Cisco Blogs


Cisco Blog > Mobility

Check your Spectrum!

October 3, 2011 at 10:28 am PST

Lately I had been spending a lot of time in the office rather than on the road.  Which isn’t all bad, as it gives me some semblance of a routine rather than living out of a suitcase.   It has also has given me some spare time to come up with another blog topic, which actually stems from some of the work I have been doing for customers lately.

Typically when a site survey is being done, we will do spectrum analysis work as well, part of my job entails creating and reviewing documents from this work, prior to delivering them to customers, which means I have been watching a lot of  spectrum analysis lately.   Most of the customers I have worked with recently have been with CleanAir APs, so they will be able to monitor their environment in real time, once the WLAN is up and running.  However it’s always a good idea to perform some spectral analysis while you are walking around doing a site survey.  And really why not?  If you are there and you have a few minutes, fire up the old spectrum card and get a capture of whats going on with your RF.   This helps make sure there aren’t any major layer 1 surprises when you go to install the new WLAN.  It doesn’t mean things won’t change, and they often will, due to the dynamic nature of RF.  It’s an ever changing environment, so what wasn’t there on Monday, might show up on Tuesday and be gone again by Wednesday.

Before jumping into particular types of interferes let’s talk about some of the data that Cisco Spectrum Expert can show you.  Two of the things I like to look at when looking at the RF in Cisco Spectrum Expert, are Real Time FFT and Duty Cycle plots, as pictured below.

The Real Time FFT is showing you is the RF energy in real time measured in dBm, so how loud or quiet the device is.  The next is the FFT Duty Cycle, which simply put it’s how utilized the RF is. Let’s say you have a device that is being captured as having a 1% duty cycle.  This means it’s using a very small amount of the available ‘air time’ to transmit its data.  Conversly if there is a device that is showing a 100% duty cycle it is using up all the ‘air time’ and not allowing other devices to use the RF medium to transmit.

Two other views I find helpful are the Spectrogram views.  These display the same info as the plots above, but are plotted out over time.  I use them in a few of the examples below.

Read More »

Tags: , , , , , , , , , ,

A Customer Story: Hospital uses Cisco CleanAir technology to rapidly isolate radio interference in “noisy” environment

We all see a growing trend of using wireless technologies in hospitals due to its benefits in cutting healthcare costs and increasing accessibility for patients and healthcare providers. Wireless applications have the potential to improve care by providing real-time access to a patient’s medical history including treatments, medications, laboratory tests, insurance information and more.

Our customer, Children’s Mercy Hospitals and Clinics – one of the leading children’s hospitals in the U.S.—works tirelessly to help ensure healthcare providers, administrators, and patients have access to leading technologies. So when it came to managing the hospitals’ wireless network, IT managers knew they needed a best-in-class solution.  Deploying the right wireless technologies is not only a matter of adopting reliable solutions – it’s also about putting the systems in place to identify and mitigate wireless interference, which can be a major challenge at a busy hospital.

To combat this, the hospital deployed the Cisco Aironet 3500 Series access points throughout the campus to enable high-performance 802.11n wireless services and Cisco CleanAir technology to both troubleshoot problem areas and optimize the wireless environment. The IT team quickly identified and addressed many areas of interference, including pinpointing that some interference was coming from public buses changing traffic lights at a nearby bus stop.  With the powerful Cisco environment, Children’s Mercy Hospitals is moving to a “self-healing” wireless network that will automatically fix itself when interference is encountered.

Listen to what the customer has to say about their deployment and Cisco CleanAir: Watch now. You can also read and download the PDF version.

Tags: , , , , , , ,

Tablets Welcomed: Will you create the “killer” enterprise app?

Last week’s blog highlighted ways you can improve the user experience by preparing your network to meet the challenges associated with the sea of devices entering the corporate networks. Ultimately however, productivity is not only going to be depended on the freedom to choose a device, or the ease of access to information, or the quality of the connection when consuming bandwidth intensive content. It will largely be depended on the tools available on those devices – in other words “the apps”.

Most desk-bound knowledge workers will be quite content using existing productivity tools such as word processing, spreadsheet, or presentation software already available in the various app stores. There will however be many other types of workers that can tremendously benefit from having applications that are turbo-charged with network intelligence.

What do I mean by that? Well, you will just have to watch the video where Jagdish Girimaji, product manager for the Mobility Services Engine (MSE), outlines what network information can be exposed to make tablet applications more intelligent.

Read More »

Tags: , , , , , , , , , , , , ,

Tablets Welcomed. Can Your Wireless Network Support the User Experience Expected of These Sleek Devices?

Ok, so maybe you are starting to give in to the idea that, employees bringing personally owned tablets at work, is indeed not a fad and you have to deal with it. You have decided on a BYOD strategy that protects company and network resources, while (mostly?) satisfying user appetite for connectivity anywhere from any device.

Great! Now. Is your 802.11n wireless network capable of delivering the user experience that is associated with these new sleek gadgets?

If you thought your network is “good enough”, then think again. This client wave is about to disrupt everything in multiple ways.

  • First, more devices on the network translate to significantly higher demands for bandwidth. In many cases bandwidth requirements can grow exponentially because the ratio of user to devices is no longer 1:1 but 1:2 and often 1:3. We therefore expect to see network utilization significantly rise over time.
  • Second, tablet form factor now allows users to truly be mobile. Unlike laptops, users can now walk/move and be productive at the same time. This new type of behavior will increase the number of clients roaming between access points.
  • Finally, it has been observed that tablets are primarily used for content consumption (as opposed to creation), and video is one of the predominant types of content being consumed, which further complicates bandwidth issues, but also creates new challenges.

Read More »

Tags: , , , , , , , , , , , , , , , , , ,

Summertime 2011: Observations of a CTO

By Bob McIntyre, CTO, Cisco Service Provider Group

I was digging around my PowerPoints on the laptop recently, getting ready for our “Cisco Live!” event, and came across a set of predictions I’d made, five years ago.

A CTO, making predictions five years out? What could possibly go wrong, right? Well, I wouldn’t be bringing it up unless it was so off base as to be funny, — or close enough to “correct” to boast a little.

Turns out it was mostly the latter, so allow me to boast a little. -- Just a little. I promise.

Back then, in 2006, I said what will make service providers successful would be the delivery to consumers of their own personal HD video stream, on any device, wherever they were. A two-way stream. (This was the year before the iPhone and smart phones hit the market, and four years before “pads” did.)

I also surmised that triple and quad play (voice, video, data and wireless) bundles would continue to be the big thing; that operators needed to move drastically faster on what we now call “apps;” and that what we now call Wi-Fi mobile hot spots and 4th generation wireless (back then, we called it “fixed mobile convergence”) would be critical. Read More »

Tags: , , , , , ,