Site survey and installation recommendations

To install a wireless network, proper planning is critical. First you need to identify the coverage requirements. Is 100% coverage required, you will need to do a lot more work than if say 80% coverage is required. Required bandwidth and quality of service along with weather conditions could also play a role.

Overview

This section gives a short description on how to perform a site survey and how to plan and install a wireless network for installation in industrial environments.

 

 

The roles

This guide looks at two roles in a network installation. The planner and the Installer. Both have essential roles in a successfull wireless LAN installation. Here are the task divisions:

  1. Planner

    • Link budgets
    • Site surveys
    • Proximate placement of AP/antennas
    • HMS cautions

  1. Installer

    • Exact placement of AP/antennas
    • Cabling and Connector termination
    • Antenna adjustments
    • Equipment knowledge
    • EX Certification and requirements
    • HMS cautions

Technical recommendations

Through 10 years of experience in designing wireless networks, we share some essential

  1. Choose the shortest cable length possible (place APs in field if possible)
  2. Place antennas visible from several angles (corners etc)
  3. Generally place antennas in the upper part of walls (10 cm clearance to ceiling)
  4. Leave two wavelenghts (24 cm) between wall and antenna.
  5. Don’t hide the antenna behind obstacles
  6. Don’t place the antenna horizontally
  7. Angle the antenna slightly downward when placed above ceiling height (check pattern)
  8. Use a site survey tool to determine coverage. (Netstumbler etc)
  9. Check for Wi-Fi channel interference (using Netstumbler etc)
  10. We recommend max 30 meters antenna cable for the standard configuration and maximum 50 meters cable for the amplified configuration.

HMS cautions

There are some very important conciderations when it comes to HMS

 

  • Secure workplace. Some sectorial antennas are heavy and can cause damage when accidentally dropped.
  • Follow EX instructions
  • Follow EX maintenance instructions.
  • Concider Lightning protection of antennas where applicable.
  • Power supply is 220 V AC.

 

 

Link budgets and signal calculation

There are several online tools for calculating signal budgets. These are very useful for getting an indication of what link quality you will achiece.

 

 

Wifi link budget

 

 

Equipment and software

You can take two approaches to site surveys. Purchase a site survey softwate

 

Commercial approach:

Ekahau has an excellent site survey software that provides a complete solution for performing network planning.

 

 

Budget approach.

To perform a site survey on a budget you really need only a laptop, a battery driven AP and a free software tool like http://www.netstumbler.com/downloads/

 

Wireless network Site survey tools

 

 

 

 

Free site survey tool: Netstumbler.

Netsumbler site survey software