In March 2014 I was tasked with a new wireless deployment in a unique environment. The building had plaster on top of two inch plywood with stone inside and outside the structure. Aesthetics was a high priority which made the task that much more difficult.
Going into this project I knew I had to perform a wireless site survey before deploying a Cisco WLAN Controller and about 15 access points. Another vendor was working on a separate project that relied on the wireless network. They initially walked through the building with their wireless phones stating dropped areas (there was a previous wifi installation but was being revamped by me.)
With much research, I decided to purchase Ekahau Site Survey with the purpose of planning, deploying, and troubleshooting this new wireless deployment.
The Ekahau Site Survey purchase included the USB Adapter for the survey and the software. Through my reseller, the cost was $3,500. It supports Windows 7 and 8 and you need at least 4GB of RAM or more. Sorry OS X users. It might work through Parallels.
In the rest of this blog post I will be referring to the planning portion of Ekahau Site Survey.
Before we jump into planning a wireless network deployment, there are a few things to consider. For one, you need a floor plan. Without it, you cannot do anything else. Acquire the floor plan from facilities in the format of any of the following:
After adding the floor plan to Ekahau Site Survey, you must set the scale. This is important. The application has no idea what the length of a wall is, or a window, or how large the property is. Another reason for setting the scale is for the application to properly calculate things such as free space path lost and other wireless survey calculations.
In addition to setting the scale you need to lay out the walls. In a typical office environment this is dry wall but there are many options to select from. Select the wall material, click where the wall is on the floor plan – beginning to end – and right click to mark the end of the wall. Defining the walls on your floor plan will help create an accurate plan as Ekahau Site Survey calculates wifi signal propagation.
If you’re working with multiple floors you will need to set alignment points to align each floor properly.
Before we move on to the next step, have you gathered the client’s requirements? Requirements such as where there needs to be wireless coverage, how many wireless clients are expected on this network, any QoS requirements? There are many more questions to ask but you need to have this list before moving on.
How do we know if our wireless network will support the capacity? We can estimate this by inputting devices into the Capacity Requirements window. Add in how many wifi devices you believe will be on the network and what type. It’s straight forward but the amount of devices you put in will affect the outcome of the plan provided by Ekahau Site Survey. This is a good window to estimate BYOD.
What is the end user expecting from the wireless network? Are the requirements just email and web usage? Is it going to be high usage? Maybe voice is primarily utilizing the wireless network? Whatever the requirements are, gather them from your end user.
In Ekahau Site Survey, set the Coverage Requirements by clicking on Project and then clicking on Coverage Requirements.
Ekahau Site Survey includes a handful of template requirements which you can select from and tune. The Criteria you can set is the following:
- Signal Strength
- Signal-to-noise ratio
- Data rate
- Number of access points (when signal strength is x dBm)
- Ping round trip time
- Packet loss
Additionally, you can set different conditions such as source of noise, network load, and adapter type.
Once you’ve performed the actions above, it’s time to plan. Ekahau Site Survey includes a feature called Auto-Planner. This plan is based on the coverage and capacity requirements you previously configured. Access points are automatically placed on the floor plan to optimize channels and minimize channel interference.
First, define the coverage area by clicking on the Coverage Area button then define the area on the floor plan. The selected coverage area will be displayed in purple (lilac to be accurate). Right click to end the coverage area and you will see a bordered dash line.
Next, click on the Auto-Planner button.
Define the Coverage and Capacity requirements that you had previously configured.
Under the Access Point section you have the option of selecting a Generic AP or you can click on the drop down to select another vendor such as Aruba, Cisco, Linksys, etc.
Enable the Advanced settings and modify the Transmit power and Antenna height as necessary.
An important option at the bottom are the Channel patterns. Selection of channels will depend on your country’s standards. The options I selected are used for United States.
When you’re ready click on Create Plan.
If you’re not happy with the placement of access points on the map you have the ability to move them around as you see fit. You can also change the type of antenna on the access point list.
No more guessing at where to place access points. You’re doing a disservice to yourself and the end users. Placing access points in the blind may affect wireless performance. Ekahau Site Survey Pro provides tremendous value for the cost. It includes the USB adapter and the software. Additionally, it makes wireless site surveys simple to perform. With that said, it doesn’t mean you can skimp on knowing wireless technologies. Performing a wireless site survey requires the knowledge of wireless networks with the end goal of successfully planning a wireless network with client requirements.
To learn more about wireless I highly suggest reading the CWNA Study Guide. It’s full of so much information pertaining to planning and deploying wireless networks. If it’s a Cisco wireless network you’re deploying, also check out the CCNA Wireless book.
Additional online resources are Andrew Von Nagy’s blog, revolutionwifi, and Keith Parson’s Wireless LAN Professional site and podcast. One specific podcast that helped a lot was the 7 Rules for Accurate Site Surveys.