Networking PPT on WiMAX vs WiFi

WiMAX Vs Wi-Fi

Ashwin Shegaonkar. Roll No. : 227

WiMAX

Worldwide Interoperability for Microwave Access Brand licensed by the WiMax Forum. a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL WiMAX was seen as more of a Metropolitan Area Network (MAN) technology providing a much larger coverage. Based on IEEE 802.16

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WiMAXWiMAX, in fact, comes in two forms, a so called fixed WiMAX and a mobile WiMAX.

WiMAX in its fixed form is seen as a possible alternative to expensive cable and fibre deployment.It is faster to deploy and less expensive and it also offers operators more flexibility in terms of deployment time frame and possible installation areas. 3G or other cellular network operators could see this as a potential substitute or as a complement to their cellular product.

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WiMAX Architecture

MIB Management Information Base4

Wi-Fi

Stands for Wireless Fidelity. Brand licensed by the Wi-Fi Alliance. Wi-Fi is a local area network technology that was originally thought to replace the thousands of miles of LAN cables. Wireless Local Area Networks (WLAN) Based on IEEE 802.11

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Wi-FiWi-Fi has grown from being just a LAN cable replacement technology to a public wireless access technology. Cheap and readily available equipment. WiFi has been viewed as complementary to 3G and other mobile standards as it has worked to enhance mobile services offered by operators. Its coverage is not as great as that of 3G, but it gives a much higher transmission rate than mobile technology. Handoff between WiFi access points is still not possible and, therefore, it is known more as a wireless access technology than a mobile technology.6

Wi-FiNew developments are taking place within the 802.11 standardization group With the increasing popularity of VoIP, many see WiFi as one of the possible means of using VoIP with some form of mobility

802.11r for wireless VoIP and other real time applications802.11s for meshed WiFi networking Making WiFi more mobile could make it more of a substitute to mobile technologies7

Wireless Systems

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802.11 Protocol Stack

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802.16 protocol stack

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Scalability802.11Wide,

802.16Channel

fixed (20MHz) frequency channels

bandwidths can be chosen by operator (e.g. for sectorization) 1.5 MHz to 20 MHz width channels. MAC designed for scalability independent of channel bandwidthMAC

MAC

designed to support 10s of users

designed to support thousands of users.

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Bit Rate: Relative PerformanceChannel Bandwidth 802.11a 20 MHz 10, 20 MHz; 1.75, 3.5, 7, 14 MHz; 3, 6 MHz Maximum Data Rate 54 Mbps Maximum bps/Hz ~2.7 bps/Hz

802.16a

63 Mbps

~5.0 bps/Hz

802.16a is designed for metropolitan performance

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Coverage802.11

802.16Optimized for outdoor NLOS performance Standard supports mesh network topology Standard supports advanced antenna techniques

Optimized for indoor performance

No mesh topology support within ratified standards

802.16 is designed for market coverage13

Range802.11

802.16

Optimized for ~100 meters No near-far compensation. Designed to handle indoor multipath(delay spread of 0.8 seconds). Optimization centers around PHY and MAC layer for 100m range.

Optimized for up to 50 Km Designed to handle many users spread out over kilometers Designed to tolerate greater multi-path delay spread (signal reflections) up to 10.0 seconds PHY and MAC designed with multimile range in mind

802.16 is designed for distance14

Quality of Service (QoS)802.11

802.16a

Contention-based MAC (CSMA/CA) => no guaranteed QoS

Grant-request MAC Designed to support Voice and Video from ground up Supports differentiated service levels: e.g. T1 for business customers; best effort for residential. TDD/FDD/HFDD symmetric or asymmetric Centrally-enforced QoS

Standard cannot currently guarantee latency for Voice, Video

Standard does not allow for differentiated levels of service on a per-user basis TDD only asymmetric 802.11e (proposed) QoS is prioritization only

802.16a is designed for carrier class operation15

Security802.11 Existing 802.11i

802.16a Triple-DES

standard is WPA + WEP

(128-bit) and RSA

(1024-bit) in process of addressing security

802.16a maintains fixed wireless security16

WiMAX vs Wi-Fi

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WiMAX vs Wi-Fi

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Comparison of WiMAX, WiFi and 3G technology

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802.11 vs 802.16: Summary 802.11 and 802.16 both gain broader industry acceptance through conformance and interoperability by multiple vendors 802.16 complements 802.11 by creating a complete MAN-LAN solution802.11 is optimized for license-exempt LAN operation

802.16 is optimized for license-exempt and licensed MAN operation.

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Thank You