802.11 and all that – what’s happening in the wireless ... 802.20 – mobile broadband ......

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© 2006 Cisco Systems, Inc. All rights reserved.

802.11 and all that – what’s happening in the Wireless Networking world?

Past, present and future……

Mike Weaver – Cisco Networking Academy

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© 2006 Cisco Systems, Inc. All rights reserved. 802.11 etc – 2

Wireless LANs

The current Networking Academy course ‘Fundamentals of Wireless LANs’ has now been available for two yearsIn that time, there have been some significant changes in the wireless networking arenaSome of these changes were mentioned briefly in the course material…...whilst others were not even‘on the radar’ when the coursewas developed

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Wireless LANs

The aim of this presentation is to investigate some of the enhancements that have been made, or are being proposed, in the wireless world – and not specifically WLAN technologyThese will be considered on a ‘standardized’basis, looking at the IEEE 802 standards working groups – where they are at, and where the work may lead……

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Wireless – 802 Working Groups

Wireless LAN technology is standardized within the IEEE 802.11 working groups (WG)Other IEEE 802 working groups that are likely to have a significant effect on wireless technology include:-• 802.15 – Wireless Personal Area Networking• 802.16 – Broadband Wireless Access (‘WiMAX’)• 802.18 – Radio Regulatory Technical Advisory Grp• 802.20 – Mobile (Broadband) Wireless Access• 802.22 – Wireless Regional Area Networks

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Wireless – 802 Working Groups (WG)

The major standards that are likely to be of interest within the Academy program are:• 802.11 standards (“WiFi”)• 802.16 standards (“WiMax”)

However, we will initially look at a brief summaryof the responsibilityof the other groups…..

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802.15 – Wireless Personal Area Networks

The 802.15 WG has publisheda wireless personal area networkstandard based on Bluetooth (802.15-1)In addition, standards have been published for:• co-existence of PANs and WLANs (802.15-2) • low rate, low power, low complexity, short range

and long life (sensor) technology (802.15-4) aka “ZigBee”

The 802.15 – 3 WG is currently investigating high rate (20 Mbits/s) wireless PANs, that will provide for low power, low cost solutions for multimedia and digital imaging applications

PAN = Personal Area Network

Bluetooth – allows communication up to 100m. 3 classes of power available:Class 1 – 100mW – range to 100mClass 2 – 2.5mW- range to 10mClass 3 – (rare) tx to 10cm with max range 1m

Developed by Ericsson – named after Danish king Harald Blatand who unified previous warring tribes in Scandinavia.

The Bluetooth RF (physical layer) operates in the unlicensed ISM band at 2.4GHz. The system employs a frequency hop transceiver to combat interference and fading, and provides many FHSS carriers. RF operation uses a shaped, binary frequency modulation to minimize transceiver complexity. The symbol rate is 1 Megasymbol per second (Msps) supporting the bit rate of 1 Megabit per second (Mbps) or, with Enhanced Data Rate, a gross air bit rate of 2 or 3Mb/s. These modes are known as Basic Rate and Enhanced Data Rate respectively.

http://www.bluetooth.com/Bluetooth/Learn/Works/

http://www.internetweek.cmp.com/showArticle.jhtml?articleId=180207141 ref faster Bluetooth rates

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ZigBee

ZigBee builds upon the 802.15-4 standard to define application profiles that can be shared among different manufacturersThe specification for the physical layer defines a low-power spread-spectrum radio operating at 2.4 GHz with a basic bit rate of 250 Kb/s The ZigBee Alliance starts with the 802.15-4 standard, and is currently defining “application profiles” that will allow devices manufactured by different companies to talk to one another• For example, the ZigBee “Lighting Profile” will define all the

protocols so you can purchase a ZigBee light switch from company A and know that it will work properly with lights manufactured by company B

http://rfdesign.com/mag/radio_designing_zigbeeready_ieee/ - good technical article

The application sphere of this wireless personal area network (WPAN) technology ranges from industrial monitoring and control, home automation, sensor networks to gaming, medical and automotive solutions.

Earlier this year, Texas Instruments (TI) entered the ZigBee space in a big way with its $200 million acquisition of Chipcon, the first company credited for launching a 2.4 GHz IEEE 802.15.4 compliant and ZigBee-ready RF transceiver. A key original equipment manufacturer (OEM) – Siemens AG – joined the ZigBee Alliance in March. And more recently, Huawei Technologies, Schneider Electric and STMicroelectronics joined the effort at the "promoter" level, which grants them positions on the ZigBee Alliance Board of Directors.

http://www.wirelessweek.com/article/CA6353645.html

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802.18 – Radio Regulatory TAG

The 802.18 WG is responsible for monitoring and advising on various national and international regulations as they relate to the use of the wireless spectrum within the six other IEEE 802 working groups with projects for radio based systems

There is probably not a lot more to say here! Spectrum usage internationally is a minefield. For example, some countries allow the spectrum to be treated as unlicensed – others don’t.

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Broadband Wireless Technology

There are three major working groups within IEEE that are exploring differing technologies for supporting wireless broadband• 802.20 – Mobile broadband• 802.22 – Wireless Regional Area Networks• 802.16 – WiMaxWe will look at each in turn, and present a brief

comparison• The mobile operators’ 3G technology will not be

considered in this presentation, but should not be ignored! It cost them a great deal of money……

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IEEE 802.20 – Mobile broadband

The 802.20 WG is tasked with developing specifications for mobile broadband wireless access (MBWA) systems.A draft 802.20 specification was balloted and approved on 18 Jan this yearSuch systems will be optimised for peak data rates > 1Mb/s based on cell ranges of 15 Km on vehicles moving at up to 250 Km/h in a MAN environment i.e. high speed trainsOperation will be in licensed bands below 3.5GHz

Metrically challenged conversions……9.3 miles – 155 miles/h ☺

Mission The mission of IEEE 802.20 is to develop the specification for an efficient packet based air interface that is optimized for the transport of IP based services. The goal is to enable worldwide deployment of affordable, ubiquitous, always-on and interoperable multi-vendor mobile broadband wireless access networks that meet the needs of business and residential end user markets.

MBWA Scope Specification of physical and medium access control layers of an air interface for interoperable mobile broadband wireless access systems, operating in licensed bands below 3.5 GHz, optimized for IP-data transport, with peak data rates per user in excess of 1 Mbps. It supports various vehicular mobility classes up to 250 Km/h in a MAN environment and targets spectral efficiencies, sustained user data rates and numbers of active users that are all significantly higher than achieved by existing mobile systems.

15 Jun 06 In an unprecedented move, the IEEE's SA Standards Board has temporarily suspended deliberations by the 802.20 working group on mobile broadband wireless technology.

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IEEE 802.22

The charter of the IEEE 802.22 Working Group on Wireless Regional Area Networks (‘WRANs’) is to develop a standard for a cognitive radio-based air interface, including the MAC layer and physical layer, for use by license-exempt devices on a non-interfering basis in fixed point-to-multipoint wireless regional area networks operating in the VHF/UHF TV broadcast bands between 54 MHz and 862 MHz - spectrum that is allocated to the TV Broadcast Service

A possible IEEE specification for using the "white space" between broadcast-TV channels for wireless broadband.In October, 2004, the IEEE set up a working group to develop the 802.22 Standard for Wireless Regional Area Networks (WRAN).The idea behind 802.22 is that there are considerable unused frequencies between VHF and UHF broadcast channels between 54 and 865 MHz - which could be used to beam wireless broadband as far as 40 kilometres, to serve areas not well served by alternatives such as cable or DSL.The FCC has proposed opening much of this between-channel spectrum to such unlicensed uses.

Cognitive:“Protocols in the standard will ensure that this new service does not cause harmful interference to the licensed incumbent services in the TV broadcast bands. The standard will provide for broadband systems that choose portions of the spectrum by sensing what frequencies are unoccupied.”

See: http://standards.ieee.org/announcements/pr_80222.html

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IEEE 802.22

This standard is intended to enable deployment of interoperable 802 multi-vendor WRAN products, to facilitate competition in broadband access by providing alternatives to local loop (wired) broadband access

It will also extend the deployment of such systems into diverse geographic areas, including sparsely populated rural areas, while preventing harmful interference to incumbent licensed services in the TV broadcast bands

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IEEE 802.22

There is a large, untapped market for broadband wireless access in rural and other unserved/underserved areas where wired infrastructure cannot be economically deployed

Products based on this standard will be able to serve those markets and increase the efficiency of spectrum utilisation in spectrum currently allocated to, but unused by, the TV broadcast service (so called ‘white space’)

WiFi Wireless (http://www.wifiwirelessinc.net/) provides an expanded network technology to the traditional wi-fi (802.11) system. Currently, wi-fi systems are confined to "Hot Spot" locations within a limited radius. WiFi Wireless focuses on "Space-Time" technology applications by using current UHF frequencies that enables WiFi Wireless' hardware to provide 10 miles of service from the POP Point Of Presence, rather than the conventional wi-fi (802.11) retail space application. WiFi Wireless utilizes a base station antenna with a capacity that will allow up to 25,000 simultaneous users without degradation in performance. Business franchises can now be part of the WiFi Wireless network by providing a POP site in one central location, instead of multiple, costly, small networks at a fraction of the price of current T-Span charges affiliated with standard "Hot Spot" networks.

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IEEE 802.16 WiMAX

WiMAX (Worldwide Interoperability of Microwave Access) is a wireless Internet service designed to cover wide geographical areas serving large numbers of users at low costWiMAX is the synonym given to the IEEE 802.16 standard defining wide area wireless data networkingWiMAX is considered one of the best solutions for "last mile" distributionIn contrast, wireless LANs (WLANs – 802.11) are designed to provide network access within an environment once Internet service has been delivered to that point

http://www.wimaxforum.org/news/downloads/Applications_for_802.16-2004_and_802.16e_WiMAX_networks_final.pdf

http://www.intel.com/netcomms/technologies/wimax/index.htm?ppc_cid=ggl|wng_wimax|kC61|s#jumplink3

802.16 in Operation802.16 supports point-to-multipoint architecture in the 10-66 GHz range, transmitting at data rates up to 120Mbps. At thosefrequencies, transmission requires line-of-site, and roofs of buildings provide the best mounting locations for base and subscriber stations. The base station connects to a wired backbone and can transmit wirelessly up to 30 miles to a large number of stationary subscriber stations, possibly hundreds. To accommodate non-line-of-site access over lower frequencies, IEEE published 802.16a in January 2003, which includes support for mesh architecture. 802.16a operates in the licensed and unlicensed frequencies between 2GHz and 11GHz using orthogonal frequency division multiplexing (OFDM), which is similar to 802.11a and 802.11g. The 802.16 medium access control (MAC) layer (define) supports many different physical layer specifications, both licensed and unlicensed. Through the 802.16 MAC, every base station dynamically distributes uplink and downlink bandwidth to subscriber stations using time-division multiple access (TDMA). This is a dramatic difference from the 802.11 MAC, with current implementations operating through the use of carrier sensing mechanisms that don't provide effective bandwidth control over the radio link. Mobility is ComingThe next step for the 802.16 working group is to add portability and mobility to the standard. In March 2002, the working group began the 802.16e Study Group on Mobile Broadband Wireless Access. This group will address many different mobility issues, including providing connectivity to moving vehicles within a base station's sector.

http://en.wikipedia.org/wiki/Wimax

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IEEE 802.16 WiMAX

WiMAX access technology is an integral part of the Internet access portfolio, complementing 2G/3G mobile access, DSL and cable fixed access, and Wi-Fi hotspot access:

“WiMAX provides portable high-speed packet data services for IP applications that complement the

• full mobility, • nationwide coverage, • voice support at high speeds, and • moderate data rates

of 2G/3G mobile access”

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IEEE 802.16 WiMAX (continued)

• WiMAX complements broadband by helping delivery in new markets. WiMAX allows DSL operators to extend service rapidly and cost effectively into areas of poor wire quality and lower population density

• WiMAX, with its long range and quality-of-service (QoS) capabilities in licensed bands, complements current public WLAN hotspot offerings

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Markets for WiMAX

Ref: http://www.alcatel.com/com/en/appcontent/apl/S0406-WiMAX-EN_tcm172-44791635.pdf

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802.16 - 2004

There are two major .16 specifications to provide optimized solutions for fixed, nomadic, portable and mobile broadband wireless access - 802.16-2004 and 802.16e802.16-2004• based on the -2004 version of the original IEEE 802.16

standard and on ETSI HiperMAN. • previously known 802.16d and was ratified in July 2004.• uses Orthogonal Frequency Division Multiplexing (OFDM)

and supports fixed and nomadic access in Line of Sight (LOS) and Non Line of Sight (NLOS) environments

ETSI - European Telecommunications Standards Institute - Institut européen des normes de télécommunication

The WiMAX Forum is committed to providing optimized solutions for fixed, nomadic, portable and mobile broadband wireless access. Two versions of WiMAX address the demand for these different types of access:

• 802.16-2004 WiMAX. This is based on the 802.16-2004 version of the IEEE 802.16 standard and on ETSI HiperMAN. It uses Orthogonal Frequency Division Multiplexing (OFDM) and supports fixed and nomadic access in Line of Sight (LOS) and Non Line of Sight (NLOS) environments. Vendors are developing indoor and outdoor Customer Premises Equipment (CPE) and laptop PCMCIA cards. The initial WiMAX Forum profiles are in the 3.5 GHz and 5.8 GHz frequency bands. The first certified products are expected by the end of 2005.• 802.16e WiMAX. Optimized for dynamic mobile radio channels, this version is based on the 802.16e amendment and provides support for handoffs and roaming. It uses Scalable Orthogonal Frequency Division Multiplexing Access (SOFDMA), a multi-carrier modulation technique that uses sub-channelization. Service providers that deploy 802.16e can also use the network to provide fixed service. The WiMAX Forum has not yet announced the frequency bands for the 802.16e profiles, but 2.3 GHz and 2.5 GHz are the most likely initial candidates. Certification is expected to start in the middle of 2006 when the certification labs open, with the first certified products available in the first quarter of 2007.

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802.16 - 2004 Frequencies

In the 2.5 GHz band, a time division duplex (TDD) solution with a 5 MHz channel bandwidth will be used In the 3.5 GHz band a frequency division duplex (FDD) solution with dual 3.5MHz bandwidth channels will be used.

– (n.b. 802.11 b/w is 20 MHz)• These are not the only WiMAX equipment solutions

that are expected to be available in these two bands but they are representative

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the 2.5 GHz and 3.5 GHz Licensed BandsThis paper addresses some of the deployment considerations for a wireless metropolitanarea network based on the IEEE 802.16-2004 Air Interface Standard, commonly referredto as WiMAX. This paper will focus on deployments using licensed spectrum in the 2.5GHz and 3.5 GHz frequency bands. With support for COFDM1, deployments in thesebands are especially interesting in today’s wireless access market since they offer thepotential for achieving ubiquitous coverage for high speed access over an entiremetropolitan area with adequate range and capacity for a cost-effective access network.In addition to presenting a detailed view of base station channel capacity versus range,specific deployment examples will be analyzed to the relationship between base stationinfrastructure costs and available spectrum in both frequency bands. The impact onchannel capacity and range when deploying with indoor self-installable customerterminals will also be discussed.

2.5 GHz Band: This band is allocated for fixed microwave services in many countriesincluding the United States. Although many of these countries have rules which do notsupport two-way services it is expected that this will change as WiMAX equipmentbecomes more readily available worldwide and operators lobby for more licensedspectrum for both fixed and mobile broadband services.

3.5 GHz Band: The "3.5 GHz" band is available as a licensed band in many countriesoutside the United States for fixed broadband wireless access. Although the regulationsfor deployment and specific allocations vary considerably country by country, this bandis undoubtedly the most used spectrum for wireless metropolitan area networks (MANs)today.

Portland pre-802.16 story:

http://www.dailywireless.org/modules.php?name=News&file=article&sid=2027

In line with the objective 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 :

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802.16 - 2004 Frequencies

Other expected solutions include:• A TDD solution for the 3.5 GHZ band with a 7 MHz

channel b/w• Over a period of time, different channel bandwidths will

be made available in both bands to provide operators with more deployment options

• WiMAX-compliant equipment will also be available in other frequency bands

• 5.8 GHz products are anticipated at about the same time as 3.5 GHz and 2.5 GHz products

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802.16e Mobile Access

802.16e• Optimised for dynamic mobile radio channels, this version is

based on the .16e amendment and provides support for handoffs and roaming

• It uses Scalable Orthogonal Frequency Division Multiplexing Access (SOFDMA), a multi-carrier modulation technique that uses sub-channelisation

• Service providers that deploy 802.16e can also use the network to provide fixed service

• 802.16e operates in the 2.3 Ghz, 2.5 Ghz, 3.5 Ghz (licensed) and 5.8 Ghz (unlicensed) bands

• The standard was ratified on 7 Dec 2005 and is likely to be known as 802.16e – 2005 (confirmed)

http://www.dailywireless.org/modules.php?name=News&file=article&sid=5004

http://news.bbc.co.uk/1/hi/business/4363196.stm Southern trains on London -Brighton

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802.16 example

Nomad, a UK Company, in conjunction with T-Mobile, are providing Hi speed Internet access on the 50 mile London –Brighton commuter route using (pre) 802.16 trackside stations that interface with trains wired for 802.11The links can pass data to and from any train at up to 32Mb/s, making it the fastest data link to a train anywhere in the world.

http://news.bbc.co.uk/1/hi/business/4363196.stm

Nomad Delivers World's First Broadband Internet Service on TrainsRAIL travellers will soon be surfing the internet and sending e-mails at high speed from their notebook PCs and laptops, thanks to a deal signed by high-tech company Nomad Digital

The Northumbrian-based company has teamed up with mobile telecoms giant T-Mobile and train operator Southern to launch the world's first truly broadband WiFi service on trains.

T-Mobile announced the new service today (February 15) at the 3GSM World Congress in Cannes (See Press Release).

Nomad's system allows travellers with suitably equipped laptop computers or PDAs to access internet and e-mail services via wireless broadband, without the need for cables or connection sockets.

Nomad has spent two years developing the technology behind the system and, although there are already a small number of other existing services based upon satellite technology that provide internet access on trains, Nomad's is the first in the world to offer a true bi-directional broadband connection, making it many times faster than any existing system. Nomad's system uses a small number of trackside radios (utilising IEEE 802.16 technology, also known as (pre)WiMax technology), which create a link to the train as it speeds past. The links can pass data to and from any train at up to 32Mb/s, making it the fastest data link to a train anywhere in the world.

Nomad chief executive Graeme Lowdon said: ``The potential is enormous. The system can be used to provide passengers with high speed internet access. For busy commuters, who perhaps spend up to two hours a day travelling to and from work, this technology will allow them to use that time productively, sending and receiving e-mails, or accessing the internet and their own corporate networks - all on broadband, with all the speed and convenience that entails. That could mean a shorter working day.

"More than that, the system can also be used to support other services for train operators, such as closed circuit television (CCTV)''

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WiMAX Access

yesnoSoft handoffs

Multiple/ Low vehicular speed

Laptop PCMCIA or mini cards, PDAs or smartphones

Full mobility

yesnoHard handoffs

Multiple/ Low vehicular speed

Laptop PCMCIA or mini cards, PDAs or smartphones

Simple mobility

yesnoHard handoffs

Multiple / Walking speed

Laptop PCMCIA or mini cards

Portability

yesyesnoMultiple/ Stationary

Indoor CPEs, PCMCIA cards

Nomadic access

yesyesnoSingle/ Stationary

Outdoor and indoor CPEs

Fixed access

802.16e 802.16-2004

HandoffsLocations/ Speed

DevicesDefinition

Types of access to a WiMAX network

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Mobile Architecture Comparison

High latencyLow latencyLow latency

Circuit ArchitecturePacket ArchitecturePacket Architecture

Licensed Bands below 2.7 GHz

Licensed Bands below 3.5 GHz

Between 2-6 GHz

Evolving GSM or IS-41Optimized for full mobilityBackward compatible with 802.16a

W-CDMA & CDMA-2000New MAC and PHY with IP and adaptive antennas

Extensions to MAC and PHY from 802.16a

Circuit-switched cell data (<1Mb/s)

IP roaming and handoff (>1Mb/s)

IP 802.16a mobility (>1Mb/s)

3G802.20802.16e

Mobile Data Architectures

n cellular telephone communication, soft handoff refers to the overlapping of repeater coverage zones, so that every cell phone set is always well within range of at least one repeater (also called a base station). In some cases, mobile sets transmit signals to, and receive signals from, more than one repeater at a time. Soft handoff technology is used by code-division multiple access (CDMA) systems.

With hard handoff, the link to the prior base station is terminated before or as the user is transferred to the new cell’s base station. That is to say that the mobile is linked to no more than one base station at a given time. Initiation of the handoff may begin when the signal strength at the mobile received from base station 2 is greater than that of base station 1. The signal strength measures are really signal levels averaged over a chosen amount of time. This averaging is necessary because of the Rayleigh fading nature of the environment in which the cellular network resides.

http://people.deas.harvard.edu/~jones/cscie129/nu_lectures/lecture7/cellular/handoff/handoff.html

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Breaking News

In a deal announced recently (RCR Wireless News 10 Jul 2006) Intel and Motorola will invest $M900 in Clearwire CorporationClearwire already provides wireless broadband services and has announced it will migrate its networks to the WIMAX standardThe deal with Intel and Motorola almost guarantees that 802.16e-2005 based mobile WIMAX will ‘take off’

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IEEE 802.20 vs 802.16e

802.20 (also know as ‘Mobile-Fi’) has some similarity to the recently approved 802.16e (‘WiMAX’) standard802.16e adds mobility in the 2 to 6 GHz licensed bands – and is backed by Intel• but 802.20 is backed by Qualcomm…..

However, 802.20 is inherently more mobile. It has a latency of just 10ms (500ms is standard for 3G) and can maintain integrity at as much as 250km/h, compared to just 100km/h for 802.16eWiMAXSince it uses more common spectrum - licensed bands up to 3.5GHz - it also offers global mobility, hand-off and roaming supportHowever, 802.20 could reduce the value of the expensive 3G licenses held by mobile operators, and so it may not be widely deployed if the mobile operators can block it

WiMAX, IEEE 802.16e is designed for long range broadband access. But competition from 802.20 - nicknamed Mobile-Fi - could shatter the dreams of those backing WiMAX, according to the paper. Whilst the data rate and range is only half that of WiMAX, it is inherently more mobile. It has an astonishing latency of just 10ms - 500ms is standard for 3G communications - and can maintain integrity at as much as 250km/h, compared to just 100km/h for WiMAX. Since it uses more common spectrum - licensed bands up to 3.5GHz - it also offers global mobility, hand-off and roaming support. Cristian Patachia-Sultanoiu says in his paper Deploying WiMAX Certified Broadband Wireless Access Systems(Journal of the Communications Network) that he believes WiMAX will end up being the defining standard. Mobile operators, who are generally friendly to WiMAX, see 802.20 as a competing standard that could make their 3G licenses worth rather less than they paid for them. As with any standard, the ability to bring products to market is crucial - and with Intel pushing WiMAX hard, it's difficult to imagine a situation where it won't have its way.

There several hurtles 802.20 will have to overcome: •It can only be used in licensed bands below 3.5GHz. •It trails the 802.16e standards process by a couple of years •Who needs 180 mph handoff? •Mobilized 802.16e will be nationalized in Korea. •Why should cellular companies undercut their 3G service? A workable 802.20 standard might be weighed against the $100B investment in 3G spectrum by European mobile carriers, alone. If Nextel goes with Flarion (an original proponent of the 802.20 standard), and T-Mobile follows, that could mean a proprietary system will be in place for at least 5 years. By then, 802.16e will be backward compatible with 802.16 fixed services. Licensed or unlicensed. 802.20 won't be ubiquitous. WiMaxprobably will.

The 802.16 and 802.20 standards will be utilized by two different types of carriers, the study also finds. The 802.16 networks will be deployed by fixed carriers initially targeting stationary broadband users while 802.20 will be used by mobile carriers in an effort to offer high-end data services. http://www.3g.co.uk/PR/Nov2003/6084.htm

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IEEE 802.22 vs 802.16

As with 802.20, there is some speculation as to who will ultimately control this very valuable spectrumAt stake is a swath of sub-900 MHz TV bandwidth the FCC proposes to open to unlicensed wireless useAt sub-900 MHz, wireless signals pass through buildings, trees and other obstacles • All such gear is non-line of sight (NLOS)• Those signals travel up to three times farther than 2.4 Ghz,

resulting in fewer base stationsFor WiMax (802.16), the advantages of sub-900 MHz access would translate to being more competitive with 3G, as well as gaining the fixed and mobile ubiquity it so dearly desires • Using the sub-900 MHz space could also solve the problems

of 802.16e (mobile access)

ubiquity n. Existence or apparent existence everywhere at the same time;omnipresence:

Intel CTO Pat Gelsinger said the UHF/VHF spectrum represented "some of the most valuable spectrum available." For over half a century, vacant TV channels have been underutilized, Gelsinger said, and opening the spectrum "will help foster new technologies, create opportunities for business, and bring exciting new products to consumers." http://www.wi-fiplanet.com/columns/article.php/3494676

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Likely Broadband Wireless evolution

The battle for the city, town, and suburb:- it's on the way, and the outcome will have a major impact on future mobile broadband services. With cellular, WiFi, and WiMAX all poised to grow in the metro market, will we see an outright battle, competition, on perhaps hybrid alliances that challenge event business-school professors? What kinds of services will result, when will we see them, and what impact will they have on the enterprise. And is a future of entirely-mobile broadband - for both businesses and consumers - going to become a reality?

How do the new, somewhat esoteric wireless standards (802.16 WiMAX and 802.20) compare with each other, and with conventional 802.11 Wi-Fi?802.16 is designed as a point-to-multipoint technology, similar to the cell network, in which base stations provide access to multiple users. 802.16 uses frequencies in the 10-66 MHz range, so line of sight between the client and the base station is required. At those frequencies, it supports data rates up to 120 Mbps at ranges of up to 30 miles.

802.16a is an extension to 802.16 that loosens some of these restrictions and makes 802.16 behave a bit more like 802.11. 802.16a uses OFDM at the PHY, at frequencies from 2 to 11 MHz, both licensed and unlicensed depending on the user's need and capabilities. At those frequencies, line of sight restrictions are similar to those we are used to with 802.11: line of sight is preferred, but not required. 802.16a supports data rates of up to 70 Mbps. In addition, it has built-in support for a mesh architecture, as opposed to 802.16's hub-and-spoke architecture. Neither 802.16 nor 802.16a supports stations moving at faster than walking speed, but the 802.16e working group is studying this. 802.16e is an extension to 802.16 that is designed to address 802.16's lack of support for mobile stations (defined as stations moving faster than approximately walking speed--cars, trains, and so forth).

802.20 is similar in scope to 802.16 in that it is designed to provide WLAN throughput over MAN areas, but it differs from 802.16 in several ways. Whereas 802.16 is currently designed to support devices moving slower than walking speed, 802.20 is designed to support devices moving at up to 150 miles per hour relative to the antenna. Although 802.16e is designed to address 802.16's lack of support for mobile stations, 802.20 may support higher speeds. 802.20 is specified up to 150 mph relative to the antenna, while 802.16e is only specified for "vehicular speeds", and claims speeds up to about 90 mph in simulations. 802.20 provides very low latency--20 ms or less--but at much lower data rates than 802.16--up to only 1 Mbps. The approximate range of an 802.20 base station is 15 km.

At its core, 802.16 is intended to be used in more of a distribution role, such as a telco beaming phone service to many subscribers, each of which has an antenna on the top of his or her building. Some have predicted that the phone companies intend 802.16 as an eventual replacement for their aging in-ground wire networks. In this form, 802.16 has a range of approximately 30 miles. Interestingly, the 802.16 MAC layer provides support for at least two key protocols: ATM and TCP/IP. The ATM component supports the proposition that 802.16 is eventually intended to carry voice. Because of its line-of-sight restriction, 802.16 would not be appropriate for "man on the street" wireless access.

802.16a, with its mesh architecture and relaxed line-of-sight requirements, would be particularly appropriate for "man on the street" wireless access, especially considering its much higher throughput compared to 802.20. Where 802.16 stumbles and 802.20 shines is in support for mobile users. In addition, 802.20's guaranteed low latency may also make it more appropriate for voice communications, and some have even suggested that it may be able to act as a replacement for the existing cellular network.http://www.connect802.com/tech_notes.htm

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Wireless LANs

Wireless LAN technology is standardized within the IEEE 802.11 working group (WG)The major standards that are dealt with are the ‘Radio Standards’The original standards dealt with in the Academy program were:• 802.11b – max 11 Mb/s using 2.4GHz band• 802.11a – max 54 Mb/s using 5GHz band• Later revisions of the Academy program include

802.11g (max 54 Mb/s in 2.4 GHz band) labs

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IEEE 802.11b

The 802.11b amendment to the original standard was ratified in 1999 and led to the rapid adoption of WLAN technologyIt is now considered a mature standard, generally superseded in new equipment by 802.11g802.11b has a maximum raw data rate of 11 Mbit/s and uses the same CSMA/CA media access method defined in the original standard. The CSMA/CA protocol overhead means that, in practice, the maximum 802.11b throughput an application can achieve is about 5.9 Mb/s over TCPand about 7.1 Mb/s over UDP

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IEEE 802.11a

802.11a is an IEEE standard for a wireless network that operates at 5GHz with rates up to 54Mb/sThe 802.11a amendment to the original standard was also ratified in 1999The 802.11a standard uses the same core protocol as the original standard, and uses a 52-subcarrier orthogonal frequency-division multiplexing (OFDM) with a maximum raw data rate of 54 Mb/s, which yields realistic net achievable throughput in the mid-20 Mb/s• It is not interoperable with 802.11b, except if using equipment

that implements both standards (dual standard)

11a was not initially popular

http://www.theregister.com/2004/10/11/802_11a_fights_back/

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802.11a

Since the 2.4GHz band is heavily used, using the 5GHz band gives 802.11a the advantage of less interference.Disadvantages of this high carrier frequency include:• Restricting the use of 802.11a to almost LOS,

necessitating the use of more access points; • 802.11a signals cannot penetrate as far as 802.11b

since it is absorbed more readily, other things (such as power) being equal.

.

The FCC seems to have quietly approved the rules necessary to allow 11 more 802.11a channels to the 5 gigahertz (GHz) band: Joanie Wexler of Network World reports the 255 megahertz (MHz) chunk added to unlicensed 5 GHz use comes as a result of compromise between the Department of Defense and the "industry," which wasn't well defined. Public process doesn't seem to have been broadly involved here, but it may just be less transparent to someone not trained in the intricacies of FCC interaction with other parts of government.

The new rules went into effect Jan. 20, and allow the use of 5.47 to 5.725 GHz--11 channels in the 802.11a version of Wi-Fi--with a couple of key signal usage modifiers. The rule also changes the requirements for the next-down stretch of spectrum, 5.25 to 5.35 GHz to conform to those modifiers.

Both bands must now use dynamic frequency selection (DFS) to avoid in-use spectrum, and transmit power control (TPC), which throttles power to the minimum necessary for given communication. Older equipment using 5.25 to 5.35 GHz is exempt, although one might expect manufacturers to push out firmware upgrades. These requirements are part of 802.11h, which extended 802.11a for legal European operation.

Interest in 5 GHz has increased in the last year or so with the recognition that having no 802.11b devices to support in that band makes voice over IP over WLAN (VoWLAN) easier to operate in corporations. The band is also being used for backhaul on mesh networks and will be one of the early profiles for WiMax.

33


802.11a

802.11a products started shipping in 2001, lagging 802.11b products due to the slow availability of the5GHz rf components needed to implement products802.11a was not widely adopted overall because• 802.11b was already widely adopted• 802.11a's disadvantages• poor initial product implementations, making its range

even shorter..• ..and because of national / local regulations

PS Extra 11 channels added between 5.47 & 5.725 GHz on 20 Jan

This appears to be changing as the price of 802.11a equipment continues to fall. The major advantage is the far less crowded 5.0GHz band. Major disadvantage is likely to be requirement for greater number of wireless AP to give equivalent coverage

34


802.11g

Ratified In June 2003, a third modulation standardThis works in the 2.4 GHz band (as does 802.11b) but operates at a maximum raw data rate of 54 Mb/s, or about 24.7 Mb/s net throughput like 802.11a. 802.11g hardware will work with 802.11b hardware. • Details of making b and g work well together occupied much

of the lingering technical process• In older networks the presence of an 802.11b participant

significantly reduces the speed of an 802.11g network

11g is not covered in detail in the Academy program, but it does have labs for the technology.

DBPSK/DQPSK = Differential binary phase shift keying ; Differential quaternary phase shift keyingDBPSK - Differential Binary Phase Shift Keying DQPSK - Differential Quadrature Phase Shift Keying DSSS - Direct Sequence Spread Spectrum (DSSS)

35


802.11g modulation

The modulation scheme used in 802.11g is orthogonal frequency-division multiplexing (OFDM) for the data rates of 6, 9, 12, 18, 24, 36, 48, and 54 Mbit/s, and reverts to • Complementary Code Keying (CCK) for 5.5 and 11 Mbit/s• DBPSK/DQPSK+DSSS for 1 and 2 Mbit/s

Even though 802.11g operates in the same frequency band as 802.11b, it can achieve higher data rates because of its similarities to 802.11aHowever, it suffers from using the crowded 2.4GHz spectrum

36


Additional 802.11x standards

The 802 standards that are likely to have major impact on wireless LANs include:• 802.11i – security enhancements• 802.11n – high throughput improvements• 802.11e – QOS enhancements• 802.11s – Standard For Wireless Mesh Networks

– N.b. there is no standard or task group named “802.11x”– The IEEE 802.1X standard for port-based network access

control, is often mistakenly called “802.11x” when used in the context of wireless networks

ESS Mesh - An IEEE 802.11 Extended Service Set (ESS) Mesh* is a collection of APs interconnected with wireless links that enable automatic topology learning and dynamic path configuration

StandardsThe following IEEE standards and task groups exist within the IEEE 802.11 working group:IEEE 802.11 - The original 1 Mbit/s and 2 Mbit/s, 2.4 GHz RF and IR standard (1999) IEEE 802.11a - 54 Mbit/s, 5 GHz standard (1999, shipping products in 2001) IEEE 802.11b - Enhancements to 802.11 to support 5.5 and 11 Mbit/s (1999) IEEE 802.11c - Bridge operation procedures; included in the IEEE 802.1D standard (2001) IEEE 802.11d - International (country-to-country) roaming extensions (2001) IEEE 802.11e - Enhancements: QoS, including packet bursting (2005) IEEE 802.11F - Inter-Access Point Protocol (2003) IEEE 802.11g - 54 Mbit/s, 2.4 GHz standard (backwards compatible with b) (2003) IEEE 802.11h - Spectrum Managed 802.11a (5 GHz) for European compatibility (2004) IEEE 802.11i - Enhanced security (2004) IEEE 802.11j - Extensions for Japan (2004) IEEE 802.11k - Radio resource measurement enhancements IEEE 802.11l - (reserved, typologically unsound) IEEE 802.11m - Maintenance of the standard; odds and ends. IEEE 802.11n - Higher throughput improvements IEEE 802.11o - (reserved, typologically unsound) IEEE 802.11p - WAVE - Wireless Access for the Vehicular Environment (such as ambulances and passenger cars) IEEE 802.11q - (reserved, typologically unsound, can be confused with 802.1Q VLAN trunking) IEEE 802.11r - Fast roamingIEEE 802.11s - ESS Mesh Networking IEEE 802.11T - Wireless Performance Prediction (WPP) - test methods and metrics IEEE 802.11u - Interworking with non-802 networks (e.g., cellular) IEEE 802.11v - Wireless network managementIEEE 802.11w - Protected Management Frames Note - there is no standard or task group named "802.11x". Rather, this term is used informally to denote any current or future 802.11 standard, in cases where further precision is not necessary. (The IEEE 802.1X standard for port-based network access control, is often mistakenly called "802.11x" when used in the context of wireless networks.)Note - 802.11F and 802.11T are recommendations, not standards and are capitalized as such.

37


IEEE 802.11i – security enhancements

IEEE 802.11i is an amendment to the 802.11standard specifying security mechanismsThe draft standard was ratified in June 2004, and supersedes the previous security specification, Wired Equivalent Privacy(WEP), which was known to have severe security weaknessesWi-Fi Protected Access (WPA) had previously been introduced by the Wi-Fi Alliance as an intermediate solution to WEP insecurities• WPA implemented a subset of 802.11i.

38


IEEE 802.11i WPA2

The Wi-Fi Alliance refers to the approved, interoperable implementation of the full 802.11i as WPA2 802.11i makes use of the Advanced Encryption Standard (AES) block cipher• WEP and WPA use the RC4 software stream cipher• RC4 falls short of the high standards of security

set by cryptographers, and some ways of using RC4 lead to WEP being very insecure. It is not recommended for use in new systems.

RC4 was designed by Ron Rivest of RSA Security in 1987; while it is officially termed "Rivest Cipher 4", the RC acronym is alternatively understood to stand for "Ron's Code“.RC4 was initially a trade secret, but in September 1994 a description of it was anonymously posted to the Cypherpunks mailing list. It was soon posted on the sci.crypt newsgroup, and from there to many sites on the Internet. Because the algorithm is known, it is no longer a trade secret. The name "RC4" is trademarked, however.

39


802.11i WPA2 Security

The 802.11i WPA2 architecture contains the following components: • 802.1X for authentication (entailing the use of extensible

authentication protocol (EAP) and an authentication server)• Robust Security Network (RSN) for keeping track of

associations, and• AES-based counter mode with cipher block chaining

message authentication code protocol (CCMP) to provide confidentiality, integrity and origin authentication

The authentication process leaves two considerations:-• the access point (AP) still needs to authenticate itself to the

client station (STA) • keys to encrypt the traffic need to be derived

40


WPA2 four-way handshake

The earlier EAP exchange provides the shared secret Pairwise Master Key (PMK)This key is designed to last the entire session and so should be exposed as little as possibleAnother important element of the authentication process is the four-way handshake• confirms mutual possession of a Pairwise Transient

Key (PTK)• distributes a group temporal key (GTK), used to

decrypt multicast and broadcast traffic.

41


WPA2 PTK generation

The Pairwise Transient Key is generated by concatenating the following attributes:-• Pairwise Master Key (PMK)• AP nonce (ANonce)• STA nonce (SNonce)• AP MAC address and• STA MAC address.

The product is then put through a cryptographic hash function

Nonce = In security engineering, a nonce is a 'number used once'. It is often a random or pseudo-random number issued in an authentication protocol to ensure that old communications cannot be reused in 'replay attacks'. For instance, noncesare used in HTTP digest access authentication to calculate an MD5 digest of the password. The nonces are different each time the 401 authentication challenge response code is presented, thus making the replay attack virtually impossible.

42


802.11i pre-shared key mode

802.11i also has a pre-shared key mode (PSK) known as personal mode designed for SOHO networks that cannot afford the cost and complexity of an 802.1X authentication serverEach user must enter a passphrase to access the network• The passphrase is typically stored on the user's computer,

so it need only be entered once• The weak passphrases users typically employ creates a

major vulnerability to password cracking attacksIt is recommended that passphrases be at least 8 characters and contain numbers and special charactersThe IEEE 802.11i standard allows strong PSKs to be entered as 64 character hex numbers

This would be the recommended mode for home users

43


802.11n high-throughput WLAN

802.11n is the standard that is likely to have the most visibility in the near futureThe proposed standard will enable high-performance, next-generation wireless local area networking (WLAN) products that supports speeds of up to 600 Mb/s, and will enable wireless systems to deliver greater rangeThis will allow wireless products across multiple market segments to support advanced multimedia applications

802.11n Moves Forward with Consortium Proposal----------------------------------------------By Glenn FleishmanSpecial to Wi-Fi Networking NewsPermanently archived item <http://wifinetnews.com/archives/006207.html>

The Joint Proposal (JP) team in the IEEE 802.11n high-throughput wireless task group has accepted the Enhanced Wireless Consortium (EWC) proposal: This is the penultimate step to the EWC proposal, originally developed outside the main standards process by the four overall largest chipmakers, and which eventually included most parties in 802.11n. Task Group N will produce a standard that uses multiple antennas and a host of other strategies to produce at least 100 Mbps of raw throughput, but more likely 200 Mbps. Net throughput, or real data transferred, will be much higher than the current 50% of raw data passed across.

The JP at the task group was composed of the members of two previously at-loggerheads proposals led (in the least nuanced way I can put this) by Intel on the one side and Airgo, leading MIMO chipmaker, on the other. The EWC proposal had many points of similarity with work in the JP. The acceptance of the EWC proposal by the JP sets the stage for supermajority voting of 75 percent that will allow the JP to become the draft upon which final ratification of the standard is based.

The vote passed the JP group 40 to 0, with two members not casting ballots. The JP includes all major players in the industry.

802.11n Proposal Confirmed; Broadcom Has Chips----------------------------------------------By Glenn FleishmanSpecial to Wi-Fi Networking NewsPermanently archived item <http://wifinetnews.com/archives/006227.html>

Word just in that the 802.11n proposal was confirmed: The IEEE task group on high-throughput wireless local area networking has confirmed the joint proposal group draft which itself came out of the Enhanced Wireless Consortium. Now 802.11n will move forward relatively rapidly to ratification, even though that formal process of finalizing details could take until 2007. That won't delay shipping products at this point.

Broadcom meanwhile announced that what it's dubbed its Intensi-fi chips are now available in sampling and incorporated in reference designs for manufacturers and support all mandatory draft 802.11n specifications. The chips will also support any changes in the spec through ratification via software updates. The chips will support over 300 Mbps of throughput.

44


IEEE 802.11n

In a newly released report, the Dell'Oro Group forecasts that sales of 802.11n WLAN equipment will exceed $1 billion in 2007, only the second year of shipments for this new technology:-

“We expect 802.11n will comprise 90 percent of the consumer WLAN shipments in 2009. We also expect enterprises to begin widely adopting 802.11n in 2009, once this new technology has become established in notebook computers”

In recent quarters the consumer market for WLAN equipment has stagnated, especially from a revenue perspective, because 802.11g-based products have been in the market for three years, and consumers have not seen a cost-benefit to upgrading to 802.11a. Due to its better coverage and higher data rates, 802.11n will likely become a key enabling technology for distributing video to multiple devices in the home. We expect 802.11n will comprise 90 percent of the consumer WLAN shipments in 2009. We also expect enterprises to begin widely adopting 802.11n in 2009, once this new technology has become established in notebook computers,"

45


802.11n history

In January 2004 IEEE announced that it had formed a new 802.11 Task Group (TGn) to develop a new high throughput amendment to the 802.11 standard for WLANsInitially, there were two competing proposals for the 802.11n standardIn July 2005 the competitors (and a third group), proposed that they would merge their respective proposals as a draft which would be sent to the IEEE in September; a final version was submitted in November. The standardization process was then expected to be completed by the second half of 2006.

46


802.11n history

The Enhanced Wireless Consortium (EWC) was formed to help accelerate the IEEE 802.11n development process and promote a technology specification for interoperability of next-generation wireless local area networking (WLAN) productsOn 19 Jan 2006, the IEEE 802.11n Working Group approved the EWC's specification as the draft approval of 802.11nBreaking news! 03 May 2006 - The IEEE 802.11 working group voted down an initial draft of the proposed 802.11n standard, virtually ensuring development of a 2.0 version

IEEE votes down 802.11n proposal03 May 2006PISCATAWAY, N.J.—The IEEE 802.11 working group voted down an initial draft of the proposed 802.11n standard, virtually ensuring development of a 2.0 version.

47


802.11n detail

802.11n builds upon previous 802.11 standards by adding MIMO (multiple-input multiple-output) and orthogonal frequency-division multiplexing (OFDM)MIMO uses multiple tx and rx antennas to allow for increased data throughput through spatial multiplexing and increased range by exploiting the spatial diversity, using coding schemes such as Alamouti codingThe real data throughput is estimated to reach a theoretical 540 Mbit/s (which may require an even higher raw data rate at the physical layer), and should be up to 40 times faster than 802.11b, and near 10 times faster than 802.11a or 802.11gIt is projected that 802.11n will also offer a better operating distance than current networks (4 – 5x)

Alamouti coding – a space time block code

48


“Pre 802.11n”

A number of vendors have announced ‘pre-N’ equipment. However, as the standard has not been ratified, it is recommended that purchasers be careful of buying technology that may not be upgradeable to the eventual standard….caveat emptor!A noticeable external difference of 802.11n equipment is likely to be the inclusion of extra antennas to support MIMO

An interesting test of pre-N equipmenthttp://www.eweek.com/article2/0,1895,1952659,00.asp

49


802.11n

The ‘killer app’ for this technology is likely to be the wireless distribution of video and other multimedia content in the home environmentThere are a number of ‘pre-N’ devices already available on the marketHowever, some industry commentators say that ‘… purchasers should wait for approval of chip-sets that meet the actual standard..’This is unlikely to be before late-2006 / early 2007

50


802.11n

However, it is not only the home user that will benefit from the .11n technologyThe increased range is likely to mean less AP are required to cover an equivalent areaFaster data throughput rates will also be seen as an advantageHowever, the wired network could now be a limit with wireless rates >100Mb/s requiring Gigabit ethernet backhaul……

51


802.11s

The fact that many municipalities around the world have started to set up city wide ‘meshed’ wifinetworks cannot have escaped notice!Such networks introduce problems that were never considered when the original 802.11 standards were first developedThere have been many proprietary solutions to solve the problems of extending (meshing) LAN technology into a MAN environmentThe IEEE has now set up a WG under the auspices of 802.11 to develop standards for such Extended Service Set (ESS) mesh networking

52


802.11s

802.11s is the (currently unapproved) IEEE 802.11 standard for ESS mesh networkingAs defined by the IEEE, an Extended Service Set (ESS) mesh is a collection of Mesh Points (MPs) interconnected with wireless links that enable automatic topology learning and dynamic path configurationThe proposed standard specifies an extension to the IEEE 802.11 MAC to solve the interoperability problem and defines an architecture and protocol that support both broadcast/multicast and unicast delivery using "radio-aware metrics over self-configuring multi-hop topologies”

A merged proposal from the two major interest groups (the Wi-Mesh group and SEEMesh - a consortium made up of Intel, Nokia, Motorola, NTT DoCoMo and Texas Instruments)

was presented and confirmed unanimously at the March 2006 WG meeting. Belair, a major player in this area, announced they would support the proposed standard in late March 2006.

53


802.11s

When final, the new standard will use mesh networking techniques to extend the range of WLANs in a standardized, secure and reliable fashion

Mesh networking reduces backhaul and installation costs when many wifi “LANs” are interconnected

A good introduction to the difficulties associated with meshing:

http://informationweek.com/story/showArticle.jhtml?articleID=170100887

54


802.11s

Current mesh technology can use single, dual or triple radio technologyIn single radio, one radio performs as an AP and also handles ingress and egress into the meshDual radio systems use one radio – often 2.4GHz – for AP and another radio – often 5GHz – for mesh ingress/egress trafficThe most sophisticated mesh network design uses three or more radios per node. These additional radios can be used for one of two purposes• a multisector and/or multichannel access system can be created

using directional antennas to extend range and provide more client access capacity

• mesh traffic can be optimized by separating ingress and egress traffic onto different radios/channels.

This multiradio approach offers excellent performance, but is more costly and complex to install.

55


IEEE 802.11e

Approved in late 2005 as a standard that defines a set of Quality of Serviceenhancements for WLAN applications, The standard is considered of critical importance for delay-sensitive applications, such as Voice over Wireless IP and Streaming MultimediaThe protocol enhances the 802.11 MAC layer.

56


So what for the future…..?

Prediction is very difficult, especially about the future.Niels Bohr, physicist

Which technologies will survive, which will fall by the wayside and which might never deliver? Ken Greene, European technical director at wireless service provider iPass suggests:“… all of these technologies are likely to survive in some form. Mobile workers will access networks that seamlessly incorporate a range of access technologies…”

The answer is that all of these technologies are likely to survive in some form, says Ken Greene, European technical director at wireless service provider iPass. In the future, mobile workers will access networks that seamlessly incorporate a range of access technologies, Greene believes. "Ask me how I see business mobility in five years, and I'd sum it up as unconscious connectivity," he says.

From Mesh to UWB: Untangling the wireless future http://insight.zdnet.co.uk/communications/wireless/0,39020430,39152270,00.htm

57


So what for the future…..?

It's not likely - but possible - that WiMAX will end up playing the role of "IBM Token Ring" to the "Ethernet" of rapidly evolving 802.11 systems. WiMAX will not enter a virgin Broadband Wireless Internet Access (BWIA) marketplace; WiMAX will have to prove itself as more cost-effective, morerobust, seamlessly interoperable, and generally better overall.That could likely happen... but it's far from a given, especially when the competing technologies aren't "standing still" such as the development of 802.11s Mesh Networkinghttp://www.corante.com/bwia/archives/004499.html

58


Wi-Fi Alliance

The WiFi alliance an independent organization who perform testing, certify interoperability of products, and promote the WLAN (802.11) technology. The Wi-Fi Alliance is based in Austin, TexasToday, most producers of 802.11 equipment are members, and (as at Dec 2005) the Wi-Fi Alliance has some 260 members.

It's not likely, but possible, that WiMAX will end up playing the role of "IBM Token Ring" to the "Ethernet" of rapidly evolving 802.11 systems. WiMAX will not enter a virgin BWIA marketplace; WiMAX will have to prove itself as more cost-effective, more robust, seamlessly interoperable, and generally better overall. That could likely happen... but it's far from a given, especially when the competing technologies aren't "standing still" such as the development of 802.11s. http://www.corante.com/bwia/archives/004499.html

59


Wi-Fi Certification

The Wi-Fi Alliance has certified over 1,500 Wi-Fi products for interoperability since testing began in April 2000 Certification includes three categories:• Wi-Fi products based on IEEE radio standards: 802.11a, 802.11b,

802.11g in single, dual-mode (802.11b and 802.11g) or multi-band (2.4GHz and 5GHz) products

• Wi-Fi wireless network security: WPA (Wi-Fi Protected Access) -Personal and Enterprise, WPA2 (Wi-Fi Protected Access 2) -Personal and Enterprise

• Support for multimedia content over Wi-Fi networks: WMM (Wi-Fi Multimedia).

60


References

Excellent daily newsletter:-Wi-Fi networking news http://wifinetnews.com“Fierce Wireless” – wireless industry monitorwww.fiercewireless.comZigbeewww.zigbee.orgWimaxwww.wimaxforum.org

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WiFi802.11a/g

PAN LAN MAN WAN

Bandwidth

1 Gb/s

100 Mb/s

10 Mb/s

1 Mb/s

IEEE 802.15 IEEE 802.11 IEEE 802.16 3GPP **

802.15.3UWB

HiSpeedWireless

PAN

802.15.1Blutooth

WiFi802.11b

4G

WiFi802.11n

WiMax802.16

(802.166-2004 & 802.16-2005)

Overlap zone

Overlap zone

2.5G

3G

10 m 100 m Up to 50 Km Up to 30 Km *

* Larger installed base** Third Generation Partnership Project

Overlap zone

Wireless technologies target segments

Ref: Understanding WiFi and WiMax as Metro Access Solutions – Intel Corp

<1 m

62


63


802.16 range

IEEE 802.16 provides up to 50 km (31 miles) of linear service area range and allows connectivity between users without a direct line of sightThis should not be taken to mean that users 50 km away without line of sight will have connectivityPractical limits from real world tests seem to be around 3 - 5 miles (5 - 8 kilometres) The technology has been claimed to provide shared data rates up to 70 Mbit/s, which is enough bandwidth to simultaneously support more than 60 businesses with T1-type connectivity and well over a thousand homes at 1Mbit/s DSL-level connectivity. Real world tests, however, show practical maximum data rates between 500kb/s and 2 Mb/s, depending on conditions at a given site.

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Bluetooth Range

~1 metre0 dBm1 mWClass 3

~10 metres4 dBm2.5 mWClass 2

~100 metres20 dBm100 mWClass 1

Range(approx)

Max Permitted Power(dBm)

Max Permitted Power(mW)

Class

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802.11 and all that – what’s happening in the wireless ... 802.20 – mobile broadband ......

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