IT285 Unit 2: Wireless Devices & Standards. NIC Card Access Points Remote Wireless Bridge Wireless Gateway CWNA Guide to Wireless LANs, Second

IT285

Unit 2: Wireless Devices & Standards

NIC Card Access Points Remote Wireless Bridge Wireless Gateway

CWNA Guide to Wireless LANs, Second Edition

2

NIC (Network Interface Cards) Connects the computer to a network

allowing it to send and receive data

NICs break data down into “packets” and add additional coding necessary for routing, decoding, and reassembling data packets

Many laptops are equipped with internal 3G and 4G wireless NICs


3


4

Figure 2-6: An access point acts as a bridge between the wireless network and a wired network

APs perform a function similar to a cellular Base Station and also serve as a Bridge between the wired and wireless network elements.


5

Figure 2-8: Point-to-point remote wireless bridge

A bridge connects network elements.

A remote wireless bridge connects two wired or wireless networks together. Remote wireless bridges use a directional antenna.


6

Figure 2-9: Point-to-multipoint remote wireless bridge


7

Figure 2-10: Root and non-root modes

4-ModesAccess Point Mode: functions as a standard AP connecting wireless devices to the wired networkRoot Mode: connects to other bridges NOT in root mode

Non-Root: communicates with bridges in root mode

Repeater Mode:Used to extend the range of the network


8

Figure 2-11: Repeater mode


9

A wireless gateway is a device that combines wireless management and security

•Authentication•Encryption•Intrusion detection•Manages bandwidth and traffic


10

Standards have been established to provide interoperability guidelines for a wide range of wireless devices manufactured by different companies.

While some argue the standards stifle advances in technology, others maintain that without them consumers would be bound to single manufacturers for their wireless products.


11

What are your thoughts on the standards?

Do you see them as a boon or burden to the industry?


12

Standards have been a huge benefit to wireless and telecommunication industries.

By establishing interoperability standards we ensure that wireless devices produced by “company A” will function as desired on network components designed by “company B”


13


14

De-facto Standards: Common industry practices, usually driven by success in the marketplace

De-jure Standards: Official established standards


15

De-jure standards can take a very long time to be established. The 802.11n addition to 802.11 (WLAN standard) was drafted in 2007 but not approved until 2009.

Standards are created by a Consortia or SIG that represents numerous industry factions. Many of these organizations are in direct competition in the marketplace…


16

De-facto standards are self-enforced by the marketplace and consumer levels of satisfaction.

De-jure standards may be enforced by an official regulatory agency


17

IEEE- Institute of Electrical and Electronics Engineers

Wi-Fi Alliance- association of hundreds of leading companies devoted to the proliferation of Wi-Fi technology


18

FCC- Federal Communications Commission

Charged with regulating interstate and international communications by radio, television, wire, satellite and cable. The FCC's jurisdiction covers the 50 states, the District of Columbia, and U.S. possessions.


19

IEEE 802.11 Infrared Transmissions

INFRARED

Advantages:•Does not cause interference•Not subject to interference

Disadvantages:•Limited range•LOS•Slow•No mobility


20

RADIO WAVES- Penetrate solid objects- Travel long distances at light

speed- Indoor/outdoor application- Much higher transmission

speeds than possible with Infrared


21

802.11 Standard- 2mbps

802.11b Standard- 5.5mbps/11mbps 115m range

802.11a Standard- up to 54mbps 35m range


22

802.11g Standard- 54mbps 40m

802.11n Standard- optimum speeds as high as 500mbps+ 70m


23

WLAN devices share many common characteristics with their wired network counterparts. The primary difference being in a WLAN data is transmitted via over the air-interface rather than a physical connection.

An access point, or AP acts as the Base Station for the wireless network and a bridge between networks.

A remote wireless bridge is a device used to connect two or more networks

Wireless standards have been adopted to ensure interoperability between devices


24

The IEEE, the Wi-Fi Alliance, and the FCC are agencies responsible for establishing and enforcing standards. The IEEE and Wi-Fi alliance drive standards across international boarders, the FCC enforces standards here in the USA. Other countries have similar enforcement agencies and may develop other standards.


25

The IEEE 802.11b, 802.11a, 802.11g, 802.11n standards are all amendments to the original 802.11 standard


26

Documents

IT285 Unit 2: Wireless Devices & Standards. NIC Card Access Points Remote Wireless Bridge Wireless Gateway CWNA Guide to Wireless LANs, Second