Useful Links:

IT Online Dictionaries

• Webopedia - an online dictionary and search engine you need for computer and Internet technology.
• Whatis.com - definitions for thousands of the most current IT-related words.
• Wikipedia - a free encyclopedia that anyone can edit.

• IEEE Standards Association - an international membership organization serving today's industries with a complete portfolio of standards programs.
• ITU - International Telecommunications Union
• U.S. Federal Communications Commission - the primary regulatory agency for telecommunications in the United States
• IETF home page - the TCP/IP folks
• Internet RFCs - Internet "Request For Comments."
• Internet drafts - possibly future RFC's in a draft stage
• How OSI works
• Get IEEE 802
• IEEE 802
• Wireless Communications Technologies
• Wireless Communications FAQ
• Protocols.com - Offers a comprehensive listing of data communications protocols, their functions in respect to the OSI model, the structure of the protocol and various errors and parameters.

• Personal Area Networks (PANs) - a group of technologies that are designed for short-range communications
• Personal Area Networks: Near-field intrabody communication
• Infrared Data Association
• Infrared WPANs (IrDA)
• IEEE 802.15 Working Group for WPAN
• Bluetooth
• IEEE 802.15.1 and Bluetooth
• IEEE 802.15.1 standard - fully compatible with Bluetooth version 1.1.
• IEEE 802.15.1
• IEEE 802.15.4-Low Rate WPANs (ZigBee)
• ZigBee
• QuickStudy: ZigBee
• WiMedia Alliance
• Bluejacking
• Bluesnarfing

• IEEE 802.11 - first IEEE standards for wireless LANs
• IEEE 802.11 from TechWeb
• IEEE 802.11 from Wikipedia
• Wireless Local Area Network (WLAN)
• Wireless LAN from Wikipedia
• IEEE 802.11a standard
• IEEE 802.11b standard - also known as Wi-Fi
• An article comparing performance of 802.11b and 802.11a wireless technologies
• IEEE 802.11g - enhances 802.11b networks
• Read an article about the advantages and disadvantages of IEEE 802.11g.
• IEEE 802.11e Standard - defines enhancements to the MAC layer of 802.11 to expand support for LAN applications that require Quality of Service (QoS).
• IEEE 802.11e Standard from Wikipedia
• IEEE 802.11n Standard - aimed at providing data rates higher than 100 Mbps
• Unified 802.11n Wi-Fi Standard to Emerge in Mid-2006
• IEEE 802.11r Standard - expected to enhance the convergence of wireless voice, data, and video.
• IEEE 802.11r Standard from Wikipedia
• IEEE 802.11s Standard - help you solve a task, such as deploying a wireless network over the entire downtown area of a medium-sized city to provide seamless connectivity to all city employees.
• HiperLAN - offers high-speed wireless connectivity with up to 54 Mbps and seamless connectivity with other types of communications systems, such as cellular telephone systems and FireWire networks.
• Enabling Fast Wireless Networks with OFDM
• Access Points - provides wireless LAN devices with a point of access into a wired network
• Power over Ethernet (PoE) - how DC power is delivered to the AP through the unused wires in a standard UTP Ethernet cable
• Power over Ethernet (PoE)
• Wireless Bridges - expand the functionality of WLANs

• Wireless Metropolitan Area Networks (WMAN) - a group of technologies that provide wireless connectivity across a substantial geographical area such as a large city
• Wireless MAN from Wikipedia
• Local Multipoint Distribution Service (LMDS)
• What is LMDS?
• Multichannel Multipoint Distribution Service (MMDS) - sometimes called wireless cable
• Multichannel Multipoint Distribution Service (MMDS) from Wikipedia
• What is MMDS?
• IEEE 802.16 (WiMAX) - a standard for wireless broadband metropolitan area networks

• Wireless Short Message Service (SMS) SMS allows for the delivery of short, text-based messages between wireless devices.
• SMS from Wikipedia
• Cellular Networks
• 1G Cellular Networks
• 1G: Advanced Mobile Phone Service (AMPS) from Wikipedia
• 1G: Advanced Mobile Phone Service (AMPS)
• 2G: Global System for Mobile communications (GSM)
• How a GSM Network Operates
• GSM from Wikipedia
• 2.5G: General Packet Radio Service (GPRS)
• 2.5G: General Packet Radio Service (GPRS) from Wikipedia
• 3G Cellular Networks
• 3G Today
• Wireless Application Protocol (WAP) - provide a standard way to transmit, format, and display Internet data for devices such as cell phones.
• Wireless Application Protocol (WAP)
• i-mode - an Internet access system
• i-mode from Wikipedia
• Java 2 Micro Edition (J2ME) - a Java subset for programming wireless devices, which enables a cellular phone to access remote applications and e-mail as well as run programs on the cellular phone itself.
• Sun Java Wireless Toolkit for CLDC
• Binary Runtime Environment for Wireless (BREW) - a very small program that resides on a wireless device and is capable of running applications that can be downloaded by the device on demand.
• Binary Runtime Environment for Wireless (BREW) from wikipedia
• Wi-Fi VoIP and Cellular Network Integration
• Low Earth Orbit (LEO) - LEO satellites circle the Earth at an altitude of 200 to 900 miles.
• Elliptical Orbits - Medium Earth Orbit (MEO). MEO satellites orbit the Earth at altitudes between 1,500 and 10,000 miles.
• Geosynchronous Earth Orbit (GEO) - GEO satellites are stationed at an altitude of 22,282 miles. A GEO satellite’s orbit matches the rotation of the Earth and moves as the Earth moves.
• Geostationary Operational Environmental Satellite

• Radio Frequency Identification (RFID) - from Wikipedia
• Radio Frequency Identification (RFID)
• About RFID
• Frequencies for RFID Systems
• Electronic Product Code (EPC) - a standardized numbering scheme that can be programmed in a tag and attached to any physical product.
• Electronic Product Code (EPC)
• Electronic Product Code (EPC) from Wikipedia
• EPCglobal Inc.
• RFID Tags - commonly known as transponders, a combination of transmitter and responder.
• RFID Tags
• RFID Tag Balances Privacy and Retailer Interests
• RFID Tag Privacy Concerns
• Security Concerns Regarding RFID Applications
• Inductive Coupling - Some RFID tags and readers exchange information using inductive coupling between their antennas.

• Decimal Number System
• Binary Number System - a number system uses a base number of 2 instead of 10
• A Tutorial on Binary Numbers
• Conversion Between Different Number Systems
• Analog vs. Digital
• ASCII code
• Radio Waves - Radio waves are the most common and effective means of wireless communications today. Energy travels through space or air in electromagnetic waves.
• Radio Frequency - the rate at which a radio circuit creates the waves or the number of times a cycle occurs within one second.
• Frequency of a Wave
• Wavelength
• Infrared
• Infrared Light - adjacent to visible light (although invisible), and is a much better medium for data transmission because it is less susceptible to interference.
• Modulation - the process of encoding the digital signals (bits) onto an analog wave.
• Binary Signals
• Quadrature Amplitude Modulation (QAM)
• Spread Spectrum - Spread spectrum transmission takes a narrow band signal, and spreads it over a broader portion of the radio frequency band, resulting in less interference and fewer errors.
• Frequency Hopping Spread Spectrum (FHSS)
• Direct Sequence Spread Spectrum (DSSS)
• Baud Rate vs. Bits per Second (bps) - both used in measuring the speed of radio transmission.
• Bandwidth
• Decibel
• Decibel A, B and C:
• Calculate Decibel
• Radiation Patterns
• Radiation Pattern from Wikipedia
• Antenna Polarization Considerations in Wireless Communications Systems
• Horn Antenna
• Smart Antenna
• Coaxial Cable

• Bandpass Filters
• Low-pass filter
• High-pass filter
• Frequency Mixers - combine two radio frequency inputs to create a single output
• Amplifiers
• Frequency Division Multiple Access (FDMA) - divides the bandwidth of a channel into several smaller frequencies bands
• Time Division Multiple Access (TDMA) - divides the transmission time into several slots
• Code Division Multiple Access (CDMA) - used primarily for cellular telephone communications
• Wideband Code Division Multiple Access (W–CDMA)
• Orthogonal Frequency Division Multiplexing (OFDM) - splits a high-speed digital signal into several slower signals running in parallel, and sends the transmission in parallel across several lower-speed channels.
• Orthogonal Frequency Division Multiplexing (OFDM) from Wikipedia
• Orthogonal Frequency Division Multiplexing (OFDM) Forum
• Orthogonal Frequency Division Multiple Access (OFDMA)
• Circuit Switching - A dedicated and direct physical connection is made between the sender and the receiver.
• Packet Switching - Data transmissions are broken into packets, and each packet is sent independently.
• CSMA
• CSMA/CA & CSMA/CD
• Ultra Wideband (UWB) Technology
• UWB Forum
• Unlicensed National Information Infrastructure (U-NII) band - intended for devices that provide short-range, high-speed wireless digital communications
• Baseband and Broadband Transmissions
• Free Space Optics (FSO) - an optical, wireless, point-to-point, line-of-sight broadband technology
• Fixed Wireless

• Advanced Encryption Standard
• Public Key Infrastructure (PKI) - a unique security code, or key, provided by a certificate authority
• Wired Equivalent Privacy (WEP)
• Wi-Fi Protected Access (WPA)
• IEEE 802.11i - a robust security network association (RSNA)

• Uganda Wireless Health-Care Aid
• For more information about wireless communications in the health care industry, read the following articles: article 1 and article 2
• Voice over Wireless LAN (VoWLAN) - VoWLAN takes advantage of Voice over IP (VoIP) technology but uses the wireless infrastructure to carry both voice and data.
• Voice over Wireless LAN (VoWLAN)
• Voice over Wireless LAN (VoWLAN)
• Voice over Wireless LAN (VoWLAN)
• Smartphone - a full-featured mobile phone with personal-computer-like functionality

• CNet Tech News - current technical for computers, networking and IT
• CertCities - news and information about computer and IT certifications
• Tom’s Hardware Guide: Home page and News - a leading website for hardware and technology reviews and news
• The PC Guide - offers detailed PC reference information
• Network Magazine - a good entry level magazine for networking
• Windows and .NET Magazine - a good magazine highlighting Microsoft networking
• CertTutor.net - practice exams and practical advice for people seeking IT certification
• Braindump Central - a valuable site to get sample questions for certification exams