What can you expect in a WiFi site survey?
Type of devices
What devices are going to be used onsite? Will they be handheld barcode scanners, VoWiFi handsets, laptops or tablets? We’ll need to know the make and model of the devices that will use the wireless networks – to determine frequency ranges – and which standards (802.11a, b, g, n, ac) are supported.
Number of devices of each type
The density of client devices will determine the WiFi design. So during the WiFi site survey we need to know how many devices could be present for any given area. Capacity planning helps us determine the model of Access Points (APs) required. Also if the AP is at or near capacity, you'll see some issues.
Applications to be used
During the wireless site survey we’ll need to know if the WiFi network is being used for video, VoWiFi, e-mail, web browsing, Cloud storage, or RTLS (Location Tracking). Certain traffic requires QoS (Quality of Service) to work well.
Redundancy or location services
For example RTLS (Real Time Location Systems) generally require three Access Points (APs) to be visible at less than -75dBm. Cisco VOIP requires two APs to be seen at -75dBm or better, and an SNR of 25dB or better. Obviously, this means more APs are required. We’ll also need to figure out during a WiFi site survey if the required APs are being “seen”.
Preferences on the manufacturer and models used
Different manufacturers such as Cisco, Aruba or Ruckus have different Access Points with different characteristics. These include antenna patterns (depending on the gain), weight, mounting, and polarization. Also, older models usually provide less throughput and interference mitigation. We will also need to know what switches and firewalls are in use.
For a fault-finding or post-deployment WiFi survey, we’ll need to know what symptoms or issues are being seen onsite. Are there issues with VOIP, video or a certain application? Is it throughout the premises or one area in particular? Or are issues seen at a certain time of day?
CAD drawings are preferred (but not essential) as the wireless survey software can use the layers on import to set the different floor and wall materials, and giving the attenuation properties of each. A scale is also usually provided here, which means you will receive an accurate heatmap. We also support use of PDF, BMP, JPG, JPEG, PNG, GIF and SVG files. When CADs files cannot be supplied, then we will need to define these properties manually. Once the scale is set correctly we can then define the differing wall and floor types. This is very important to ensure the WiFi design uses a 3D model of the whole building, and not just each floor individually. A 3D model means the software considers interference from the Access Points (APs) on all floors - which creates the optimal plan. Get in touch if you need more help with building plans.
So once onsite, the engineer will setup the wireless survey kit in accordance with the building type. This could be anything from standard office, factory, warehouse, or laboratory environment. The building could be single or multiple floors. During a fault-finding WiFi survey, the engineer will again discuss any main issues being experienced with the site contact. The engineer will then document the location of a Comms Cabinet and the equipment within (such as switches, firewalls and Internet router). Also, they will confirm the type of cabling if possible – is it CAT5/5e/6/6a? If possible they will also note the physical location of the wireless Access Points (APs) in use. During this walk of the building they will also be checking out any potential problem areas or safety issues Survey Kit includes:
Laptop with Ekahau Site Survey Pro software
This measures and reports on all WiFi signals
Spectrum Analysis tool
This measures and reports on all WiFi and non-WiFi interference
Various Access Points (APs)
Directional and Omni-directional.
Camera – to show AP locations
Electronic tape measure
To verify building size and scale
PoE (Power over Ethernet) battery packs
To power the APs
up to 3.5Metres for AP
Generally, the first task will be to walk the building checking out any potential problem areas or safety issues. Once complete the engineer will walk the building using the spectrum analysis tool, recording the data as they go. This stage should show any possible sources of interference from WiFi or non-WiFi devices. Next is the main WiFi site survey. The engineer will place the APs in the correct locations using the Tripod. This could be vertically mounted near a wall, or horizontally next to the ceiling - Which benefits from the way the most antennas are aligned in modern indoor Access points. Using the Ekahau software they will walk the area taking readings. When they get to the edge of the coverage area for that AP, they will then “freeze” the software and move the AP to the next location. This is repeated until the entire building or location has been completed. The coverage area size will be determined by the type of WiFi network that is required, which will have been ascertained during step 1. One NIC(Network Interface Card) will be used to perform a passive wireless survey, where the laptop and software just “listens” to the signals. Another NIC will perform an active WiFi survey, where data is sent to test connectivity (PING) and optionally throughput (using Iperf). Extra NICs can be added to speed up the passive survey. The extra NICs then listen to different parts of the spectrum, so sharing the load. Once complete, the engineer will then summarise the initial findings with the onsite contact.
In the case of a fault-finding wireless site survey the report will also include recommendations on what is required to improve the network. If any clarification is required upon receipt the WiFi survey report, then our engineers will be more than happy to go through it with you.
*If you have received a predictive, or pre-deployment wireless survey, then a follow up post install WiFi/RF (Radio Frequency) site survey is always recommended to verify the WiFi network is working effectively*
*If you would like to see an example of a report showing what is covered, then please contact us.*
*A follow up post install WiFi/RF (Radio Frequency) site survey is always recommended to verify the WiFi network is working effectively*
Some of our Clients
Performance Networks Limited,
The Sir Colin Campbell Building,
Nottingham, NG7 2TU
Head Office: +44 (0) 115 822 1212
London Office: +44 (0) 207 148 1780