April 11, 2007 Healthcare Engineering Course Online 1 Wireless Internet Shigeki Goto Waseda University

April 11, 2007 Healthcare Engineering Course Online 2 Wireless and Wired In earlier days, Wireless = long distance, International, short wave, satellite. Wired = subscriber line, LAN (Ethernet). In our modern life, Wireless = cellular phone, wireless LAN. Wired = optical fiber for long distance, and international communications.

April 11, 2007 Healthcare Engineering Course Online 3 Long Distance Wireless comm. 11.3km 2.4GHz KDDI Lab. IP communications cover schools and clinics.

April 11, 2007 Healthcare Engineering Course Online 4 Modern Wireless Communications 1.Cellular phone Japanese culture, i-mode browser on the phone vs. SMS, short message. 2.Wireless LAN At home, office and hospital and in the town 3.IP, Mobile IP  Dr Hongbo Shi

April 11, 2007 Healthcare Engineering Course Online 5 Cellular phone and PHS (PCS) PHS (PCS) is preferable in a hospital because of low power. A patient has a PHS unit which receives a call from the receptionist.

April 11, 2007 Healthcare Engineering Course Online 6 Wireless LAN in the town San-gen-jaya in

April 11, 2007 Healthcare Engineering Course Online 7 Wireless LAN or IEEE x issues Security Quality High speed

April 11, 2007 Healthcare Engineering Course Online 8 Security MAC address filtering WEP, Wired Equivalent Privacy IEEE802.1X, authentication, RADIUS PSK ： Pre-Shared Key TKIP, Temporal Key Integrity Protocol AES, Advanced Encryption Standard

April 11, 2007 Healthcare Engineering Course Online 9 Security Wi-Fi Protected Access StandardAuthenticationEncryption --MACWEP WPA IEEE801.1X, PSK TKIP WPA2, IEEE802.11i AES

April 11, 2007 Healthcare Engineering Course Online 10 Another approach to Security Upper level solutions VPN ssh portforwarding

April 11, 2007 Healthcare Engineering Course Online 11 Quality (Congestion)

April 11, 2007 Healthcare Engineering Course Online 12 Quality (Congestion) 20 clients can use a single access point.

April 11, 2007 Healthcare Engineering Course Online 13 How to accommodate 80 PC’s? Use multiple access points.

April 11, 2007 Healthcare Engineering Course Online 14 Class room (100 students)

April 11, 2007 Healthcare Engineering Course Online 15 Network Configuration

April 11, 2007 Healthcare Engineering Course Online 16 First experiment

April 11, 2007 Healthcare Engineering Course Online 17 First experiment (1)

April 11, 2007 Healthcare Engineering Course Online 18 First experiment (2)

April 11, 2007 Healthcare Engineering Course Online 19 First experiment (3)

April 11, 2007 Healthcare Engineering Course Online 20 Summary — First experiment Many clients use AP2 intensively. Throughput: AP1: 50 ～ 350KB/sec AP2: 0 ～ 100KB/sec AP3: 100 ～ 600KB/sec

April 11, 2007 Healthcare Engineering Course Online 21 Second experiment

April 11, 2007 Healthcare Engineering Course Online 22 Second experiment (1)

April 11, 2007 Healthcare Engineering Course Online 23 Second experiment (2)

April 11, 2007 Healthcare Engineering Course Online 24 Second experiment (3)

April 11, 2007 Healthcare Engineering Course Online 25 Summary — Second experiment Distributed usage Throughput: AP1: 0 ～ 150KB/sec AP2: 50 ～ 300KB/sec AP3: 0 ～ 150KB/sec

April 11, 2007 Healthcare Engineering Course Online 26 Zero 0 Mbps is a serious problem Roaming, or hand off at physical level very fast recovery, 1mili-second Device driver selects the strongest signal among multiple Access Points.

April 11, 2007 Healthcare Engineering Course Online 27 QoS in Wireless LAN In earlier days, QoS technology is applied to Backbone networks. DiffServ, RSVP In modern life, QoS is applied to Wireless LAN

April 11, 2007 Healthcare Engineering Course Online 28 QoS control, IEEE e IEEE e Extended capability for QoS control. HCCA, HCF Controlled Channel Access EDCA, Enhanced Distributed Coordination Access Put some priority among packets

April 11, 2007 Healthcare Engineering Course Online 29 EDCA, Enhanced Distributed Channel Access Waiting time = Const. + TimeSlot X Rand. CW ( Contention Window) Random waiting time AIFS ( Arbitration Inter Frame Space) Constant TXOP ( Transmission Opportunity) Continuous transmission time

April 11, 2007 Healthcare Engineering Course Online 30 Experiment 1. No EDCA function Cross Traffic Voice traffic Traffic generator XTraffic generator Y Wireless Access Point Terminal A Terminal C Terminal B

April 11, 2007 Healthcare Engineering Course Online 31 Result — Experiment 1 When packet loss happens? 7Mbps

April 11, 2007 Healthcare Engineering Course Online 32 Experiment 2, EDCA basic Traffic generator X Terminal A Terminal B Terminal C Cross traffic 7Mbps total Voice traffic EDCA Traffic generator Y Wireless Access Point

April 11, 2007 Healthcare Engineering Course Online 33 Result — Experiment 2

April 11, 2007 Healthcare Engineering Course Online 34 Experiment 3-1, No cross traffic Traffic generator X Terminal A Terminal B Terminal C Voice traffic EDCA Traffic generator Y Wireless Access Point

April 11, 2007 Healthcare Engineering Course Online 35 Experiment 3-2, Cross Traffic Traffic generator X Terminal A Terminal B Terminal C Cross traffic 7Mbps total Voice traffic EDCA Traffic generator Y Wireless Access Point

April 11, 2007 Healthcare Engineering Course Online 36 R E-model formula is calculated from 20 parameters in IP telephony. IP telephony classification: ClassRDelay A80100 ms B70150 ms C50400 ms

April 11, 2007 Healthcare Engineering Course Online 37 Result — Experiment 3 R (3-1) 77.8 No EDCA (3-1) 76.5 EDCA (3-2) 23.7 No EDCA (3-2) 65.4 EDCA ・ For heavy traffic, EDCA is not effective (3-2). ・ Investigating the optimum value for EDCA parameters

April 11, 2007 Healthcare Engineering Course Online 38 Experiment 4, EDCA parameters Traffic generator X Terminal A Terminal B Terminal C Cross traffic 7Mbps total Voice traffic EDCA Traffic generator Y Wireless Access Point

April 11, 2007 Healthcare Engineering Course Online 39 Experiment 4 (1/3)

April 11, 2007 Healthcare Engineering Course Online 40 Experiment 4 (2/3)

April 11, 2007 Healthcare Engineering Course Online 41 Experiment 4. (3/3)

April 11, 2007 Healthcare Engineering Course Online 42 New method vs. Default value DefaultNew CWmin 31 CWmax 73 AIFS 11 TXOP R R

April 11, 2007 Healthcare Engineering Course Online 43 High Speed IEEE n 100Mbps MIMO, Multiple Input Multiple IEEE WiMAX, Worldwide Interoperability for Microwave Access 75Mbps IEEE802.16e WiBro in Korea 1Mbps/3Mbps/4Mbps

April 11, 2007 Healthcare Engineering Course Online 44 High speed solves many problems? YES