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Mobile Computing CSE 40814/60814
Fall 2012
Course Overview
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• Instructor: Christian Poellabauer – 325D Cushing Hall – [email protected] – 574-631-9131 – Office hours: Monday 9.30-10.30, Wednesday
11.30-12.30, and by appointment • Teaching Assistants: Sal Aguinaga & Nikhil Yadav
– 213 Cushing Hall – [email protected], [email protected] – Office hours: Tuesday 2-3 & Thursday 12-1 (Sal); Monday
2-3 & Wednesday 3-4 (Nikhil) • Website!!
Course Project • Mobile system/app development • “Communica?ons” oriented app • Two parts of project:
– Course part: grade based on difficulty, novelty, execu?on, deliverables, final presenta?on, etc.
– Challenge part: opportunity to present project to industry sponsor, who will determine “Innova?on Challenge” winners (cash prizes).
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Course Project • Android, iOS preferred, but others (MicrosoT etc.) also accepted if desired
• Teams of 1-‐2 students • Start thinking about team forma?on, plaWorm, development needs, and project ideas
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Course Goal • To understand what are the fundamental
challenges in Mobile Computing and what are some of the solutions towards solving these fundamental challenges
• But also: – To get you a high-paying job – To enrich you with new ideas – To train you in (mobile) systems oriented thinking – To prepare you for research/profession in mobile
computing – but more generally – in “adaptive” (next-generation) computer systems
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Mobile Computing • Computing enabled by presence of wireless enabled
portable devices (PDAs, cell phones etc.) • Many other names/overlapping computing paradigms:
– Pervasive Computing – Ubiquitous Computing – Wireless Computing – Embedded Computing – Nomadic Computing – Wireless Sensor Networks – Ad-Hoc Networks – Mesh Networks – Vehicular Networks – …
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Mobile Computing
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• Applications • Location-awareness • Mobility Support • Security • Resource Management • Network Protocols • Broadcast • Technologies • Standards • Wireless Medium
Wireless Communica?on
Mobile Compu?ng
Trends in Mobile
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“Between 2010 and 2015, the global installed base of smartphones will increase at a compound annual growth rate (CAGR) of 33 percent. The tablet market will move even faster, achieving a CAGR of 81 percent during the same period. Along with this incredible explosion of devices, network capacity, applicaJons, video, mobile transacJons and M2M deployments will grow to match global demand” – Yankee Group
“By 2015, more U.S. Internet users will access the Internet through mobile devices than through PCs” – IDC
“�Global mobile subscripJons will reach over six billion by the end of this year and the Asia-‐Pacific region will account for more than half of the worldwide figure in 2011” – ABI Research
“�Demand for tablets in Asia-‐Pacific will increase by 95 percent in 2012, outstripping equivalent shipments in North America or Europe.” – Gartner
“In 2012, mobile workers and consumers will embrace tablets, mobile content, mobile video and personal cloud services at unprecedented levels..” – Yankee Group
“Mobile Revolution” by the Numbers
• US: 103% rate of cell phone penetra?on • More than 10T SMS in 2013 • Almost 25B apps downloaded • Angry Bird: 500 million downloads (across all plaWorms) • 6.5B mobile phones (4.2B toothbrushes) (2012) • 500,000+ iPhone apps • 450,000+ Android apps • 1B Facebook members (2011) • ½ of all searches are done via mobiles (smartphone, tablet)
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1990 2010
Internet Users 2.8 million 1.8 billion
Mobile Phone Subscribers 12.4 million 5.2 billion (79% of world popula?on)
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Mobile Revolution • Mobile is global • Cost effec?ve, convenient • Any?me and anywhere • Contextual
• Cellphone: special-‐purpose device • Smartphone: general-‐purpose device
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The Rise of the Apps
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“There’s An App For That” • Some App Store stats (as of yesterday):
– 574,607 apps – 706 submissions/day – $1.92 average price
5: Lifestyle: 47,351 4: Educa?on: 55,772 3: Entertainment: 58,962 2: Books: 61,175 1: Games: 99,795
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Universities and the Mobile Revolution
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Universities and the Mobile Revolution
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Mobility • User Mobility:
– User should be able to move from one physical loca?on to another loca?on and use the same service.
– The service could be in the home network or a remote network.
– Example: a user travels for business and uses corporate services and applica?ons as if the user were in the office.
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Mobility • Network Mobility:
– User should be able to move from one network to another network and use the same service.
– Example: a user travels from Hong Kong to New Delhi and uses the same GSM phone to access the corporate applica?on through WAP (Wireless Applica?on Protocol). In the home network, the user uses this service over GPRS (General Packet Radio Service), whereas in Delhi he accesses it over the GSM network.
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Mobility • Bearer Mobility:
– User should be able to move from one bearer to another and use the same service.
– Example: a user was using a service through a WAP bearer in his home network in Bangalore. He travels to Coimbatore, where WAP is not supported, so he switches over to a voice or SMS (Short Message Service) bearer to access the same applica?on.
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Mobility • Device Mobility:
– User should be able to move from one device to another and use the same service.
– Example: sales representa?ves use soTware and services on their desktops in the office and con?nue to use these servers/SW seamlessly while on the road.
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Mobility • Session Mobility:
– A user session should be able to move from one user-‐agent environment to another.
– Example: a user was using a service through a CDMA (Code Division Mul?ple Access) network. The user drives through a tunnel and gets disconnected from the network. The user then returns to the office and uses the desktop computer, con?nuing the unfinished session from where it was when the user got disconnected.
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Mobility • Service Mobility:
– User should be able to move from one service to another.
– Example: a user writes an Email and to complete the Email, the user needs to refer to some other informa?on. On a desktop PC, the user simply opens another service (e.g., browser) and moves between services using the task bar. The user should similarly be able to switch among services on resource-‐constrained wireless devices.
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Enablers • Wireless communicaCon networks
– mul?ple networks “covering” the globe – world-‐wide deregula?on and spectrum auc?ons – standard communica?on systems and air link interfaces
• Portable informaCon appliances – laptops, notebooks, sub-‐notebooks – hand-‐held computers, tablets – smartphones
• Internet: – TCP/IP & de-‐facto applica?on protocols – ubiquitous web content
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Wireless versus Fixed Networks • Higher loss-rates due to interference
– emissions of, e.g., engines, lightning • Restrictive regulations of frequencies
– frequencies have to be coordinated, useful frequencies are almost all occupied
• Low transmission rates – local some Mbit/s, regional currently, e.g., 53kbit/s with GSM/GPRS or about
150 kbit/s using EDGE • Higher delays, higher jitter
– connection setup time with GSM in the second range, several hundred milliseconds for other wireless systems
• Lower security, simpler active attacking – radio interface accessible for everyone, base station can be simulated, thus
attracting calls from mobile phones • Always shared medium
– secure access mechanisms important
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History of Wireless Communications • Many people in history used light for communication
– heliographs, flags (“semaphore”), ... – 150 BC smoke signals for communication;
(Greek historian Polybius) – 1794, optical telegraph, Claude Chappe
• Electromagnetic waves: – Faraday demonstrates electromagnetic induction (1831) – J. Maxwell (1831-79): theory of electromagnetic fields, wave equations
(1864) – H. Hertz (1857-94): demonstrates
with an experiment the wave character of electrical transmission through space (1888)
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History of Wireless Communications • 1896 Guglielmo Marconi
– first demonstration of wireless telegraphy (digital!)
– long wave transmission, high transmission power necessary (> 200kW)
• 1907 Commercial transatlantic connections – huge base stations
(100m high antennas) • 1915 Wireless voice transmission New York - San Francisco • 1920 Discovery of short waves by Marconi
– reflection at the ionosphere – smaller sender and receiver, possible due to the invention of the vacuum
tube • 1928 many TV broadcast trials (across Atlantic, color TV, news) • 1933 Frequency modulation (E. H. Armstrong) • 1982 Start of GSM-specification • 1983 Start of the American AMPS (Advanced Mobile Phone System,
analog)
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History of Wireless Communications • 1996 HiperLAN (High Performance Radio Local Area Network)
– ETSI, standardization of type 1: 5.15 - 5.30GHz, 23.5Mbit/s – recommendations for type 2 and 3 (both 5GHz) and 4 (17GHz) as wireless
ATM-networks (up to 155Mbit/s) • 1997 Wireless LAN – IEEE 802.11
– IEEE standard, 2.4 - 2.5GHz and infrared, 2Mbit/s – already many (proprietary) products available in the beginning
• 1998 Specification of GSM successors – for UMTS (Universal Mobile Telecommunications System) as European
proposals for IMT-2000
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History of Wireless Communications • 1999 Standardization of additional wireless LANs
– IEEE standard 802.11b, 2.4-2.5GHz, 11Mbit/s – Bluetooth for piconets, 2.4GHz, <1Mbit/s – Start of WAP (Wireless Application Protocol) and i-mode
• first step towards a unified Internet/mobile communication system • access to many services via the mobile phone
• 2000 GSM with higher data rates – HSCSD offers up to 57,6kbit/s – first GPRS trials with up to 50 kbit/s (packet oriented!)
• 2001 Start of 3G systems – Cdma2000 in Korea, UMTS tests in Europe, Foma (almost UMTS) in Japan
• 2002 – WLAN hot-spots start to spread
• 2005 – WiMax starts as DSL alternative (not mobile) – first ZigBee products
• 2006 – WLAN draft for 250 Mbit/s (802.11n) using MIMO – WPA2 mandatory for Wi-Fi WLAN devices
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