Benefits of Extended DFS Reports in 802.11h Month 2000 doc.: IEEE 802.11-00/xxx Benefits of Extended DFS Reports in 802.11h Author: Christopher J. Hansen Broadcom Corporation John Doe, His Company

Contents Review of the objections to Extended DFS Reports Month 2000 doc.: IEEE 802.11-00/xxx Contents Review of the objections to Extended DFS Reports Review of the PAR, ERC 93, and the goals of TGH Benefits of Extended DFS Reports Summary Zunächst werde ich unterschidliche Wireless Data Lösungen vorstellen. Dann stelle ich dar, warum WLAN - Cellular Interworking eine richtige und wichtige Idee ist. Die zwie Nezwerk-Architeckur Optionen für Interworking, die bis jetzt vorgeschlagen sind, werden präsentiert und einige Pros und Cons werden diskutier. Bevor ich meinen Vortrag mit einigen Schlussbemerkungen abschliesse, wird der Status der Standardisierung kurz erläutert. John Doe, His Company

Some Objections to the D1.0 Draft Letter ballot comments that 802.11h D1.0 violated the PAR >90% of these comments refer to hidden station reporting, not to DFS mechanisms PAR: Scope of Proposed Project: [Enhance the 802.11 Medium Access Control (MAC) standard and 802.11a High Speed Physical Layer (PHY) in the 5GHz Band supplement to the standard; to add indoor and outdoor channel selection for 5GHz license exempt bands in Europe; and to enhance channel energy measurement and reporting mechanisms to improve spectrum and transmit power management (per CEPT and subsequent EU committee or body ruling incorporating CEPT Recommendation ERC 99/23).]

Review of PAR and ERC 99/23 Text from ERC 99/23 It was also recognised that HIPERLAN equipment must be capable of avoiding occupied channels by employing a Dynamic Frequency Selection mechanism and ensuring a uniform spreading of the devices over all the available channels for HIPERLANs. In addition a transmitter power control process capable of ensuring a mitigation factor of at least 3 dB is also required. These constraints do not apply to the already standardised HIPERLANs Type 1 in the band 5150 – 5250 MHz.

Benefits of Extended BSS Reports All BSS Reports contain: Total RSSRI histogram Measurement summary field Extended CCA Reports contain: CCA Busy Fraction CCA Busy Duration CCA Busy Interval Extended BSS Reports contain: Unknown RSSI Histogram BSS Information Individual Station Histograms

Benefits of Extended BSS Reports Once a radar is detected, the AP needs to quickly move the BSS to a new channel No time to look around Completely random choice may be very bad if it collides with another BSS Extended BSS reports allow the AP to know about other BSSs BSSID and STA ID information help correlated measurements from different stations – are they seeing the same interference? Histograms let the AP know how the interference conditions Will my BSS be interfered with if it moves? What interference will my BSS cause if it moves?

Benefits of Extended BSS Reports Are Extended BSS Reports hard to implement? No. RSSI MAC Addresses Recognizing Beacons These are all things that stations recognize today. What is new is the frame they are assembled into.

Summary All DFS algorithms are implementation dependent. We need to provide the reporting mechanisms necessary for good algorithms. Let’s not make a bad DFS standard and then wait (3 years?) for another task group to come around to implement good DFS. Let’s maintain (and improve, if necessary) the extended DFS reporting mechanisms in the next TGH draft. Let’s keep extended DFS reports mandatory.