It’s a fact – everyone wants wireless access. Recent research indicates that by 2015, more US internet users will be accessing the internet over their mobile devices than on traditional computers. With that many people online and on their mobile devices not having stable, secure wireless access is surely an impediment for companies as well as every day users. Companies leverage mobile devices to enable a more efficient workforce. Mobile devices are used to leverage “always-on” applications, increasing access for employees and as a better means of time management. Both of which increase employee productivity. Companies also often rely on their wireless network for regulating employee safety. Such is the case for the iron manufacturing company, North American Hoganas Inc.
With 11 production facilities across four continents in eight countries including the United States, where it staffs 250 employees, North American Hoganas Inc. needed to deploy an end-to-end wireless network in order to keep up with market demands and target new operational efficiencies. Up to the minute communication is vital not only for business operations, but also for the safety of their plant employees. Updating employees on risk assessments, proper product handling techniques, and work schedules are just some examples of mission-critical, daily communication from management to employees. There was one problem that stood between North American Hoganas Inc and a successfully deploying a pervasive wireless network: North American Hoganas Inc. itself.
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.
A key segment in the Public Sector wireless market to keep an eye on in 2011 is the U.S. DoD and Global Defense industry which is in the early stages of a major transformation around secure mobile communications and next-gen wireless LANs. One such transformation is the U.S. Department of Navy’s transition from NMCI to Next Generation Enterprise Network (NGEN) which supports over 700,000 users in over 3000 locations and includes requirements for 802.11a/g/n for voice and data support.
The ramp of WLAN technology into large Military installations (Air, Land, and Sea) and Defense operations is being driven by the obvious benefits associated with secure 802.11n networking along with critical WLAN functionality such as purpose-built Spectrum Intelligence for Wi-Fi communications (i.e. Cisco CleanAir). For the Defense industry, Cisco CleanAir changes the game for wireless in a big way as it delivers on the promise to run mission critical communications over the unlicensed (and sometimes messy…) RF spectrum of Wi-Fi. But there is a catch…without the required product approvals and security certifications, Defense agencies are limited in what they are allowed to deploy…but that’s soon to change in 2011--more on this later.
