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BASIC TELECOMMUNICATIONS

BASIC TELECOMMUNICATIONS . WiFi networks Part ll. BASIC TELECOMMUNICATIONS . WiFi is an unlicensed RF technology, in other words anybody can set up a wireless hot spot without having to obtain a license

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BASIC TELECOMMUNICATIONS

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  1. BASIC TELECOMMUNICATIONS WiFi networks Part ll

  2. BASIC TELECOMMUNICATIONS • WiFi is an unlicensed RF technology, in other words anybody can set up a wireless hot spot without having to obtain a license • Cellular on the other hand is a licensed spectrum and is limited to the LECs (Local Exchange Carriers) • There is a limit to the amount of power that can be transmitted by a wireless access point

  3. BASIC TELECOMMUNICATIONS • The FCC (Federal Communications Commission) has set the maximum transmitter power output (TPO) of a WAP to 1000mW (1 watt) • The total amount of gain or equivalent isotropically radiated power (EIRP) including amplification of an antenna and adding a higher gain antenna is 36dBm • dBm is a measure of power ratio of the measured power referenced to 1mW (milliwatt)

  4. BASIC TELECOMMUNICATIONS • WiFi operates in the 2.4GHz and 5GHz range How many hertz is 2.4GHz?

  5. BASIC TELECOMMUNICATIONS • Because of the low power transmission and frequency range of WAPs they’re susceptible to interference from other devices that transmit energy in the same frequency range Can you name a few of the common household devices that might cause interference with the WiFi signal?

  6. BASIC TELECOMMUNICATIONS Sources of interference come from: • Microwave ovens • 2.4 and 5GHz cordless phones • Baby monitors • Garage door openers • Competing wireless routers (all of your neighbors and businesses that are close by)

  7. BASIC TELECOMMUNICATIONS • An alternative RF network is Bluetooth which is used for short distance connections approximately 30’ • You are probably familiar with the Bluetooth headset that can mate up to your phone

  8. BASIC TELECOMMUNICATIONS • Bluetooth operates in the ISM (Industrial, Scientific and Medical) band, 2400 to 2480MHz or 2.4GHz • There are also quite a few standard releases such as Bluetooth 1.0, 1.1, 1.2, 2.0 EDR, 2.1EDR, and 3.0 EDR (Enhanced Data Rate) • As of June 2010 the Bluetooth 4.0 standard was released Official Bluetooth logo

  9. BASIC TELECOMMUNICATIONS The release of these new standards has made it possible to wirelessly connect to many more devices: • Pairing up your vehicle • Headsets and intercom • Key boards and mouse • Speakers • File transfers between devices • Game controllers • The list keeps growing

  10. BASIC TELECOMMUNICATIONS • Another network that is gaining notoriety is WiMax (Worldwide Interoperability for Microwave access) • This network was first rolled out in South Korea in 2006 and in the U.S. the first WiMax capable phones and network was rolled out in 2008 • So the WiMax networks are still fairly new and under continued development

  11. BASIC TELECOMMUNICATIONS • WiMax is both a licensed and unlicensed spectrum, however most LECs and ISPs are the main providers • WiMAXis an IP based, wireless broadband access technology that provides performance similar to 802.11/Wi-Fi networks with the coverage and QOS (quality of service) of cellular networks

  12. BASIC TELECOMMUNICATIONS • WiMAX can provide broadband wireless access (BWA) up to 30 miles for fixed stations, and 3 - 10 miles for mobile stations • WiMax is part of the 4G wireless communication technology and can provide up to 1Gbps through put “WiFi on steroids” • The main advantage of WiMax over WiFi is the distances that can be covered with WiMax, whereas the max distance for WiFi is approximately 300’

  13. BASIC TELECOMMUNICATIONS • Devices that provide connectivity to a WiMAX network are known as the subscriber station (SS) • connectivity to a WiMAX network is made through a device that is called a dongle, generally these devices are connected to a notebook or netbook computer via USB port

  14. BASIC TELECOMMUNICATIONS • The WiMax frequency allocation is currently 2.3GHz, 2.5GHz and 3.5GHz • In the U.S. the 2.5GHz frequency range is being used which is just above the WiFi frequency of 2.4GHz • WiMax standards are being developed to provide a dedicated wireless TV spectrum, so far Verizon and AT&T have purchased large chunks of this spectrum which is in the 500 to 800MHz range

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