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

Doc.:IEEE /0007r0 Submission Doc.: IEEE /0007r0 January 2009 Whetten (Boeing), Auluck (Intel), Kennedy (ETS)Slide 2 Abstract ECC WG SE24 has issued a draft report [IEEE ] 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 MHz 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 ]. 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.

Doc.:IEEE /0007r0 Submission Doc.: IEEE /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 –These increasingly strict DFS requirements are being applied in phases was required as of 30 June is required as of 1 July is required as of 1 January 2013

Doc.:IEEE /0007r0 Submission Doc.: IEEE /0007r0 EN V1.3.1/ V1.4.1 EN V1.5.1 EN V ParameterAll Channels MHzOther channels Date of Withdraw (DOW)1 July 2010 (April 09 for 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)

Doc.:IEEE /0007r0 Submission Doc.: IEEE /0007r0 January 2009 Whetten (Boeing), Auluck (Intel), Kennedy (ETS)Slide 5 Current Regulations in EU (2) EN V1.3.1/ V1.4.1 EN V1.5.1 EN V Detection Threshold-64 dBm (>200 mW) -62 dBm (<200 mW) 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 MHz band from the channel plan or to exclude these channels from the list of usable channels NoYesV1.5.1

Doc.:IEEE /0007r0 Submission Doc.: IEEE /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)

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

Doc.:IEEE /0007r0 Submission Doc.: IEEE /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 D , 18 Feb [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 (