Transcript Wireless Communication

Mobile and Ad hoc Networks
Background of Ad hoc
Wireless Networks
Wireless Communication
Technology and Research
Ad hoc Routing and
Mobile IP and Mobility
Wireless Sensor and Mesh
Networks
Student Presentations
Wireless Adhoc and Sensor Networks
http://web.uettaxila.edu.pk/CMS/SP2012/teAWNms/
Outline
 Wireless Networks
 Cellular Networks
 Ad hoc Networks
 Sensor Networks
 Areas of research
Coverage of Wireless Mobile Systems
Transmission Capacity
Transmission capacity as a function of mobility in some radio access systems
Medical and Healthcare Applications
 Possibility for Remote consulting (including
Audio Visual communication)
Applications - I
 Vehicles
 transmission of news, road condition, weather,
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music via DAB
personal communication using GSM
position via GPS
local ad-hoc network with vehicles close-by to
prevent accidents, guidance system, redundancy
vehicle data (e.g., from busses, high-speed trains)
can be transmitted in advance for maintenance
Applications – I (Contd.)
 Emergencies
 early transmission of patient data to the hospital,
current status, first diagnosis
 replacement of fixed infrastructure in case of
earthquakes, hurricanes, fire etc.
 crisis, war, ...
Typical application: road traffic
Mobile and wireless services – Best Connected
Applications - II
 Travelling salesmen
 direct access to customer files stored in a central
location
 consistent databases for all agents
 mobile office
 Replacement of fixed networks
 remote sensors, e.g., weather, earth activities
 flexibility for trade shows
 LANs in historic buildings
Applications – II (Contd.)
 Entertainment, education, ...
 outdoor Internet access
 intelligent travel guide with up-to-date location
dependent information
 ad-hoc networks for multi user games
Location dependent Services
 Location aware services
 what services, e.g., printer, fax, phone, server etc.
exist in the local environment
 Follow-on services
 automatic call-forwarding, transmission of the actual
workspace to the current location
 Information services
 „push“: e.g., current special offers in the supermarket
 „pull“: e.g., where is the Black Forrest Cherry Cake?
Location dependent Services (Contd.)
 Support services
 caches, intermediate results, state information etc.
„follow“ the mobile device through the fixed network
 Privacy
 who should gain knowledge about the location
Wireless systems: overview of the development
Simple reference model
Influence of mobile communication to the layer model
Scope of Wireless technologies
The envisioned future of communication
Overlay Networks – Solution of the future
Areas of research in mobile communication
 Wireless Communication
 transmission quality (bandwidth, error rate, delay)
 modulation, coding, interference
 media access, regulations
 ...
 Mobility
 location dependent services
 location transparency
 quality of service support (delay, jitter, security)
 Routing
 ...
Areas of research in mobile communication
 Portability
 power consumption
 limited computing power, sizes of display, ...
 usability
 Security
 …
Classic Mail Store and Forwarding Technique?
Fundamentals of Cellular Systems
Traffic and Control channels
Automatic Location Update
Automatic Call Forwarding using HLR-VLR
Call Setup from MH (Cell Phone) to BS?
Mobility and Handoff
Handoff Scenarios with Mobility Locations
MANETs: Mobile Ad hoc Networks
Mobile Ad hoc Network Characteristics
 An autonomous system of nodes (MHs)
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connected by wireless links
Lack of fixed infrastructure relays
Absence of centralized authority
Peer-to-peer connectivity Multi-hop
forwarding to ensure network connectivity
Topology may change dynamically
Random Multi-hop Graph
Energy-constrained
Bandwidth-constrained, variable capacity links
Mobile Ad Hoc Network (MANET)
Applications of MANETs
 Defense applications: On-the-fly communication
set up for soldiers on the ground, fighter planes
in the air, etc.
 Crisis-management applications: Natural
disasters, where the entire communication
infrastructure is in disarray
 Tele-medicine: Paramedic assisting a victim at a
remote location can access medical records,
can get video conference assistance from a
surgeon for an emergency intervention
Applications of MANETs (Contd.)
 Tele-Geo-processing applications: Combines
geographical information system, GPS and high
capacity MS, Queries dependent on location-
information of the users, and environmental
monitoring using sensors
 Virtual navigation: A remote database contains
geographical representation of streets,
buildings, and characteristics of large metropolis
and blocks of this data is transmitted in rapid
sequence to a vehicle to visualize needed
environment ahead of time
Applications of MANETs (Contd.)
 Education via the internet: Educational
opportunities on Internet to students and other
interested individuals and it is possible to have
last-mile wireless Internet access
Embedded Sensor Networks
Embedded Sensor Networks
Micro-sensors, on-board
processing, and wireless
interfaces all feasible at
very small scale
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 can monitor phenomena
“up close”
Will enable spatially and
temporally dense
environmental monitoring
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 Embedded Networked Sensing
will reveal previously
unobservable phenomena
Example use of a Sensor Network
 Measuring pollutant
 concentration
 Pass on information to
 monitoring station
 Predict current
location of pollutant
contour based on
various parameters
 Take corrective action
Wireless Sensor Networks – Architecture
What is a Sensor and a Sensor Network?
 Portable and self-sustained (power, communication, intelligence)
 Capable of embedded complex data processing
 Note: Power consumed in transmitting 1Kb data over 100m is equivalent
to executing 30M Instructions on 10MIPS processor
 Technology trends predict small memory footprint may not be a limitation
in future sensor nodes
 Equipped with multiple sensing, programmable computing and
communication capability
Sensors and Wireless Radio
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Types of sensors:
 Pressure,
 Temperature
 Light
 Biological
 Chemical
 Strain, fatigue
 Tilt
• Capable of surviving harsh environments
(heat, humidity, corrosion, pollution, radiation,
etc.)
• Could be deployed in large numbers
Wireless Sensor Networks
 Wireless sensor networks are a collection of tiny
disposable and low power devices
 A sensor node is a device that converts a sensed
attribute (e.g. temperature, vibration) into a form
understandable by users
 Wireless sensor networks have been used for years
for a number of applications
 The number of sensors can be large to cover as much
area as desirable
 Sensor networks are usually unattended and some
degree of fault tolerance needed
Characteristics of Wireless Sensor Networks
 Advantages:
 Ease of deployment
 Extended range
 Fault tolerance
 Mobility (some)
 Limitations:
 Low-bandwidth
 Error-prone transmissions
 Need for collision-free channel access
 Limited amount of energy available
 Usually sensors placed where it is difficult to replace their
batteries
Assignment #2
 Define terms and IEEE standards mentioned in Slide 17
Q&A
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