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.
In a classic performance, captured here on Youtube, Steve Balmer does a pretty good job of illustrating his feelings on the importance of developers. We share his enthusiasm.
You have probably already heard that we have an enterprise tablet, the Cius, with corporate telepresence, baked-in security/encryption, VXI, docking stations, display out and a bunch of other features that make it the ideal corporate citizen. One of those features of particular note to developers is the enterprise app store, AppHQ. The AppHQ makes it easier for Cius owners to find apps, while providing an easy route to market for developers. Of course, things like the AppHQ are far more interesting when well stocked with interesting apps, which brings us to the next point…
To help get the word out on the Cius Developer program, Cisco will be at Droidcon London. Participate in our “Crack the Code” breakout session with Marcus O’ Sullivan, Business Development at Cisco on the first day at 2:40 PM in room two. Then, have a drink on us; we’ll be sponsoring drinks later in the exhibit hall. On the second day, Tim Stone, Cisco Business Development Director will give a key note on the insights on enterprise mobility strategies first day at 9:35 AM in the auditorium.
If you miss some of these events, that’s okay, you can always drop by our booth, [booth number] any time—you wouldn’t be able to miss it. Bring some ideas, we’ll be glad to chat with you about the possibilities that are out there for you.
We are also giving away two Cius tablets at Droidcon—just drop your business card off at one of the events or at our booth and we will pick two winners!
So, if you can, please join us at Droidcon – we look forward to hearing from you. If you can’t make it to Droidcon, we certainly encourage you to join the Cius Developer Program.
Remember, there are lots of ecosystems out there but the good ones all have one thing in common…
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.
During last month’s Cisco Live event in Las Vegas, we invited a few guests to take a tour of the data center of one of our customers, Switch Communications Group. Switch hosts data and servers for several casinos and government agencies, among other high-profile customers, and they take security VERY seriously.
As Don Clark of the Wall Street Journal described, once the guests passed through security – which included a holding room and confiscated IDs – armed guards monitored every step the guests took while inside the data center, and strictly enforced all policies that disallowed any photography and basically touching anything.
My first project at Cisco was a wireless site survey at a large hospital complex. The hospital wanted a new 802.11n network with CleanAir APs and the ability to track hospital equipment, make Vo-Fi calls and provide guest access for devices like the iPad. The scope was to survey an estimated 3 million square feet of the facility, which wasn’t even all of the buildings! My retail background consisted of either stores or distribution centers, mostly with fairly large square footage, so my first thought was this shouldn’t take long. What is 3 million square feet, when an average distribution center was 1.5 million square feet?
What didn’t occur to me initially, but did very shortly after looking at a floor plan, is the huge difference in the purpose of the buildings. For starters there are a lot of rooms in a hospital, where as in retail there is primarily just large open spaces. Having to walk in and out of room after room, really adds a lot of time to a survey. Additionally many of the rooms have been re-purposed over time to meet the changing needs of the hospital. For example, rooms now used as administrative or doctor offices were at one time used as isolation rooms for patients, or various other uses that make RF propagation less than ideal. Another challenge was restricted pharmaceutical areas where badge and key access is tightly controlled. This doesn’t necessary pose a challenge in terms of providing coverage, but it does when you are walking your survey and you suddenly find yourself locked out of a room!
After many trips to the hospital and countless number of hours roaming hallways and going in and out of room, I have found that a few things have become almost second nature when I am getting things prepped or planning for a return trip. Below I have a few things that might help WLAN Engineers when planning for their next survey project. While none of these are directly related to the finer technical points of a survey, like configuring your survey APs power level importing floor plans into tools like Air Magnet, they will make life much less frustrating!