Blog

• CWNP
• October 26, 2008
• 

Nigh Wi-Fi

http://www.ubnt.com/products/

Ubiquiti builds some neat stuff, I have to tell you.  I have a couple of their products.  Unique, compatible, powerful, simple to use.  But full-featured 802.11 radios, compliant with the various 802.11 amendments that live in the 700 and 900 MHz bands?  What?  "Based on 802.11g OFDM" the specs say.  Take note of the 600 mW output power on that 700 mW radio.  Yikes!

I hadn't really considered this type of thing until a CWNE friend of mine started checking out some new mesh products.  He asked me about the positives and negatives of such a thing, and the first thing I thought of was interoperability and analysis.   The Wi-Fi Alliance is only interoperability testing and certifying equipment operating in 2.4 and 5 GHz.  So, 700 MHz (public safety), 4.9 GHz (public safety), and 900 MHz (ISM) is kind of left out in the cold for now.  Additionally, analyzer vendors don't make drivers for cards that work in non-Wi-Fi bands, so site surveying, protocol analysis, and spectrum analysis is out.  That would mean you'd be flying blind.  No thanks.  Been there, done that.

• CWNP
• October 20, 2008
• 

MIMO 4x4 with TxBF Has Arrived - Dang That Was Fast!

• CWNP
• October 14, 2008
• 

Customer Service...Hmph...You Ain't Seen Nothin'

I just got back from Ruckus Wireless's First Annual Big Dogs Conference.  It was the best thing since...sliced cheese. (inside joke)  Two long days of back-to-back meetings, but these were no ordinary meetings, and this was no ordinary conference.  Dreamed up, brought to fruition, and even MC'd by Ruckus's own David Callisch and his team of marketing geniuses (including June Eidson and Lisa Lavarias), this was a chance for Ruckus's customers, partners, employees (including all senior management and top engineers), and others with a vested interest to pour into one gigantic place to get to know each other, to share their knowledge and problems, and to become something akin to Ruckus family.

Now I have to tell you that Ruckus, for such a small company, knows how to treat its customers and partners.  Holy cow batman.  They spared no expense.  I felt like royalty, and for a country boy from Bremen, GA (yes, it's actually on Google Maps), it was...um..."off the hook...or chain...or whatever that saying is."  There were roadmap sessions (Niv kicked butt), sessions on RF design (Victor just rules), and my personal favorite: The Firing Line.  Yes, it's just what it sounds like.  CXO's and VP's were on stage taking pot shots from the quite-large audience for over an hour.  No question was off limits, and they did their best and were transparent and honest.  Big Kudos.

• CWNP
• October 06, 2008
• 

The Right Amount of Power

We've all heard, "Turn the power down, shrink the cell size, and you'll get more aggregate capacity in your Wi-Fi network."  It's an incomplete and bogus statement.  I know, you're thinking, "OK, Mr. Smarty Pants, where are you going with this...?"  First, consider that Cisco's VoWLAN 4.1 Design Guide, Page 3-3, starting with the section entitled, "Co-channel Interference Considerations" starts on a 15-page commentary that spells out in great detail something that it sums up in the beginning by saying, "The reality is somewhat more complicated because the AP influences the WLAN RF environment around it for a much greater distance than just the bit-rate boundary."  I give Cisco big kudos for the clarity of explanation and visual representation given of co-channel interference in these 15 pages.  

Let's restate the problem for clarity:

Regardless of how much power you're using at the AP or client, transmissions will affect the RF environment around the device at a much greater range than the data transmission actually needs to go.

Cisco makes another statement within those same 15 pages that I very much agree with, "It is not an effective strategy to reduce the overlap in order to reduce co-channel interference.  As users satisfaction can be greatly affected by poor roaming performance.  In contrast, call capacity can be addressed in planning and design."

What they're saying here is that you can't spread the APs out far enough to mitigate this RF interference problem because you'll break roaming, which is true for most systems.  So what is this blog post all about?  It's about something totally different that needed this information as a pre-requisite. :)

• CWNP
• September 30, 2008
• 

Aruba copies Meru? You decide.

http://www.wi-fiplanet.com/news/article.php/3774851

If you haven't read the articles or gotten the countless press releases, Aruba just released ARM 2.0.  The more I read about ARM 2.0, the more it sounds like Meru...someone who's technology Aruba dedicated a 31-page whitepaper to dismissing earlier this year.  "Coordinated Channel Access", "Airtime Fairness", and "Performance Protection" are all concepts pioneered by Meru and absolutely TRASHED by Aruba in their whitepaper here:

http://www.arubanetworks.com/pdf/technology/whitepapers/wp_RFARCH.pdf

So now we trash the ideas and features of the competition publicly in long, detailed, inaccurate whitepapers - immediately followed by announcing the same ideas and features in our own company and products?   What the @!#$&^ ??  It's not like people aren't watching and listening already.

• CWNP
• September 15, 2008
• 

RF Barrier

As you may have already read in various online high-tech rags about Meru Networks' new offering: RF Barrier.  If not, here's a good one by Lisa Phifer: http://www.wi-fiplanet.com/news/article.php/3761666

What's missing from these articles is the technical details, which are nothing short of COOL!  For example, the RF Barrier APs listen on their "internal" antenna, read in the MAC header (analyzing the source and destination MAC addresses), and then make a decision on whether or not this traffic is part of the internal (authorized) network.  If it is, then it immediately begins transmission on its directional, externally-facing antenna to "talk over" the frame.  The AP typically transmits a data frame (that's essentially just saying, "hello") to corrupt the original transmission on the exterior side of the building.  By transmitting at the same time as the original transmission, additional airtime is not used.  That makes RF Barrier a very good neighbor.

• CWNP
• September 08, 2008
• 

802.11r - R is for 'Radar, not on the'

I'm shocked.  I've been pinging infrastructure manufacturers, VoWiFi manufacturers, client vendors, and anyone else who will eventually add a new form of standardized key management to their equipment.  Everyone says basically the same thing, 'It's on our roadmap, but not a big priority at this time.'  They all elude to the fact that they are either waiting on the Wi-Fi Alliance to finalize the Voice-Enterprise certification or they are waiting to see what other vendors are doing.

• CWNP
• September 01, 2008
• 

The Price of Education - A Follow-Up

Wow.  I heard the mother of all Wi-Fi horror stories today.  Believe me, I've heard some doosies in my time, but this one is the worst.  Fortunately for the customer, it has a good ending.

My good friend, and CWNA, Jeff works for a company that manufacturers an application that uses Wi-Fi as a transport.  Like other such applications (Wi-Fi, RTLS, etc), this application depends on having a dependable and somewhat-optimized Wi-Fi infrastructure in place.  And so the story begins...

• CWNP
• August 26, 2008
• 

802.11r - R is for Rapid

Soap Box: On

802.11r ratification is the most important standard to hit the Wi-Fi industry in a long time - yes, even more important than 802.11n.  802.11i was sorely lacking - giving us only fast roam-back (to an AP to which your client was previously associated) and preauthentication, which is slow and rarely supported by WLAN infrastructure providers.  In the absence of a standard, many WLAN infrastructure vendors (Motorola, Colubris, Aruba, Cisco, Meru, etc.) have been using Opportunistic Key Caching (OKC) - also called Opportunistic PMK Caching.  Both the client device and the WLAN infrastructure have to support this for it to work, and on laptop computers, that gives us only Microsoft's WZC client and Juniper's Odyssey client.  While both are popular, they don't represent the entire industry - not even half when you consider how many appliances like VoWiFi phones there are in the market.

• CWNP
• August 18, 2008
• 

Apple MAController?

Ha!  Made you look.  Wouldn't that be the coolest thing though.  Is there anyone not sick of overly-complicated WLAN controller and WNMS interfaces?  In fact, if Apple would make their latest AirPort Extreme in a 2-radio version that could be powered with 802.3at PoE and managed by something as simple as their AirPort Utility, small companies wouldn't need much else really.  Stick in a USB2 Hub, USB2 HDD, and a USB Printer or two, Bonjour zero-config networking, and presto: instant, fast, user-friendly mobile networking.  Not bad really, for a small-to-medium office. Continue reading...