Regulatory Information for Low Latency Scanning in 5 GHz bands November 2003 doc.: IEEE 802.11-02/973r0 July 2004 Regulatory Information for Low Latency Scanning in 5 GHz bands Amjad Soomro, Zhun Zhong and Javier Del Prado Philips Soomro et. al., Philips Soomro et. al., Philips

European Regulations in 5 GHz Bands July 2004 European Regulations in 5 GHz Bands For any STA, before transmitting on a channel Detect radars Know maximum transmit power levels Apply transmit power mitigation, if applicable However, STAs are allowed to rely on measurements and ‘Mitigation’ requirements announced by AP Soomro et. al., Philips

Situation Results in long scan times July 2004 Situation STAs are forced to do passive scanning while roaming in 5 GHz bands in European regulatory domains Similar requirements might become applicable in US in upper 5 GHz bands Limits on maximum transmit power might be desirable for administrative reasons where regulatory requirements do not exist Passive scanning may result in wait times of up to one beacon period per scanned channel 5 GHz bands has at least twelve channels Many more to be available in future (US) Results in long scan times Soomro et. al., Philips

Proposal 1 Include regulatory information in Site Report July 2004 Proposal 1 Include regulatory information in Site Report Enables active scanning Specifically, include additional four bytes Maximum Transmit Power Level Local Power Constraint Map field (as defined in 802.11h amendment) Information supplied by neighboring AP’s Maximum Transmit Power Level Local Power Constraint Map Octets 1 2 Soomro et. al., Philips

Proposal 2 Site Reports may not be always available. July 2004 Proposal 2 Site Reports may not be always available. No neighbor information available APs may choose to not include neighbor information Soomro et. al., Philips

July 2004 Proposal 2 Add capability for APs to transmit regulatory information in between beacons Define new Regulatory Domain Information frame The frame to be transmitted, autonomously, by an AP in between beacons, zero or more times. Category Action Dialog Token Regulatory Domain Information Element Octet: 1 5 Figure 0-6 – Regulatory Domain Information frame body format Element ID Length Maximum Transmit Power Level Local Power Constraint Map/Detected Signal Map Octets: 1 Figure 1— Regulatory Domain Information Element field format Soomro et. al., Philips

July 2004 Field Definitions The definitions for Maximum Transmit Power Level, Local Power Constraint and Map are the same as defined in IEEE 802.11h amendment. Soomro et. al., Philips

Benefits Beacons have lots of other information July 2004 Benefits Beacons have lots of other information Regulatory Domain Information frame keeps the frame length small Efficiently announces regulatory domain information, making it easier to transmit it multiple times within a beacon interval Reduces Passive Scanning Times By enabling on-demand active scanning Measurements Results/Information already exists in AP/neighboring APs No additional measurement burden – just reporting No hardware changes required Soomro et. al., Philips

Comparison Table for Two Proposals July 2004 Comparison Table for Two Proposals Site Report Regulatory Domain Frame Benefit at Initial Start up while passive scanning No Yes Dependent on Neighbor Information Available Channel Information Supplied Current Channel Other Channels Benefit while operating in the same channel Benefit when moving to a different channel The two proposals are complementary Soomro et. al., Philips

July 2004 Conclusions Only passive scanning possible with the current protocol in 5 GHz European bands The proposal Enables active scanning Reduces time spent in passive scanning Simple additions in the protocol Without hardware changes Soomro et. al., Philips

July 2004 Straw Poll 1 Would you support including regulatory information in Site Report to enable active scanning YES NO Soomro et. al., Philips

July 2004 Straw Poll 2 Would you support adding a protocol frame to report regulatory information/measurements YES NO Soomro et. al., Philips

July 2004 Motion 1 Instruct the editor to incorporate changes submitted in the document 11-04-0753 in the next TGk draft Soomro et. al., Philips

July 2004 Motion 2 Instruct the editor to incorporate changes submitted in the document 11-04-0754 in the next TGk draft Soomro et. al., Philips