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Enterprise extensions - overview

Enterprise extensions - overview. Authors:. Date: 2011-04-12. Problem statement Overview of Proposed Solution Details The Centralized Coordination Service Set and the Extended Centralized PCP/AP Cluster Summary of Control mechanisms Interference reporting in an ECPAC Summary of Benefits

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Enterprise extensions - overview

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  1. Enterprise extensions - overview Authors: Date:2011-04-12 Brian Hart, Cisco Systems

  2. Problem statement • Overview of Proposed Solution • Details • The Centralized Coordination Service Set and the Extended Centralized PCP/AP Cluster • Summary of Control mechanisms • Interference reporting in an ECPAC • Summary of Benefits • Step-through normative text in 11/533 Outline Brian Hart, Cisco Systems

  3. In OBSS, a TXSS such as within the BTI, A-BFT or DTT is a directional jammer • A badly behaved transmission in a dense environment • In OBSS, a pseudo-static SP without CCA (or NAV) is a simple jammer • Enterprise use cases are presently not well addressed, such as: • “sea” of open desks • “sea” of cubes with embedded offices • open lecture theaters • etc Problem statement: Dense 60GHz devices in open environments Brian Hart, Cisco Systems

  4. TXSS overlap is avoided by centralized synchronization of “wired/2.4/5GHz” APs (S-APs) then scheduling their BIHs so they do not overlap • Via out of scope mechanism • Use a modified clustering mechanism to extend this behavior to BSSs in the neighborhood and/or passing through • Neighboring PCP/APs that don’t hear a S-AP aren’t required to do anything (areas experiencing density issues need to carpet the area with S-APs) • Neighboring PCP/APs that do hear a S-AP must cluster or go to the guaranteed reserved channel(s) (advertised via 11v Channel Usage) not subject to these clustering requirements • Via a modified clustering that involves association from one STA in a MA-STA PCP/AP to the S-AP • Each S-AP indicates which cluster time offsets are free • Respecting other BSSs’ BTI, A-BFT & AT can be mandated • Performing all DTT TXSSs within a universal pseudo-static SP can also be mandated • Protected Periods can be mandated for the DTT • Interference reporting is extended suitably • Involves a non-backwards-compatible change to Cluster Report element Overview of Proposed Solution Brian Hart, Cisco Systems

  5. Centralized Coordination Service Root synchronizes and configures “wired” APs = S-APs • The Centralized Coordination Service Root + S-APs = Centralized Coordination Service Set (CCSS) • Nearby PCP/APs cluster to these S-APs • New cluster type, called “Centralized PCP/AP cluster” • The CCSS + clustered PCP/APs, plus clients = Extended Centralized PCP/AP Cluster (ECPAC) The Centralized Coordination Service Set and the Extended Centralized PCP/AP Service Set New Modified Brian Hart, Cisco Systems

  6. The Beacon Interval Header (BIH, = BTI, A-BFT and AT) is confined to Beacon SPs • TXSSs are confined to the TXSS CBP, which is a regular allocation across the ECPAC • i.e. the “badly-behaved” communication modes are confined to the Beacon SP and TXSS CBP • S-APs are assigned non-overlapping Cluster Time Offsets by the Coordination Service Root The Beacon Interval Header and TXSS CBP BTI A-BFT AT DTT • Nearby PCPs and APs are advised of free Cluster Time Offsets by their S-AP • Beacon SPs prevent contention during BIHs • Any STA can use a TXSS CBP for TXSSing (or sending data) TXSS CBP TXSS CBP TXSS CBP BIH DTT Beacon SP DTT Beacon SP DTT BIH DTT S-AP1 TXSS CBP TXSS CBP TXSS CBP TXSS CBP TXSS CBP TXSS CBP TXSS CBP TXSS CBP TXSS CBP TXSS CBP TXSS CBP TXSS CBP Out of range Beacon SP BIH Beacon SP Beacon SP S-AP2 Clustered Beacon SP Beacon SP BIH Beacon SP AP3 BIH Beacon SP Beacon SP BIH PCP4 Beacon Interval Brian Hart, Cisco Systems

  7. When in range of an S-AP within an CCSS, a PCP/AP shall either join the S-AP’s Centralized PCP/AP cluster or go to a free channel • As advertised by the S-AP via 802.11v’s Channel Usage procedures • A PCP/AP shall select an unused Cluster Time Offset if one is advertized by its S-AP • If mandated by an S-AP, a PCP/AP shall respect the BIH • Complete its own BTI, A-BFT and AT within the Beacon SP Duration • Reserve Beacon SPs for Cluster Time Offsets in use • If mandated by an S-AP (and potentially echoed via a PCP/AP), STAs shall respect the TXSS CBP • Complete any TXSSs within the TXSS CBP • If mandated by an S-AP (and potentially echoed via a PCP/AP), STAs shall use Protected Periods for their SPs Summary of Control Mechanisms ECPAC Policy Detail field Brian Hart, Cisco Systems

  8. DBand Beacons are reported from client to PCP/AP to S-AP to Centralized Coordination Service Root • To avoid the “Beacon of Death” problem, a PCP/AP with only one antenna and one sector must jitter the timing of its DBand beacon • Cluster Report element is changed in a non-backwards compatible way (TSCONST should be an element) Interference reporting in an ECPAC • Key • Beacon causes interference • Cluster Report (different ECPAC Cluster or same Cluster Time Offset) Brian Hart, Cisco Systems

  9. Sample Simulation Results:ClusterMaxMem=32 • Data CINR: • No OBSS TXSSing: Centralized-clustering and Decentralized-clustering are similar (PP not modeled) • During OBSS TXSSing • Decentralized-clustering: average CINR is reduced by 12 dB due to TXSS • Centralized-clustering: No impact • Beacon: • No OBSS TXSSing • Centralized-clustering: no issue • Decentralized-clustering: 15%~20% STAs may have an issue receiving the beacon, since CINR is less than 7 dB (3dB sensitivity + 2stddev lognormal shadowing) • Beacon CINR in Centralized-clustering is about 15 dB higher than that in Decentralized-clustering • During OBSS TXSSing • Decentralized clustering: CINR drops by 4 dB • Centralized clustering: without impact Beacon difference with centralized Beacon difference with centralized, even without TXSS TXSS impact on decentralized Data Brian Hart, Cisco Systems

  10. On selected channels within an isolated space, complete avoidance of directional jamming from OBSS DBand Beacons in BTI and Sector Sweeping in A-BFT • More Cluster Time Offset indices prevents PCP/AP lockout • 15-20% of clients reduced to ~0% of clients that can’t receive their beacons • Ditto for TXSSing within DTT (10 dB CINR recovered) • SPs are prevented from creating uncontrolled directional interferers • Still 1-hop maximum wireless clustering only • Since the requirements from large scale field trials requirements are not fully known yet, these mitigation measures can be selectively enabled where found necessary • Devices not supporting Centralized clustering are guaranteed their own channel(s) to use • See backup slides for simulation study Summary of Benefits Brian Hart, Cisco Systems

  11. Performance comparisons between Centralized-clustering and Decentralized-clustering in an enterprise environment Note: For many overlapped environments, Centralized clustering may involve more complexity/performance than required. A DS or a Coordination Service Root may not be available. For these use cases, channel selection and/or Decentralized clustering remains the best choice. Simulation Study Brian Hart, Cisco Systems

  12. 16x16=256 cubicles • Area size= 44.8 x 48 meters • 32 APs: set on the ceiling, height: 3m • One STA and one PCP in each cubicle, with height 1 meter • Conference room: one AP , 8 STAs • AP/PCP: 32 antennas • STA: (50%,50%) 32, 4 antennas • Channels: 11 ad models • AP to AP: LOS, 1.5dB lognormal • AP/PCP/STA: NLOS • Conference room to cubicles: additional 2dB lognormal • ClusterMaxMem: 8/16/32 • Multiple directional Beacon: 32 • Simulation realizations: 3000 Simulation Environment and Setup Brian Hart, Cisco Systems

  13. The Decentralized/Centralized-Clustering generating procedures • Decentralized/Centralized-Clustering maintenance • Comparisons of CINR coverage between Decentralized-Clustering and Centralized-Clustering • Impact of the conference room door open/close on Decentralized- Clustering and Centralized-Clustering: • Number of S-APs, APs and PCP in the Decentralized/Centralized-clustering need to update their cluster-roles or change their Beacon offset is provided. What is Simulated Brian Hart, Cisco Systems

  14. Beacon • Without TXSS • Decentralized-Clustering • 10%~20% area has issues receiving the Beacon, where the Beacon CINR is less than 7 dB (3dB due to -78dBm RSSI/noise floor + 2 sigma of log-norm gives 4 dB) • Sensitive to environment change: multiple co-channel APs may need to update their cluster role, change their Beacon offset or change their channel when open/close the door of conference room • Centralized-Clustering • There is no issue to receive Beacon with a larger ClusterMaxMem • Robust to the environment change • With TXSS • Decentralized-clustering: about 4 dB CINR degradation compared to without TXSS • Centralized-clustering: without impact from TXSS • Data CINR • Without TXSS • CINR of Centralized-Cluster and Decentralized-Cluster are similar • With TXSS • Decentralized-clustering: big impact from TXSS, 12 dB CINR is reduced • Centralized-clustering: without impact from TXSS Summary of Simulation Results Brian Hart, Cisco Systems

  15. Summary of Simulation Results Brian Hart, Cisco Systems

  16. Simulation Results: ClusterMaxMem=8 • Data CINR: • Without TXSS: Centralized-clustering and Decentralized-clustering are similar • With TXSS: • Decentralized-clustering: average 12 dB CINR is reduced due to TXSS • Centralized-clustering: No impact • Beacon: • Without TXSS: • Centralized-clustering: no issue • Decentralized-clustering: 10%~20% STAs have issue to receive Beacon, where CINR less than 7 dB • Beacon CINR in Centralized-clustering is about 7 dB higher than that in Decentralized-clustering • With TXSS • Decentralized-clustering: CINR drop 4 dB • Centralized-clustering: without impact Beacon difference with centralized Beacon difference with centralized, even without TXSS TXSS impact on decentralized Data Brian Hart, Cisco Systems

  17. Simulation Results:ClusterMaxMem=16 • Data CINR: • Without TXSS: Centralized-clustering and Decentralized-clustering are similar • With TXSS: • Decentralized-clustering: average 12 dB CINR is reduced due to TXSS • Centralized-clustering: No impact • Beacon: • Without TXSS • Centralized-clustering: no issue • Decentralized-clustering: 12%~20% STAs have issue to receive Beacon, where CINR less than 7 dB • Beacon CINR in Centralized-clustering is about 10 dB higher than that in Decentralized-clustering • With TXSS • Decentralized clustering: CINR drop 4 dB • Centralized clustering: without impact Beacon difference with centralized Beacon difference with centralized, even without TXSS TXSS impact on decentralized Data Brian Hart, Cisco Systems

  18. Simulation Results:ClusterMaxMem=32 • Data CINR: • Without TXSS: Centralized-clustering and Decentralized-clustering are similar • With TXSS: • Decentralized-clustering: average 12 dB CINR is reduced due to TXSS • Centralized-clustering: No impact • Beacon: • Without TXSS • Centralized-clustering: no issue • Decentralized-clustering: 15%~20% STAs have issue to receive Beacon, where CINR less than 7 dB • Beacon CINR in Centralized-clustering is about 15 dB higher than that in Decentralized-clustering • With TXSS • Decentralized clustering: CINR drop 4 dB • Centralized clustering: without impact Beacon difference with centralized Beacon difference with centralized, even without TXSS TXSS impact on decentralized Data Brian Hart, Cisco Systems

  19. Decentralized-clustering • Beacon: Frequency reuse 3+. TXSS of neighbor co-channel clustering makes impact on CINR • Sensitivity to the environment change: multiple s-AP/PCP, member AP/PCP may need to update their cluster role , change cluster offset or change channels • Data: • Frequency reuse is 3+ • Big impact from TXSS: CINR 7 dB is reduced due to TXSS • CINR variation is large due to TXSS • Centralized-clustering • Beacon: frequency reuse changes from 3+ to 3xClusterMaxMem+, Beacon can be perfectly received • Sensitivity to the environment change: robust • Data: • frequency reuse is still 3+, CINR is similar to that of Decentralized-clustering when the TXSS impact on Decentralized-clustering is not taken into account • Without impact from TXSS Conclusions Brian Hart, Cisco Systems

  20. Sensitivity Level used in the simulations Brian Hart, Cisco Systems

  21. The impairment antenna pattern is the one used in the simulations Imperfect BF-Antenna Pattern Brian Hart, Cisco Systems

  22. Randomly select the AP on the ceiling to join the Centralized Clustering first • Become an S-AP unless all the channels and Beacon offsets are used up • Failure: if there is no empty Beacon offset detected • Randomly select the PCPs to join the Centralized Clustering • Become a member PCP, if at least one Beacon from S-AP is received with available/empty Beacon offsets. • Failure: if there is no empty Beacon offset detected • STAs associate with S-AP, member AP/PCP • 90% chance associated with the S-AP, member AP/PCP with the strongest RSSI • 10% chance associated with the S-AP, member AP/PCP with the second strongest RSSI Centralized Clustering Formation Brian Hart, Cisco Systems

  23. Randomly select the AP on the ceiling first • Become an S-AP if there is no Beacon from S-AP received. Randomly select one (of three) channel and set beacon offset 0 • Become a member AP if Beacon from an S-AP received with an empty Beacon offset being detected. Set Beacon offset at one of empty Beacon offsets. • Failure: if there is no empty Beacon offset detected • Randomly PCPs to join the Decentralized clustering • Become a S-PCP if there is no Beacon from S-AP/PCP received. Randomly select one (of three) channel and set beacon offset 0 • Become a member PCP if a Beacon from a S-AP/PCP received with an empty Beacon offset being detected. Set Beacon offset at one of empty Beacon offsets. • Failure: if there is no empty Beacon offset detected • STAs associate with S-AP/PCP, member AP/PCP • 90% chance associate with the S-AP/PCP, member AP/PCP with the strongest RSSI • 10% chance associate with the S-AP/PCP, member AP/PCP with the second strongest RSSI Decentralized Clustering Formation Brian Hart, Cisco Systems

  24. CINR: STA received signal (from AP/PCP) to interference and noise ratio • Data CINR: (BFed transmitting and BFed receiving) • CINR of STAs in data receiving: the impact of TXSS is not taken into account. Received BF is taken into account • Reason of CINR in Centralized-clustering is a little bit less than that in Decentralized-clustering: more AP/PCPs are assigned in Centralized clustering than that in Decentralized clustering, with more co-channel AP/PCPs • ECPAC-TXSS CBP CINR: (BFed transmitting and BFed receiving) • CINR of STAs in data receiving: when data is transmitted in TXSS CBP • CINR for Beamforming training: similar to CINR of ECPAC-data (due to the beamforing isolation) • Beacon CINR: (BFed transmitting and omni receiving) • Received Beacon CINR at STAs, omni receiving antenna is used • Decentralized Clustering: may face the TXSS of neighbor co-channel clustering. The TXSS impact from neighbor co-channel clustering is not taken into account • Beacon successfully receiving: consider the implementation loss and link margin, it need CINR about 3 dB to successfully the Beacon with control PHY CINR Calculation Brian Hart, Cisco Systems

  25. Data/Beacon CINR with TX SS • Data CINR with TXSS • Decentralized Clustering: The CINR of STAs in data receiving when facing a TXSS transmission from one neighboring co-channel AP/PCP. We go through all the possible co-channel AP/PCP in the simulation scenario. • Centralized Clustering: will not face such issue when TXSS CBP is required • Beacon CINR with TXSS • Decentralized Clustering: The CINR of STAs in Beacon receiving when facing a TXSS transmission from one neighboring co-channel clustering AP/PCP. We go through all the possible co-channel AP/PCP in the simulation scenario. • Centralized Clustering: will not face such issue when TXSS CBP is required Brian Hart, Cisco Systems

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