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Wireless Protocols You Just Have to Know About!
Todd Lammle (FCC RF Licensed)
Certified Wireless Administrator (CWA) instructor, Sybex author
www.wirelesstechnologygroup.org
www.globalnettraining.com www.routersim.com
About Todd Lammle
President, GlobalNet Training, inc CEO, RouterSim, LLC Sybex author
Objectives
To understand the term “WLAN” To understand the current IEEE wireless
standards To understand the future IEEE wireless
standards To gather information that will allow you to
make informed decisions
Why do we care?
Can I just use it till I need glasses?
P lease Mr. IT guy, don't take my Wireless!
Wireless Is Addicting
Once You Use It
You Can’t Live without ItYou Can’t Live without It
What’s a typical “LAN”?
What’s a typical WLAN?
It’s a “hub” without wires
Wireless LANS (WLANs) use “Cells”
Channel Overlap to cover distance
Audio
AM Broadcast
Short-Wave Radio FM Broadcast
TelevisionInfrared Wireless LAN
Cellular (840MHz)
NPCS (1.9GHz)
ExtremelyLow
VeryLow
Low Medium High VeryHigh
UltraHigh
SuperHigh
Infrared VisibleLight
Ultra-violet
X-Rays
ISM Unlicensed Frequency Bands
902–928 MHz26 MHz
902–928 MHz26 MHz
5 GHz(IEEE 802.11)
HyperLANHyperLAN2
5 GHz(IEEE 802.11)
HyperLANHyperLAN2
2.4–2.4835 GHz83.5 MHz
(IEEE 802.11)
2.4–2.4835 GHz83.5 MHz
(IEEE 802.11)
What is the Wireless LAN Hardware?
Access Points Client Adapters Bridge Antennas
Devices In a Wireless Network
Access Point: An AP operates within a specific frequency spectrum and uses an 802.11 standard specified modulation technique.
It also informs the wireless clients of its availability and authenticates and associates wireless clients to the wireless network.
An AP also coordinates the wireless clients' use of wired resources.
Wireless Access Points
Serves as a connection point for wireless users to connect to the wired LAN
Contention-based, half-duplex deviceNot necessary in Ad Hoc networksPhysical/Data Link Layer deviceHas Layer-2 filtering capabilities1, 2, 5.5, or 11 Mbps connectivity depending on
standard implemented
Think of this device as a 10BaseT hub
Access Point Example
Servers
Wireless Components
Network interface card (NIC)/client adapter: A PC or workstation uses a wireless NIC to connect to the wireless network.
The NIC scans the available frequency spectrum for connectivity and associates it to an access point or another wireless client.
The NIC is coupled to the PC/workstation operating system using a software driver.
Wireless Components
Bridge: Wireless bridges are used to connect multiple LANs (both wired and wireless) at the Media Access Control (MAC) layer level.
Used in building-to-building wireless connections, wireless bridges can cover longer distances than AP’s (IEEE 802.11 standard specifies 1 mile as the maximum coverage range for an AP).
Wireless Bridged Network
Wireless Workgroup Bridge
Users are connected via wired Ethernet to the bridge, which is then connected via wireless Ethernet to the Access Point, which then connects to the wired backbone
Used to connect a small group of users (8 or less) to the wireless network
Users are a "collective client" on the wireless network
Wireless Components
Antenna: An antenna radiates the modulated signal through the air so that wireless clients can receive it.
Characteristics of an antenna are defined by propagation pattern (directional versus omnidirectional), gain, transmit power, and so on.
Antennas are needed on both the AP/bridge and the clients.
Campus Antenna Example
IEEE 802.11 WLAN
Physical
MAC layerIEEE 802.11
LLC layer IEEE 802.2 SNAP
InfraredLight
Direct Sequence
Spread Spectrum
Frequency Hopping Spread
Spectrum
Packet Layer Convergence Protocol (PLCP)
802.11g2.4 GHz – OFDM*
>20Mbps
Proprietary IEEE 802.11a/b Ratified
802.11a Standard5 GHz – OFDM* 54 Mbps
802.11b Standard2.4 GHz – DSSS
11Mbps
1999 2000 2001 2002
NetworkRadioSpeed
2003
*
WLAN Road Map
*Orthogonal Frequency DivisionMultiplexing (OFDM)
802.11b uses complementary Code Keying (CCK) as its modulation scheme
Quadrature Phase Shift Keying
IEEE 802.11 who?
Original recipe 802.11: Ratified June, 1997, 1 or 2Mbps at 2.4Ghz.
The big event- 802.11b (Wi-Fi): 1, 2, 5.5 and 11Mbps, 2.4 GHz, ratified in 1999. Didn’t take off until late 2000. Backward compatible to 802.11
First in line, last to produce products- 802.11a: Up to 54Mbps, 5 GHz, ratified in 1999. Not compatible with 802.11 and 802.11b
802.11a is 5Ghz
Range of 5Ghz is about 30% less then 2.4Ghz Overall investment of infrastructure is much
higher with 5Ghz (for now) Typical 2.4 Ghz range is 150 feet Typical 5Ghz range is 50 feet Not compatible with 802.11a and 802.11b The data rates specified by IEEE 802.11a are
6, 9, 12, 18, 24, 36, 48, and 54 Mbps, with support for 6, 12, and 24 Mbps
IEEE 802.11-tag-along’s
802.11c: Management Group802.11d: Committee trying to add 802.11 into other
countries that can’t use 2.4Ghz. Only Spain now…802.11e: Quality of Service (QoS), multimedia and security
as well as error correction. Uses TDMA like Cisco’s up and coming 802.11a products.
802.11f: Inter-Access Point Protocol (IAPP), Mobile IP802.11g: 54Mbps in 2.4Ghz range802.11h: Group trying to take 802.11a into Europe with
802.11e specs.802.11i: Wireless Authentication and Security802.11j: So new, there is still no members! Group will focus
on 802.11a and HiperLAN2 coexistence
11 and 54Mbs WLAN’s 802.11g
Provides higher date rates at 2.4 Ghz Similar to 802.11b Backward compatible to
– 80211– 802.11b
Other Committees
Wireless Ethernet Compatibility Alliance (WECA): Drafted the Wi-Fi System Interoperability testing document
Wireless Fidelity (Wi-Fi): Agilent Technologies in San Jose performs the independent WLAN products testing. After testing, the WECA board awards the Wi-Fi seal
Wireless Ethernet Compatibility Alliance (WECA)
Mission statement—WECA’s mission is to certify interoperability of Wi-Fi™ (IEEE 802.11b) products and to promote Wi-Fi as the global wireless LAN standard across all market segments
Goal—Provide users with a comfort level for interoperability
Presently over 100 different product certified and growing
• Supports ONLY 802.11b 11MB DS products• Supports ONLY 802.11b 11MB DS products
Other Wireless Technologies
BlueTooth HomeRF ZigBee HiperLAN Homeplug
BlueTooth
Bluetooth is a personal-area network (PAN) specified by the Bluetooth Special Interest Group for providing low-power and short-range wireless connectivity using frequency-hopping spread spectrum in the 2.4-GHz frequency environment.
HomeRF
In 1988, The HomeRF SWAP Group published the Shared Wireless Access Protocol (SWAP) standard for wireless digital communication between PCs and consumer electronic devices within the home.
SWAP supports voice and data over a common wireless interface at 1 and 2-Mbps data rates using frequency-hopping and spread-spectrum techniques in the 2.4-GHz band.
SigBee
Was known as “HomeRF Light” Less then $2 per module for manufacturer Runs off of cheap AA batteries Up to 115kbps From 10 meters to 75 meters All-in-one product (power, tx, rx, ant.)
HiperLAN
HiperLAN is a European Telecommunications Standards Institute (ETSI) standard ratified in 1996. HiperLAN/1 standard operates in the 5-GHz radio band up to 24 Mbps.
ETSI has recently approved HiperLAN/2, which operates in the 5-GHz band at up to 54 Mbps using a connection-oriented protocol for sharing access among end-user devices.
HomePlug Powerline Alliance
• Not-for-profit corporation formed to provide a forum for the creation of open specifications for high speed home powerline networking products and services.
Supposedly works at 14Mbps Don’t turn on a blow dryer… Newly released spec’s fix power spikes
WLAN is not all you need to know…
Third Generation Cell service will provide…..???
Reality: WLAN will deliver mobile high-speed ahead of 3G
802.11b/WiFi
50
500
1 000
10 000
50 000
100 000
Tra
nsm
issi
on r
ate
(kb
it/s)
Terminal device location
HomeRFBluetooth
Fixed LAN
Blackberry (US)
HomeRFBluetooth
802.11a and HiperLAN2
UMTSGPRS
GSM
Wireless Security Methods
Default Settings
Unique SSIDwith Broadcast
SSIDDisabled
Shared KeyAuthentication
with WEP
OpenAuthentication
with WEP
MAC BasedAuthentication
with WEP
EAPAuthentication
with WEP
EAPAuthentication
with MIC,broadcast Keyrotation, and
WEP
Less Secure More Secure
No Security by default….
Internet
Radius Authentication
WLAN Security
Internet
BlueSocket
SummaryThis cable
has GOT
to go! Don’t Delay-
Get “UN”-Hookedwith Wireless…
Hands-on Demonstrations Give Away Time!