrum Anlayzer to the receive antenna / DUT Antenna. Configure the spectrum analyzer for a span not to exceed 30 MHz.  Insure the transmit and receive antennas are co-polarized  Measure and record the average power of the received signal in dBm as measured by the spectrum analyzer.  Calculate the Antenna EiRP output: o EiRP (dBm) = Amplifier Output (dBm) – Cable Loss (dB) + Antenna Gain (dBi)  Calculate the Shielding Effectiveness: o SE (dB) = EiRP (dBm) – 20log(4/) - DUT Antenna Gain (dBi) + Spectrum Analyzer Cable Loss (dB) – Spectrum Analyzer Signal level (dBm)

D.5 Shielded environments with linear dimensions less than 2.0 Meters, alternate method

D.5.1 –Recommended Equipment (alternate method):

 Shielded enclosure to be tested, with at least one RF bulkhead connector. Any additional bulkhead connectors must be terminated.  Amplifier capable of providing at least 30dBm from the source side of the Network Analyzer. The tester should insure that the Network Analyzer output remains 3dB or more below the 1dB compression point of the amplifier.  Power Meter  Horn antenna – preferred or other directional antenna whose gain and directivity are known to a high degree. Vendor data sheets should be independently verified.  Receive antenna, or DUT with attached antenna modified to remove antenna input from DUT radio. The gain and directivity should be known to a high degree. Vendor data sheets should be independently verified.  Network Analyzer with sufficient dynamic range and sensitivity to measure the amplified network analyzer output signal. D.5.2

Enclosure

WLCP Amplifier

Power Meter 10 l input

SpectrumNetwork Analyzer output

D.5.3 – Recommended Verification Procedure (alternate method)

 Prepare the test set up as shown in D.5.2. The shaded area depicts an RF safety zone. No person or part thereof should enter this area anytime the amplifier is active and transmitting.  Measure and record cable losses with the Network Analyzer: Amplifier to Antenna, Receive Antenna to Network Analyzer including bulkhead if possible, and cables / attenuators used from amplifier to power meter  Set the Network Analyzer to take a S21 measurement to cover the band of interest. Calibrate the network analyzer without the amplifier include cables to be used  Connect the power meter to the amplifier output, and add any characterized attenuation required to measure the power within the dynamic range of the power meter.  Measure and record the average output power in dBm.  Place the receive antenna/ DUT in the center of the enclosure, and connect the Network Anlayzer input to the receive antenna / DUT Antenna. Configure the Network Analyzer for a span to cover the band of interest.  Insure the transmit and receive antennas are co-polarized  Measure and record the S21 measurement in dB as measured by the Network Analyzer.  Calculate the Antenna EiRP output: o EiRP (dBm) = Amplifier Output (dBm) + Antenna Gain (dBi)  Calculate the Shielding Effectiveness: o SE (dB) = EiRP (dBm) – 20log(4/) - DUT Antenna Gain (dBi) - Network Analyzer S21 (dB)

Add or change the following text in the P802.11.2 draft to resolve CIDs 27 as follows:

Change all instances of “far field” to “radiating far field” in Clause 5.2

Remove Note in Clause 5.2.3.1

Add the following in text in Clause 3:

Radiating Far-Field: Also known as the Fraunhofer Region, defined as the distance r from the antenna with largest dimension D at r > 2D2 / . This region can also be approximated as 10 .

Add the following text to section 5.2.4:

The SUT and associated antenna may be used alone to characterize the environment as an alternate method in lieu of a reference receiver antenna, provided the SUT antenna is known to a high degree of accuracy. In the case where the SUT antenna is utilized, system effects due to the packaging of the SUT will likely be calibrated out. As a result, the utilization of the SUT antenna method should be noted in the test report.

After 5.2.3.2.1 j) add the following text as a bullet point or a note:

The path-loss for any combination of transmit and receive antenna gains is calculated as follows:

Path Loss = Measured overall loss (dB) – measured cable losses (dB) – transmit antenna gain (dBi) – receive antenna gain (dBi).

Correct Figure 4 to match the text in 5.2.3.2.1

Submission page 9 Dennis Ward, Sirius Satellite Radio