Wireless InternetAn technology overview and guide to effective

use at home, work, and in the classroom.

Larry MacPheee-Learning Center

Northern Arizona University

Infrared

• Found on older PDAs, Laptops, Printers

• Requires Line-of-sight• Short range• Flaky• Not widely adopted• Now used mostly for remotes

GPRS and Cell Phones

• Discussion for another day

But consider how these devices can be used in the classroom by students…with or without instructor encouragement!

• Bluetooth http://www.bluetooth.com• Named after Danish King Harald “Bluetooth”

Blaatand (910-985 AD), credited with uniting Denmark and Norway.– Radio waves– “Short” range (30 ft.)– Computer to Mouse, Keyboard, Cell Phone, PDA– Data rate: 1 Mbps (megabits per second)

Wi-Fi• Wi-Fi = wireless fidelity• http://www.wi-fi.org• IEEE 802.11 protocol• “Long” range (~150 ft)• Uses Radio Frequency (RF)

What we mean by “wireless”• An extension of an existing Internet connection

– Not a stand-alone connection

• Allows computers to connect to:

– other computers (directly)

– local networks and devices

– the Internet

Ways to Connect• PC to PC

– (Ad Hoc)• PC to Wireless Access Point

– (Infrastructure) “Hot Spot”

What do I need?1. Computer

• Wi-Fi card

• Built-in wireless

2. Wireless Access Point (WAP)• Public or Private?

• Open or Secure?

• Free or Paid?

Does my PC have Wi-Fi?Start / Control Panel / Network Connections

•If you see “Wireless Network Connection” you’re all set!

•Double-click to see available networks

Joining a Wi-Fi Network: Win XP

Open Secure

Joining a Wi-Fi Network: Mac On the Mac, Wi-Fi is called “AirPort”

Adding Wireless Capabilities

• Desktop $30 - $60+ for 802.11g

•PCI card

•External USB

• Where to buy?

•NAU bookstore

•Computer store

•Office supply store

•Laptop $30 to $60+ for 802.11g

•PC card (PCMCIA)

•External USB

Setting up a WAP at home• High Speed Internet Connection

– Cable Modem

– DSL Modem

• Instructions vary, but are usually poor!

• Apple, Linksys, Belkin, D-Link are good brands

• Take the time to set up the security!

• Skill Level Required: Intermediate to High

Finding a Hot Spot

• Search the web:http://www.wifi411.comhttp://www.jiwire.com

• Scan your locale:– “stumbler” software– hotspot finder gizmo.

Free (Usually Open)• Late For the Train

• Macy’s

• Uptown Billiards

• Pay ‘n’ Take

• NAU (Guest access)

• Know of Others?

Paid (Usually Secure)• Kinko’s

• Barnes and Noble

• Campus Coffee Bean

• Starbucks

• Embassy Suites

• UPS Store

• Varsity Espresso

• McDonald’s

• Days Inn

Public Hot Spots in Flagstaff

Access Points at NAUInstitute for Human Development Hotel/Restaurant Management Health ProfessionsFacilities ServicesColorado Plateau Studies Riles Biology Ashurst Social and Behavioral SciencesNorth UnionNursing Cline LibraryGammage Bookstore

University UnionDubois CenterLearning Resources CenterInformation Technology Services Eastburn Education CenterEngineering and TechnologyBabbitt Administrative CenterProject Management OfficePhysical SciencesCollege of BusinessSouthwest Forest Science ComplexWettaw Biology/BiochemistryGateway Center

WAPs at NAU

Connecting at NAU

• http://www.nau.edu/wireless

• VPN – for security

vpn.nau.edu

• Solution Center at 3-1511 (faculty/staff)

Current Wi-Fi Protocols

– Detailed Comparisons of a, b, and g– Performance degrades on mixed b/g networks

Protocol Data Rate Range Compatibility

802.11b 11 Mbps Long First out

802.11a 54 Mbps Short No

802.11g 54 Mbps Long With b

Future Wi-Fi Protocols

Protocol Data Rate Range Compatibility

802.11n 100 Mbps+ Longer(~250 ft)

b and g

Wi-Max 70 Mbps Longest (5 - 30 mi)

802.16

• Pre-802.11n is being sold now• Wi-Max promises very long distance

• (ideal when Cable and DSL are not practical)

Wireless Speed & Range• A “g” base station can transmit at

maximum data rate (54 Mbps) up to about 50 ft, but declines to 11 Mbps by 150 ft.

• Max range ~ 500 ft. outdoors• Physical site conditions vary• Antennas can help• Signal is omni-directional

Roaming Wirelessly

Wi-Fi Interference• “b” and “g” use RF in 2.4 GHz range• 11 channels, but…

• Interference from– Microwave Ovens– Cordless Phones– Bluetooth Devices– Baby Monitors

• More reading…

Wireless Security• Hide your SSID• Restrict MAC Addresses• Use Data Encryption

– 40 Bit WEP– 128 Bit WEP– WPA

• Use a VPN• Look for https:

Why Use Security?– To Control Access to WAP– To Protect Confidential Data

Geek fun: Build a Cantenna

• Extend the range by shaping the signal• Point-to-point• Line of sight• 10 miles?• Buy it• Build it!

Geek Fun II: Wi-Fi PrintingMake your old laser printer wireless!

Skill Level: HighCost: $100

Instructions

Classroom Uses of Wi-FiAdvantages of a Mobile Laptop Lab:

• Saves space• Multi-use room• Equipment sharing• Wireless Access Point• Charging• Printing• Security• Accountability

A Wired Classroom

A Wireless Meeting Place

Outdoor Roaming Wireless

A Wireless Lecture Hall

Tablet PCs and PDAs?

• How can they be used?• What advantages?• What disadvantages?

Final Thoughts

• What if you don’t want Wireless?• IM during tests?• Bootleg WAPs• Unwelcome surfing?• WiFi free zone?• Enforcement? PDAs, Cell Phones, etc.

Acknowledgements

• Stephanie McCarthy - Graphics• Don Carter - Additional Content• Kevin Mackett - Additional Content