Regulatory Information for Low Latency Scanning in 5 GHz bands

1. Regulatory Information for Low Latency Scanning in 5 GHz bands Amjad Soomro, Zhun Zhongand Javier Del Prado Philips Soomro et. al., Philips

2. 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

3. 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

4. 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 Soomro et. al., Philips

5. 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

6. 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. Figure 0-6 – Regulatory Domain Information frame body format Figure 1— Regulatory Domain Information Element field format Soomro et. al., Philips

7. 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

8. 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

9. Comparison Table for Two Proposals The two proposals are complementary Soomro et. al., Philips

10. 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

11. Straw Poll 1 Would you support including regulatory information in Site Report to enable active scanning Soomro et. al., Philips

12. Straw Poll 2 Would you support adding a protocol frame to report regulatory information/measurements Soomro et. al., Philips

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

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