1. Doc.:IEEE 802.18-09/0007r0 Submission Doc.: IEEE 802.18-09/0007r0 January 2009 Whetten (Boeing), Auluck (Intel), Kennedy (ETS)Slide 1 [5GHz RLANs and Radars in EU] Date: 2009-01-20 Authors:

2. Doc.:IEEE 802.18-09/0007r0 Submission Doc.: IEEE 802.18-09/0007r0 January 2009 Whetten (Boeing), Auluck (Intel), Kennedy (ETS)Slide 2 Abstract ECC WG SE24 has issued a draft report [IEEE 18-09-0006-00] which concludes that airborne 5GHz RLANs are incompatible with meteorological radars. The report also assesses compatibility between airborne 5GHz RLANs and other radar systems, including military radars, and raises a number of concerns. The report concludes by asserting that airborne RLANs are not compatible with weather radars operating in 5600-5650MHz band, implicating perhaps that airborne RLANs should not be authorized in any 5GHz band which requires DFS capabilities. Several companies have reviewed this report, and concluded that the prevailing analysis and test data do not support the conclusions of the draft report [IEEE 18-09-0009-00-0000]. Additionally, there is concern among the RLAN industry that this analysis may be extended to all mobile (trains & buses) RLANs, and potentially all RLANs whether mobile or not.

3. Doc.:IEEE 802.18-09/0007r0 Submission Doc.: IEEE 802.18-09/0007r0 January 2009 Whetten (Boeing), Auluck (Intel), Kennedy (ETS)Slide 3 History Over the past few years, there have been several instances of RLAN interference into meteorological radars within the European Meteorological Network (UMETNET). –In all cases, the offending RLAN was found to not have implemented DFS properly Partially as a response to these interference events, the EU TCAM published a series of upgraded DFS requirements for RLAN equipment distributed within EU, published as EN 301 893 –These increasingly strict DFS requirements are being applied in phases 1.4.1 was required as of 30 June 2008 1.5.1 is required as of 1 July 2010 1.6.1 is required as of 1 January 2013

4. Doc.:IEEE 802.18-09/0007r0 Submission Doc.: IEEE 802.18-09/0007r0 EN 301 893 V1.3.1/ V1.4.1 EN 301 893 V1.5.1 EN 301 893 V.1.6.1 ParameterAll Channels5600-5650 MHzOther channels Date of Withdraw (DOW)1 July 2010 (April 09 for 5600-5650 MHz band) 1 January 2013N/A Minimum pulse width (see detailed test signals in table below) 1 μs0.8 μs0.5 μs PRF (see detailed test signals in table below) FixedFixed, Staggered and InterleavedV1.5.1 Channel Availability Check (CAC) time 1 minute10 minutes1 minuteV1.5.1 Off-Channel CAC (Note 1)NoYesV1.5.1 CAC and Off-Channel CAC detection probability (Note 2) 60%99.99%60%V1.5.1 In-service monitoring detection probability 60% V1.5.1 CAC for slave devices with power above 200 mW (after initial detection by In-service) NoYesV1.5.1 Current Regulations in EU (1) January 2009 Slide 4Whetten (Boeing), Auluck (Intel), Kennedy (ETS)

5. Doc.:IEEE 802.18-09/0007r0 Submission Doc.: IEEE 802.18-09/0007r0 January 2009 Whetten (Boeing), Auluck (Intel), Kennedy (ETS)Slide 5 Current Regulations in EU (2) EN 301 893 V1.3.1/ V1.4.1 EN 301 893 V1.5.1 EN 301 893 V.1.6.1 Detection Threshold-64 dBm (>200 mW) -62 dBm (<200 mW) -62 +10 -EIRP Spectral Density (dBm/MHz) + G (dBi), however the DFS threshold level shall not be lower than -64 dBm assuming a 0 dBi receive antenna gain V1.5.1 Channel Move time10s V1.5.1 Channel closing time260 ms1sV1.5.1 Non-occupancy period 30 minutes V1.5.1 Possibility to exclude 5600-5650 MHz band from the channel plan or to exclude these channels from the list of usable channels NoYesV1.5.1

6. Doc.:IEEE 802.18-09/0007r0 Submission Doc.: IEEE 802.18-09/0007r0 Environment Canada, which operates the national Canadian weather radar network, collaborated with Boeing in testing the performance of DFS in airborne platforms. A joint report was submitted [1] along with AMS conference proceedings [2], which concludes that airborne DFS is highly effective in detecting weather radars before the radars experience any interference. Further detailed analysis has also shown that there is little reason to conclude that airborne DFS poses any significant risks to either meteorological or military radars Available Test Data January 2009 Slide 6Whetten (Boeing), Auluck (Intel), Kennedy (ETS)

7. Doc.:IEEE 802.18-09/0007r0 Submission Doc.: IEEE 802.18-09/0007r0 It is proposed that IEEE 802.18 engage with the EU authorities concerning any regulatory limitations of use of the 5GHz bands. It is further proposed that IEEE 802.18 RR-TAG submit a letter to WGSE and SE24 requesting industry involvement in any future work in this area. Proposed 802.18 Action January 2009 Slide 7Whetten (Boeing), Auluck (Intel), Kennedy (ETS)

8. Doc.:IEEE 802.18-09/0007r0 Submission Doc.: IEEE 802.18-09/0007r0 January 2009 Whetten (Boeing), Auluck (Intel), Kennedy (ETS)Slide 8 References [1]Whetten, F; Whetten, D.; Joe, P.; Scott, J., “Dynamic Frequency Selection (DFS) Functionality with Airborne Radio Local Area Networks (RLANs); Flight Tests, Results, and Conclusions”, Boeing Doc D6-83753, 18 Feb 2007. [2]Joe, P., Whetten, F., Scott, J., Whetten, D., “Airborne RLAN and Weather Radar Interference at C-Band”, Presentation to 33 rd Conference on Radar Meteorology, 10 Aug 2007. (http://ams.confex.com/ams/pdfpapers/123523.pdf)http://ams.confex.com/ams/pdfpapers/123523.pdf