path:
/opt/httpd/root-www_shtml-8005/htdocs/global/AP/powernow/hinav/

main filename:
asiapac_powernow_wlan_focus_t_class_shtml.html

alt main filename:
http___www_cisco_com_asiapac_powernow_wlan_focus_t_class_shtml.html

filename2:
asiapac_powernow_wlan_focus_t_class_shtmlindex.shtml_hi_nav.html

alt filename2:
http___www_cisco_com_asiapac_powernow_wlan_focus_t_class_shtmlindex.shtml_hi_nav.html

filename2_1:
asiapac_powernow_wlan_focus_t_class_shtmlindex_shtml.html

alt filename2_1:
http___www_cisco_com_asiapac_powernow_wlan_focus_t_class_shtmlindex_shtml.html

filename3:
asiapac_powernow_wlan_focus_t_class.shtml_hi_nav.html

alt filename3:
http___www_cisco_com_asiapac_powernow_wlan_focus_t_class.shtml_hi_nav.html

	WLAN Masterclass

There's nothing new about wireless communication between computers - it's been going on for two decades. But it's only in recent years that wireless has begun to deliver the speed and security that businesses demand, while still offering total freedom of movement within the network area.

But what has made all these advances in wireless security and performance possible? Read more about how Cisco has worked to develop international standards for Wireless LAN technology here: WLAN Migration Path.

Find out how easy it is to manage the deployment of a Wireless LAN, and to maintain it, in WLAN Management.

Find out more below about:

• IEEE 802.11a Standard
• IEEE 802.11g Standard
• 802.1x Wireless Security

STANDARDS AND PERFORMANCE

Cisco Systems and Microsoft jointly developed the most widely deployed wireless standard. Ratified by the Institute of Electrical and Electronics Engineers (IEEE) as the 802.11b standard, it defines operation in the 2.4 GHz unlicensed radio band delivering a maximum data rate of 11 Mbps. But increased expectations and applications that require high bandwidth demand a new generation of products that will deliver even greater throughput, access, and functionality.

Wireless vendors are responding. IEEE task groups are now focusing on two higher-performance standards - 802.11a and 802.11g. It is important for customers migrating to higher-performance wireless technology to learn about the benefits and limitations of each wireless standard, and then decide which technology or technologies are best suited to their specific wireless network requirements.

IEEE 802.11a STANDARD

The IEEE ratified the 802.11a standard in 1999, but the first 802.11a-compliant products did not begin appearing on the market until December 2001. The 802.11a standard delivers a maximum data rate of 54 Mbps and eight non-overlapping frequency channels - resulting in increased network capacity and improved scalability. Operating in the unlicensed portion of the 5 GHz radio band, 802.11a is also immune to interference from devices that operate in the 2.4 GHz band, such as microwave ovens, cordless phones, and Bluetooth (a short-range, low-speed, point-to-point, personal-area-network wireless standard).

The 802.11a standard is not, however, compatible with existing 802.11b-compliant wireless devices. Organizations with 802.11b equipment that want the extra channels and network speed offered by 802.11a technology must install an entirely new wireless infrastructure with 802.11a Access Points and client adapters. It is important to note that 2.4 GHz and 5 GHz equipment can operate in the same physical environment without interference.

A barrier to the worldwide adoption of 802.11a is that the standard has not been approved for use in all parts of the world by the applicable regulatory bodies. To date, 802.11a has not been approved in Europe; however, the IEEE and European Telecommunications Standards Institute (ETSI) are currently working to reach an agreement through the IEEE 802.11h task group to address power issues and channel settings of 802.11a.

Another barrier to adoption of 802.11a is the lack of certification of interoperability. Currently, there is no assurance of compatibility among multiple vendors. WECA will provide interoperability testing for 802.11a products and work to promote the adoption of the technology. However, WECA will not begin this testing until two chip vendors are producing chips and at least three manufacturers are shipping products based on these chips. WECA anticipates that the certification process will begin during the second half of 2002.

IEEE 802.11g STANDARD

The 802.11g standard has been in draft form since November 2001 and is unlikely to be finalized until 2003. 802.11g will deliver the same 54 Mbps maximum data rate as 802.11a, yet it offers an additional and compelling advantage - backward compatibility with 802.11b equipment. This means that 802.11b Client Cards will work with 802.11g Access Points, and 802.11g Client Cards will work with 802.11b Access Points. Because 802.11g and 802.11b operate in the same 2.4 GHz unlicensed band, migrating to 802.11g will be an affordable choice for organizations with existing 802.11b wireless infrastructures.

It should be noted that 802.11b products cannot be "software upgraded" to 802.11g because 802.11g radios will use a different chipset than 802.11b in order to deliver the higher data rate. However, much like Ethernet and Fast Ethernet, 802.11g products can be operated alongside 802.11b products in the same network. Because 802.11g operates in the same unlicensed band as 802.11b, it shares the same three channels, which can limit wireless capacity and scalability.

802.1X WIRELESS SECURITY

Cisco collaborated with Microsoft to define the enterprise-class security architecture that was adopted by IEEE as the 802.1x wireless standard. The 802.1x standard and its Extensible Authentication Protocol (EAP) are the basis of the Cisco Wireless Security Suite, as employed by the Cisco Aironet 1200 Series. The Cisco Aironet 1200 Series supports all 802.1x authentication types, including EAP Cisco Wireless (LEAP), EAP-TLS, and types that take advantage of EAP-TLS. When coupled with a Remote Access Dial-In User Server (RADIUS) that supports the same authentication types, such as the Cisco Secure Access Control Server (ACS), the result is a scalable, centrally managed security solution that includes:

• Strong, mutual authentication to ensure that only legitimate clients associate with legitimate and authorized wireless Access Points.
• Dynamic 128-bit encryption keys can be set to automatically change for each user and for each session to protect the privacy of transmitted data.
• Stronger WEP keys are provided by Temporal Key Integrity Protocol (TKIP) enhancements such as message integrity check (MIC) and per-packet keys via initialization vector hashing, and RADIUS accounting records for all authentication attempts.