Introduction

Goal of Wireless Networking and Mobile Computingslide 5

• 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.

Enabling Technologiesslide 6

• Development and deployment of wireless/mobile technology and infrastructure
• Miniaturization of computing machinery
• . . . -> PCs -> laptop -> PDAs/smart phones ->embedded computers/sensors
• Development environments, e.g.,
  • Andriod: http://code.google.com/android/
  • iPhone: http://developer.apple.com/iphone/
  • Windows mobile

Pervasive Use of Mobile Wireless Devicesslide 7

• There are around 4 billion mobile phones
• Penetration rates higher than that of the population
• The mobile device is the primary connection
• Tool to the Internet for most people in the world.

List of some countries by number of mobile phones in useslide 8

Source: https://en.wikipedia.org/wiki/List_of_countries_by_number_of_mobile_phones_in_use

List of some countries by smartphone penetrationslide 9

Source: https://en.wikipedia.org/wiki/List_of_countries_by_smartphone_penetration

Disaster Recoveryslide 10

• Tsunami, Hurricane Katrina, South Asian earthquake, Haiti …
• Wireless communication and mobile computing capability can make a difference between life and death !
  • rapid deployment
  • efficient resource and energy usage
  • flexible: unicast, broadcast, multicast, anycast
  • resilient: survive in unfavorable and untrusted environments

Social Networking On the Moveslide 11

Mobile Systemsslide 12

Mobile Cellular Networksslide 13

• PSTN: Public switched telephone network
• PLMN: Public land mobile network
• PSDN: Public switched data network

WLAN Networksslide 14

MANETsslides 15–16

• is a continuously self-configuring, infrastructure-less network of mobile devices connected without wires.
• Each device in a MANET is free to move independently in any direction and will therefore change its links to other devices frequently
• In MANET each device continuously maintain the information required to properly route traffic
• MANETs are a kind of Wireless ad hoc network that usually has a routable networking environment
• The growth of laptops and 802.11/Wi-Fi wireless networking have made MANETs a popular research topic nowadays

Types of MANETSslide 17

• Vehicular Ad hoc Networks (VANETs): are used for communication between vehicles and roadside equipment.
• Smart Phone Ad hoc Networks (SPANs): leverage the existing hardware (primarily Bluetooth and Wi-Fi) in commercially available smart phones to create peer-to-peer networks without relying on cellular carrier networks.
• Internet based mobile ad hoc networks (iMANETs): are ad hoc networks that link mobile nodes and fixed Internet-gateway nodes

Architectural Comparisonslide 18

Mobile and wireless challengesslides 19–22

• Challenge 1: Unreliable and Unpredictable Wireless Coverage
• Wireless links are not reliable: they may vary over time and space

• Challenge 2: Open Wireless Medium
• User/device/system verification is more difficult, mutual authentication may be required, currently, rogue BTS and BS can be deployed, and availability is difficult.
• Most systems aren't designed with redundancy resilience to malicious behavior

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

• Challenge 4: Portability
• Limited battery power
• Limited processing, display and storage

Challenge 5: Changing Regulation and Multiple Communication Standardsslide 23

Common Considerationsslide 24

• Nothing is free
  • Security costs $$$, time, CPU cycles, bandwidth,user-experience, etc.
  • Incentives?

Wireless LANsslide 25

• Advantages
  • very flexible within the reception area
  • ad-hoc networks without previous planning possible
  • (almost) no wiring difficulties (e.g., historic buildings)
  • more robust against disasters like, e.g., earthquakes, fire - or users pulling a plug...
  • cheap (additional users don’t increase cost)
• Disadvantages
  • typically, low bandwidth compared to wired networks
  • (1-10 Mbit/s) due to shared medium, more interferences
  • many proprietary solutions, especially for higher bit-rates, standards take their time (e.g., IEEE 802.11n)
  • products have to follow many national regulations, takes time for global solutions (IMT-2000).
  • safety/security