Millimeter Wave Regulation IEEE EMC – DC/No. VA Mitchell Lazarus 703-812-0440 | [email protected]...
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Transcript of Millimeter Wave Regulation IEEE EMC – DC/No. VA Mitchell Lazarus 703-812-0440 | [email protected]...
Millimeter Wave Regulation
IEEE EMC – DC/No. VA
Mitchell Lazarus703-812-0440 | [email protected]
January 31, 2012
2
Overview
FCC restricted bands Communications
57-64 GHz (unlicensed) 92-95 GHz (unlicensed) 71-76, 81-86, 92-95 GHz (licensed)
Radar – Current Rules 57-64 GHz 76-77 GHz
Radar – Waivers and Proposed Rules 76-77 GHz 77-81 GHz 78-81 GHz
3
Millimeter Wave Signals in General
Advantages tight beams from small antennas can reuse same frequency nearby high data capacity
Disadvantages need direct line-of-sight high free space attenuation high rain attenuation poor penetration of walls and
terrain.
At X GHz, a one-foot antenna has a diameter of X wavelengths.
4
FCC Restricted Bands
In the late 1980s, the FCC listed 64 “restricted bands”: closed to unlicensed transmitters range from 90 kHz to 36.5 GHz to protect sensitive receivers: – GPS, radio astronomy, satellite
downlinks, air traffic radars, etc. FCC also declared all bands above 38.6 GHz to be “restricted” Authorizing unlicensed use above 38.6 GHz always requires
removal from the restricted list part of the FCC rulemaking proceeding.
5
Communications
6
57-64 GHz (Unlicensed) – 1
Max average power 9 µW/cm² at 3 meters (40 dBm EIRP) max peak 500 mW
Disadvantage: attenuation by O2 molecules in atmosphere
WiGig Alliance: in-room data communications 1-6 Gbits/sec wireless HDMI, gaming,
home storage network, etc. proposed IEEE 802.11ad.
Frequency (GHz)50 60 70
Source: Adelia C. Valdez
Va Tech 2001
57–64 GHz
16
8
dB
/km
0
7
57-64 GHz (Unlicensed) – 2
Rulemaking proposal: average power 82 dBm EIRP
minus 2 dB for every dB that antenna gain is below 51 dBi antenna must be outdoors or pointed outdoors
Pending since June 2007 new rules possible in 2nd or 3rd quarter 2012.
8
92-95 GHz (Unlicensed)
Coextensive with 92-95 GHz licensed band (next slide) Max average power 9 µW/cm² at 3 meters (40 dBm EIRP)
max peak 500 mW indoor only – minimizes interference to and from licensed users
No FCC certifications issued to date.
9
71-76, 81-86, 92-95 GHz (Licensed)
Each applicant receives a non-exclusive, nationwide license no limit on number issued
For each link: electronic, real-time interference checks with Federal gov’t and
non-gov’t incumbents interference cases are rare (except on certain rooftops)
Max power 55 dBm EIRP No licensed use on 94-94.1 GHz
reserved for Federal research applications Minimum bit rate:
71-76, 81-86: 0.125 bits/sec/Hz 92-95 GHz: 1.0 bits/sec/Hz.
10
Radar(Current Rules)
11
57-64 GHz
61.0-61.5 GHz fixed field disturbance sensors: max average power 9 µW/cm² at 3 meters (+40 dBm EIRP) peak power density 18 µW/cm² at 3 meters (+43 dBm EIRP)
non-fixed or elsewhere in band: max peak power density 9 nW/cm2 at 3 meters (+10 dBm EIRP) max peak transmitter output power 0.1 mW
Unlicensed.
12
76-77 GHz
Vehicle-mounted radars only Unlicensed. Power limits:
Forward-Looking(dBm EIRP)
Side- or Rear-Looking
(dBm EIRP)
Vehicle moving +48.3 +45.3
Vehicle stopped +23.5
13
Radar(Waivers and Proposed Rules)
14
76-77 GHz (Proposed Rule)
100 watt (50 dBm) power limit regardless of direction; moving or stopped any application (not just vehicle-mounted)
Pending since May 2011.
15
76-77 GHz (Waiver)
Fixed use of 10 radars at Atlanta airport for tracking aircraft and vehicles on ground
Must meet emissions limits for forward-looking, in-motion vehicle radars ( +48.3 dBm EIRP)
Granted September 2009.
16
77-81 GHz (Proposed Rule & Waiver)
Use as in-tank level probing radars limited to commercial use at fixed locations
Unlicensed Proposed emissions limits:
+23 dBm EIRP average (measured with no tank wall) +43 dBm EIRP peak (measured with no tank wall)
but pulse radars often have >20 dB P/A ratio –41.3 dBm EIRP (§15.209) (measured through metal or concrete)
FCC acknowledges need to protect radio astronomy operations Pending since January 2010 Waiver granted pending rulemaking
subject to above emissions limits.
17
78-81 GHz (Proposed Rule & Waiver)
Airport use to detect “foreign object debris” (FOD) on runways aircraft parts, tools, equipment and supplies, rocks, pavement
fragments, luggage, wildlife FCC open to allowing other applications No proposal as to licensed vs. unlicensed No proposal as to power limits
FCC acknowledges need to protect radio astronomy operations Pending since December 2011 Waiver granted pending rulemaking:
airport FOD detection only 35 dBW EIRP license required.
18
Conclusion
Millimeter wave spectrum is the target of extensive engineering innovation
FCC rules at 57 GHz and above are badly out of date FCC moving to update rules, but regulatory process is inherently
slow.