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Mobile Computing CSE  40814/60814  

Fall  2012  

Course Overview

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•  Instructor: Christian Poellabauer –  325D Cushing Hall –  cpoellab@cse.nd.edu –  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 –  saguinag@nd.edu, nyadav@nd.edu –  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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