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Improving WLAN Efficiency and QoE – A Top Down Approach. Date: 2013-11-10. Authors:. Abstract. This is a submission for 802.11HEW SG in Dallas November 10 th -15 th A potential system level approach is suggested for HEW SG consideration. The key message.
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Improving WLAN Efficiency and QoE – A Top Down Approach Date: 2013-11-10 Authors: Veli-Pekka Ketonen (7signal Solutions)
Abstract This is a submission for 802.11HEW SG in Dallas November 10th-15th A potential system level approach is suggested for HEW SG consideration Veli-Pekka Ketonen (7signal Solutions)
The key message WLAN needs to regain the capacity and performance advantage in wireless market Ample of potential – Need to be utilized much better 10X improvements already available by manually optimizing networks No need to re-define everything, lose compatibility and still be unsure if the gains will ever be realized Reuse/refine existing standards - address bottlenecks Make this available with smaller steps Veli-PekkaKetonen (7signal Solutions)
The Problem No single problem causes lack of efficiency and QoE, but many factors accumulate No single change will radically change this either General RF configuration must improve. No MAC/PHY protocol can deliver utmost user experience and capacity in current uncoordinated RF build ups as they stand today in many public areas WLAN are widely deployed by non-wireless experts. Addressing practical aspects becomes very important. Preventing harmful configurations and making the optimal Fit-for-Purpose product selection easy Veli-Pekka Ketonen (7signal Solutions)
Suggested elements for HEW concept • TRI-BAND WLAN 2.4 (n) - 5 (n/ac) - 60 (ad) – Use all spectrum already available • “Un-limited” future dense area scalability with 60 GHz band – Overlapping BSS with 802.11ad • Simultaneous dual band – Seamless coverage and capacity evolution • Simultaneously use two-of-three bands – APs reconfigure based on environment • CSMA/CA ACCESS REMAINS – Defines Wi-Fi, innovation in flexibility • CSMA/CS remains but is improved - dynamically adjusting to conditions • MAC “SERVICE PACK” – Room to improve, in several areas • A number of MAC protocol improvements, possibly on the current HW platforms • Introduction of Radio Profiles and Dynamic Protocol Reconfiguration • PHY IMPROVEMENT – Non-RF experts & general purpose prod., prevent errors… • No new PHY standard. Instead introduce Efficiency Classes and Fit-for-Purpose products • Minimize/remove opportunities for major mistakes in RF deployments by non-experts • Utilize better RF and antenna technology. Prevent RF pollution and increase radio link budgets several dBs • Self-Organizing & Optimizing– No fixed set can handle all the conditions • Dynamic control and reconfiguration of MAC/PHY operation against continuously validated SLA targets • Define an open API for selected MAC/PHY settings. This would speed up ecosystem development Veli-Pekka Ketonen (7signal Solutions)
“WAVE2” 1. TRI-BAND WLAN2.4 GHz (n) – 5 GHz (n/ac) - 60 GHz (ad) Adding 60 GHz does not solve existing QoE and inefficiency issues at the 2.4 GHz and 5 GHz bands that HEW in about However, WLAN competes also against other technologies, like LTE evolution A clear tri-band vision would put WLAN back to significant lead as preferred future solution for highest wireless capacity Personal empirical study: 95% of consumer/SME laptop models still sold with 2.4 GHz only with sales argument that it supports 802.11n. Sales personnel does not know what is 5 GHz band. => Vendors need to reassess strategy here. Current situation is not beneficial for industry or end users Veli-Pekka Ketonen (7signal Solutions)
“WAVE2” 2. Simultaneous dual band,Overlapping BSS Access point Access point Access point 2.4 5 60 2.4 5 2.4 5 60 STA STA STA STA STA STA STA • Dynamically alternating connection to one physical AP • Dynamically alternating the best connection, both connected, one transmitting at a time • Parallel connection to one physical AP • Single path TCP over one AP. Processing within client and AP radios • Parallel Multipath TCP (MPTCP) to two physical APs • A natural extension as IP/TCP technology evolves (Ref. Siri MPTCP, [1]) Why would this matter in HEW? • Additional redundancy and capacity with parallel 2.4 & 5 GHz connection • 60 GHz signal attenuate very rapidly with a person leaving the room. Without instant seamless roaming, 802.11ac may not serve Enterprise WLAN needs Veli-Pekka Ketonen (7signal Solutions)
“WAVE1” 3. CHANNEL ACCESS • CSMA/CS remains but improved • Asymmetric priority control. Promising research results available on this topic [2] [3] • Dynamic Sensitivity Control [4] • Other optimizations • 802.11 remains backwards compatible • Full duplex APs with interference cancellation (“Wave 2”) • Once interference cancellation is sufficiently mature [5] • APs would benefit more from full duplex than STAs Veli-Pekka Ketonen (7signal Solutions)
“WAVE1” 4. MAC “SERVICE PACK” Veli-Pekka Ketonen (7signal Solutions)
“WAVE1” 5. PHY ENHANCEMENTS Veli-Pekka Ketonen (7signal Solutions)
“WAVE1” 6. Self-Organizing and Optimizing, OPEN API “WAVE2” Network performance management, self-organizing and self-optimizing networks are a major research, development and operational focus area in mobile networks Current state of performance management and radio automation is WLAN is very modest and performance significantly lacking (= one key reason for HEW) Carefully done manual optimization provides already now even order of 10x improvements to throughputs under load compared to current automation Networks are often operated by non-specialists and conditions vary constantly No single configuration can service optimally different environments WLAN has to become truly automatically reconfiguring and optimizing towards a target performance Standardizing an open API for network radio control as an alternative to vendor internal implementation would likely increase speed of evolution and innovation towards seamless HetNets Veli-Pekka Ketonen (7signal Solutions)
Suggested High Efficiency Initiative Scope Industry/WFA (2013-2015) HEW “WAVE 1” SW/FW (2016-2017) HEW “WAVE 2” HW (2018-) 2.4 GHz clean up and legacy impact reduction w/ better settings High Efficiency Certification programs with Efficiency Classes Tri-band WLAN products Bring 5 GHz (n/ac) support to end users devices Fit-to-Purpose products with predefined std. Radio Profiles Simultaneous Dual Band with overlapping BSS to single AP 802.11ac Wave 1 & Wave 2 MAC “Service Pack” Dynamic sensitivity control Asymmetric ch. access priority Master beacon Basic power control Feature to prevent legacy probing Others to be agreed HARQ with incremental redundancy Implementation improvements: chselection, rate control, power cntrl, antennas,... Open Radio API Self-Optimizing and Reconfiguring products Full duplex APs with interference cancellation Optimize networks with addition of Performance Management Self-optimizing and reconfiguring Simultaneous dual band Multipath TCP over two APs/other radios Open Radio Control API definition “10X” “10X” “10X” • [6] Veli-Pekka Ketonen (7signal Solutions)
Suggested High Efficiency Initiative Scope Industry/WFA (2013-2015) HEW “WAVE 1” SW/FW (2016-2017) HEW “WAVE 2” HW (2018-) 2.4 GHz clean up and legacy impact reduction w/ better settings High Efficiency Certification programs with Efficiency Classes Tri-band WLAN products VERY HIGH CAPA Enable seamless use of all three bands Benefit from open interface innovations Seamless HetNets Fully utilize the obvious and easy opportunities Reduce non-intentional “damage” Standardize Wave 1 QUICK GAINS Help non-RF experts implement correctly Improve robustness Improve efficiency Auto-reconfigure Accelerate innovation Standardize Wave 2 Bring 5 GHz (n/ac) support to end users devices Fit-to-Purpose products with predefined std. Radio Profiles Simultaneous Dual Band with overlapping BSS to single AP 802.11ac Wave 1 & Wave 2 MAC “Service Pack” Dynamic sensitivity control Asymmetric ch. access priority Master beacon Basic power control Feature to prevent legacy probing Others to be agreed HARQ with incremental redundancy Implementation improvements: chselection, rate control, power cntrl, antennas,... Open Radio API Self-Optimizing and Reconfiguring products Full duplex APs with interference cancellation Optimize networks with addition of Performance Management Self-optimizing and reconfiguring Simultaneous dual band Multipath TCP over two APs/other radios Open Radio Control API definition “10X” “10X” “10X” • [6] Veli-Pekka Ketonen (7signal Solutions)
References • [1] Multipath TCP lets Siri seamlessly switch between WiFi and 3gLTE • http://arstechnica.com/apple/2013/09/multipath-tcp-lets-siri-seamlessly-switch-between-wi-fi-and-3glte/ • [2] WiFox: Scaling WiFi Performance for Large Audience Environments • http://conferences.sigcomm.org/co-next/2012/eproceedings/conext/p217.pdf • [3] A Measurement Study of WiFiBackoff Protocols • https://mentor.ieee.org/802.11/dcn/13/11-13-0494-00-0wng-ieee-presentation-backoff.ppt • [4] Dynamic Sensitivity Control • https://mentor.ieee.org/802.11/dcn/13/11-13-1012-04-0wng-dynamic-sensitivity-control.pptx • [5] Considerations for In-Band Simultaneous Transmit and Receive (STR) feature in HEW • https://mentor.ieee.org/802.11/dcn/13/11-13-1122-01-0hew-considerations-for-in-band-simultaneous-transmit-and-receive-str-feature-in-hew.pdf • [6] Possible Vision of HEW-driven Wi-Fi’2020 • https://mentor.ieee.org/802.11/dcn/13/11-13-1115-00-0hew-possible-vision-of-the-hew-driven-wi-fi-2020.ppt Veli-Pekka Ketonen (7signal Solutions)
MAC EFFICIENCY IMPROVEMENTSSUGGESIONS FOR SIMULATIONS Veli-Pekka Ketonen (7signal Solutions)