july 2005 gregg levin, bridgewave communications slide 1 doc.: ieee 802.15-05/433/r0 submission...

July 2005July 2005

Gregg Levin, BridgeWave CommunicationsGregg Levin, BridgeWave CommunicationsSlide Slide 11

doc.: doc.: IEEE 802.15-05/433/r0IEEE 802.15-05/433/r0

SubmissioSubmissionn

Project: IEEE P802.15 Working Group for Wireless Personal Area NetworksProject: IEEE P802.15 Working Group for Wireless Personal Area Networks

Submission Title: [Reply to Comments on WCA Petition to Change FCC Regulations Governing the Unlicensed 57 – 64 GHz Band]Date Submitted: [July 2005]Source: [Gregg Levin] Company [BridgeWave CommunicationsAddress [3350 Thomas Road, Santa Clara, CA 95054]Voice: 408 567 6999], E-Mail: [[email protected]]

Re: [Reply to contribution by Gilb July 2005 commenting on WCA Petition]

Abstract: [Replies to the comments contributed by James Gilb] replies-to-gilb-wca-comments-ppt

Purpose: [Contribution to 802.15 TG3c at July 2005 meeting in San Francisco, California]

Notice: This document has been prepared to assist the IEEE P802.15. 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 acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15.

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Change from PD to EIRPChange from PD to EIRP

1.1. For historical reasons, many Radio Regulations For historical reasons, many Radio Regulations written in units of Power Density at 3 meterswritten in units of Power Density at 3 meters*** Agreed*** Agreed

2.2. 9 9 W/cmW/cm22, measured at 3 meters, is equivalent , measured at 3 meters, is equivalent to saying EIRP = 10 Wto saying EIRP = 10 W*** Not true – there is no EIRP limit in the *** Not true – there is no EIRP limit in the current rules as transmitters using large-current rules as transmitters using large-aperature antennas have increasingly large aperature antennas have increasingly large EIRPs, yet have decreasing 3-meter PD levelsEIRPs, yet have decreasing 3-meter PD levels

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continuedcontinued

3.3. Changing to EIRP would need to be done Changing to EIRP would need to be done throughout all parts of Radio Regulationsthroughout all parts of Radio Regulations*** Part 15 2.4GHz and 5GHz already based on *** Part 15 2.4GHz and 5GHz already based on EIRP – 60GHz rules are the exceptionEIRP – 60GHz rules are the exception

4.4. Changing from PD to EIRP need not be Changing from PD to EIRP need not be donedone “to ensure compliance with . . . Section “to ensure compliance with . . . Section 15.255(b)(1) . . . in the 15.255(b)(1) . . . in the near fieldnear field.”.”*** 3-meter PD does not make sense when in *** 3-meter PD does not make sense when in near fieldnear field

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continuedcontinued

5.5. In fact, Sec. 15.31 states that Part 15 In fact, Sec. 15.31 states that Part 15 equipment >30 MHz must be measured in the equipment >30 MHz must be measured in the far field.far field.*** Sec 15.31(3)(b) says that “All parties …are *** Sec 15.31(3)(b) says that “All parties …are urged to use these measurement procedures. urged to use these measurement procedures. Any parties using other procedures should Any parties using other procedures should ensure that such other procedures can be ensure that such other procedures can be relied on to produce results compatible with the relied on to produce results compatible with the FCC measurement procedures.”FCC measurement procedures.”

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Change from PD to EIRP (cont’d.)Change from PD to EIRP (cont’d.)

7.7. PD measurements only make sense in the far field (FF).PD measurements only make sense in the far field (FF).*** Agreed*** Agreed

8. Current regulations specify PD measurements at 3 m.8. Current regulations specify PD measurements at 3 m.*** Agreed*** Agreed

9. For high-gain systems with FF > 3 m, 9 9. For high-gain systems with FF > 3 m, 9 W/cmW/cm22 at 3 m can be at 3 m can be extrapolated to 2.2 extrapolated to 2.2 W/cmW/cm22 at 6 m, 1 at 6 m, 1 W/cmW/cm22 at 9 m, and so on. at 9 m, and so on.*** Grossly overstates PD at 3 meters when 3 meters is in near *** Grossly overstates PD at 3 meters when 3 meters is in near fieldfield

10. Except for the virtue of clarity, there is no good reason to make this 10. Except for the virtue of clarity, there is no good reason to make this change.change.*** Clarity is good. Technical correctness is also good.*** Clarity is good. Technical correctness is also good.

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Request for Increase in Power LimitsRequest for Increase in Power Limits

1.1. WCA has asked for increase in EIRP limits from 40 WCA has asked for increase in EIRP limits from 40 dBm (10 W) to “82 dBm less 2 dB for every dB that dBm (10 W) to “82 dBm less 2 dB for every dB that antenna gain is below 51 dB.”antenna gain is below 51 dB.”

2.2. This could result in an increase in antenna gain and This could result in an increase in antenna gain and transmitter power, up to an transmitter power, up to an EIRP of 63,000 Watts!EIRP of 63,000 Watts!*** EIRP is NOT power nor PD. EIRP itself does *** EIRP is NOT power nor PD. EIRP itself does not cause interference. Power and PD increases not cause interference. Power and PD increases are on the order of 13dB.are on the order of 13dB.

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Request for Increase in Power LimitsRequest for Increase in Power Limits1.1. What are the benefits? An increase in range. How much?What are the benefits? An increase in range. How much?2.2. Estimates are that, for most US cities, range approximately doubles in all cases Estimates are that, for most US cities, range approximately doubles in all cases

(see Appendix A)(see Appendix A)*** 2X distance increase = 4X building pairs that can be connected.*** 2X distance increase = 4X building pairs that can be connected.

3.3. But so does the interference range!But so does the interference range!*** Oxygen attenuation reduces interference range by 14-16dB per kilometer. *** Oxygen attenuation reduces interference range by 14-16dB per kilometer. Walls, windows, and antenna directionality significantly reduce risk to indoor Walls, windows, and antenna directionality significantly reduce risk to indoor systems. Users typically use the smallest antennas possible for the required systems. Users typically use the smallest antennas possible for the required range – energy reaching indoor systems will typically be approaching threshold. range – energy reaching indoor systems will typically be approaching threshold. P-to-P links are no worse than other low-gain antenna users of the band.P-to-P links are no worse than other low-gain antenna users of the band.

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1.1. The nearby 71 – 76 GHz band actually offers greater The nearby 71 – 76 GHz band actually offers greater range (lack of oxygen absorption).range (lack of oxygen absorption).

2.2. This band also allows operation with EIRP up to 55 WThis band also allows operation with EIRP up to 55 W

3.3. Therefore, we recommend that The Commission make Therefore, we recommend that The Commission make no changes to the existing EIRP for the 57 – 64 GHz no changes to the existing EIRP for the 57 – 64 GHz band.band.

*** Yes, but E-Band systems are much more costly, will *** Yes, but E-Band systems are much more costly, will remain more costly, and coordination procedures are remain more costly, and coordination procedures are beyond acceptability for enterprise users.beyond acceptability for enterprise users.

Request for Increase in Power LimitsRequest for Increase in Power Limits

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Request for Exemption to Call Sign Request for Exemption to Call Sign Requirement Requirement

The WCA argues in favor of “window links” with high EIRP.The WCA argues in favor of “window links” with high EIRP. There is great potential for interference on both the receiving There is great potential for interference on both the receiving

side side as well as the transmitting side.as well as the transmitting side. Window glass can reflect significant amounts of incident Window glass can reflect significant amounts of incident

radiated power (see Appendix B).radiated power (see Appendix B). Conservatively, an outgoing beam could scatter back into a Conservatively, an outgoing beam could scatter back into a

room a signal only 10 dB weaker than the transmitted beam.room a signal only 10 dB weaker than the transmitted beam. The combination of ultra-high power and lack of call sign The combination of ultra-high power and lack of call sign

sets the stage for high indoor interference.sets the stage for high indoor interference.*** 13dB increase is not “ultra-high” power*** 13dB increase is not “ultra-high” power

We recommend continuation of moderate power levels and We recommend continuation of moderate power levels and a publicly-declared call sign.a publicly-declared call sign.*** Power increase request is on the same order as window *** Power increase request is on the same order as window reflective losses. Window links under proposed rules will be reflective losses. Window links under proposed rules will be comparable to P-to-P indoor links under existing rules.comparable to P-to-P indoor links under existing rules.

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Request for Support of P802.15-05/0308r0 Request for Support of P802.15-05/0308r0

We request an endorsement of this letter and that it be sent We request an endorsement of this letter and that it be sent to the FCC.to the FCC.

Thank you!Thank you!

*** Request that TG3c:*** Request that TG3c:- Set up liaison with WCA committee- Set up liaison with WCA committee- Allocate time to seek compromises that support needs of - Allocate time to seek compromises that support needs of both PAN and P-to-P usesboth PAN and P-to-P uses- Hold off on FCC letter until above steps are taken- Hold off on FCC letter until above steps are taken

july 2005 gregg levin, bridgewave communications slide 1 doc.: ieee 802.15-05/433/r0 submission...

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