May 2009 doc.: IEEE 802.11-09/0111r2 Broadband V2I Access for High Speed Transportation Date: 2009-5-12 Authors: Name Company Address Phone email Hitoshi MORIOKA ROOT Inc. 2-1-22-307 Momochihama, +81-92-832-3391 email@example.com Sawara-ku, Fukuoka 814-0001 JAPAN Hiroshi MANO ROOT Inc. 8F TOC2 Bldg. 7-21-11 +81-3-5719-7631 firstname.lastname@example.org Nishi-Gotanda, Shinagawa- ku, Tokyo 141-0031 JAPAN Notice: This document has been prepared to assist IEEE 802.11. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. 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If you have questions, contact the IEEE Patent Committee Administrator at <firstname.lastname@example.org>. Submission Slide 1 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 Abstract • We talk about WLAN broadband access for high speed transportation. – Motivation – Market – Applications – Why Wi-Fi? – Why standardization is needed? – Requirement • Handover Latency Case Study – Comparison with Existing IEEE802.11 Standards – Straw Poll Submission Slide 2 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 Motivation • Many high speed trains (>200km/h) are already in operation in Europe and Asia. • Developments of 10,000km of express railway tracks are estimated in next 20 years in the world. • Train operators want broadband network between rail-side and train for such as train survey, passenger service and so on. • And they want to operate the network by their own. Wi-Fi will meet their needs. (Equipments cost, Operation cost, Bandwidth…) Submission Slide 3 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 Markets • Train (Railway Transportation) Existing High Speed Train (> 300km/h) • Total extension of railway is approximately 1,350,000km in the world. Name Country Max. Speed – North America: 278,000km Shanghai – EU: 236,000km China 430km/h Transrapid – Russia: 128,000km – East Asia: 110,000km Beijing-Tianjin China 350km/h – Central/South America: 110,000km HSCL TGV France 320km/h • Existing high speed train (> 200km/h operation) ICE Germany 320km/h – 22 systems in operation in 15 countries. Shinkansen Japan 300km/h • Expected new high speed train AVE Spain 300km/h – 10,000km in next 20 years. Eurostar EU 300km – In US, President Obama unveiled his plan to develop new high speed passenger railway. Thalys EU 300km/h Treni Eurostar • Of cause, not only high speed train but also Italy 300km/h ordinary train can use this technology. Italia Taiwan HSR Taiwan 300km/h KTX Korea 300km/h Submission Slide 4 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 Expected Applications Internet • Hot-spot service for passengers. • Passenger information services. • Cabin monitoring. • Backbone for femtocell. – Subway – Tunnel Submission Slide 5 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 Backbone for Hot-spot Service • Passengers can access to the Internet while traveling at low price and high speed. Web Mail Servers Servers Roadside AP WLAN AP Train Internet STA LAN Misc. Servers Web Servers Submission Slide 6 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 Backbone for Femtocell • Passengers can use their celluler phone even in a tunnel or underground. Cellular Phone Network Roadside AP Femtocell Train Internet STA LAN Cellular Phone Network Submission Slide 7 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 Passenger Information Services • Passengers can get information such as news, travel information, advertisement in real time. Info. Servers Roadside AP Train Internet STA News Advertisement Travel Info… LAN Info. Servers Submission Slide 8 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 Cabin Monitoring • Train operators can monitor the cabin. Roadside AP Train Internet STA LAN Submission Slide 9 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 Why Wi-Fi? • Wi-Fi can be easily operated by train/railway operators. • It means the networks are under their control, not rely on others. • And Wi-Fi has world-wide interoperability on frequency use. Standards Bandwidth Equipment Cost Operation Cost 14.4Mbps 3G, 3.5G (Downlink) Very High High 11.5Mbps (Uplink) 100Mbps (Downlink) LTE Very High High 50Mbps (Uplink) WiMAX (IEEE802.16e) 21Mbps High Low 100Mbps IEEE802.11 Low Low (11n MAC) Submission Slide 10 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 Why standardization is needed? • Multiple vendor and long term support is needed for sustainable operation. • A train may run across multiple railway network. So inter-/intra-national interoperability is needed. • According to these reasons, international standardization is needed. Submission Slide 11 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 Requirements • Target Speed – TGV plans 360km/h operation. – TransRapid in Shanghai is operated in 430km/h. – JR-Maglev records 581km/h and JR plans to start service in 2025. – 500km/h is enough? • Scalability – Many trains are running on a railway simultaneously. – Railway networks are vast. So a train may run across many communication networks. – Inter-network handover is required. • Security – Security is very important because private information will flow on networks. – For example, a train survey application will transfer a video which includes a passenger’s face. Submission Slide 12 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 Inter-Network Use Network A Network B Network C Network D AP AP AP AP AP AP AP AP AP Inter-Network Handover Inter-Network Handover IEEE802.11r does not support inter-network handover. Submission Slide 13 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 Inter-network Handover Latency 1. Discover a new AP. • Latency can be reduced by 11k or multiple radio interfaces. 2. Association with new AP. (includes authentication/key exchange…) • 11i authentication is NOT fast. • It needs many packet exchanges. 3. Network layer setup. Submission Slide 14 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 MAC Requirements • Fast Association – Train must handover during passing overlap zone for seamless handover. – Handover latency impacts distance between APs. (= cost) – Low handover latency is needed. Old AP New AP Overlap Zone Submission Slide 15 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 Case Study • Assumption – Maximum speed: 500km/h = 140m/s – Cell Radius: 200m – Route Length: 1,000km Case 1: Handover Latency = 100ms Minimum Overlap Zone length= 14m Distance between adjacent APs = 386m Number of APs = 2,591 Old AP New AP 200m 14m 200m 386m Submission Slide 16 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 Case Study (cont.) Case 2: Handover Latency >1.43s Minimum Overlap Zone distance > 200m Old AP New AP New AP 200m STA must begin new handover process before completing old handover process. Submission Slide 17 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 Protocol Sequence of IEEE802.11+IEEE802.1x(EAP-MD5) • At least 6 roundtrip packet exchanges STA AP RADIUS between STA and AP, and 2 roundtrip Beacon Server packet exchanges between AP and Probe Request RADIUS server are needed. Probe Response • EAP-TLS, EAP-TTLS, etc. needs more Authentication Request packet exchanges. Authentication Reply Association Request Association Accept EAPOL-Start EAP-Request/Identity It increases handover latency EAP-Response/Identity RADIUS-Access-Request EAP-Request/Credentials RADIUS-Access-Challenge EAP-Response/Credentials RADIUS-Access-Request EAP-Success RADIUS-Access-Accept Submission Slide 18 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 Comparison with Existing IEEE802.11 Standards Inter-Network Fast Roaming Standards Security Use (Handover) IEEE802.11/a/b/g/n +IEEE802.11i +IEEE802.11r We need Approaches a. Fast authentication/key exchange. b. Inter-network fast roaming. Submission Slide 19 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 PHY Compatibility • Existing PHY can be used in high speed environment. (08/1020r1) • So existing WLAN chipset can be used with some firmware and/or driver modification. LOW COST Submission Slide 20 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 Questions & Comments Submission Slide 21 Hitoshi MORIOKA, ROOT Inc. May 2009 doc.: IEEE 802.11-09/0111r2 Straw Poll • “A Study Group to develop a PAR and 5C for High- speed Broadband Access for 802.11 should be created” Yes: No: Don’t Know, Need More Discussion: Don’t Care: Submission Slide 22 Hitoshi MORIOKA, ROOT Inc.