MOBCOMP LECTURE 1

MOBILE COMPUTING
Chapter 1: Outline
 1.1 Introduction to Mobile Computing
 1.2 Radio Propagation
 1.3 Antennas
 1.4 Cellular Systems
 1.5 Wireless Link Characteristics




ERIC SAVIOUR ARYEE OKAI OCT,2013

MOBILE COMPUTING
1.1 INTRODUCTION
 What is Mobile Computing?
 Mobile Computing is a technology that allows transmission of data, voice and video via a computer or any other wireless enabled device without having to be connected to a fixed physical link.


ERIC SAVIOUR ARYEE OKAI OCT,2013

Why Go Mobile?
• Enable anywhere/anytime connectivity
• Bring computer communications to areas without pre-existing infrastructure
• Enable mobility
• Enable new applications
• An exciting new research area

ERIC SAVIOUR ARYEE OKAI,

OCT, 2013

Comparison to Wired Net.
• Wired
Networks

• Mobile
Networks

-

- low bandwidth
- hidden terminal problem - low power machines
- low resource machines - need proximity
- higher delay
- disconnected operation high bandwidth can listen on wire high power machines high resource machines - need physical access(security) - low delay
- connected operation

ERIC SAVIOUR ARYEE OKAI,

OCT, 2013

WIRELESS TRANSMISSION
1.2 RADIO PROPAGATION: Radio propagation is the behavior of radio waves when they are transmitted, or propagated from one point on the Earth to another, or into various parts of the atmosphere.
 As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, diffraction, and scattering. 

ERIC SAVIOUR ARYEE OKAI,

OCT, 2013

ASSIGNMENT #1


With the aid of simple diagram(s), explain the three propagation phenomena.

ERIC SAVIOUR ARYEE OKAI,

OCT, 2013

Radio Propagation Cont’d


Radio propagation is also affected by several other factors determined by its path from point to point. This path can be a direct line of sight path or an over-thehorizon path aided by refraction in the ionosphere, which is a region between approximately 60 and 600 km.[

ERIC SAVIOUR