1. doc.: IEEE 802.11-12/1093r0 Submission September 2012 Jeongki Kim, LG ElectronicsSlide 1 System information update procedure for 11 ah Date: 2012-09-17 Authors: NameAffiliationsAddressPhoneEmail Jeongki KimLG Electronics LG R&D Complex Anyang-Shi, Kyungki- Do, Korea +82-31-450-7808jeongki.kim@lge.com Yongho SeokLG Electronics Jinsoo ChoiLG Electronics Jin Sam KwakLG Electronics Eric WongBroadcomSunnyvale, CA+1 408 922 6672ewong@broadcom.com Matthew FischerBroadcommfischer@broadcom.com Minyoung ParkIntelHillsboro, OR+1 503 712 4705minyoung.park@intel.com Adrian StephensIntel Tom TetzlaffIntel Emily QiIntel Simone MerlinQualcommSan Diego, CA+1 858 845 1243smerlin@qualcomm.com Santosh AbrahamQualcomm Menzo WentinkQualcomm Alfred AsterjadhiQualcomm Amin JafarianQualcomm Hemanth SampathQualcomm VK jonesQualcomm

2. doc.: IEEE 802.11-12/1093r0 SubmissionSlide 2 NameAffiliationsAddressPhoneEmail Yong LiuMarvell Hongyuan ZhangMarvell Sudhir SrinivasaMarvell George CalcevHuaweiRolling Meadows, IL, USA George.Calcev@huawei.co m Osama Aboul MagdHuawei Young HoonHuawei Betty ZhaoHuawei David YangxunHuawei Bin ZhenHuawei ChaoChun WangMediaTek James WangMediaTek Jianhan LiuMediaTek Vish PonnampalamMediaTek James YeeMediaTek Huai-Rong Shao Samsung Electronics Chiu NgoSamsung Electronics Minho CheongETRI Jae Seung LeeETRI Hyoungjin KwonETRI Heejung YuETRI Sok-kyu LeeETRI Sun, Bo ZTE Lv, Kaiying ZTE Authors: September 2012 Jeongki Kim, LG Electronics

3. doc.: IEEE 802.11-12/1093r0 SubmissionJeongki Kim, LG ElectronicsSlide 3 Authors: NameAffiliationsAddressPhoneEmail Sayantan ChoudhuryNokia Taejoon KimNokia Klaus DopplerNokia Chittabrata GhoshNokia Esa TuomaalaNokia Ken MoriPanasonic Rojan ChitrakarPanasonic Haiguang WangI2R Shoukang ZhengI2R Yeow Wai LeongI2R Zander LeiI2R Jaya ShankarI2R Anh Tuan HoangI2R Joseph Teo Chee MingI2R September 2012

4. doc.: IEEE 802.11-12/1093r0 Submission Introduction The short beacon frame format is adopted in 11 ah in order to reduce the medium occupancy and reduce the power consumption of STA [1],[2] The STA can know if the network configuration information is changed by ‘ change sequence’ in short beacon when the STA receives the short beacon For STA to update the changed network configuration information in case that the network configuration information is changed, –Case 1: the STA may receive the next full beacon –Case 2: the STA may send the probe request and receive the probe response Examples of Case 2 –In case that AP does not send the full beacon periodically [1][2] E.g., Operation by short beacon + probe request/response w/o full beacon –When a station receiving short beacon wants to receive the updated information as fast as possible September 2012 Jeongki Kim, LG ElectronicsSlide 4

5. doc.: IEEE 802.11-12/1093r0 Submission Motivation In case 2 AP will send the probe response frame including all system information although only one system information element is changed –Note that the size of probe response is similar to the size of beacon frame in legacy 802.11 system It will result in unnecessary medium occupancy In this case if AP sends the probe response including only the changed network configuration information, we can reduce the unnecessary medium occupancy September 2012 Jeongki Kim, LG ElectronicsSlide 5

6. doc.: IEEE 802.11-12/1093r0 Submission Proposal When the change sequence value in short beacon is different from the value which the station has, the STA will send the AP the probe request frame including change sequence which the station stores Whenever the system information is updated, AP will store the previous change sequence and the changed information element’s ID –E.g, ) In case of change sequence = ‘3’, the stored information by AP. [change sequence = 0, ID = ‘x’], [change sequence = 1, ID = ‘y’], [change sequence = 2, ID = ‘Z’] If AP receives from the STA the probe request frame including the change sequence, the AP finds updated information by comparing its change sequence with the received change sequence. Then the AP will send the STA the optimized probe response frame including only the updated system information and change sequence about the updated system information September 2012 Jeongki Kim, LG ElectronicsSlide 6

7. doc.: IEEE 802.11-12/1093r0 Submission Analysis (1/2) Probe response frame will include the same information elements as beacon frame except for TIM IE –The size of beacon frame/probe response[1] > 100 byte(typical 802.11 BSS), > 230 bytes (enterprise environment) Mandatory fields: Timestamp (8B), Beacon Interval (2B), Capability (2B) –The following system information elements can be changed in legacy system [3] Channel Switch Announcement (5B) Extended Channel Switch Announcement (6B) EDCA parameters (20B) Quiet element (8B) DSSS Parameter Set (3B) CF Parameter Set (8B) FH Parameter Set (7B) HT Operation element (24B) September 2012 Jeongki Kim, LG ElectronicsSlide 7

8. doc.: IEEE 802.11-12/1093r0 Submission Analysis (2/2) Comparison between legacy probe response size and optimized probe response –Size of mandatory fields: 12 bytes –Best case: > 83% (typical BSS), > 92% (enterprise environment) –Worst case: > 64% (typical BSS), > 84% (enterprise environment) September 2012 Jeongki Kim, LG ElectronicsSlide 8 Updated IELegacy probe response (>100B) in typical 802.11BSS Legacy probe response (>230B) in enterprise environment Optimized Probe ResponseGain (%)Optimized Probe ResponseGain (%) Channel Switch Announcement (5B) 17 B> 83%17 B> 92 % Quiet element (8B)20 B> 80%20 B> 91% EDCA parameters (20B)32 B> 68%32 B> 86% HT Operation element (24B)36 B> 64%36 B> 84%

9. doc.: IEEE 802.11-12/1093r0 Submission Summary When the system information changes, for AP to send the probe response including full system information may not be efficient in terms of resource overhead. For updating the system information, if a STA sends the probe request including the AP’s change sequence which the STA has, the AP can send the optimized probe response including the updated system information September 2012 Jeongki Kim, LG ElectronicsSlide 9

10. doc.: IEEE 802.11-12/1093r0 Submission References [1] IEEE 802.11-11/1503r2, Short beacon [2] IEEE 802.11-11/1137r9, Proposed Specification Framework for Tgah [3] IEEE 802.11-2012, Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications September 2012 Jeongki Kim, LG ElectronicsSlide 10

11. doc.: IEEE 802.11-12/1093r0 Submission Straw poll 1 SP1: Do you support that a STA may send the probe request frame including the change sequence which the STA has to AP when the STA receives the short beacon including the change sequence which is different from the change sequence which the station stores? –Yes:, No:, Abstain: SP2: Do you support that AP may send the optimized probe response frame which includes only system information elements which need to be updated by STA and the change sequence when the AP receives the probe request including the change sequence from the STA? –Yes:, No:, Abstain: September 2012 Jeongki Kim, LG ElectronicsSlide 11