CS434/534: Mobile Computing and Wireless Networks Y. Richard Yang 08/30/2012

2 Outline r Pervasive wireless networks and mobile applications r Challenges facing wireless networks and mobile computing r Course information

3 Goal of Mobile Computing “People and their machines should be able to access information and communicate with each other easily and securely, in any medium or combination of media – voice, data, image, video, or multimedia – any time, anywhere, in a timely, cost-effective way.” Dr. G. H. Heilmeier, Oct 1992

Pervasive Mobile Devices r “In many parts of the world, more people have access to a mobile [wireless] device than to a toilet or running water.” [Time Aug. 2012] r Many industrial countries reach at least 90% mobile phone subscription penetration rate m [see phone penetration rates sheet] r PEW Internet and American Life Project: m “The mobile device will be the primary connection tool to the Internet for most people in the world in 2020” 4

Pervasive Wireless Networks r Wireless coverage: m -coverage-area-map.shtml m wer/ 5

6 Mobile Device Usage Source: O2

Mobile Traffic Growth 7 Source: Cisco

Mobile Computing Changing Our Lives 8 Source: TIME mobility survey; June-July 2012

10 Use Cases of Mobile Computing Changing the World 9 Source: TIME survey; June-July 2012

Mobile Computing Features with Larger Effects 10 Source: TIME survey; June-July 2012

Mobile Computing Changing Our Lives 11 Source: TIME survey; June-July 2012

Mobile Computing Changing Our Lives 12 Source: TIME survey; June-July 2012

Mobile Computing Changing Our Lives 13 Source: TIME survey; June-July

14 Use Case: Home Networks WiFi cellular bluetooth UWB satellite WiFi g/n WiFi Bluetooth NFC

15 Use Case: Mesh Networks r Many users still don’t have broadband m reasons: out of service area; some consider expensive

16 Use Case: Mesh Network for Disaster Recovery/Military r 9/11, Tsunami, Hurricane Katrina, South Asian earthquake … r Wireless communication and mobile computing capability can make a difference between life and death ! m rapid deployment m efficient resource and energy usage m flexible: unicast, broadcast, multicast, anycast m resilient: survive in unfavorable and untrusted environments

17 UMTS, DECT 2 Mbit/s UMTS Rel kbit/s LAN 100 Mbit/s, WLAN 54 Mbit/s UMTS Rel kbit/s GSM 115 kbit/s, WLAN 11 Mbit/s GSM 53 kbit/s Bluetooth 500 kbit/s GSM/EDGE 135 kbit/s, WLAN 780 kbit/s LAN, WLAN 780 kbit/s Use Case: Seamless Handoff--Always Best Connected

18 Use Case: Traffic Signal Advisor

19 Use Case: Vehicular Networks r Traffic crashes resulted in more than 41,000 lives lost/year r Establishing m vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I) and m vehicle-to-hand-held- devices (V2D) communications More info:

20 Collision Avoidance : V2V Networks r stalled vehicle warning r bland spots

21 Collision Avoidance at Intersections r Two million accidents at intersections per year in US Source:

22 Google Glass

23 Use Case: Habitat Monitoring Patch Network Transit Network Basestation Gateway A 15-minute human visit leads to 20% offspring mortality

24 Wireless and Mobile Computing r Driven by technology and vision m Mobile device capabilities and platforms m Global communication infrastructures r The field is moving fast

25 Enabling Infrastructures r Development and deployment of wireless infrastructures m networking: in-room, in-building, on-campus, in-the- field, MAN, WAN r Development and deployment of localization infrastructures m location: GPS, AGPS, … r Development and deployment of sensor networks

Wireless Bit Rates kbps9.6 kbps NMT 1981 GSM 1992 IMT (WCDMA; CDMA) 384 kbps 2 Mbps 100 Mbps 1 Gbps IMT-Advanced ~2012

27 Enabling Infrastructure: Networks StandardPeak DownlinkPeak UplinkTech GSM GPRS Class GSM EDGE Evolution TDMA/FDD CDMA EV-DO Rev CDMA/FDD CDMA EV-DO Rev. A CDMA/FDD CDMA EV-DO Rev. B CDMA/FDD WiFi: b 11 DSSS Flash-OFDM: Flash-OFDM Flash-OFDM WiFi: g 54 OFDM WiFi: a 54 OFDM LTE OFDMA/MIMO WiMAX: m MIMO/SOFDMA WiFi: n 600 OFDM/MIMO HSPA CDMA/FDD/MIMO LTE Advanced (Cat 8) MIMO WiFi: ac (8aAP; 4a ST) 3470 MU-MIMO All units are Mbps

28 Enabling Infrastructure: Measurements Source: A Close Examination of Performance and Power Characteristics of 4G LTE; Mobisys’12

29 Improving Infrastructure: Power Efficiency Source: A Close Examination of Performance and Power Characteristics of 4G LTE; Mobisys’12

30 Enabling Device Capabilities, Platforms r Improving device capabilities, mobile application frameworks, applications, e.g., m andriod m iphone/ipad m windows phone

31 Processing Capability: Javascript Benchmark

32 Processing Capability: Javascript Benchmark

33 Processing Capability: Javascript Benchmark

34 Processing Capability: Javascript Benchmark

35 Processing Capability: Javascript Benchmark

36 Processing Capability: Javascript Benchmark

37 Processing Capability: Javascript Benchmark

38 Sensing Capability (iphone 4)

Why is the Field Challenging?

40 Challenge 1: Unreliable and Unpredictable Wireless Coverage * Cerpa, Busek et. al What Robert Poor (Ember) calls “The good, the bad and the ugly” r Wireless links are not reliable: they may vary over time and space Reception v. DistanceReception vs. Power

41 Challenge 2: Open Wireless Medium r Wireless interference S1 S2 R1

42 Challenge 2: Open Wireless Medium r Wireless interference r Hidden terminals S1 S2 R1 S1R1 S2

43 Challenge 2: Open Wireless Medium r Wireless interference r Hidden terminals r Exposed terminal S1 S2 R1 S1R1 S2 R1S1S2R2

44 Challenge 2: Open Wireless Medium r Wireless interference r Hidden terminals r Exposed terminal r Wireless security m eavesdropping, denial of service, … S1 S2 R1 S1R1 R2 R1S1S2R2

45 Challenge 3: Mobility r Mobility causes poor-quality wireless links r Mobility causes intermittent connection m under intermittent connected networks, traditional routing, TCP, applications all break r Mobility changes context, e.g., location

46 Challenge 4: Portability r Limited battery power r Limited processing, display and storage Sensors, embedded controllers Mobile phones voice, data simple graphical displays GSM/3G/4G Smart phone data smaller graphical displays /3G Tablet/Laptop Performance/Weight/Power Consumption

47 Challenge 5: Changing Regulation and Multiple Communication Standards

48 Challenge 5: Changing Regulation and Multiple Communication Standards cellular phonessatellites wireless LAN cordless phones 1992: GSM 1994: DCS : IMT : CT : Inmarsat- A 1992: Inmarsat-B Inmarsat-M 1998: Iridium 1989: CT : DECT 199x: proprietary 1997: IEEE : b, Bluetooth 1988: Inmarsat- C analogue digital 1991: D-AMPS 1991: CDMA 1981: NMT : NMT : CT0 1984: CT1 1983: AMPS 1993: PDC 2000: GPRS 2000: IEEE a Fourth Generation (Internet based)

Wireless Communication Standards 49

What Will We Cover?

51 r Instructor Y. Richard Yang, AKW 308A office hours: to be posted Ramki Gummadi, AKW r Teaching fellow To be posted office hours: to be posted on class page r Course home page m Class Info: Personnel

52 Class Goals r Learn both fundamentals and applications of wireless networking and mobile computing r Obtain hands-on experiences on developing on wireless, mobile devices m wireless networking: GNU radio m mobile computing: Android (you may explore IOS or Windows Mobile in your project) r Discuss challenges and opportunities in wireless networking and mobile computing

53 Application Transport Network Data Link Physical Medium Data Link Physical Application Transport Network Data Link Physical Data Link Physical Network Radio Often we need to implement a function across multiple layers. The Layered Reference Model

54 Course Topic: Communications/Connectivity r Physical layer: channel and diversity r Link layer: channel sharing r Network and transport: routing, reliability

Course Topic: Mobile OS/App Framework r Android app framework m Activity, service, intent, content provider, handler/AsyncTask, … m Virtualizing mobile OS r Measuring/profiling mobile app m Why are web browser slow on smartphones? m Why did some small percentage of Pandora’s traffic is responsible for a large fraction of energy use on my phone? … 55

Course Topic: Mobile Network App Techniques r Informed usage of networks m MatchMaking r Using peer-to-peer connections m Wifi Direct, Microcast, NFC r Hybrid mobile/cloud/server m Cloud messaging m Code partition (MAUI, Cloudlet) m Aggregation (SmartVNC) m Storage partition 56

Course Topic: Sensory Framework/App r Location m Localization (GPS, lateration, acoustic, siganture) m Location based services Google MapView, Map API r Sensing m Detecting the environment using cameras, microphones, and collaborations signalGuru, Darwin Phone 57

58 Course Topics CommunicationsSensingSecurity (will not cover) OS/Application Platform

59 Class Materials r Chapters of reference books r Selected conference and journal papers r Other resources m MOBICOM, SIGCOMM, Mobisys proceedings m IEEE Network, Communications, Pervasive magazines

60 Suggested Reference Books r “ Wireless Networks: the Definitive Guide” by Matthew Gast, O’Reilly (available online) r “Fundamentals of Wireless Communication”, by David Tse and Pramod Viswanath, Cambridge University Press (available online)

61 Suggested Reference Books (2) r “Hello, Android”, by Ed Burnette r “The Android Developer’s Cookbook”, by James Steele and Nelson To  Developer guide:

62 What You Need to Do r Your prerequisite m motivated, critical m basic programming skill Gnuradio: GUI, python, C++ Android: Java, C (if you decide to hack into the kernel) r Your workload m class participation actively participate in class discussions m 3-4 assignments m One project m One midterm

63 Class Project r Goal: obtain hands-on experience r We’ll suggest potential topics r You may also choose your own topic r Initial proposal + midterm progress report + final report + [presentation] r We provide help in obtaining m Mobile devices m Amazon/Google cloud service accounts

64 Grading r More important is what you realize/learn than the grades Project35% Assignments35% Exam20% Class Participation 10%

65 Class Survey r Please take the class survey m help me to determine your background m help me to determine the depth and topics m suggest topics that you want to be covered

Questions?

Backup 67

Evolution of Mobile Systems to 3G 68

69 3G Networks

Mobile Computing Changing Our Lives 70 Source: TIME survey

IMT Advanced Requirements r All-IP communications. r Peak data rates m 100 Mbit/s for high mobility m 1 Gbit/s for low mobility r Scalable channel bandwidth, between 5 and 20 MHz, optionally up to 40 MHz r Peak link spectral efficiency m 15 bit/s/Hz (downlink); 6.75 bit/s/Hz (uplink) r System spectral efficiency m 3 bit/s/Hz/cell (downlink) m 2.25 bit/s/Hz/cell (indoor) 71