Does anyone really care that the IEEE finally ratified the 802.11n wireless standard…anyone…anyone…Bueller?

The sorry fact is that the final ratification will have virtually no impact on the wireless industry. This is because what customers care about most is product interoperability. The Wi-Fi Alliance stepped into the standards void in 2007 and began certifying product [...]]]>

Does anyone really care that the IEEE finally ratified the 802.11n wireless standard…anyone…anyone…Bueller?

The sorry fact is that the final ratification will have virtually no impact on the wireless industry. This is because what customers care about most is product interoperability. The Wi-Fi Alliance stepped into the standards void in 2007 and began certifying product interoperability based upon IEEE 802.11n draft 2.0. The fact of the matter is that the Wi-Fi Alliance did such a great job with their 802.11n certification program as to make the final IEEE standard a non-event. The evidence for my statement is that the wireless industry currently ships over 1 million Wi-Fi products PER DAY, and well over 50% of those products are based upon 802.11n!

You can relax in knowing that no driver updates (or hardware changes!) are required for compatibility with the 802.11n standard. This is because the Wi-Fi alliance announced that they would not need to make any changes to the baseline requirements of its 802.11n certification program. So, any Wi-Fi CERTIFIED products based upon 802.11n draft 2.0 are automatically certified as interoperable with products based upon the final 802.11n standard.

… I’m still waiting…Bueller?

Many enterprises are considering Wi-Fi CERTIFIED™ 802.11n draft 2.0 deployment because it has significant advantages over existing wireless technologies. However, these advantages present the enterprise network manager with important deployment considerations. At the upcoming Burton Group Catalyst Conference in July, I will examine the various deployment considerations for 802.11n in the [...]]]>

Many enterprises are considering Wi-Fi CERTIFIED™ 802.11n draft 2.0 deployment because it has significant advantages over existing wireless technologies. However, these advantages present the enterprise network manager with important deployment considerations. At the upcoming Burton Group Catalyst Conference in July, I will examine the various deployment considerations for 802.11n in the enterprise. Some of the topics I will discuss are listed below.

Most existing 802.11 devices operate in a single frequency band, (e.g., 2.4 GHz or 5 GHz). 802.11n is different because it is specifically designed to operate in both the 5 GHz and the 2.4 GHz frequency bands. So 802.11n presents an opportunity for enterprises to reconsider which frequency band(s) to use. I will discuss some of the tradeoffs and issues enterprise managers need to consider.

Legacy 802.11 access points (APs) have a maximum power draw that is very close to the IEEE 802.3af Power over Ethernet (PoE) maximum of 15.4 watts. However, many 802.11n APs will consume more power than legacy APs. Enterprise AP vendors have addressed this problem in several ways and enterprise IT managers must consider which approach they will select.

802.11b/g/a APs typically use Fast Ethernet ports to forward traffic onto the wired network. Because the 802.11n data rate is designed to exceed the 100 Mbps capacity of Fast Ethernet (especially when using 40 MHz channels), most new APs will use Gigabit Ethernet for wired Ethernet communication. Therefore, some enterprises may choose to upgrade a portion of their wiring closet switches, and possibly their cabling, to provide gigabit Ethernet links to their 802.11n APs.

WLAN controllers that perform the data-forwarding function must backhaul all wireless traffic from hundreds of 802.11n APs, and so each controller will likely need to support several Gigabit Ethernet connections. WLAN controllers that distribute the data-forwarding function to the AP will need only a single Gigabit Ethernet connection.

802.11n presents a new security challenge because existing hardware sensors, without software updates, may not be able to recognize 802.11n APs. Therefore, it is important for enterprise managers to update wireless intrusion detection systems (IDSs), regardless of whether or not they plan to deploy 802.11n.

802.11n will impact network management tools. For example, spectrum analyzers must be able to recognize MIMO spatial streams, and visually communicate network behavior to the user. Therefore, enterprise managers will need to upgrade their network management tools in order to manage 802.11n networks.

Please join me in beautiful San Diego, July 27 – 31, for a discussion of these issues and many other interesting topics. Learn more about the Burton Group Catalyst Conference here: http://www.catalyst.burtongroup.com/Na09/.

Directional antenna pattern

Wireless LAN (WLAN) Radio Frequency (RF) management is poised to become the new competitive battlefront. This includes technologies such as beamforming, smart antennas, and any other techniques used to control the wireless LAN physical layer. One might think that 802.11 technology innovation is slowing down, and that future competitive battles will primarily rely on marketing fluff, [...]]]>

Wireless LAN (WLAN) Radio Frequency (RF) management is poised to become the new competitive battlefront. This includes technologies such as beamforming, smart antennas, and any other techniques used to control the wireless LAN physical layer. One might think that 802.11 technology innovation is slowing down, and that future competitive battles will primarily rely on marketing fluff, but not so.

Where we’ve been 

It may seem that most of the seemingly difficult WLAN problems have been solved. For example, WiFi Protected Access Two (WPA2) (802.11i-2004) provides strong, interoperable, wireless LAN security.  WiFi Multimedia (WMM) (802.11e-2005) provides basic quality of service capabilities and power save mechanisms.  And the emerging 802.11 high-throughput standard (802.11n) provides high performance improvements using various multi-input, multi-output (MIMO) configurations.

There are also other important, but lesser known standards such as fast roaming, (802.11r-2008), spectrum & power management (802.11h-2003), and radio resource management (802.11k-2008).  So, we’re done with 802.11, right?  Well, not exactly, there are still lots of standards under development and new technology hurdles to overcome.

Where we’re going

I think that the key area to keep an eye on is RF management. Companies such as Xirrus and Ruckus Wireless have used beamforming for years as a way to improve wireless performance, predictability, and reliability.  Aruba Networks uses Adaptive Radio Management (ARM) and Meru Networks uses VirtualCell/VirtualPort to manage RF.  Recently, Cisco Systems announced M-Drive and ClientLink technologies aimed at RF management.

Unfortunately, the technology is complex, difficult to understand, and filled with vendor jargon.  It seems to me that this is a perfect setup for pseudo-techno marketing spin.  The poor IT manager must learn the technology and then figure out how to compare the various vendor solutions. So over the next 4-5 weeks I am going to do a deep dive on this topic. My goal is to answer questions such as:

1. What are the important components of RF management?
2. Why is this topic important to the enterprise?
3. How does one compare the various vendor solutions?
4. Which vendor is in the best position to provide RF management innovation?
5. What does the future hold for RF management?

This research will form the basis of my next Burton Group report.  In addition, I will likely write several detailed blog posts and articles on this topic. 

How you can help

As always, I began my research by casting a fairly wide net in the hopes of quickly and thoroughly learning the topic. Naturally, I’ll speak to all the major vendors and read all their white papers.  I will also rely upon engineering textbooks and technical articles. But probably the most useful source of information is the collective wisdom of practicing network engineers.

So if you are willing to share your RF management experience, or you know someone that might, please contact me (here).  

Yesterday Cisco announced the Aironet 1140 series of Access Points (APs) and M-drive technology.  The Aironet 1140 is Cisco’s next-generation 802.11n access point and is a significant advancement over its predecessor, the Aironet 1250. The most significant difference is the fact that the Aironet 1140 has a maximum power draw [...]]]>

Yesterday Cisco announced the Aironet 1140 series of Access Points (APs) and M-drive technology.  The Aironet 1140 is Cisco’s next-generation 802.11n access point and is a significant advancement over its predecessor, the Aironet 1250. The most significant difference is the fact that the Aironet 1140 has a maximum power draw that is within Power over Ethernet (PoE) limits. The Aironet 1140 is also thinner and lighter than the Aironet 1250, and uses internal antennas (see the table below).  In addition, the Aironet 1140 uses the same mechanical brackets as the Aironet 1250 in order to simplify AP replacement.

Cisco claims that they are the first vendor to have an 802.11n AP with a maximum power draw that is within PoE limits, but they are actually not the first vendor to make this claim.  To be fair, not all PoE claims are created equal.  Some vendors must reduce transmit power or turn off encryption in order to fulfill their PoE claim.  So to be specific, the Aironet 1140 can use a single PoE connection to power both 802.11n radios, at full transmit power, running two spatial streams, with encryption turned on, using either the 2.4 GHz or 5 GHz frequency bands.  (When your wireless vendor tells you that a single PoE connection can power their 802.11n access point you should ask them to be more specific.)

M-Drive

M-Drive Technology is not a single technology, per se, but rather an integrated collection of capabilities that aim to simplify the adoption of 802.11n. M-Drive is primarily a branding announcement because many of the capabilities already exist in the Aironet 1250.  M-Drive provides Cisco with a name that they can use for competitive marketing, much like Aruba Networks did with Adaptive Radio Management (ARM). M-Drive includes capabilities such as: 

1. Automatic client load balancing
2. Dynamic channel and power setting
3. Extensive client compatibility testing
4. Beamforming technology (that Cisco calls ClientLink)

Cisco’s competitors already support many of the M-Drive capabilities.  For example, Aruba’s ARM 2.0 software supports features such as automatic client load balancing, dynamic channel/power setting, and airtime fairness. Aruba’s access points do not incorporate transmit beam forming but instead implement Cyclic Delay Diversity (CDD) to improve the downlink transmission quality for each client.

I anticipate that as this market matures, competitive differentiation will become more RF oriented and more technical.  So we can expect to see Cisco enhance and market M-Drive aggressively.

ClientLink

Cisco’s ClientLink technology is interesting because it works in both the uplink (Client to AP) and downlink (AP to Client) directions to improve transmission quality for legacy (802.11b/g/a) clients.  Most 802.11n access points can improve uplink transmission using an algorithm called maximal ratio combining (MRC) that combines several received signals from a client to create an single optimal signal.  ClientLink remembers the MRC signal adjustments for each client, and then uses that information to form an optimized transmit beam for every client, on a packet-by-packet basis.

ClientLink can improve throughput, coverage, and reduce the lost packet rate for legacy clients. This is important because legacy clients consume an inordinate amount of airtime due to their slower transmission rate, and therefore they can significantly reduce the remaining channel capacity for 802.11n clients. (Note that ClientLink is supported on both the Aironet 1140 and 1250 and is available April 2009 via the Cisco Unified Wireless Network release 6.0).

The Bottom Line

The Aironet 1140 is a significant advancement over the Aironet 1250 and will be widely deployed in carpeted enterprise environments.  The collection of capabilities called M-Drive brings Cisco into competitive alignment with similar capabilities from other vendors. Lastly, enterprises should take advantage of the ClientLink capability because it measurably improves throughput, coverage, and the lost packet rate for legacy clients.

Overall, this announcement strengthens Cisco’s competitive position in the enterprise WLAN market. It may also expand the size of the WLAN market for all vendors by helping enterprises become more comfortable with 802.11n and therefore more likely to deploy the technology.