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Winning Back the Weather Radio Channels Adds Capacity to 5GHz Wi-Fi Spectrum

In my last blog on 5 GHz spectrum, I discussed the recent FCC ruling that permitted outdoor access points to use the U-NII 1 band (5150-5250 MHz).

But the story doesn’t  stop there. As mentioned last time, there are significant technical challenges to using the 5 GHz band. It is not cleared spectrum. It contains incumbent uses that are important for national security and public safety. Therefore, it is imperative that Wi-Fi not create harmful interference to these incumbent systems. Cisco will not settle for less.

On the topic of interference, a particularly interesting component of the same  FCC ruling that opened the U-NII1 band for outdoor AP’s is that it also re-opened the Terminal Doppler Weather Radar (TDWR) band (channels 120, 124, 128) with new test requirements for DFS protection. Hold on, let’s backtrack a bit before diving into what this means:

What is TDWR?

In brief, Terminal Doppler Weather Radar (TDWR) “is a Doppler weather radar system used primarily for the detection of hazardous wind shear conditions, precipitation, and winds aloft on and near major airports situated in climates with great exposure to thunderstorms in the United States.” TDWR uses the frequency band from 5600-5650 MHz which is why wireless network equipment needs to be proven to “do no harm” to TDWR. If you’re curious for more information on TDWR, then please click here and/or here.

A Brief History

Many of you reading this will recall that the FCC closed the use of the TDWR band several years ago as the result of numerous reports of wireless equipment creating interference with TDWR. Read More »

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How Does a Cisco Aironet AP2700 Perform Under Stress?

There’s been some speculation about the performance of the AP2700--just how good could our latest AP fly under stress? We were talking with Blake Krone and Sam Clements from the No Strings Attached Show, where they produce independent discussion and commentary on a variety of wireless equipment and technology across vendors. The idea came up that they could do an independent performance test on the Cisco Aironet AP2700. The guys received no compensation for the testing with the exception of arranging their travel out to Richfield, OH facility for the testing. We also provided 2 AP’s per person just in case they wanted to do some further testing.  

Sam & Blake along with several Cisco TMEs loaded up an AP2700 with 100 real clients to see what happens.   The testing was meant to be as real world as possible, so they did things like setup the clients at varying distances and angles, use a mix of 11n and 11ac clients, tested with CCO code (7.6MR2), and even factory reset and configured the controller then in front of Blake and Sam to show there’s no funny business.  The idea being, if you had 100 clients, and wanted to do the testing yourself and repeat the results, you could. I don’t want to spoil the results, so head to www.nsashow.com/AP2700/ to check out the whitepaper. 

Here’s a sneak peek at the client setup:

test

For full details as well as the results, visit www.nsashow.com/AP2700/

 

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DHCPv6 in the Cloud – DHCP Performance Testing and Results

As service providers move to cloud-based services, their IP addressing management system must operate efficiently in the virtualized environment of the cloud.  And within the cloud environment, these systems for DHCP, DNS and IP address management must also be fast. For example, many organizations have expressed a concern that poor DHCP performance could be the weak link when thousands of customers come back online after a failure event.  If DHCP address requests are handled in a slow or scattered manner, servers will not be able to service all requests in a timely fashion.

Another requirement for IP address management systems is support for IPv6, as the depletion of IPv4 addresses has led to many organizations finding themselves facing a rather accelerated and mandatory migration to IPv6 (read: yesterday’s World IPv6 Launch). While one of IPv6’s promises was the elimination of the need for DHCP, the reality is that centralized network management has made DHCPv6 a necessity.  DHCP allows network devices to Read More »

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