1chapter

Introducing WirelessNetworking

Wireless networks allow you toconnect computers together andaccess the Internet without wires orcables. You can use wireless networksin businesses of all types and sizes,the military, schools, churches, andmunicipalities. Today, workers canconnect to workplace networksand remain in contact with otherworkers through e-mail, Web sites,file sharing, and shared calendaringeven when physically away fromthe office. This chapter discussesthe different types of wirelessnetworks and other importantissues, such as security concerns.

WirelessNetworking

WirelessNetworking

WirelessNetworkingWirelessNetworking

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COPYRIG

HTED M

ATERIAL

Discover Wireless Networks ..............................4

Understanding What a Network Is ..................6

Discover the Benefits of Wireless Networking ......................................................10

Understanding the Disadvantages ofWireless Networking ....................................12

Discover the Types of Wireless Technology ......................................................14

Discover Applications for Wireless Networks ........................................16

Review System Requirements ........................18

Consider Your Networking Requirements ....20

Discover Wireless Standards ..........................22

Discover Network Configurations ..................24

Discover Networking Speeds ..........................26

Estimate Coverage Range ................................28

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Discover WirelessNetworks

4

Radio SignalsWireless networks use radio signals, similar to thosein radio and television broadcasting, to transmit databetween devices. Wi-Fi networks operate on the2.4 GHz or 5 GHz frequency band. These networkscan send data at speeds up to 54 Mbps (megabitsper second).

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Radio TransceiversA radio transceiver sends and receives radio signals.Each device in a wireless network has a radiotransceiver to send and receive information to andfrom the network. A transceiver can be locatedinside or outside a computer.

Budget

A wireless network enables a groupof connected computers and devicesto communicate without beingphysically connected to a network.It eliminates the cables used inwired networks. The most popularwireless networks are called Wi-Fi,or Wireless Fidelity, networks.

One of the main problems in the past withwireless networks has been the speed withwhich users could communicate with eachother. Because of new standards andemerging technologies, wireless networksnow have similar connectivity speeds ashard-wired networks.

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Introducing Wireless Networking chapter1

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SpeedThe faster the network speed, the faster that filesand other data move from one computer to anothercomputer. Newer wireless network technologies enablefaster data transmission than some wired networks.However, Fast Ethernet and gigabit Ethernet networkscan move at least twice the data of the fastest wirelessnetwork technologies.

CostPrices for wireless networking equipment are rapidlyfalling, making it possible to create an inexpensive, fast,and reliable wireless network. While wired networkscan be much faster, they often involve intrusive wiringthroughout a home or office.

Mobility of NetworkYou can move laptop computers and other wireless-enabled devices while remaining connectedto the network. Depending on the technology andother factors, a wireless network has a range of 150 to350 feet. In addition, as a laptop computer user, youcan connect to other wireless networks while traveling.

FinishFinishFinish

BudgetBudgetBudget

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Understanding Whata Network Is

6

A network comprises manydifferent components. Some ofthese components include anetwork adapter — also called anetwork interface card, or NIC —cables, routers, servers, hubs,switches, and network operatingsystems.

PC AdapterCard

PC AdapterCard

CommunicationNetworks enable different computers and devices toexchange information such as files and documents.If a network is connected to the Internet, thenetwork also enables connected devices to accessinformation available on the Internet. A networkcan consist of many different components or as fewas two.

Budget

Budget

InfrastructureThe infrastructure of a network is the term used todescribe the physical bits and pieces across whichinformation travels. Cabling, routers, hubs, andswitches are all considered part of the networkinfrastructure. A small home network can consistof very few components, while large networks canconsist of thousands of pieces of equipment andrequire a full-time team of personnel to maintain it.

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Introducing Wireless Networking chapter1

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ServersServers are computers that are dedicated to performingone or a few tasks on a network. Most businessnetworks use dedicated servers for services such as filestorage, Internet access, and running applications suchas a database program. It is possible to run multipleservers on one physical computer. For example, a singlecomputer on a network may be an e-mail server and aWeb server at the same time.

ClientsClients are computers that require services from the network. Most computers require communicationwith network servers using applications called clientapplications. For example, a Web browser is the clientapplication for accessing information from a Web server.

Access PointsAccess points are the locations on a network that provideaccess to the network for devices and computers. Whenused with wireless technology, a network can use a singleaccess point to allow multiple wireless devices to accessthe network.

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Understanding What aNetwork Is (continued)

8

TopologyThe topology of a network determines the physicallayout of the network. The most common topology is thestar topology that has a device such as a hub or routeras the center of the star, connected to different devices.Other lesser-used topologies are the bus and the treetopologies.

BackboneThe backbone of a network is the term used todescribe the main cable within a network where mostnetwork traffic transverses. A backbone is typicallyconnected to many other devices such as routers andswitches, rather than to single computers. The backboneof a network must be able to handle large amounts ofinformation or bandwidth. Large networks typically usefiber-optic cables and very fast network devices.

PeripheralsA peripheral refers to the devices you can connecteither directly to the network or to computers that areconnected to a network. Once you have connected adevice to a network, anyone on the network can accessthe device with the appropriate authorization. Someexamples of the numerous types of devices you canconnect to a network are printers, scanners, storagedevices, and cameras.

Star TopologyStar TopologyStar TopologyStar Topology

BACKBONEBACKBONEBACKBONE

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Introducing Wireless Networking chapter1

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CablesApart from very simple wireless networks, all networkscontain cabling, which exchanges information betweencomputers and devices such as switches. The mostcommon type of cable is twisted-pair cable, whichcontains four pairs of wires (eight wires total) thatare entwined with each other. The end of the cableterminates with a connector in the shape of a largetelephone connector.

SizeThe size of a network determines how the network isreferenced. A network within a single building is called alocal area network, or LAN. Networks that connect acrossa larger area or even across a country are called widearea networks, or WANs. LANs that contain wirelesstechnologies are referred to as Wireless LANs, or WLANs.

Network ProtocolsComputers and other devices connected to a networkcan communicate with each other because they allagree to use the same method of exchanginginformation called a protocol. A network can use manydifferent protocols simultaneously. For example, aWeb browser communicates with a Web site using aprotocol that specifies how Web information isexchanged, while two network cards exchangemessages over a cable using a different protocol thatdictates how information is transmitted via electricalsignals on a cable.

ProtocolsProtocolsProtocolsProtocolsProtocols

WAN

LAN

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Discover the Benefits ofWireless Networking

10

Both businesses and homes are usingwireless networks more and morebecause you can easily become mobileand still access network resources atthe same time. A corporate manager,for example, can carry her laptopcomputer to a scheduling meetingand access e-mails, shared calendars,and other resources using the wirelessnetwork, eliminating network cableconnections.

Network BenefitsRemain mobileFast Set upCostEasy to MoveExpandability

You can also become mobile using handhelddevices, such as a personal digital assistant(PDA), which are small devices that you carryin a pocket, purse, or hip holder, and thatinclude software for accessing e-mail, Webservices, shared files, and more.

Remain MobileOne of the major benefits of wireless networkingis being able to remain mobile while using acomputer, but still have access to all the servicesand resources made available from a network, suchas the Internet. You can even use a laptop computerwhile you move in a car or plane, as long as thecomputer is in range of the wireless network.

Arrivals/Departures

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Fast SetupOnce you set up the infrastructure for a wirelessnetwork, you can add more computers and devicesto the network quickly. Once you add a wirelessnetwork adapter to a computer and configure thecomputer to use wireless networking, the computercan connect to the network immediately.

Instructionscti ns

Quick Assembly

Wireless Networking

Everything You Need To Build Your Own Wireless Network! Wireless Networking

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Introducing Wireless Networking chapter1

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Easy to MoveIn traditional networks that require the use of cable,you cannot easily move a computer to a new location,because you must attach the computer to a nearby outletusing a cable. It is sometimes difficult to move a networkcomputer to a new location within the same room.A wireless network allows you to move any computeranywhere, so long as the computer is in range of thewireless network.

ExpandabilityAdding a new computer or device to a wireless networkis as simple as turning the computer on. Most wirelessdevices, such as access points, can support many differentdevices, and so long as you do not exceed the maximumnumber of devices, the access point quickly accepts newconnections. If needed, you can add multiple accesspoints to a wireless network to facilitate large numbersof computers.

CostAs opposed to networks that use cables, wirelessnetworks can be much cheaper to set up. Apart fromthe costs associated with equipment like hubs andrepeaters, the installation of cable through an existingbuilding may be very difficult and expensive. Wirelessnetworks also allow networks to transverse objects,such as roads, that require a lot of work and moneyto cross with cables.

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Understanding the Disadvantagesof Wireless Networking

12

While wireless networks have a widerange of benefits, some uniquedisadvantages include speed, batterylife of mobile devices, interference,security issues, cost, and interruptionsin services. Organizations that rely onwireless networks must test for andfix problems in areas where buildingsor stronger radio signals may interferewith transmissions.

Network

Disadvantages

Power Consumption

Interference

Network Security

Inconsistent

Connections

Lack of Managementnt

Because wireless networks use radio frequencies,it is difficult to prevent breaches in security.Companies must use access privileges to controlaccess to a network via a wireless device so thatonly authorized people and devices can accessthe network.

Power ConsumptionEach wireless device in a computer, such as a laptopor a handheld computer, has a radio transmitterand receiver. Radio devices require a relatively largeamount of power to operate effectively. Usingwireless adapters on portable devices can greatlyreduce the length of time that the devices canoperate using battery power.

INT

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InterferenceWireless networks use radio signals to transmitinformation. Unfortunately, there are many types ofdevices that use radio waves to operate. These otherdevices can interfere with the signals that thewireless network uses. Tracking down and eliminatinginterference sources can be difficult.

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Introducing Wireless Networking chapter1

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Inconsistent ConnectionsWith cable networks, computers are ensured a direct,stable connection to the network. However, movinga computer to another location or items blockingthe path of transmission can interrupt wireless networkconnections. While many applications, such as Webbrowsing, are adversely affected by temporary connectionloss, other applications, such as database-basedapplications, may result in information loss.

Lack of ManagementWith a wired network, network administrators can exercisevery tight control of the physical components of thenetwork. For example, network administrators canensure that all cables are the correct distance from devicesthat may cause disruptions, such as light systems orphotocopiers. With wireless networks, short of physicallyinspecting each wireless device, there is no way thatadministrators can determine or control the exact physicallayout of the network.

Network SecurityBy their very nature, wireless networks are moresusceptible to unauthorized access. A network may beaccessible from a location not under the control of anetwork administrator, such as a parking lot next to thebuilding housing the wireless network. While cablenetworks have the same concerns, they are not as easyto access as wireless networks.

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Discover the Types ofWireless Technology

14

Wireless technology enablescomputers and devices tocommunicate with each otherwithout the use of wires. Thereare many different types ofwireless technologies, each onewith its own set of strengthsand weaknesses.

Budget

Budget

Companies or municipalities may settle on oneor several types of technology for their networkdepending on their needs. For example, acompany that has a campus setting with severalbuildings may use microwave and infrared. Themicrowave technology can transfer data frombuilding to building, while your infrared devicestransfer data inside the building.

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Wi-FiWireless Fidelity, or Wi-Fi, is becoming the preferredtechnology for creating wireless networks both athome and at work. Wi-Fi allows computers anddevices, such as printers and hubs, to communicatewithout using cables. Most new wireless networkingdevices in use are Wi-Fi devices. Wi-Fi is also usedto facilitate Internet access in public places, such asairports.

BluetoothBluetooth is the name of the wireless technologythat is used primarily to allow individual devices tocommunicate with each other over short distances.For example, handheld computers can transmit aphone number from an address book to a mobilephone, which then dials the number. While possible,Bluetooth is not generally used to network computerstogether.

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CellularCellular wireless technology is most commonly associatedwith mobile telephones. Each telephone communicateswith a nearby transmitter, which changes as the phonemoves around a location. Laptop computers routinely usecellular phones as modems to provide dial-up access fromremote locations.

MicrowaveMicrowave technology enables two devices tocommunicate using microwave dishes that are alignedwith each other. You can use microwave systems toconnect the networks of two buildings that are separatedby obstructions such as wide roads. Microwave systemsare very expensive but can transfer large amounts ofinformation.

InfraredWireless infrared technology allows two devices tocommunicate using infrared light and you mostcommonly find them in remote controls. Infrared devicesneed to maintain a constant line of sight between thedevices and are more reliable over short distances. Themost common use of infrared technology is allowinghandheld computers to exchange data with each otherand laptop computers. Most handheld devices andlaptops have a built-in infrared port.

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Discover Applicationsfor Wireless Networks

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Wireless networks increasethe efficiency of many specificapplications, making themextremely useful when you usethem with wireless networking.

FinishFinishFinish

E-mailE-mailE-mail

SchedulingSchedulingScheduling

Data CollectingData CollectingData Collecting

By far, the main application for wirelessnetworking is person-to-personcommunication. All types of users usee-mail, messaging applications andscheduling software, from the presidentof a Fortune 500 company sendingquarterly company results, to youthbaseball coaches sending messages toplayers about upcoming practices.

E-mailE-mail is by far the most popular networkingapplication, and wireless networking now makesit possible to access e-mail constantly. You canuse laptop computers, and, increasingly, handheldcomputers, to access e-mail wirelessly at work andelsewhere with more frequency at public locations,such as airports and cafes.

@xyz.com@xyz.com@xyz.com

MessagingMost operating systems provide a messagingapplication that allows you to communicate instantlyusing text. Even inexpensive handhelds now have thecapability to provide messaging services and, whencoupled with wireless networking, allow you to stayin constant communication with your colleagues andfriends wherever you are.

Instant MessagingInstant Messaging

Jon has sent you a message.

Send

Jon:

Me:

Jon:

Do you have the updatedfigures for today’s meeting?

Did Charlotte review them yet?

Yes - I updated them thirtyminutes ago, so we’re ready.

She reviewed them beforeI IM’d you. We’re all set!

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Data CollectionMaking computers mobile increases the speed at whichyou can update data in applications such as inventorycontrol systems. For example, a person in the warehousecan immediately update information about the numberof products on a shelf instead of waiting until one hasaccess to a computer.

Web BrowsingFor most home users, the primary use of wirelessnetworks is the ability to use a mobile computer, such asa laptop, to connect to the Internet regardless of wherethey are in the house. Most wireless networks used athome are easily connected to the Internet and can provideaccess not only in the house, but also in the area outsideof the house, such as a deck or patio.

SchedulingThe ability for people to schedule activities andnotify others of their activities greatly increasesthe efficiency with which they can work together.Allowing workers to update their schedules andexchange that information immediately usingwireless technologies only further increases theefficiency of the scheduling system.

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Review SystemRequirements

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To connect to a wireless network,you must equip your computer withminimal hardware and softwarewhen connecting it to a wirelessnetwork. You should also reviewsystem requirements to ensure your computer, handheld device, orother component meets the wirelessnetworking standards that yourcompany, school, or home use.

WirelessNetworking

WirelessNetworking

WirelessNetworkingWirelessNetworking

This is analogous to you speaking Englishand your friend speaking Spanish; one orthe other must be able to understand andspeak the other person’s language or yourcommunication shuts down.

BUILT-IN WIRELESS

NETWORK SUPPORT

Operating SystemYou need a PC running Microsoft Windows XP,either the Home or the Professional version.Windows XP is an operating system thatcontrols your computer. Windows XP has built-in wireless networking support thatmakes it easy to create and maintainwireless networks. However, you do notneed Windows XP to go wireless.

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PC PortsYou need to install some basic networking equipmenton your computer. To start, your computer needs someempty slots where the equipment is connected. Yourdesktop PC should have an available PCI slot. Your laptopcomputer should have a PC card slot. If neither of theseis available, it is also possible to use the USB port withsome equipment. For more information about attachingnetworking equipment to your computer, see Chapter 3.One advantage of using USB ports for networkingequipment is the ease at which you can connect theequipment. With USB, you simply plug in the equipment,such as a network interface adapter. You do not have toopen up the computer case to make the connection.

Internet AccessIf you want to connect to the Internet with your wirelessnetwork, you need Internet access. To get the fullbenefit of a wireless network, you need high-speed, orbroadband, access. This is available through a localtelephone company’s DSL service or a cable TV system’scable modem service. You can access the Internet directlyor through another computer if that computer is usingthe Internet Connection Sharing feature available withMicrosoft Windows XP.

HardwareYou must equip your desktop PC or a laptop computerwith a Pentium 4 1.2 GHz processor, 256 megabytesof memory, and a 40GB hard drive.

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Consider Your NetworkingRequirements

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Before deciding the type of wirelessnetwork to build, consider howmany computers will connect to thenetwork and what operations youwant the network to provide. Youcan do this by taking inventory ofthe types of services, applications,and connections you use now, andthen adapt those things that can gowireless into your wireless networkdesign.

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CapabilityFor example, if you currently usee-mail, scheduling, data warehousing,and spreadsheet applications, considermaking all those available over thewireless network. You can store yourspreadsheets, for example, on a centralserver that you can access by wiredand wireless computers.

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Set Up Home or OfficeThe simplest wireless network is one homecomputer connected to a broadband Internetconnection. In a larger family, there may beseveral desktop and laptop PCs connectingto the Internet and to each other through awireless network. In an office environment, youmay want to choose one of the newer, fasternetworking technologies that use the 802.11gstandard.

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Introducing Wireless Networking chapter1

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Mixing Wi-Fi StandardsIf you connect computers and equipment that use multiple standards, you need dual-band capability.This allows you to mix and match wireless technologies.For example, if one network uses equipment withthe 802.11a standard and another operates under the802.11b standard, you can connect them together usinga dual-band router.

Number of ComputersThe number of desktop PCs, laptop computers, andother network-enabled devices determines how muchwireless networking equipment like routers and networkinterface cards — NICs — you need to purchase, install,and configure. Your wireless network may consist of oneto dozens of computers connecting to the Internet andto each other.

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802.11a 802.11b 802.802.11b 802.11a 802.802.11a 802.11b 802.802.11b 802.11a 802.802.11a 802.11b 802.802.11b 802.11a 802.802.11a 802.11b 802.802.11b 802.11a 802.802 11a 802.11b 802

Mobile AccessIf you want to access wireless networks while traveling,you need a laptop PC or personal digital assistant, orPDA. These devices let you connect to available Wi-Fi hotspots in many places you visit. You also can use the devicesto connect to your wireless network when you are athome or in your office. Laptops come in several differentvarieties, including lightweight, durable, high-performance,large screen, and so on. The one you pick should match thetype of work you plan to do. For example, if you travel a greatdeal and want a lightweight model, look for one that weighs4-6 pounds. However, if you need a high-performance laptopthat can handle graphics-intensive software, you may needto opt for a heavier laptop that weighs over 10 pounds.

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Discover WirelessStandards

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The most popular wireless networkingtechnologies today are based on the802.11 standard, which governs howdevices on the network communicatewith each other. Popularly knownas Wi-Fi, the Institute of Electricaland Electronic Engineers (IEEE)developed the standard, of whichthere are several variations.

When you set up purchasing requirementsfor your home or office wireless networkinfrastructure, take the time to understandthe wireless standards that each componentsupports. If you use Wi-Fi, for example, allyour components that connect to that Wi-Fidevice must be Wi-Fi compatible.

Wi-Fi Menu802.11a

802.11b

802.11g

802.11i

DISTANCE

Wi-FiWi-Fi stands for Wireless Fidelity. It now generallyrefers to all the 802.11 wireless networkingstandards, which specify how devices communicateusing wireless networks, although it originallyidentified networks that used the 802.11b standard.The Wi-Fi Alliance, a nonprofit industry association,works to ensure interoperability among the various802.11 wireless technology standards.

802.11aThe 802.11a standard is the least popular of the Wi-Fi technologies. While it is beneficial for someoffice networks with high-bandwidth needs andclosely located computers, it has a short range. Dual-range equipment allows 802.11a equipmentto network with the more popular 802.11b standardand the newer 802.11g standard. Otherwise, the802.11a standard is incompatible with the 802.11band 802.11g standards.

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802.11gThe 802.11g is the newest Wi-Fi standard with the samerange as the 802.11b standard but with the ability totransmit data at a much faster rate. It can communicatewith 802.11b networks, but requires dual-band equipment to interact with networks based on the802.11a standard. It suffers from interference problemssimilar to networks using the 802.11b standard, such ascordless phones, baby monitors, and microwave ovens.

802.11iThe 802.11i is an emerging standard that will increasethe security of Wi-Fi networks. When it is available, youmay be able to upgrade some older equipment to thisnewer standard.

802.11bThe 802.11b standard is the most popular of the Wi-Fitechnologies. It transmits data at a slower speed thanboth the 802.11a and 802.11g standards. Unlike802.11a networks, 802.11b radio waves can penetratemost walls, but are susceptible to interference fromcordless phones, baby monitors, and microwave ovens. DISTANCE

DISTANCE

DISTANCE

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Discover NetworkConfigurations

24

You must choose which type ofwireless network configuration youneed. Configuration is how thenetwork is laid out to allow networkcomputers to communicate with theserver and each other. The twogeneral types are infrastructure andcomputer-to-computer, or ad hoc.How you configure your networkdepends on the size of network,costs, resources you want to access,and the number of users.

INFRASTRUCTURE

COMPUTERS COMPUTERS

MAINCOMPUTER

ROUTER

MODEM

INTERNET INTERNET

COMPUTER TOCOMPUTER

Some wireless networks need a centralized accesspoint that several computers will use to “jump” to alarger network — such as the Internet. Other wirelessnetworks may be small enough where a singlecomputer can act as a shared device that can thenallow the other computers to access other networks.

InfrastructureStart

Finish

Infrastructure

InfrastructureAn infrastructure network is themost widely used wireless networkconfiguration. It uses a wireless router,also called an access point or gateway,to connect to the Internet through abroadband modem. The wirelessrouter then communicates with other wireless-enabled devices on the network.Infrastructure networks can bridgewireless networks with existing wired,or Ethernet, networks.

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Computer to ComputerA computer-to-computer, or ad hoc, networkallows computers to communicate witheach other without the use of an accesspoint, such as a router. This basic networkconfiguration permits you to exchange filesamong computers. In addition, onecomputer in a network can directly connectto the Internet and permit other computersto share the connection. Computer-to-computer networks are the easiest typesof wireless networks to create and manage.As long as one computer is set up as ahost computer, other computers can connectto the host as client computers. From there,all the computers on the network cancommunicate with each other, enablingthem to share files, share printers, andcommunicate with e-mail.

Computer to ComputerStart

Finish

Computer to Computer

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DiscoverNetworking Speeds

26

The speed of your networkdepends on many factors, suchas the technology in use andyour home or office layout.You may choose to use atechnology that gives youa faster speed but lessrange.

clinkclankUnfortunately, there are no wirelesstechnologies available that allowextremely high speeds over greatdistances. At the present time, youcan be several hundred feet awayand get high-speed connections.However, as your distance increases,your speeds deteriorate andeventually fade out.

Reality CheckYou will find that theoretical network speeds andreal network speeds are not the same. Your wirelessnetwork’s actual speed — that is, the rate at whichit transfers data — depends on the distance betweencomputers, which standard you choose, and themanufacturer of your equipment.

Your Speed may varyYour Speed may vary

802.11b 11 Mbps802.11b 11 Mbps802.11b 11 Mbps

802.11a 54 Mbps802.11a 54 Mbps802.11a 54 Mbps

802.11g 54 Mbps802.11g 54 Mbps802.11g 54 Mbps

802.11a SpeedThe 802.11a standard has a potential speed of54 Mbps.

802.11a802.11a802.11a

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Introducing Wireless Networking chapter1

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802.11g SpeedThe 802.11g standard, while operating in thesame frequency band as the 802.11b standard,has a potential speed of 54 Mbps.

Ethernet SpeedsIn contrast to wireless networking speeds, wired Ethernetnetworks are still the speed winners. Ethernets operateat only 10 Mbps, less than Wi-Fi speed. However, FastEthernets operate at 100 Mbps, and the newer gigabitEthernets are even faster. While you gain in speed withthe faster wired networks, you lose the freedom ofmobility that Wi-Fi technology provides.

802.11b SpeedThe 802.11b standard, the most popularwireless networking mode, has a potentialspeed of 11 Mbps. 802.11b

802.11b802.11b

EthernetEthernetEthernet

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EstimateCoverage Range

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The technology you use and yourenvironment determine how faryour wireless network can reach.Walls and metal structures reducethe range.

802.11b 11 Mbps802.11b 11 Mbps802.11b 11 Mbps

802.11a 54 Mbps802.11a 54 Mbps802.11a 54 Mbps

802.11g 54 Mbps802.11g 54 Mbps802.11g 54 Mbps

Planning for the coverage range of yourwireless network is an inexact science. Youcan measure the distance between buildings,compare your location with others in yourarea, and research all the standards out there.However, you cannot determine exactly howfar your wireless network reaches until youinstall it. You may end up relocating wirelessswitches and servers to eliminate or reduceobstacles.

Actual distance25-75 ft.

Possible distance225 ft.

802.11a

802.11a RangeOperating in the 5 GHz frequency range,the 802.11a standard is best suited fordense networks with high bandwidthneeds. In a typical office environment,802.11a networks have a possible rangeof up to 255 feet. The typical range is25 to 75 feet indoors. Coverage is limitedto one room.

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802.11g Range802.11g, the newest standard in the Wi-Fi networkingfamily, has the same range as the 802.11b standard:up to 300 feet, but typically 100 to 150 feet indoors.However, it is much faster than networks using the802.11b standard. Operating in the 2.4 GHz frequencyrange, 802.11g network signals can penetrate most walls.This allows homes and small businesses to add 802.11gdevices in central locations and provide wireless accessto most of their users. In addition, because of thehigh connection speeds of 802.11g devices, multiplecomputers can connect to the same 802.11g device(such as a router) without noticeable performance issues.

Other Range FactorsSome cordless phones, baby monitors, and microwaveovens can interfere with Wi-Fi networks using the 802.11band 802.11g standards, decreasing their range. Keep thisin mind when you position your wireless networks aroundchildren’s rooms, kitchens, and break rooms. You mayalso find that cellular phone towers interfere with yourwireless devices. If you are near one of these towers andinterference is an issue, consider using a combinationof conventional wired devices and wireless devices foryour network.

802.11b RangeWireless networks operating on the 802.11b standardhave a greater range than those using 802.11a. As themost popular standard, it often is used for public accesslocations, or hot spots. Its signals, operating in the 2.4GHz frequency band, penetrate most walls and have apossible range of up to 300 feet. The typical range is upto 100 to 150 feet indoors.

Actual distance100 - 150 ft.

Possible distance300 ft.

802.11b

Actual distance100 - 150 ft.

Possible distance300 ft.

802.11g

1 2 369#

580

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