In our third and final interview with Cisco standards experts, I talked with Andrew Myles. He is focused on wireless standards and interoperability activities, with a distinct Wi-Fi bias.
Andrew has contributed to standardisation activities in the IEEE 802.11 Working Group since 2001. He was the Editor of IEEE 802.11h (Spectrum Management) and is currently the Chairman of the IEEE 802.11 JTC1 ad hoc committee and the 802 Liaison to ISO/IEC JTC1/SC6. Andrew has been involved in certification activities in the Wi-Fi Alliance since 2003. He became a Director of the Wi-Fi Alliance in 2004 and Chairman of its Board of Directors in 2006. Within Cisco, Andrew has a standards coordination role with WRSTG, with a particular responsibility for IEEE standards matters and an interest in international standards policy matters.
What does an industry organization like the Wi-Fi Alliance do?
The Wi-Fi Alliance is made up of a whole range of companies involved in Wi-Fi networking across the entire value chain, from chip vendors to carriers, and across various segments, including consumer, enterprise and service provider.
The primary goal of these companies is to test and certify the interoperability of Wi-Fi standards as implemented across product lines from multiple vendors. Interoperability is usually shown by “low bar performance testing” against a test bed of “golden products,” rather than by conformance testing. This is a pragmatic, cost effective approach.
A second goal of the Wi-Fi Alliance is to promote the use of Wi-Fi generally. The industry must be doing something right, with over 450 million devices manufactured in 2009, including (believe it or not) a Wi-Fi dog collar.
How is the Wi-Fi Alliance governed?
There are two main classes of membership in the Wi-Fi Alliance. Companies are represented either as Regular members or Sponsor members.
The Sponsor members have the right to appoint Directors. However, those Directors do not represent their Sponsors; rather they have a fiduciary responsibility to represent the best interests of all members of the Wi-Fi Alliance.
Cisco was a founding member of the Wi-Fi Alliance (through its Aironet acquisition) and is one of twelve Sponsor members. Companies are elected as Sponsor members by the existing Sponsor members.
Where does the Wi-Fi Alliance obtain standards to certify?
Traditionally the standards underlying the Wi-Fi Alliance’s certifications have been sourced from the IEEE 802.11 Working Group. For example, the Wi-Fi Alliance certifies interoperability of products based on the IEEE 802.11a/b/g/n physical and MAC layer amendments and the 802.11i security amendment (also known as WPA and WPA2).
On a couple of occasions the Wi-Fi Alliance has certified a draft of an IEEE 802.11 standard to meet a perceived market need for tested interoperability. The most recent example of this was when 802.11 D2.0 was certified two years before ratification of the final standard by the IEEE. This approach was very successful because it kick started a huge market while the standard was being refined, with no impact on backward compatibility. A few years earlier, the Wi-Fi Alliance certified an early variant of 802.11e (QoS) called WMM. This example was less successful because the final version of 802.11e was incompatible with WMM. The industry continues to use WMM and its extensions and not 802.11e.
The Wi-Fi Alliance has recently developed a number of specifications independently from the IEEE, including Wi-Fi Protected Setup and Wi-Fi Direct. These specifications often begin life in small, focused industry SIGs. This trend away from IEEE sourced standards has been driven by a perceived need to be more responsive to the feature requirements and time scales of the very dynamic and fast moving Wi-Fi market.
How does the standards process start in the IEEE 802.11 Working Group?
The process generally starts when someone has an idea for a new standard or a significant amendment to an existing standard. The idea is usually relatively large in scope, like “improved network management” or “a faster PHY/MAC”, rather than a single feature.
If enough interest is generated within the Working Group, a Study Group is formed to undertake more detailed investigation. The Study Group develops a formal document called a Project Authorization Request (PAR), which defines the scope of the activity.
The PAR is then considered and hopefully approved by a defined IEEE Standards Association hierarchy. The next step is that a Task Group is then formed to do the actual work of developing a draft.
How are standards ratified in the IEEE?
The typical IEEE 802.11 Task Group usually undertakes a long period of calling for and evaluating ideas to fulfill the scope of the PAR. Sometimes the process is quick. But sometimes the process is very slow for various reasons, including scope creep, religious wars and a tendency to practice “standardisation by research.” A number of recent amendments have taken more than five years to complete.
Cisco’s preferred approach is for standardisation to focus on features that are known to work rather than theoretical concepts. For that reason, Cisco often contributes proprietary features that we have used in real Cisco products. Cisco loses the advantage of having a unique feature, but the larger market size enabled by standardisation is usually sufficient compensation.
In general, the first draft coming out of the Task Group requires thousands of changes. A series of ballots are used to identify and resolve all the issues. Although the rules require only 75% for a draft to “pass”, in practice a draft is finally approved when the vote is 95+% and all the comments are resolved, or at least addressed.
What makes Cisco successful in standards development?
The key to successful standards development is on-going and widespread collaboration, both internally and externally. Cisco’s IEEE 802.11 and Wi-Fi Alliance standards teams have a long history of working with various stakeholders, including our competitors.
We are very proud of our history of collaboration, well before “collaboration” became “cool.” It is interesting to observe that other companies have started emulating many of our techniques, including the “7am working breakfasts” at IEEE 802.11 Working Group meetings. I must admit the early start is not always popular among Cisco employees but the coordination benefit is invaluable.