Wireless Networking, Wireless Bridges, Wireless How-Tos and more

This is an excerpt from my blog post at securityinfowatch. For the entire post please click here.

Wireless Mesh seems to still be misunderstood so I though I would put down a couple of pointers explaining how it works at a high level and focusing on throughput of course, we are talking about video here…  Wireless mesh networks require a good amount of planning and unfortunately are not as easy to deploy properly as most vendors would like you to think, but can be useful for specific applications.  Here is a top down diagram of the different parts of a wireless mesh network.

A wireless mesh network normally spans a large area of land and therefore requires a distributed architecture in order to make it work.  The diagram above attempts to break down the typical components of a wireless mesh network.  You may notice that I used Motorola Canopy Visio stencils to make this diagram but I only did that because those were the only stencils I had and Moto has a nice representation on their website that helped me put this together.  I am not endorsing a specific manufacturer in this blog and recommend that you look through the many manufacturers and find the one that is right for your application.

For the entire post please click here…

The Wi-Spy family of wifi and 900Mhz spectrum analyzers allow integrators, IT professionals and do it yourselfers to troubleshoot poorly performing networks by allowing them to see the air around them. Normal spectrum analyzers run into the 1000s of dollars but MetaGeek has managed to create a powerful yet cost effective device that makes high performance more attainable!

The MetaGeek Wi-Spy comes in 3 different Flavors, 900Mhz, 2.4 Ghz Only and 2.4/5Ghz dual band.

The software behind the device.

The MetaGeek Wi-Spy devices come free with a very powerful software called Channelyzer which uses the data collected Wi-Spy sensor to plot the information in an intuitive visual manner which is conducive to quick troubleshooting.  Using the powerful Channelyzer software is a breeze.  Here is a little video taken from the MetaGeek team.  You can find more of these tutorials on MetaGeeks Vimeo Stream.

How To: Get the most out of Chanalyzer from trent on Vimeo.

The Metageek Wi-Spy might be one of the most powerful tools in your wireless toolbox.  Imagine going on a site survey and having a clear vision of the RF terrain which surrounds you.  Leave the Wi-Spy on for a bit and have it record the changes in the “air” as the day goes by.  Then play back the recording and find out exactly why you have been having trouble with your wifi network at 4pm on Fridays (just an example)!

The Wi-Spy comes in 3 different flavors 0900×1v, 2400×2v & the 2450×1v.

The 0900×1v is a cost effective yet powerful 900Mhz spectrum analyzer perfect for WISPs deploying 900 Mhz BWA networks and SCADA professionals.

The 2400×2v works in the 2.4 Ghz unlicensed wi-fi space where the rising levels of interference are causing good wireless networks to fail.  The 2400×2v will allow you to pin-point the interfering sources and take action.

Lastly the 2450×1v offers the same power features of the other models but also allows you to monitor the 5Ghz band.  This is an extremely versatile spectrum analyzer that will allow you to accurately measure the noise floor when engineering point to point wireless bridge links (no more guessing), better plan wireless mesh and WISP BWA networks.

It has been brought to my attention that I forgot to mention how to fix the problem of weak client side transmission, which I discussed back on August 18th. So I figured I would quickly fill in that void.

There are several ways to increase the range of your wireless client and each has its own benefits and drawbacks. Now, while you read this entry please remember that, like a standard wireless access point or bridge, there are always two parts to a wireless client, the “radio” and the “antenna“. The radio is the device creating the RF signal and the antenna amplifies that signal.

So that being said I am sure you can guess that the first way to increase the range of yourwireless client is…Add an antenna!

1) Add an antenna to your client device. In mobile applications you would want anomnidirectional antenna (signal is radiated in a 360 degree pattern) and for fixed environment you would be better served by a directional panel antenna or grid antenna (signal is more focused in a certain direction). Of course you need to have a client device (PC card or laptop card) that has an external antenna connector built in. The major issue is that most (99%) of laptops have integrated wireless cards and antennas that can not be upgraded in which case you might better be served by number 2 below.

2) The next step is to add a wireless card into your laptop or desktop that has the necessary external antenna connector and then add a high gain external antenna to really boost the signal. This is a pretty easy way to increase wireless transmission and is great for laptops however not so great for desktops. If you want to use this method to increase your wireless signal on your desktop you will normally be required to run a good amount of coaxial cable from the PC up and out to the external antenna. This is definitely the method of choice for laptops but I find it a little cumbersome for desktop machines. Below you can find a picture of cards with external antenna connectors.
The one of the left is made by Ubiquiti Networks and goes in the PCMCIA card slot on the side of your laptop. The one on the right is a PCI card for your PC. You can remove the rubber duck antenna that comes with the card and install coax cable that runs to the antenna you installed on your roof.

3) The third option is great for fixed environments like homes, RVs, boats, etc. Purchase anexternal wireless client that sits on the roof of whatever structure you are in. This client can be an all in one device with both the radio and the antenna built in to one unit or you can purchase one with an external connector for higher gain antennas. Here is what they look like…
Here is how you would use them…

Option 1: Install the external wireless client on your roof, point it at your ISP, run an Ethernet cable from the client to the power over Ethernet injector and then plug it in directly to you PC.

Option 2: Install the wireless client just like in option one but instead of plugging directly into your PC plug it into a wireless router! This will allow you to rebroadcast the signal from outside wireless INSIDE your house, giving you the best of both worlds!

Hope this helps!

PLEASE CLICK ON THE IMAGE TO ENLARGE

You will notice that I did not specify any gains on the antenna as every installation is different but in the 2.4 GHz range I find that the 9 dbi omni antenna with 7 degrees on downtilt works great.

OK so I know your next question. How much area will this cover??? Well in the world of wi-fi the two most used words are “It Depends“. You’ll hate to hear’em but you better get used to them as there is never a clear answer. RF signal propagation depends on many factors such as interference, environment, line of site and the most overlooked factor CLIENT TYPE!

Most people understand interference and line of sight but if not you can feel free to read more about it in our growing wireless FAQ, here. However, the one most people do not understand and sometime refuse to understand is that client type can make or break your wireless network. How so? Well…lets take an RV park for instance.

An RV park wants to set up a simple access point in the middle of the grounds to serve its 70 RV users. The client then spends time reviewing access point specs, finds a perfect bridge with a great mix of price and performance. Buys the highest gain antenna he can find and makes sure that there is no excessive loss in the RF cabling. The items arrive via UPS, he sets them up perfectly, similar to the setup shown above and starts walking around with his laptop runningnetstumbler BUT, he is only going a 3rd of the distance he was expecting. This can’t be right he thinks and starts troubleshooting his new hardware. However, what he doesn’t realize is that it has nothing to do with the new access point set up he purchased and everything to do with the low powered wifi card in his laptop.

Communication should always be looked at as a 2 way street. The base station (access point) can be uber powerful and transmit for miles but if the device receiving the signal a mile away can only transmits 300ft the base station will never hear the interesting things the client is saying and communication breaks down. I tried to illustrate this concept and hopefully succeeded but let me know if I blew it.

PLEASE CLICK ON THE IMAGE TO ENLARGE

Bottom line is know your application and build accordingly. Do not focus on one part alone as you will never get the results you are after. Look at your wireless network as a system of components working together to create cohesive communication.

• BeamFlex High gain (7 dbi) Antenna array
• Dynamic PSK Integrated, easy 802.1X
• Integrated guest access with captive portal

Who should be using Ruckus ZoneFlex??
Anyone who is looking for easy, secure, reliable wi-fi and that doesn’t have big money to spend IT staff and hardware really… but, there are great advantages to those in the following industries:

• Small to Medium Businesses
• Hotels/Motels/Resorts with limited IT Staff
• Restaurants/Coffee Shops
• Hot spot Operators
• Retail stores and distribution facilities