All About Wireless Site Surveys
Why do you need a wireless site survey?
Telcion installs wireless network solutions on a regular basis and customers often ask whether a site survey is necessary and what the cost might be. In order to provide some predictability to the results of a wireless implementation, yes, you need a site survey beforehand. Without it, there is no way to guarantee the implementation will meet the expectations for bandwidth, signal strength, coverage, and interference.
What is a wireless site survey?
A wireless site survey is the process of planning a wireless network for a particular environment to meet its unique requirements for coverage, capacity, roaming, quality of service, and other metrics that may need to be met.
A floor plan of the environment is needed, the more detailed the better. The floor plan should include dimensions, along with any structures that can impact the propagation of wireless signal, such as elevators or staircases. This floor plan will be used in conjunction with wireless site survey tools to determine the best location for access points. It also will provide the basis for the heat maps that will be generated to indicate signal strength, coverage, and problem areas.
What a wireless site survey includes:
Mounting locations
Description of cable paths
Recommended access point models and antennas
Multiple heat maps indicating coverage, signal strength, bandwidth capacity, and any trouble spots
Pictures and notes taken during the site walkthrough that will impact the implementation
Is a wireless site survey worth it?
Small businesses that need basic connectivity with a couple of access points may not benefit from a survey. However, for larger businesses where multiple access points will be deployed and where there are specific network requirements, a wireless site survey is a must.
What are the different wireless site surveys?
There are several types of surveys that can be completed depending on the results the client is looking for. For small implementations (five or fewer access points), a predictive survey is all that is needed and can be done remotely. In larger implementations, a predictive survey is completed followed by an onsite active survey, to confirm the results. Finally, a post implementation survey shows actual results.
Requirements depend on the results that are needed. The more critical the wireless network is to the business, the more time should be invested in a survey to ensure the desired results are met. Without a survey, we are just guessing at what the outcomes will be which will assuredly lead to poor coverage, lack of bandwidth, and inconsistent performance for users.
Predictive Wireless Site Surveys
In a predictive site survey, we will collect floor plans of your space, preferably as CAD drawings from your architect, if available. We will ask questions about how you use your wireless network and what your general needs are. Using the information you provided, we will recommend an access point model. This model will be used to create a heat map of your location. The heat map will feature recommended equipment placement and a visual representation of how the wireless signal will propagate within your environment.
For small environments, a predictive survey can be delivered as part of the sales process to help estimate the number of access points (APs) required in order to determine budget and project cost. However, there are some sacrifices that are made in terms of quality and accuracy. In most cases when deploying more than three wireless APs, a predictive site survey is not sufficient. Items such as AP placement, wireless signal coverage, and network performance are generally estimated and may require slight or even drastic changes in order to best align with your environment and needs.
Active Wireless Site Surveys
If accuracy is the goal, then an active site survey is ideal. An active wireless site survey will require an on-site visit by a certified wireless engineer. It can typically take from a few hours to a few days to complete, depending on the size of the location. An active site survey can be done in a new environment with no wireless equipment in place. A survey is also recommended where a wireless system exists but needs to be repaired or configured properly. The final report will offer an accurate plan for equipment placement, wireless signal coverage, network performance, cabling, and installation.
Just like in a predictive site survey, a floor plan will need to be shared and the general wireless needs will need to be discussed. This is where the similarities end. A wireless engineer uploads the floor plans into the site survey software and positions a single access point in the space. The engineer then begins to roam around the space and takes measurements of the access point’s signal strength. The site survey software will also measure outside interference from nearby wireless networks to allow the wireless engineer to provide recommendations for channel selection and other configurations.
Following the onsite visit, the wireless engineer will spend several hours drawing up walls and other structures on to the provided floor plans to provide an even more accurate representation of the wireless signal propagation in the space. Staircases, elevator shafts, windows, and walls can negatively impact the wireless signal. Construction materials also affect wireless deployments. For example, drywall is not as bad for wireless radio signals as concrete is. Cabinets, doors, and ceiling height all impact wireless coverage. And we are not only measuring for signal strength and interference, but also determining the reachability to other access points in the event of an AP failure or scheduled downtime of a specific AP.
Environments that should strongly consider a survey:
Office buildings with highly congested environments, including neighbors with their own wireless networks that will cause interference
Warehouse environments that require signal coverage in dense or noisy areas
Buildings that are filled with many solid structures like concrete pillars
Any environment where wireless is critical to day-to-day operations, including hospitals, clinics, manufacturing, etc.
How much does a wireless site survey cost?
A predictive survey, as described above, for small environments can generally be included in the design process at no cost, assuming there is no onsite walk through required. An active site survey is customized per client and is difficult to estimate. As a general rule, the price is $2,500 per day, and most buildings can be completed in two days. If it is a campus environment with multiple buildings, it will likely take five to seven days.
Factors that will affect survey cost:
Square footage of survey area
Support requirement for specific wireless applications
Ceiling height and requirements for lifts
Floor plan creation requirements
Physical location of survey environment
Wireless hardware requirements
The time it takes to compete site survey
Report turnaround requirements
Specific client requirements will impact the cost, such as needing the survey conducted during off-business hours, expedited completion, or difficult environmental areas (emergency rooms, cold storage, heavily trafficked areas).
Why Telcion?
Telcion has been performing wireless site surveys for over 10 years and has significant experience in the deployment of wireless networks in high availability environments including hospitals and manufacturing warehouses. Telcion understands networking and voice and knows how to deliver the results needed to meet our client expectations for performance on a wireless network.