April 17, 2002

By Terry Moos, News@Cisco

Rapidly evolving wireless standards can be confusing. News@Cisco asked Larry Birenbaum, VP/General Manager of Cisco's Ethernet Access Group to clarify what's going on and how Cisco is delivering future-proof solutions.

N@C: What is Cisco's wireless Internet vision?
Larry Birenbaum: From Cisco's viewpoint, the Wireless Internet is a logical extension of how we use the Internet on a wired network. Wired networks aren't going away, but wireless solutions get us closer to the reality of "anytime, anywhere" access to the Internet or corporate intranets.

I believe this is essential for companies, especially as their employees need to stay connected to business applications in order to remain productive, both within the enterprise and outside. We are analyzing the benefits of how wireless technologies boost productivity and lower costs overall. The investment payback figures are just amazing. The ability to take advantage of the wealth of information on the Internet - no matter where you are and without the restrictions of a wired connection - is powerful.

N@C: What are the differences between IEEE 802.11a and 802.11b?
Larry Birenbaum: First, the similarities. Both are part of the IEEE 802.11 standard and provide the benefits of traditional wired LANs without wires -- allowing users to access networks without being tethered by network cables. This enables a wide range of handheld devices, like PDAs, to be connected.

The differences between the two standards are in transmission speed and frequency band. 802.11b, the most widely deployed wireless standard, allows data speeds of 11 megabits per second (Mbps) and operates in an unlicensed radio frequency band around 2.4 GHz. 802.11a operates in two frequency bands around 5.4Ghz, with maximum data speeds of 54 Mbps.

The 5.4GHz frequency band assigned to 802.11a offers more channels than those afforded to 802.11b. Furthermore, because 802.11a operates in an uncluttered portion of the radio spectrum, it isn't subject to as much potential interference. However, 802.11a isn't backward compatible with 802.11b, and that presents a challenge for concurrent operation and migration. What's important is that both 802.11a and 802.11b can coexist in the same organization. Cisco's just-announced Aironet 1200 Series enables an organization using 802.11b to add 802.11a later and have it operate concurrently with 802.11b.

N@C: What's driving the need for higher-performance WLANs?
Larry Birenbaum: There are two primary drivers. The first is bandwidth intensive applications -graphically rich or multimedia applications such as medical imaging and computer-aided design. Denser and larger content is being displayed and stored on larger devices. The second driver for 802.11a is the need for greater data capacity. While 802.11b operates on three channels each at 11 Mbps, 802.11a operates on 12 channels, each at 54Mbps, and offers significantly greater data capacity.

N@C: How secure are WLANs?
Larry Birenbaum: Properly configured Cisco WLANs are extremely secure. Working with Microsoft, we helped create an enterprise authentication and security architecture based on the IEEE 802.1x and EAP security standard, which is provided in our Aironet 350 and 1200 wireless solutions. The advantage of this is that it allows enterprises to scale wireless deployments to thousands of users with a standard, centralized security management framework. Furthermore, this authentication architecture is integrated with our wireless encryption technologies such that per-user, per-session dynamic encryption keys are downloaded transparently upon the users' standard logins.

N@C: Can you discuss the 'commoditization' of the WLAN market and what value Cisco brings to the technology?
Larry Birenbaum: Certainly, WLAN commoditization is occurring in the Consumer and SOHO segments of the WLAN market. Cisco's WLAN offering is aimed at different markets, namely the enterprise, vertical and public access markets, which need more than basic connectivity. For example, Cisco's WLAN product line features high performance, robust and scalable security, and enterprise class management - such as CiscoWorks and Wavelink, to name two. Cisco also works with more than 25 applications partners, which provide customers with additional resources and guidance in the deployment of WLANs.

N@C: How is Cisco's 802.11a solution unique?
Larry Birenbaum: We have designed a 'best of all worlds' solution in the Cisco Aironet 1200 Series. Of course it supports the current 802.11b standard as well as the new 802.11a standard. In addition, the Aironet 1200's dual-radio design permits the concurrent operation of these two standards, and others that might emerge. An example of the latter is 802.11g, expected in 2003 and which provides 54 Mbps operation in the 2.4GHz band. Importantly, these radios are field-upgradeable, and the Aironet 1200 has a high performance processor and large memory to support upgrading to future software-based standards as well. As a platform that will support all currently envisioned standards the Cisco Aironet 1200 provides outstanding investment protection.

N@C: Can you describe the customer migration path to higher performance WLANs?
Larry Birenbaum: With the architecture just described, we've created a way for organizations to protect technologies they already use while preparing for the future. The Cisco Aironet 1200 Series offers customers what we view as a 'future-proof' path to higher performance WLAN technologies. The modular design means that a customer can start with today's prevalent 802.11b and upgrade it to support concurrent operation with 802.11a in the future. Later on, a customer can replace the 802.11b module with an 802.11g module, which is backwards compatible with 802.11b, for more efficient use of the 2.4GHz spectrum. When other new standards emerge, such as QoS or next generation security, customers can be confident that the Aironet 1200 has the horsepower to accommodate them.

N@C: Why should customers deploy 802.11a?
Larry Birenbaum: Again, the key benefit of 802.11a is in its 54 Mbps performance, which is a fivefold increase over that of 802.11b and which more closely matches the common 100Mbps performance of today's wired Ethernet. This will be of benefit to users of graphics-intensive and multimedia applications. Furthermore, 802.11a also provides the added benefit of operating in a band that is clear of other uses and that has more channels for greater system capacity. Thus, deployments expecting heavy usage would favor 802.11a. Gartner Research indicates that early adopters of 802.11a will be in areas of specialized applications like building-to-building connections, high-worker density, or high-throughput scenarios.

N@C: Will 802.11a change the way the Internet is used?
Larry Birenbaum: Internet technology is more prevalent and the Web itself is now a routine part of everyday life - certainly of business life. Wireless LANs extend that resource to the worker who's not tethered to their desk, making him or her more productive and efficient. I believe that WLANs are an emerging sea change in business life and will rival email and cell phones in significance. 802.11a and its successors will make the experience better and Cisco's future-proof infrastructure will help pave the way.

Terry Moos is a freelance writer based in Seattle, Washington.