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Fixed WiMAX. By, Shah Ankur Vasant. WiMAX. WIMAX stands for Worldwide Interoperability for Microwave Access The original IEEE 802.16 standard (now called "Fixed WiMAX") was published in 2001 . WiMAX adopted some of its technology from WiBro , a service marketed in Korea - PowerPoint PPT Presentation
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Fixed WiMAX
By,Shah Ankur Vasant
• WIMAX stands for Worldwide Interoperability for Microwave Access
• The original IEEE 802.16 standard (now called "Fixed WiMAX") was published in 2001.
• WiMAX adopted some of its technology from WiBro, a service marketed in Korea
• Its a communication technology for wirelessly delivering high-speed Internet service to large geographical areas
Geographical Area Coverage: 30 miles Bandwidth: 75 MbpsFrequency bands- 2 to 11 and 10 to 66 Ghz(licensed
and unlicensed bands respectively)Defines both MAC and PHY layer
WiMAX
WiMax Over Wi-Fi
Coverage Area:Below 100m for Wi-Fi
ScalabilitySupports around 10 users
Bitrate:54 Mbps in 20 Mhz Channels
CostFor Laying Cables throughout.
802.16 (Now withdrawn) - 2001• basic 802.16 standard released in
2001,provided high data links at 11 and 60 GHz frequencies.802.16a (Now withdrawn) - 2003
• Uses licensed frequencies from 2 to 11 GHz• Supports Mesh Network802.16b (Now withdrawn) • Frequencies between 5 and 6 GHz• Provided Quality of Service(QoS).
802.16 Standards
802.16c (Now Withdrawn) -2002• Provided a system profile for operating between 10 and 66
GHz and provided more details for operations within this range• Aim was to enable greater levels of interoperability.
802.16d (802.16-2004 or Fixed WiMAX)• Major revision of the 802.16 standard• Resulted in withdrawal of all previous standards• Improvements to 802.16a including the use of 256 carrier
OFDM• Only addressed fixed operation.• High Data Rates of 75 Mbps802.16e (802.16-2005 or Mobile WiMAX)• For nomadic and mobile use• Lower data rates of 15 Mbps• Enables full nomadic and mobile use including handover
Wireless access can be divided into three classes• Stationary• Pedestrian• Vehicular
802.16 Standards is classified into two types of usage models
• Fixed WiMAX•Mobile WiMAX
Types Of WiMAX
IEEE 802.16-2004•Current Standard for using fixed WiMax• 3.5 GHz and 5.8 GHz frequency bands• Frequency division duplexing (FDD) • Time division duplexing (TDD)
IEEE 802.16e - 2005• extension to the 802.16-2004• supports mobile communications• 2.3 and 2.5 GHz frequency bands.
802.16d 802.16e
Spectrum Below 11 GHz Below 6GHz
Bit Rate Up to 75Mbps @ 20MHz Channel
Up to 15Mbps @ 5MHz Channel
Modulation OFDM 256 Sub-Carrier QPSK,16QAM,64QAM Scalable OFDMA
Mobility Fixed Fixed and Mobile
Channel BandwidthSelectable Channel
Bandwidths between 1.25-20MHz
2.3 - 5 MHz
Cell Radius3-5 Miles
Depends on tower height, power etc.
1-3 Miles
1. WiMAX Base Station (BS) • Base Station is similar to a cellphone tower and Covers A radius of 30miles(3000 SqFt)
2. WiMAX receiver (WiMAX CPE)• Customer Premise Equipment• Receiver could be a small box or PCMCIA card, or they could be built into a laptop
A WIMAX system consists of
Fixed WiMAX
• P2P Point to Point• P2MP Point to Multi Point• Mesh Network
WiMAX Network Architecture
P2P and P2MP
Mesh
Non-Line-Of-Sight : • WiFi sort of service, where a small antenna on your computer
connects to the tower• uses a lower frequency range -- 2 GHz to 11 GHz• Lower-wavelength transmissions are not as easily disrupted by
physical obstructions -- they are better able to diffract or bend around obstacles.
Line-Of-Sight : • fixed dish antenna points straight at the WiMAX tower from a
rooftop or pole• stronger and more stable• Allows to send a lot of data with fewer errors• Uses High Frequencies, ranges reaching 66 Mhz• Less Interference and More Bandwidth
Modes Of Operation
Protocol Layers Of WiMAX802.16 Protocol Architecture has 4 layers: Convergence, MAC, Transmission and physical, which can be map to two OSI lowest layers: physical and data link
ConvergenceMedium Access Control
TransmissionPhysical
OSI Data Link Layer
OSI Physical Layer
MAC Protocol:Convergence sub-layer:
• Handle the higher-layer protocols Common part sub-layer:
• Channel access, connection establishment and maintenance & QoS
Security sub-layer:• Authentication, secure key exchange and encryption
Physical and transmission layer functions:• Encoding/decoding of signals• Preamble generation/removal• Bit transmission/reception
Protocol Architecture
Physical Layer Features:• Frequency Band• Channel Bandwidth• MIMO• FDD/TDD• Signal Modulation:
Data Link Layer Features:• access protocol,• security and• session establishment functions.
WiMAX PHY Frame
• Scalability• Quality of Service• Range• Coverage
Features Of WiMAX
• Faster than broadband service• No need to lay cables thus reducing cost• Easier to extend to Sub-Urban and rural areas• Much Wider coverage• Can use licensed spectrum• Provides data, telecommunication
services and portability.
Advantages of WiMAX
• Lack of Quality• Low bit rate over Long distance• Speed of connectivity• Sharing of bandwidth• WiMax over Wi-Fi• Expensive network• Bad Weather• Power consuming
Disadvantages
QUESTIONS ??