telecom, wireless & networks

Succeeding with Technology

Telecom, Wireless & Networks

Fundamentals Media, Devices, and Software Wireless Telecommunications Networks and Distributed Computing

Please discontinue use of cell phone and turn off ringer

Chapter 5


Telecommunications

Telecommunications: The electronic transmission of signals over a medium for communications.

(cables or air)

Sender and Receiver must “speak” the same language.


Voice Communication It has been said that

only about 16% of spoken communication is verbal

Sound waves demo demo

Wave characteristics: Frequency Amplitude Phase


Types of Signals

Analog Signal: transmit sound using continuously varying levels of voltage.

Digital Signal: transmits data using two discrete states of voltage: high and low


Modulation

More about wavesDifferent wavesElectromagnetic waves

Analog modulationAMFM

Examples


Digital Modulation

What might FSKLook like?


Signal Frequency

Frequency: the speed at which a signal changes from high to low.

Bandwidth: the range of signal frequencies that can be sent over a given medium at the same time. Often expressed as bits per second Broadband: typically 2 – 5 Mbps


5.2

Networking Media, Devices, and Software

• Twisted pair cable• Coaxial cable• Fiber-optic cable• Radio wave• Modem

• Network adapter• Microwave transmission• Communications satellite• Ethernet

Key Terms

The fundamental components of telecommunications networks


Networking Media Twisted Pair Cable

Used for traditional phone lines, twisted pairs of wires in plastic sheathing.

Coaxial CableUsed for home cable TV, thick copper core wire – faster than twisted pair.

Fiber Optic CableThin strands of glass are used to send light beams – highest bandwidth cable, most expensive.

Radio WavesElectromagnetic waves transmitted through the air at various frequencies.


Radio Waves Radio waves use differing frequencies to carry

many types of information: AM & FM Radio Short Wave & CB Radio Television Broadcasts Garage Doors Openers Baby Monitors Cordless Phones Cell Phones Radio Controlled Cars and Airplanes Global Positioning Systems Wireless Computer Networks Microwave Communications

http://electronics.howstuffworks.com/radio-spectrum1.htm


EHF

SHF

UHF

VHF

HF

MF

LF

VLF

AM Radio (535-1700 kHz)

FM Radio (88-108 MHz)

CB Radio (26.96-27.41 MHz)

TV CH 2-6 (54-88 MHz)

TV CH 7-13 (174-220 MHz)

Cordless Phones (40-50 MHz)

Cell Phones (824-849 MHz)

Air traffic Control (960-1,215 MHz)Global Positioning System 1.23 and 1.58 GHz

10 kHz

30 kHz

300kHz

3 MHz

30 MHz

328.6 MHz

2.9 GHz

30 GHz

900-MHz cordless phones

Deep space radio communications (2.29-2.3 GHz)

The Radio Spectrum

Wi-fi Wireless Networks (2.4 GHz)

300 GHz

The complete picture


Networking Devices

Modem: modulates and demodulates signals from one form to another.

Network Adapter: Expansion card, or external device installed on a computing device used to connect to a network.


Networking Devices

Network Control Devices: Hub/Switch

Controls flow of data between devices on a network

Router Routs packets to destinations and

connects one network to another

Wireless Access Point Allows devices to connect

wirelessly to a wired network


15

High-frequency radio signals sent up to 30 miles through the air.

Microwave Communications


16

Microwave Communications

Line-of-sight communications

!


17

Microwave CommunicationsSatelliteTransmission

Line-of-sight required


5.3

Wireless Telecommunications Technologies

• Cellular network• Cellular carrier• Global positioning system• Wireless fidelity (wi-fi)

• WiMAX• Bluetooth• Radio frequency identification• Near-field communication (NFC)

Key Terms


Cell Phone Technologies

A cellular network is a radio network in which a geographic area is divided into cells, with a transmission tower and station at the center of each cell, to support mobile communications.


Cell Phone Technologies

A cellular carrier is a company that builds and maintains a cellular network and provides cell phone service to the public.


GSM and CDMA

Digital networking standards for cell phone networks are GSM and CDMA.

GSM is the most popular global standard for mobile phones

The CDMA networking standard is predominantly used in the United States where it is in equal competition with GSM.

GSM CDMA

AT&TT-Mobile

VerizonSprint


GSM and CDMA

GSM Phones include a subscriber identity module (SIM) for security and convenient data transfer between phones.

GSM CDMA

AT&TT-Mobile

VerizonSprint


Wireless Technologies

Aircraft Navigation

The Global Positioning System (GPS) uses satellites to pinpoint the location of receivers on earth.

How GPS works


Wireless Technologies Wireless Fidelity (IEEE 802.11s), or Wi-fi, is

wireless networking technology that makes use of access points to connect devices to networks.

AccessPoint

• 250-1,000 ft range

• 802.11b 4.5 Mbps

• 802.11g 11 Mbps

• 802.11n 74 Mbps

• www.boingo.com



WiMAX (IEEE 802.16) is the next generation broadband technology that is both faster and has a longer range than Wi-fi – 31 miles!

http://en.wikipedia.org/wiki/WiMAX Seattle’s Space Needle To Become WiMax Antenna


Wireless Technologies Bluetooth is wireless technology

that enables a wide variety of digital devices to communicate directly.

• 33 ft range

• 1 Mbps

• www.bluetooth.com


Bluetooth



Infrared (IrDA) technology utilizes infrared rays to send data over a short distance wirelessly.

• 14 ft range

• Narrow-angle cone (30o)

• Line-of-sight

• 4-16 Mbps

• www.mzoop.com


Wireless Comparison

Wi-fi Access point centered LAN

Omni-direction

Through obstructions

250 ft range indoors

11 Mbps

Bluetooth Point-to-point

Omni-direction

Through obstructions

33 ft 1 Mbps

Infrared Point-to-point

Narrow-angle

Line-of-sight 14 ft 4 Mbps

telecom, wireless & networks

Documents

radio network

network adapter

wired network

mobile communications

sight communications

mhzcb radio

khzfm radio

cell phone networks