doc IEEE 802 18 080016 r 0 March

doc. : IEEE 802. 18 -08/0016 r 0 March 2008 DFS Update from the European Union Date: 2008 -3 -18 Authors: Submission Slide 1 Rich Kennedy, Oak. Tree Wireless

doc. : IEEE 802. 18 -08/0016 r 0 Dynamic Frequency Selection • In the EU, EN 301 893 defines regulatory requirements for RLAN operation in the 5 GHz band • DFS was devised to protect radar operating in that band – Radar and RLANs are co-equal users of the band (EU) – RLANs detecting radar patterns defined by 301 893 must move to a clear channel • Weather radar signatures were not included in the initial (or second) version of DFS (v 1. 3. 1 and v 1. 4. 1) • The EU has started to receive interference complaints from the meteorological community (EUMETNET) Submission

doc. : IEEE 802. 18 -08/0016 r 0 EU Weather Radar • EUMETNET Report to the Wi-Fi Alliance – Philippe Tristant attended the Prague session – Government weather radar needed to protect populace from serious weather conditions – Serious interference issues seen – Petitioned TCAM to help protect weather radar • TCAM decisions – Changes to EN 301 893 in phases – Immediate remedy for the radars – banning RLANs from 5600 – 5650 MHz band until new patterns, pulse detection becomes mandatory Submission

doc. : IEEE 802. 18 -08/0016 r 0 EU Regulatory • The TCAM Committee: – is the Telecommunication Conformity Assessment and Market Surveillance Committee – Role is defined within the Directive 1999/5/EC (R&TTE) • See articles 13 to 15 of the Directive 1999/5/EC – Formal procedures: article 5 provides for safeguards against shortcomings in standards. • The Commission (after opinion of TCAM) can: – Withdraw standards – Interpret standards or give guidelines on the conditions under which they give presumption of conformity – Informal procedures: try to manage issues through consensus • TCAM issues ‘Opinions’ based on proposals made by the representative of the Commission (TCAM Chair) • Common understanding on the way forward Submission

doc. : IEEE 802. 18 -08/0016 r 0 TCAM Decisions • Document TCAM 24(24) from the EC – Meteo radars interfered by 5 GHz RLAN – EC concluded DFS has shortcomings – Industry need to address these before 5 GHz RLAN technology is suitable for mass market development • Staggered PRF • Narrower Pulses (0, 8 µSec / 0, 5 µSec) • Solution for noise calibration of weather radars (10 min CAC or equivalent) – only for the band 5600 - 5650 MHz – Other radars have comparable characteristics, hence Staggered PRF and Narrower Pulses should be applied across the whole band. • EC conclusions/proposals above endorsed by TCAM Submission

doc. : IEEE 802. 18 -08/0016 r 0 DFS Changes • Now: RLANs can not operate in the 5600 – 5650 MHz band • After 3/31/08 must meet EN 301 893 v 1. 3. 1 or 1. 4. 1 requirements • After 6/30/08 must be able to detect staggered PRF (3 PRF values) in 5600 - 5650 MHz band; or block the band (channels 120, 124 and 128) • After 3/31/09 must also meet EN 301 893 v 1. 5. 1 requirements: – Detect 0. 8 u. S pulse width across 5250 – 5350 and 5470 – 5725 MHz bands – Detect staggered PRF across 5250 – 5350 and 5470 – 5725 MHz bands – Include a solution for weather radar noise calibration period (10 min CAC) • After 6/30/10 must meet EN 301 893 v 1. 6. 1 – All the 1. 5. 1 requirements – Detect 0. 5 u. S pulse width across 5250 – 5350 and 5470 – 5725 MHz bands Submission

doc. : IEEE 802. 18 -08/0016 r 0 Proposed Relaxation of the CAC Requirement • Non-Continuous Off-Channel CAC (for all DFS channels) – as an alternative for the continuous CAC • Scheduled CAC for weather radar channels – Avoid the weather radar band at start up and do a CAC later on or do an Off-Channel CAC while operation has started on a channel outside 5600 -5650 • CAC time for weather radar band – Full 10 min CAC (or equivalent Off-Channel CAC) only first time a channel in 5600 -5650 MHz is being checked. – If no radar found, subsequent CAC checks should only be 60 sec Submission

doc. : IEEE 802. 18 -08/0016 r 0 Proposed Relaxation of the CAC Requirement [2] • Relaxation on the Uniform Spreading requirement – Use 60% of the available spectrum in stead of 80% – Impact is < 1. 5 d. B • Some applications do not require all channels and as such they should not be impacted by the 10 min CAC • Relaxation on the Channel Closing Transmission Time – Proposed 1 sec in stead of 260 m. Sec • required for mesh networking, other applications will not need this • DFS Threshold level – Threshold level as a function of the Power Density Submission

doc. : IEEE 802. 18 -08/0016 r 0 Some Things We Can (Should) Do • TCAM has set the DOW for version 1. 4. 1 to 1 April 2009 • ETSI should progress the work with the objective to finish revision of EN 301 893 latest mid 2008 – National voting + processing time ETSI + processing time EC > 6 months – Publication in OJEC should be at least a few months prior to the DOW for version 1. 4. 1 • Once ETSI has sent the new EN 301 893 into voting, industry should ask TCAM to revise the 1 April 2009 date and move it e. g. to end of 2009 or mid 2010 – The EC is firm with regard to what should be included in version 1. 5. 1 – So once we have done 1. 5. 1 as they requested, we believe we can get a relaxation on the time line to give industry more time to implement 1. 5. 1 into their products Submission