February 10, 2006
Despite lacking documentation and not having GPS capability, this site survey and design tool is useful for indoor wireless LAN administration and deployments.
Price: $2,990 (Survey alone: $1,490)
Pros: Accurate, supports nearly all Wi-Fi cards
Cons: Documentation lacks some information, isnt GPS capable
iSite by Meritech is a site survey and design tool to aid IT professionals during the deployment and/or administration of a wireless LAN. The two modes of iSite, Site Survey and Design, can be purchased either individually or as a set. Either way, the software comes loaded with the capability to run both. You just have to complete the activation for each mode.
The site survey mode allows you to visually see the RF (radio frequency) signal coverage of an existing wireless network overlaid on building diagrams you load into the software. After taking the measurement points in your facility, you can also view other vital information, such as RF interference and rogue access points. With the design mode, you can create a network on top of the imported building diagram and then use the tool to predict coverage. The software uses data such as the transmit power of the access points, RF loss of walls and barriers, and floor height to help come up with the coverage prediction.
To get a feel for this product, I took it for a test ride by performing a site survey of my facility and creating a network in iSites design mode. In addition to learning how to use the tool, I also wanted to understand the accuracy of its signal prediction for both Site Survey and Design modes.
The first thing I did was download the 30-day evaluation of iSite from their website. Before I could begin the installation, I had to download and install the Microsoft .NET Framework 1.1, which is required by iSites software. Besides having to download and install the .NET framework, the installation went smoothly, and I had no problems.
I was pleased that iSite works with nearly all Wi-Fi network cards. This allows you to choose the most applicable radio for the testing.
The Site Survey Mode
The second task on my list was to complete a site survey with the tool and visually examine the coverage throughout the facility. I followed the step-by-step instructions in the user guide. The only problem I experienced while setting up the tool to prepare for the survey was that after scaling the image (building diagram), the image would shrink too small to be of use. I contacted their support, and since I was working with a smaller floor plan, they recommended I change some of the project settings. This wasnt obvious from reading through the documentation.
After making the necessary changes, everything looked fine and the building diagram was now at a size I could work with. Many site surveys completed with this tool may be of larger facilities and the default settings may work fine, but some surveys test smaller areas, such as specific office spaces within an office complex. Thus, I thought it would be good to include suggestions on how to configure the scaling based upon the size of the facility youre surveying, or describe the individual settings so the user would understand.
After setting up the floor plans and scaling the images, I started to take measurements. This seemed like a no-brainer: just go to a spot in the facility and click that spot on the map. However, I was a little wary. The user guide doesnt explain how long it takes to complete the measurement and if you need to stay still or turn in circles to get the best reading. To take readings I stood still for a few seconds after clicking my location on map, which seemed to work fine. The user guide recommends taking measurements every 3 meters (about 10 feet), which I followed as closely as I could.
After completing the site survey, I viewed the results, and the coverage map looked similar to what we experience while using the network. To get an idea of the accuracy of the iSite tool, I compared the site survey and prediction coverage maps to real-time measurements of certain locations within the facility. The real-time measurements using iSites tool varied 5dBm from the points within the survey coverage map. This is a small variation, and it looks like the site survey map iSite created is right on target.
The Design Mode
Setting up the tool for design mode was similar to the survey mode. I loaded in the images (building diagrams) and scaled them. As the user guide explains, I then set up the barriers, which represent walls, and the virtual access points.
I dragged a barrier line over all the walls shown on the building diagram loaded into the tool. The facility Im designing the network for has an interior drywall construction. I had to create a material type for drywall and set the estimated loss to 3dB. I thought it would have been good if they had this material type already set up so it would avoid the need for someone to research and find the loss value.
I placed the access point in the same location where the real access point was during the site survey. After placing the access point(s), you can change settings such as RF power, antenna gain and the channel to show a better prediction of coverage. I set up the transceiver settings in the tool to the same specifications of the access point used during the survey.
After completing the network design, I could see the prediction map of coverage. The design map varied 5 to 10dBm, which isnt the best -- however, it's accurate enough to aid in the process of a wireless LAN installation or redesign. Remember, the design mode is only a prediction, and shouldnt be your only approach while completing a survey.
Take it for a Test Drive
Meritech offers a 30-day evaluation copy of iSite on their Web site at http://www.meritechsolutions.com/isite/requesttrial.aspx. The evaluation copy comes with both the site survey and design modes. The only setback is that youre limited to taking 40 measurement points, giving you the ability to get a very good feel for the tool and its capabilities.
I feel the documentation could use some help, but overall, I found iSite to be very useful and accurate for those performing indoor RF site surveys or wireless network installations. Not having GPS capability with this tool prevents it from being recommended for outdoor site surveys, though. In outdoor areas, you often dont have the visual references needed to find the proper point on the map to click your position. With other tools, GPS streamlines the process for creating outdoor coverage maps by keeping track of your position.
Eric Geier is a computing and wireless networking author and consultant. Hes employed with Wireless-Nets, Ltd., a consulting firm focusing on the implementation of wireless mobile solutions and training. He is an author of Geeks on Call - Wireless Networking: 5-Minute Fixes, and Geeks on Call - PCs: 5-Minute Fixes, published by John Wiley & Sons.