Just a quick post to talk a bit about RSSI, and why it’s NOT the best way to judge your Wireless LAN.

First a bit of history, more than a decade ago I started into Wireless Networking. Back then the only tools we had were the Cisco ‘Breadcrumbs’ RSSI meter built in the Cisco (Aironet) client software.

Back then we thought Coverage was the Holy Grail – how to get the most coverage with the least amount of Access Points. So getting a strong RF signal, as measured by RSSI was everything. Then we found RF Amplifiers – and we made some HUGE RF coverage circles.

Site surveying was running around with AP-on-a-Stick and measuring how far the RF coverage went. That was all. Just RSSI.

Sad to admit, but I did hundreds of these. (I can only sleep at night knowing that everyone did it that way and no one had any better idea back then of what else to do)

But today we know it’s NOT about the RSSI! Sure, you *must* have good signal. But good signal alone won’t give you a great Wireless LAN design. It’s all about the actual throughput of data over the RF medium.

The new Holy Grail in Wi-Fi is getting the network to provide the actual data throughput and specs needed by the client devices. That is all encompassing.

So instead of measuring only for RSSI, we really need to be measuring better the net throughput, under load, of our Wireless Networks.

Sure, an RF amplifier can transmit a strong signal a long ways… but the net result is you have clients that can see the AP, but the AP can’t see the clients. And you now have HUGE contention domains (Collision Domains) where all devices must wait for the others they can see on the same channel to ‘Share’ the RF medium.

Remember – it’s not about RSSI – it’s about consistent, measured, available throughput!

Another post from Jared Griffith of Cinergy Wi-Fi. This is a cross-post from his new blog.

This summer I had the opportunity to do a large-scale roll out of Wireless LAN access for an entire school district. This project included: pulling cable, installing 625 Access Points, and complete post-install verification surveys across 43 schools, and 6 district buildings. This project was under a pretty intense time line, (school starting) and failure really wasn’t an option. Thus we needed to create an installation method and time line, that would give us a time advantage since the survey and cabling would take a lot more time than just the AP installs.

Installing access points is one thing, but knowing were to correctly place them is another. We were able to get the scaled floor plans from the district , and went on site to the locations with an access point and AirMagnet’s Survey Pro. We wanted to capture what the attenuation of the exterior walls, bearing walls, support walls and all other obstacles we could. We then took those data points and plugged them into AirMagnet’s Planner software for pre-deployment designs. Knowing what the customers design requests were, we could then create a proper design and know AP count and placement. We used the AirWise function in planner to verify the design requirements as well. This helped us to firm up our bid, and create a fixed cost environment for cabling within a target 10% margin.

With the knowledge of the installation facts, we were able to move onto the management of the installation. I knew that having this many access points could cause for a potential disaster of not knowing were the access point was. You can see it in the controller and it is on the map but is it in the correct location? We created a spreadsheet that had a tab for each location. The sheet had columns for:

• AP name
• MAC Address
• Serial Number
• Installer Name
• Installation Date
• Cable Completed Date
• Survey Completed Data

From all of this information we could calculate percentage of completion of the project.

To stage the equipment for each school we had the design map from Planner, that told us how many AP’s went to that school. The map listed a number next to the AP. If the school took 33 AP’s, we would use a barcode scanner and get the MAC and Serial Number from the AP and it would place it on the spreadsheet. We would then write a number on the AP box 1 -33 to coordinate with the map, and the spreadsheet. This gave us the exact location of every AP being installed, what the MAC and Serial Number of that AP was. This kept the install very clean as far as an administrative standpoint. Additionally, this was very useful when programming the controller with all of this information.

There were two different types of ceilings we would have to work with. A drop ceiling with T-bar mounting capabilities, and hard deck ceilings that would require a little bit more hardware. For the T-bar it was really simple, we had one single Panavise clip that would attach to the T-bar, and then our AP bracket, would attach to the Panavise clip and we would tighten it up with a 10mm driver. We could then mount the Access Point to the mounting bracket and secure it with zip-tie for safety measures. Using this system we could hang an access point in about 60 seconds or less. The hard deck ceiling on the other hand was quite a bit more difficult. The manufacturer suggested using a drill bit, to create a pilot hole, then insert two nylon anchors then attach the bracket using two screws. But experience has shown there is a better way.

My thought was too use single toggle bolt through the center of the mount that would securely attach the mounting bracket to the ceiling, with out having to measure two pilot holes for the nylon inserts, as suggested by the manufacturer. This process worked out great! We used a ½” inch drill bit to create the hole for the toggle bolt, and then we attached the toggle bolt through the bracket and pushed the toggles up through the hole. To tighten up the toggle bolt, we swapped the ½” drill bit for a Phillips head into our drill and could tighten it using power tools. We found that this procedure took us about 75 seconds or less to do. Using this method helped us save immense amounts of time on the physical installation of the Access Points.

Here are some simple photos of our method using the toggle bolts.

Hard Ceiling Bracket with Single Bolt

Hard Ceiling Mount with Access Point

We were able to physically install the 625 access points in just 7 days. We used three contract installers, in whom I was able to teach these steps to, and was able to turn them loose, to install all the access points.

With the installation of the Access Points out of the way we could focus on the cabling, turn up and post site survey of the project. We had sub contracted the cabling out to local company, that had approximately 6 full time cabling installers that did a phenomenal job in pulling, terminating, testing a tagging the cables. We gave them a copy of the same maps that we used, to install the access points. They were in turn able to punch down the cable on patch panel using standard EIA/TIA naming enclature but also added the AP number to it so it would be easy for us to find and trouble shoot also. They were able to do 625 cable pulls in less than 30 days. This included all the bearing wall penetrations, floor penetrations and testing of the cabling. I was very happy and impressed with their quality.

With the installation and cabling completed we then went to each of the schools and installed Gig POE injectors, since the customer did not have POE switches available for us to use. At each school, would name the access point in the controller, give the Access Point its configuration and place it on the map for the school. This also gave us an opportunity to trouble shoot any access points that issues while on site, saving us time from having to return to individual schools. This took us very little time, and we coordinated with the cable installers, so as finished a school we would arrive to complete the turn up.

The district had requested third-party verification for the site surveys, to ensure that all work was completed per the requirements of the contract. I hired Mike Young a certified AirMagnet instructor to survey all the buildings and using AirWise create the reports to show the work was completed to the specs of the customer. Mike and his team worked very diligently, to complete all the surveys, and I am sure he lost quite a few pounds with all the walking he did. We also ran the surveys by Keith Parsons for final sign off and approval. Mike completed the reports and we presented them to the customer for their approval.

This project was a lot of fun, and was a great win for me given all the timelines of the contract that had to be met. We had a signed contract from the customer on May 27^th, equipment on June 6^th and had to have the entire project completed by August 1, 2011.  The calendar period was peppered with both State and Federal holidays as well as not being able to have access to the buildings on the weekends. The total project was completed in 42 working days. I was really please with my team of contractors and the School district in turn is pleased with us.

Survey Equipment used.

• AirMagnet Planner
• AirMagnet Survey Pro
• Metageek DBX Spectrum Analyzer
• Motion Computing J3400 Tablet with with Intel 5300 WiFi nic
• Nike Shoes…

Installation equipment used.

• Dewalt impact drills
• Little giant ladders
• Kline 9mm drivers
• Dewalt ½ “ drill bits
• 30 lbs rated zip ties

Equipment installed.

• Ruckus Wireless Zone Director 5000 redundant controllers
• Ruckus Wireless ZoneFlex 7962 Access Points
• Ruckus Wireless FlexMaster NMS system

A guest post from Jared Griffith of Cinergy Wi-Fi. Jared allowed me to cross-post this from his new blog.

__________

The Art of Customer Service

I came up with this title, after re-reading one of my favorite books. I am a great fan of Sun Tzu’s “The Art of War”. I admire his brilliance in military strategy, and his discipline to see his plans through no matter the cost. In my opinion he has what I call grit, determination and resolve to be excellent in all that he recommends.

I have tried to model my business efforts, somewhat after Sun Tzu. I try to create a tactical plan to serve my customers, and follow it through to the end. I have had the pleasure to work in different industries within the tech field since 1999. Some of my customers have been with me through various changes and companies. When asked why they continued to be loyal, they answered “trust and customer service”, From many conversations I came up with the following five words to describe the art of customer service.

Customer service really comes down to these five basic principals.
1. Responsiveness
2. Commitment
3. Trust
4. Honesty
5. Follow Through

You are probably thinking, that’s a very simple list, what is this guy talking about? Yet I hear horror stories from customers all the time that these basic principals are lost in the industry, and they are willing to pay for them.

Take for example the first principal “Responsiveness”. We live in an age and time, were we can produce information from the Internet or Twitter in a matter of seconds. Customers tell me that some times it takes hours to days to get a response from their vendor, unless they have maintenance agreement or are asking for a quote. I know that sometimes an email or phone call comes in when you can’t take it or respond immediately. Most of us aren’t Jack Bauer and defusing a bomb constantly! With in 5 to 10 minutes we can usually make time to call, text, or email. This initial communication is critical in showing the customer “Commitment” our next principal.

Commitment makes me want to run towards a problem, and not away from it. As well as doing what ever it takes to see it through. Sometimes in organization you see sales people’s commitment end as soon as they receive a Purchase Order. In their mind, they have no more skin in the game. Some customer service people think that because they haven’t heard from the customer it must be fixed. There is no need to do a follow up call. Their commitment level is just not there. Each person should sit down with them selves and figure out just how committed they are at what their doing in life. Then be honest with all people and let them know up front, where they plan on getting off the commitment bus, or are they going to see it at the end of the line. With Commitment to your customers this will build “Trust” our third principal.

Trust is a beautiful thing if you have it, and it can be a big black eye if you loose it. Customers don’t just hand trust out easily. That is why many times the sales cycle takes so long. Customers will have you do a series of events, to see if you are trustworthy enough to go to the next level with in their organization. Some customers have trust in a product, some in the company their buying the product from. No customer buys something with out some level of trust. Once their trust is earned, you have to maintain it, by always telling the truth, even when the truth will cause an issue. The customer has the right to always know it, and their “BS” detectors can filter wither or not their getting it pretty quickly. The keys to the kingdom are only given to a trustworthy person.

Honesty and trust go hand in hand, honesty is the fastest way to earn trust. If some one asks you a question, you have to choices to be honest or not. If you always go down the path of being honest, you can have a poor memory and get through life unscathed. If the customer asks you something and you don’t know the answer, I always say I don’t know, but give me a little bit and I will find out. It actually gives you credibility with people, and isn’t an insult on your intelligence. Nobody knows everything, and if they think they do, they just aren’t being honest with themselves.

Follow Through – this is a favorite of mine. I grew up in Idaho working on a farm, and my father always told me and I quote “ there is a beginning, a middle, and an end to every job. With out one of those parts completed the work is never done”. You have to finish what you started, its that simple call the customer and ask them if you have taken care of the problem and if everything is now okay. If you start a task with a customer, you have to follow through till the end. If you follow these steps and embrace them, you will be known as a person that has a commitment of excellence.

So remember, to provide great customer service, just remember these five simple items:
1. Responsiveness
2. Commitment
3. Trust
4. Honesty
5. Follow Through

Today’s post, instead of your weekly Podcast on some Wireless LAN topic, will be the first of a three part series on Spectrum Analysis. This is a highly graphical topic, and though important to the working of a Wireless LAN Professional, is hard to do in an audio format. Thus no podcast, but instead I’ll be sharing slides, graphics, and concepts that I’ve been sharing with my students for the last decade… all in PDF format so we can visualize the concepts.

This week is Part 1 – Fundamentals.

In the attached PDF white paper we’ll cover the basics and vocabulary needed to get started with Spectrum Analysis. Including talking a bit on how regular WiFi NIC’s operate. We need to know what spectrum analysis is NOT as well as what it is.

In subsequent weeks we’ll continue talking about basics of Spectrum Analysis and then how to intepret the results of using a SpecAn.

In the final week, I’ll talk about the various options available from $50 to $20,000. And the costs and benefits of choosing your Spectrum Analysis tools wisely.

I’m no longer teaching WLAN technologies full-time, I’ve taken a position with Ruckus Wireless to head up the professional services group, so I thought it would be appropriate to share these concepts and slides freely to the Wireless LAN Professionals community.

Enjoy!

Keith Parsons

Comments and questions are always welcome.

Wireless LAN Answers
This audio Podcast will be starting sometime in March 2010. Hosted by some of the world’s best Wireless LAN Professionals, we’ll answer live your questions concerning all things concerning Wireless Networking.  Working with other co-hosts, Keith R. Parsons answers e-mail and voice-mail questions about Wireless LAN questions.

To help launch this new Podcast, please leave voice mail questions at the 801.418.9018 number, or e-mail you questions to [email protected]

Subscribe To The Wireless LAN Answers Podcast:

It’s sad… but I’ve worked with each of these (except for the wax cylinder)

How far back do you go?

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