Site Survey

Posted onCategoriesWireless Computing

When conducting a wireless site survey, consider the following steps:

To understand the wireless requirements

In order to identify appropriate locations for deployment of access points (APs), we need to thoroughly understand specific requirements for the network and any possible impacts to the signal coverage. By knowing the target throughput and data rates, we are able to correctly interpret the results of site survey. And also, some devices of users may have lower transmitting power, so we must take this into consideration.

To obtain detailed diagram

Locate a set of building blueprints of the site; prepare a drawing that depicts the actual location of walls, windows, furniture and interior spaces. The detailed diagram helps us to identify any potential obstacles or impediments in the area to be served.

Visual inspection of site

By walking through the site before performing any testing to verify the accuracy of the detailed diagram, we are able to identify any potential attenuation barriers that may obstruct and degrade the propagation of RF signals.

Assessment of existing network infrastructure

Verifying the capacity of the existing wired networks that can interface the access points and check on how much of the existing networks can be made available for supporting the wireless network.

To identify the coverage areas

Indicating all areas where signal coverage is needed by marking on the detailed diagram, and also, identifying the areas where wireless coverage is not required is also important for site survey as we can avoid wasting time on surveying. In addition to time saving, we can also reduce the number of access points and lower the costs of equipment.

To determine locations for preliminary access point

To determine the preliminary access point locations, we need to consider the wireless network equipments products we are using, and analyze the locations of access points that will provide adequate coverage throughout the areas. And plan for some overlap of propagation among adjacent access points, also assign the channel for access points to be far enough from each others to avoid inter-access point interferences. The mounting locations also need to be considered as it could be vertical posts or metal supports above ceiling tiles. Identify appropriate locations for installing the access point and data cable. Various types of antennas will be taken into consideration when the positions of access points are determined.

Verification of access point locations

When the site survey testing is ready to begin, we can utilize good wireless network surveying software to assess the signals on the site. This kind of software can help us to pick up the signals, trace and evaluate various parameters such as:

  • Strength of signal
  • Signals at channel
  • Presence of access points
  • Signal-to-noise ratio
  • Potential interference
  • Best location to place access points

Next, when an access point is installed at each preliminary location, we will have to walk by varying distances away from the access point in order to obtain the readings from the site survey tool. This procedure is just to ping the access point or obtain the beacon signal strength, therefore connecting the access point to the distribution system is not necessarily need.

Documenting

Once all the locations of access points that capable of providing adequate signal coverage is confirmed, we will document our findings on the detailed diagrams by marking the location of each access point as this information is needed by the installer later.