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Asstt. Professor
Adeel Akram
A Technological
Overview
Content for some slides is taken from HowStuffWorks.com
Some information is gathered from WiMAXForum documents
Internet Today
 How we access the Internet today.
Photo courtesy Intel
There are basically three different options:
 Broadband access - In your home, you have either a DSL or cable modem.
At the office, your company may be using a E1 or a E3 line.
 WiFi access - In your home, you may have set up a WiFi router that lets
you surf the Web while you lounge with your laptop. On the road, you can
find WiFi hot spots in restaurants, hotels, coffee shops and libraries.
 Dial-up access - If you are still using dial-up, chances are that either
broadband access is not available, or you think that broadband access is too
expensive.
 The main problems with broadband access are that it is pretty
expensive and it doesn't reach all areas.
 The main problem with WiFi access is that hot spots are very small, so
coverage is sparse.
Solution: WiMAX
 What if there were a new technology that solved all of
these problems?
This new technology would provide:
 The high speed of broadband service
 Wireless rather than wired access, so it would be a lot less
expensive than cable or DSL and much easier to extend to suburban
and rural areas
 Broad coverage like the cell phone network instead of small WiFi
hotspots
 This system is actually coming into being right now, and it is called
WiMAX. WiMAX is short for Worldwide Interoperability for
Microwave Access, and it also goes by the IEEE name 802.16.
What is WiMAX
 WiMAX stands for Worldwide Interoperability for
Microwave Access.
 WiMAX/IEEE 802.16 is a global standard-based
technology for Broadband Wireless Access
 Equivalent to Wi-Fi Alliance for IEEE 802.11
 WiMAX forum will certify Interoperability of IEEE
802.16 and ETSI HiperMAN
What is WiMAX
 WiMAX is a broadband wireless technology that is largely
supported by the computer and the telecom industry, costeffective and standard base.
 It is engineered to deliver the latest type of ubiquitous,
fixed and mobile services such as VoIP, Information
Technology services and Video at very low cost.
 WiMAX systems are able to cover a large geographical area,
up to 50 km and to deliver significant bandwidth to endusers up to 72 Mbps
WiMAX Future
 WiMAX could replace cable and DSL services,
providing universal Internet access just about
anywhere you go.
 WiMAX will also be as automatic as WiFi -- turning
your computer on will automatically connect you to
the closest available WiMAX antenna.
WiMAX vs WiFi
 In practical terms, WiMAX would operate similar to WiFi but at:
 Higher speeds
 Over greater distances and
 For a greater number of users.
 A WiMAX system consists of two parts:
Logo courtesy Intel
 A WiMAX tower, similar in concept to a cell-phone tower - A single
WiMAX tower can provide coverage to a very large area -- as big as 3,000
square miles for a single tower versus 10 sqr miles for cell [Rhode Island is
2000 sqr miles; Bermuda 22 sqr miles; and Delaware 2489 sqr miles]
 A WiMAX receiver - The receiver and antenna could be a small box or
PCMCIA card, or they could be built into a laptop the way WiFi access is
today.
WiMAX Tower
 A WiMAX tower station can connect
directly to the Internet using a highbandwidth, wired connection (for
example, a E3 line).
 It can also connect to another WiMAX
tower using a line-of-sight, microwave
link.
 This connection to a second tower (often
referred to as a backhaul), along with the
ability of a single tower to cover up to 3,000
square miles, it is what allows WiMAX to
provide coverage to remote areas.
Photo courtesy Intel
WiMAX transmitting tower
WiMAX Service Modes
 WiMAX actually can provide two forms of wireless service:
 Non-line-of-sight, WiFi sort of service, where a small antenna on
your computer connects to the tower. In this mode, WiMAX uses a
lower frequency range -- 2 GHz to 11 GHz (similar to WiFi).

Lower-wavelength transmissions are not as easily disrupted by physical
obstructions -- they are better able to diffract, or bend, around obstacles.
 Line-of-sight service, where a fixed dish antenna points straight at
the WiMAX tower from a rooftop or pole. The line-of-sight
connection is stronger and more stable, so it's able to send a lot of
data with fewer errors. Line-of-sight transmissions use higher
frequencies, with ranges reaching a possible 66 GHz.

At higher frequencies, there is less interference and lots more
bandwidth.
WiMAX Service Modes
WiMAX Service Modes
 WiFi-style access will be limited to a 4-to-6 mile radius
(perhaps 25 square miles or 65 square km of coverage, which
is similar in range to a cell-phone zone).
 Through the stronger line-of-sight antennas, the WiMAX
transmitting station would send data to WiMAX-enabled
computers or routers set up within the transmitter's 30-mile
radius (2,800 square miles or 9,300 square km of coverage).
 This is what allows WiMAX to achieve its maximum range.
WiMAX: Speed
 A computer (either a desktop or a laptop) equipped with
WiMAX would receive data from the WiMAX transmitting
station, probably using encrypted data keys to prevent
unauthorized users from stealing access.
 The fastest WiFi connection can transmit up to 54
megabits per second under optimal conditions.
 WiMAX should be able to handle up to 70 megabits per
second.
 Even once that 70 megabits is split up between several dozen
businesses or a few hundred home users, it will provide at least the
equivalent of cable-modem transfer rates to each user.
WiMAX: Distance
 WiMAX outdistances WiFi by miles.
 WiFi's range is about 100 feet (30 m).
 WiMAX will blanket a radius of 30 miles (50 km) with
wireless access.
 The increased range is due to the frequencies used and
the power of the transmitter.
WiMAX: Initiatives
 Intel will start making their Centrino laptop
processors WiMAX enabled in the next two to three
years.
 This will go a long way toward making WiMAX a
success.
 If everyone's laptop already has it (which is predicted
by 2008), it will be much less risky for companies to set
up WiMAX base stations.
IEEE 802.16 Specifications
 Range - 30-mile (50-km) radius from base station
 Speed - 70 megabits per second
 Line-of-sight not needed between user and base station
 Frequency bands - 2 to 11 GHz and 10 to 66 GHz (licensed and
unlicensed bands)
 Defines both the MAC and PHY layers
Network Scale
 The smallest-scale network is a personal area network
(PAN).
 A PAN allows devices to communicate with each other over short
distances. Bluetooth is the best example of a PAN.
 The next step up is a local area network (LAN).
 A LAN allows devices to share information, but is limited to a fairly
small central area, such as a company's headquarters, a coffee shop or
your house. Many LANs use WiFi to connect the network wirelessly.
 WiMAX is the wireless solution for the next step up in scale,
the metropolitan area network (MAN).
 A MAN allows areas the size of cities to be connected.
Network Scale
Why WiMAX
 Compared with other wired solution such as ADSL, or any
other wireless or satellite system, WiMAX based access
networks will enable operators and service providers to
cost-effectively reach million of new potential customers
providing them with broadband access.
 This is even truer for developing countries and rural areas
for which the cost/profitability and the demand factors are
essential.
 This obviously includes adequate coverage, reliability,
performances (throughput), capacity and applications.
WiMAX: The ease to install
 Ease of installation is one of the key issues to lower deployment costs in
developing countries or rural areas.
 In rural areas, the consequences of the long distances from the core
network access point and the scattered location of villages, farms... in
the countryside makes any deployment very costly.
 In developing countries, the lack of main infrastructure (electricity,
roads.), and environmental condition (temperature, humidity.) adds on
the difficulty.
 Thanks to the NLOS/LOS coverage advantage, the operator/service
provider can easily plans a 95% predictability coverage ensuring high
installation success rates and controls deployment costs. A quicker and
simpler installation with a much greater rate of success means
operators spend less money rolling out their networks.
 WiMAX NLOS capability also allows indoors self install CPEs within
several Km radius.
WiMAX: The wide Coverage
 Even more important is the coverage, i.e. the capability to reach any
potential customer within the base station covering area, is essential
for the operator/service provider.
 While many currently available wireless broadband solutions can only
provide Line-Of-Site (LOS) coverage, WiMAX, thanks to its OFDM
technology, has been optimized to provide excellent Non-Line-Of-Site
(NLOS) coverage (up to 15 Km around the base station) and long range
transmission up to 50Km in LOS conditions.
 Combining both LOS and NLOS coverage, WiMAX is the ideal solution
for getting the exact requested coverage in the most economical way.
WiMAX: The Flexibility
 Wireless is more flexible and thus easier to deploy
according to the market demand
 Although most of the existing wireless technologies
suffer from limited range and coverage (usually a few
hundred meters around the base station) resulting in
very costly combination of technologies (wired and/or
wireless)
 WiMAX technology benefits of a wide coverage and can
be deployed as a Point to Multipoint ”last mile”
connection but also as part of the backhaul to the PSTN
and Internet access points.
WiMAX: Role in Access Network
WiMAX: Multi-application Technology
 Following the normal trend of digitalization and packet
transmission and switching, WiMAX uses the Internet
protocol and thus supports all multimedia services from
Voice over IP (VoIP) to high speed internet and video
transmission.
 WiMAX allows service providers to offer all the latest
generation of services and beyond, thanks to a throughput
up to tens of Mbps.
 With regard to the potential users, this means that WiMAX
have the capacity to deliver services from households to
SMEs, SOHOs, Cybercafés, Multimedia Telecentres,
Schools and Hospitals
WiMAX: Worldwide Standardization
 Developed and supported by the WiMAX forum
(more than 300 members), WiMAX will become
the worldwide technology based standard for
broadband and will guaranty interoperability
(i.e.multivendor CPEs), reliability and evolving
technology
 High volumes and integration, will ensure
equipments with very low cost.
 With CPEs under 100$ as one of the first objective,
business model can easily be profitable even in
developing countries.
WiMAX: The spectrum flexibility
 To become the worldwide standard based technology
for broadband, WiMAX will use a single radio covering
all licensed and unlicensed frequency bands allocated
by the ITU for such services i.e.:
 The one licensed band 3.3-3.8 GHz
 Two license exempt bands and 2.3-2.7 GHz and 5.7255.85 GHz.
WiMAX Technology Vision
WiMAX QoS
WiMAX can be dynamically optimized for the mix of traffic that is
being carried. Four types of service are supported:
WiMAX: Applications
References
Intel: The Technology Vision for WiMAX
Ars Technica: WiMAX panned as mere hype?
IEEE 802.16 Backgrounder, May 24, 2002
NetworkDictionary.com: IEEE 802.16: Broadband Wireless MAN Standard (WiMAX)
TechTarget: Replacing your T1 with nothing but air
WiMAX Video
 Courtesy:
 Intel Corporation
Questions
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