LECTURE‐2

HIGH SPEED LANHIGH-SPEED LANs

ContentsContents

• Standard EthernetStandard Ethernet• Fast Ethernet• Gigabit EthernetGigabit Ethernet• 10 Gigabit Ethernet• Fibre Channel• Fibre Channel• Wireless LANs

The Emergence of High‐speed LANs

• The speed and computing power of personal computers hascontinued to enjoy explosive growth. Today’s more powerfulplatforms support graphics intensive applications and everplatforms support graphics intensive applications and evermore elaborate graphical user interfaces to the operatingsystem.

• MIS organizations have recognized the LAN as a viable andindeed essential computing platform, resulting in the focus onnetwork computing.p g

• Both of these approaches involve the frequent transfer ofpotentially large volumes of data in a transaction‐oriented

i tenvironment.• The effect of these trends has been to increase the volume of

data to be handled over LANs and, because applications are, ppmore interactive, to reduce the acceptable delay on datatransfers.

Requirements for High‐Speed LANs• Centralized server farms: In many applications there is a need for• Centralized server farms: In many applications, there is a need for

user or client systems to be able to draw huge amounts of datafrom multiple centralized servers, called server farms. An exampleis a color publishing operation in which servers typically containis a color publishing operation, in which servers typically containhundreds of gigabytes of image data that must be downloaded toimaging workstations. As the performance of the serversthemselves has increased, the bottleneck has shifted to thethemselves has increased, the bottleneck has shifted to thenetwork.

• Power workgroups: These groups typically consist of a smallnumber of cooperating users who need to draw massive datanumber of cooperating users who need to draw massive datafiles across the network. Examples are a software developmentgroup that runs tests on a new software version, or a computer‐aided design (CAD) company that regularly runs simulations ofaided design (CAD) company that regularly runs simulations ofnew designs. In such cases, large amounts of data are distributedto several workstations, processed, and updated at very highspeed for multiple iterations.p p

• High‐speed local backbone: As processing demand grows, LANsproliferate at a site, and high‐speed interconnection is necessary.

High‐Speed LANs • The most widely used high‐speed LANs today are based onThe most widely used high speed LANs today are based on

Ethernet and were developed by the IEEE 802.3 standardscommittee.T k ith th h i l l t ki d f• To keep pace with the changing local networking needs ofbusiness, a number of approaches to high speed LAN designhave become commercial products. The most important of theseare:are:• Fast Ethernet and Gigabit Ethernet: The extension of 10‐MbpsCSMA/CD(Standard Ethernet) to higher speeds is a logicalt t b it t d t th i t t i i tistrategy because it tends to preserve the investment in existingsystems.• Fibre Channel: This standard provides a low‐cost, easilyp yscalable approach for achieving very high data rates in localareas.•High‐speed wireless LANs: Wireless LAN technology andHigh speed wireless LANs: Wireless LAN technology andstandards have at last come of age, and high‐speed standardsand products are being introduced.

Characteristics of Some High‐Speed LANs

IEEE 802

• IEEE 802 refers to a family of IEEE standards dealing with localarea networks and metropolitan area networks.

• More specifically the IEEE 802 standards are restricted to• More specifically, the IEEE 802 standards are restricted tonetworks carrying variable‐size packets.

• The services and protocols specified in IEEE 802 map to thelower two layers (Data Link and Physical) of the seven‐layerOSI networking reference model.

• IEEE 802 splits the OSI Data Link Layer into two sub layers• IEEE 802 splits the OSI Data Link Layer into two sub‐layersnamed Logical Link Control (LLC) and Media Access Control(MAC), so that the layers can be listed like this:

Data link layer‐ LLC Sublayer‐MAC Sublayery

Physical layer

IEEE 802 Workgroups

The Generations of Ethernet

The original Ethernet was created in 1976 at Xerox’s Palo AltoResearch Center (PARC). Since then, it has gone through fourgenerations.

Standard Ethernet• In Standard Ethernet the MAC sub layer governs the operation ofIn Standard Ethernet, the MAC sub layer governs the operation ofthe access method.

• It also frames data received from the upper layer and passes themto the physical layer for encodingto the physical layer for encoding.

• An Ethernet frame needs a minimum length of 512 bits or 64 bytesand maximum length (without preamble and SFD field) as 1518bbytes.

• Standard Ethernet uses 1‐persistent CSMA/CD.

Table : Standard Ethernet implementations

Standard EthernetMAC Sublayer• In Standard Ethernet, the MAC sublayer governs the operation of the access

method.• It also frames data received from the upper layer and passes them to the

h l l fphysical layer for encoding.Frame Format• The Ethernet frame contains seven fields: preamble, SFD, DA, SA, length or

type of protocol data unit (PDU), upper‐layer data, and the CRC.• Ethernet does not provide any mechanism for acknowledging received

frames, making it what is known as an unreliable medium.A k l d t t b i l t d t th hi h lAcknowledgments must be implemented at the higher layers.

Frame FormatStandard Ethernet

• Preamble: A 7‐octet pattern of alternating 0s and 1s used by the receiverto establish bit synchronization.

• Start Frame Delimiter (SFD): The sequence 10101011, which indicates theactual start of the frame and enables the receiver to locate the first bit ofthe rest of the frame.

• Destination Address (DA): Specifies the station(s) for which the frame isintended It may be a unique physical address a group address or a globalintended. It may be a unique physical address, a group address, or a globaladdress.

• Source Address (SA): Specifies the station that sent the frame.• Length/Type: Length of LLC data field in octets or Ethernet Type field• Length/Type: Length of LLC data field in octets, or Ethernet Type field,

depending on whether the frame conforms to the IEEE 802.3 standard orthe earlier Ethernet specification. In either case, the maximum frame size,excluding the Preamble and SFD, is 1518 octets.

• LLC Data: Data unit supplied by LLC• Pad: Octets added to ensure that the frame is long enough for proper CD

operation.• Frame Check Sequence (FCS): A 32‐bit cyclic redundancy check, based on

all fields except preamble, SFD, and FCS.

Frame Lengthh h i d i i b h h i i d i

Standard Ethernet

• Ethernet has imposed restrictions on both the minimum and maximumlengths of a frame. The minimum length restriction is required for thecorrect operation of CSMA/CD.

• An Ethernet frame needs a minimum length of 512 bits or 64 bytes Part of• An Ethernet frame needs a minimum length of 512 bits or 64 bytes. Part ofthis length is the header and the trailer.

• If we count 18 bytes of header and trailer, then the minimum length ofdata from the upper layer is 64 ‐ 18 = 46 bytesdata from the upper layer is 64 18 46 bytes.

• If the upper‐layer packet is less than 46 bytes, padding is added to make upthe difference.

• The maximum length of a frame (without preamble and SFD field) as 1518• The maximum length of a frame (without preamble and SFD field) as 1518bytes. If we subtract the 18 bytes of header and trailer, the maximumlength of the payload is 1500 bytes.

Fast Ethernet

• IEEE created Fast Ethernet under the name 802.3u• Fast Ethernet is backward‐compatible with Standard Ethernet,p ,

but it can transmit data 10 times faster at a rate of 100 Mbps.• The goals of Fast Ethernet can be summarized as follows:

1. Upgrade the data rate to 100 Mbps.2. Make it compatible with Standard Ethernet.3 Keep the same 48 bit address3. Keep the same 48‐bit address.4. Keep the same frame format.5. Keep the same minimum and maximum frame lengths.5. Keep the same minimum and maximum frame lengths.

• The access method is the same (CSMA/CD) for the half‐duplexapproach; for full duplex Fast Ethernet, there is no need forCSMA/CDCSMA/CD.

Fast Ethernet Implementation

• Fast Ethernet can be categorized as either a two wire or a four wire implementation.

• The two wire implementation is called 100Base X which can• The two wire implementation is called 100Base‐X, which can be either twisted pair cable (100Base‐TX) or fiber optic cable (100Base‐FX). 

• The four wire implementation is designed only for twisted pair cable (100Base‐T4). 

O f h h f h F E h h i h i

Fast Ethernet Mixed Configuration • One of the strengths of the Fast Ethernet approach is that it

supports a mixture of existing 10‐Mbps LANs and newer 100‐MbpsLANs.

• 100‐Mbps technology can be used as a backbone LAN to support anumber of 10‐Mbps hubs.h h b d h h b h f• These hubs are in turn connected to switching hubs that conformto 100BASE‐T and that can support both 10‐Mbps and 100‐ Mbpslinks.

• Additional high‐capacity workstations and servers attach directlyto these 10/100 switches. These mixed‐capacity switches are int t d t 100 Mb h b i 100 Mb li kturn connected to 100‐Mbps hubs using 100‐Mbps links.

• The 100‐Mbps hubs provide a building backbone and are alsoconnected to a router that provides connection to an outsidepWAN.

Fast Ethernet Mixed Configuration 

Gigabit Ethernet

• In late 1995, the IEEE 802.3z committee formed a High‐SpeedStudy Group to investigate means for conveying packets inEthernet format at speeds in the gigabits per second range.

• As more organizations move to 100BASE‐T, putting huge trafficloads on backbone networks, demand for Gigabit Ethernet hasintensified.

• Provides speeds of 1000 Mbps (i.e., 1Gbps) for half‐duplex andfull‐duplex operation.Th 1000 Mb ifi i ll f h CSMA/CD f• The 1000‐Mbps specification calls for the same CSMA/CD frame format and MAC protocol as used in the 10‐Mbps and 100‐Mbps version of IEEE 802.3.

• All Gigabit Ethernet configurations are point‐to‐point!

Gigabit Ethernet Configuration

Gigabit Ethernet Architecture Standard

Media Access Control (MAC)full duplex and/or half duplex

Gigabit Media Independent Interface (GMII)(optional)

full duplex and/or half duplex

(optional)

1000 Base – X PHY8B/10B auto‐negotiation

1000 Base T

1000 Base TPMA

8B/10B auto‐negotiation PCS 

1000 Base‐LXFiber optic

1000 Base‐SXFiber optic

1000 Base‐CXCopper

transceiver

Unshielded twisted pairIEEE 802.3ab

ptransceiver

ptransceiver

pptransceiver

MultimodeFiber

ShieledCopper Cable

Single Mode orMultimode Fiber

IEEE 802.3z

Gigabit Ethernet Technology 

Gigabit Ethernet cabling.1000 BASE SX fiber ‐ short wavelength

f b l l h1000 BASE LX fiber ‐ long wavelength1000 BASE CX copper  ‐ shielded twisted pair1000 BASE T copper  ‐ unshielded twisted pair

10‐Gbps Ethernet• The principle driving requirement for 10 Gigabit Ethernet is the

increase in Internet and intranet traffic. A number of factorscontribute to the explosive growth in both Internet andcontribute to the explosive growth in both Internet andintranet traffic:

• An increase in the number of network connections.• An increase in the connection speed of each end‐station (e.g.,

10 Mbps users moving to 100 Mbps, analog 56‐kbps usersmoving to DSL and cable modems)moving to DSL and cable modems).

• An increase in the deployment of bandwidth‐intensiveapplications such as high‐quality video.

• An increase in Web hosting and application hosting traffic.

10‐Gbps Ethernet

• Initially network managers will use 10‐Gbps Ethernet toprovide high‐speed, local backbone interconnection betweenlarge capacity switcheslarge‐capacity switches.

• As the demand for bandwidth increases, 10‐Gbps Ethernetwill be deployed throughout the entire network and willwill be deployed throughout the entire network and willinclude server farm, backbone, and campus wide connectivity.

• This technology enables Internet service providers (ISPs) andnetwork service providers (NSPs) to create very high‐speedlinks at a low cost, between co‐located, carrier class switchesand routers.and routers.

( h ) i d f i i l i d

10‐Gbps Ethernet Implementation10GBASE‐S (short): Designed for 850‐nm transmission on multimodefiber. This medium can achieve distances up to 300 m.10GBASE‐L (long): Designed for 1310‐nm transmission on single‐( g) g gmode fiber. This medium can achieve distances up to 10 km.10GBASE‐E (extended): Designed for 1550‐nm transmission onsingle mode fiber This medium can achieve distances up to 40 kmsingle‐mode fiber. This medium can achieve distances up to 40 km.10GBASE‐LX4: Designed for 1310‐nm transmission on single‐mode ormultimode fiber. This medium can achieve distances up to 10 km.

10‐Gbps Ethernet Configuration

40 & 100 Gbps Ethernet

• IEEE P802.3ba Task Force states that bandwidth requirementsfor computing and networking applications are growing atfor computing and networking applications are growing atdifferent rates, which necessitates two distinct data rates, 40Gb/s and 100 Gb/s

• IEEE target for standard completion of 40 GbE & 100 GbE in2010.

• 40 GbE products shipping today supporting existing fiber plant• 40 GbE products shipping today supporting existing fiber plantand plan is for 100 GbE to also support 10m copper, 100mMMF and SMF.

• Cost of 40 GbE or 100 GbE is currently 5 – 10 x 10 GbE.

A th d d it f l t

Fibre Channel • As the speed and memory capacity of personal computers,

workstations, and servers have grown, and as applications havebecome ever more complex with greater reliance on graphicsd id th i t f t d i d li i d tand video, the requirement for greater speed in delivering data

to the processor has grown.

• This requirement affects two methods of data communicationsThis requirement affects two methods of data communicationswith the processor: I/O channel and network communications.

• An I/O channel is a direct point‐to‐point or multipointi ti li k d i tl h d b d dcommunications link, predominantly hardware based and

designed for high speed over very short distances.

• The I/O channel transfers data between a buffer at the source/device and a buffer at the destination device, moving only theuser contents from one device to another, without regard to theformat or meaning of the data.format or meaning of the data.

Fibre Channel • Many small businesses and organizations—from localMany small businesses and organizations from local

government, real estate, and insurance agencies to school anduniversity departments—require fast, frequent access todatabase filesdatabase files.

• Such workgroups would benefit greatly from the speed andreliability of a storage area network with Fibre Channel

it hiswitching.

Fibre Channel Features 

• Full‐duplex links with two fibers per link• Performance from 100 Mbps to 800 Mbps on a single line

(full duplex 200 Mbps to 1600 Mbps per link)(full‐duplex 200 Mbps to 1600 Mbps per link)• Support for distances up to 10 km• Small connectorsSmall connectors• High‐capacity utilization with distance insensitivity• Greater connectivity than existing multi drop channelsGreater connectivity than existing multi drop channels• Broad availability (i.e., standard components)• Support for multiple cost/performance levels, from smallpp p /p ,

systems to supercomputers• Ability to carry multiple existing interface command sets for

existing channel and network protocolsexisting channel and network protocols

Fibre Channel Network• The Fibre Channel network is quite different from the IEEE 802 LANs.q

• Fibre Channel is more like a traditional circuit‐switching or packet‐switching network, in contrast to the typical shared‐medium LAN.

• Fibre Channel need not be concerned with medium access controlissues.

• The key elements of a Fibre Channel network are the end systems,The key elements of a Fibre Channel network are the end systems,called nodes, and the network , which consists of one or moreswitching elements referred to as a fabric.

• These fabrics are interconnected by point to point links between• These fabrics are interconnected by point‐to‐point links betweenports on the individual nodes and switches.

• Communication consists of the transmission of frames across thei i li kpoint‐to‐point links.

Fibre Channel Physical Media• Fibre Channel can readily accommodate new transmission• Fibre Channel can readily accommodate new transmission

media and data rates.• The transmission media options that are available under Fibre

Channel include shielded twisted pair, video coaxial cable, andoptical fiber.

• Standardized data rates range from 100 Mbps to 3.2 Gbps.Standardized data rates range from 100 Mbps to 3.2 Gbps.• Point‐to‐point link distances range from 33 m to 10 km.

Wireless LAN

• A wireless LAN or WLAN is a wireless local area network thatuses radio waves as its carrier.

• The last link with the users is wireless, to give a networkconnection to all users in a building or campus, the backbonenetwork usually uses cables.network usually uses cables.

• Wireless communication is one of the fastest‐growingtechnologies.

• The demand for connecting devices without the use of cablesis increasing everywhere.

• Wireless LANs can be found on college campuses in office• Wireless LANs can be found on college campuses, in officebuildings, and in many public areas.

• IEEE 802.11 defined the specifications for a wireless LANwhich covers the physical and data link layers.

Wireless LAN

Single Cell WLAN Multi Cell WLAN

Architecture of WLAN 

• The standard defines two kinds of services:• The standard defines two kinds of services:The basic service set (BSS) andThe extended service set (ESS).

Basic Service Set (BSS):• IEEE 802.11 defines the basic service set (BSS) as the building

block of a wireless LAN.block of a wireless LAN.• A basic service set is made of stationary or mobile wireless

stations and a central base station (optional), known as theaccess point (AP).access point (AP).

• The BSS without an AP is a stand‐alone network and cannotsend data to other BSSs. Such a network is called ad hocnetwork.network.

• In this architecture, stations can form a network without theneed of an AP; they can locate one another and agree to be partof a BSSof a BSS.

• A BSS with an AP is referred to as an infrastructure network.

Architecture of WLAN‐BSS

The Extended Service Set (ESS):

Architecture of WLAN The Extended Service Set (ESS):• An extended service set (ESS) is made up of two or more BSSs with

APs.I thi th BSS t d th h di t ib ti t• In this case, the BSSs are connected through a distribution system,which is usually a wired LAN.

• The distribution system connects the APs in the BSSs.• The ESS uses two types of stations: mobile and stationary.• The mobile stations are normal stations inside a BSS and the

stationary stations are AP stations that are part of a wired LAN.• When BSSs are connected, the stations within reach of one

another can communicate without the use of an AP.• However, communication between two stations in two differentHowever, communication between two stations in two different

BSSs usually occurs via two APs.• Note that a mobile station can belong to more than one BSS at the

same timesame time.

Architecture of WLAN‐ESS

802.11 Protocol Stack 

Upper Layers

bb

IEEE 802 11 defines two MAC sub layer protocols:

MAC SublayerIEEE 802.11 defines two MAC sub layer protocols:Distributed Coordination Function(DCF):

• Does not use any kind of central control/ h h d• DCF uses CSMA/CA as the access method.

Point Coordination Function (PCF):• The point coordination function (PCF) is an optional accessp ( ) pmethod that can be implemented in an infrastructure network(not in an ad hoc network).

• It is implemented on top of the DCF and is used mostly for time‐It is implemented on top of the DCF and is used mostly for timesensitive transmission.

• PCF has a centralized, contention‐free polling access method.Th AP f lli f t ti th t bl f b i• The AP performs polling for stations that are capable of beingpolled.

• The stations are polled one after another, sending any data theyhave to the AP.

• 802.11 standard specifies three transmission techniques allowedi th h i l l

802.11 Physical Layer

in the physical layer.802.11 Infrared:• The Infrared method uses the same technology as televisiongy

remote controls.• Transmit at two speeds of 1Mbps and 2 Mbps.• Range is 10 to 20 meters and cannot penetrate walls.Range is 10 to 20 meters and cannot penetrate walls.• Does not work outdoors.802.11 DSSS:• Use in short range radio, cordless telephone and microwave oven

etc.• Operate at 1 or 2Mbps and at low power.802.11 FHSS:• Uses 2.4Mhz ISM band.• Over longer distance FHSS offer resistance to multipath fading• Over longer distance FHSS offer resistance to multipath fading.• Insensitive to radio interference.• Lower bandwidth.

802.11a OFDM:

802.11 Physical Layer

• Use Orthogonal Frequency Divisional Multiplexing.• Operate at 54Mbps and 11 Mbps in wider 5.5 GHz ISM band.• Uses 52 FDM channels (48 for data; 4 for synchronization)Uses 52 FDM channels (48 for data; 4 for synchronization).• Encoding is complex.• More difficulty penetrating walls.802 11b HR DSSS802.11b HR‐DSSS:• High Rate Direct Sequence Spread Spectrum use 11 million chips/ sec

to achieve 11 Mbps in 2.4 GHz ISM bandAlth h l th 802 11 i 7 ti t th 11• Although slower than 802.11a range is 7 times greater than 11a.

• 11b and 11a are incompatible!!802.11g OFDM: 

– An attempt to combine the best of both 802.11a and 802.11b.– Supports bandwidths up to 54 Mbps.– Uses 2.4 GHz frequency for greater range.q y g g– Is backward compatible with 802.11b.

Implementations of WLAN

ISM Frequency BandsISM Frequency Bands

ISM (Industrial, Scientific and Medical) frequency bands:

b d ( )• 900 MHz band (902 … 928 MHz) • 2.4 GHz band (2.4 … 2.4835 GHz)• 5.8 GHz band (5.725 … 5.850 GHz)

Anyone is allowed to use radio equipment for transmitting inthese bands (provided specific transmission power limits are not

d d) i h b i i liexceeded) without obtaining a license.

• Wi‐Fi is a wireless technology that uses radio frequency to transmit data

Wireless Fidelity (Wi‐Fi)gy q y

through the air.• Wi‐Fi the short form of Wireless Fidelity is meant to be used

generically when referring to any type of 802.11 network, whethergenerically when referring to any type of 802.11 network, whether802.11b, 802.11a, 802.11g etc

• The Wireless Ethernet Compatibility Alliance started the Wi‐Ficertification program to ensure that equipment claiming 802 11certification program to ensure that equipment claiming 802.11compliance was genuinely interoperable.

• 802.11b was first to reach the marketplace. It is the slowest and leastexpensive of the three 802 11b transmits at 2 4 GHz and go up to 11expensive of the three. 802.11b transmits at 2.4 GHz and go up to 11Mbps.

• 802.11a was next. It operates at 5 GHz and can handle up to 54 Mbps.f b h ld h ( h• 802.11g is a mix of both worlds. It operates at 2.4Ghz (giving it the cost

advantage of 802.11b) but it has the 54Mbps speed of 802.11a. It isalso backward compatible to 802.11b.

• Most Wi‐Fi cards nowadays are capable of all three of these radiotechnologies.

Wireless Personal Area Network (WPAN)

• Wireless personal area networks (WPANs) are used to conveyinformation over short distances among a private, intimategroup of participant devicesgroup of participant devices.

• Unlike a wireless local area network (WLAN), a connectionmade through a WPAN involves little or no infrastructure ordi i i h ld id h li kdirect connectivity to the world outside the link.

• This allows small, power‐efficient, inexpensive solutions to beimplemented for a wide range of devices.p g

• Two common protocol for WPAN are:‐ IEEE 802.15.1 WPAN (Bluetooth)‐ IEEE 802.15.4 LR‐WPAN (ZigBee)

BluetoothA id l d WPAN t h l i k Bl t th ( i 1 2• A widely used WPAN technology is known as Bluetooth (version 1.2 orversion 2.0).

• Bluetooth is a wireless LAN technology designed to connect devices ofdifferent functions such as telephones notebooks computers (desktop anddifferent functions such as telephones, notebooks, computers (desktop andlaptop), cameras, printers, coffee makers, and so on.

• A Bluetooth LAN is an ad hoc network, which means that the network isformed spontaneously; the devices sometimes called gadgets find eachformed spontaneously; the devices, sometimes called gadgets, find eachother and make a network called a piconet.

• A Bluetooth LAN can even be connected to the Internet if one of thegadgets has this capabilitygadgets has this capability.

• A Bluetooth LAN, by nature, cannot be large.• If there are many gadgets that try to connect, there is chaos.• Peripheral devices such as a wireless mouse or keyboard can communicatewith the computer through this technology.

• The current data rate is 1 Mbps with a 2.4‐GHz bandwidth.• This means that there is a possibility of interference between the IEEE802.11b wireless LANs and Bluetooth LANs.

Piconets

• A Bluetooth network is called a piconet, or a small net that can have upto eight stations, one of which is called the primary and the rest arecalled secondaries.

• All the secondary stations synchronize their clocks and hoppingsequence with the primary.

• Note that a piconet can have only one primary station.p y p y• The communication between the primary and the secondary can be

one‐to‐one or one‐to‐many.

Scatternet• Piconets can be combined to form a scatternet.• A secondary station in one piconet can be the primary in another

piconet.p• This station can receive messages from the primary in the first

piconet (as a secondary) and, acting as a primary, deliver them tosecondaries in the second piconet.p

• A station can be a member of two piconets.

ZigBee• IEEE 802.15.4 LR‐WPAN is a low rate wireless personal area networkwhich is commonly known as Zig‐Bee.

• ZigBee technology is simpler (and less expensive) than Bluetooth.g gy p p• The main objectives of an LR‐WPAN like ZigBee are:

‐ ease of installation,‐ reliable data transfer,‐ short‐range operation,extremely low cost and‐ extremely low cost, and

‐ a reasonable battery life,‐ simple and flexible protocol.

• The raw data rate will be high enough (maximum of 250 kbit/s) tosatisfy a set of simple needs such as interactive toys, but is alsoscalable down to the needs of sensor and automation needs (20 kbit/s( /or below) using wireless communications.

Wi‐MAX

• Worldwide Interoperability for Microwave Access (Wi‐MAX) is acertification mark for products that pass conformity andinteroperability tests for the IEEE 802.16 standards.p y

• Use wireless links with microwave or millimeter wave radios at 10‐66GHz and 802.16a extension to 2‐11 GHz (Mobile extensions: 802.16e)

• Use licensed spectrum (unlicensed too in 802 16a)• Use licensed spectrum (unlicensed too in 802.16a)• Metropolitan in scale• Provide public network service to fee‐paying customers• Point‐to‐multipoint architecture with rooftop or tower‐mounted

antennas.• Provide efficient transport of heterogeneous traffic supporting QoS• Provide efficient transport of heterogeneous traffic supporting QoS• Capable of broadband transmissions at 2‐75 Mbps)

• WiMax is well suited to offer both

Wi‐MAXWiMax is well suited to offer bothfixed and mobile access

• WiMAX is expected to provide fixed ,nomadic, portable and, eventually,nomadic, portable and, eventually,mobile wireless broadbandconnectivity without the need fordirect line‐of‐sight (LOS) with a basestation.

• In a typical cell radius deployment ofthree to ten kilometers, WiMAX

b lsystems can be expected to delivercapacity of up to 40 Mbps perchannel, for fixed and portableaccess applicationsaccess applications.

• Mobile network deployments areexpected to provide up to 15 Mbpsof capacity within a typical cell radiusof capacity within a typical cell radiusdeployment of up to threekilometers.

Wireless Networks Protocols

Network Standard Topology Access Method

Modulation/ Spreading

Method

Data Rate

MethodWPAN (Bluetooth)

IEEE 802.15.1

Ad-hoc TDMA / TDD Gaussian FSK / FHSS

1 Mbit/s (Bluetooth v. 1.2)3 Mbit/s (Bluetooth v. 2.0)

LR-WPAN (ZigBee)

IEEE 802.15.4

Ad-hoc CSMA/CA Offset-QPSK / DSSS

250 kbit/s

WLAN (WiFi)

IEEE 802.11IEEE802.11aIEEE802.11b

Infrastructure(ad hoc also possible)

CSMA/CA DQPSK/ DSSS(802.11b) 64-QAM/OFDM

11 Mbit/s (802.11b)54 Mbit/s

IEEE802.11g (802.11g) (802.11g)WMAN (WiMAX)

IEEE 802.16IEEE 802.16e

Infrastructure TDM/TDMA(down/uplink)TDD or (semi

128-QAM / single carrier64 QAM /

134 Mbit/s

TDD or (semi-duplex) FDD

64-QAM / OFDM

Electromagnetic Spectrum