WLAN Site Survey Fundamentals

A wireless site survey is a crucial step in designing a reliable wireless network. A site survey helps network engineers identify potential sources of interference, determine the best access point placement, and optimize network performance. In this post, we will cover everything a CCNA candidate needs to know about WLAN site survey fundamentals before taking the CCNA exam.

Wireless Site Survey Types:

There are two types of wireless site surveys: predictive and physical. Predictive surveys use software tools to simulate the wireless network and predict coverage areas, signal strength, and potential interference. Physical surveys involve physically walking through the site and taking measurements to determine the actual signal strength and coverage areas. Both types of surveys have their benefits and limitations, and network engineers should choose the appropriate survey type based on the network requirements and site characteristics.

Site Survey Tools:

To perform a wireless site survey, network engineers need specific tools such as spectrum analyzers, wireless network analyzers, and signal strength meters. These tools can help identify sources of interference, measure signal strength, and determine the optimal access point placement. Some of the commonly used site survey tools include Ekahau, NetSpot, and AirMagnet.

Predictive Site Surveys:

Conduct predictive site surveys before physical site surveys to predict wireless coverage and performance in a given area. This involves using software tools to model the wireless environment and simulate wireless coverage, signal strength, and potential interference. Use predictive site surveys to determine the number and placement of access points, antenna types, and other network equipment required for the network.

Physical Site Surveys:

Conduct physical site surveys by walking through the site while taking measurements. The purpose of this exercise is to determine actual signal strength and coverage areas. Use site survey tools to measure signal strength and identify areas of low signal strength, interference, and potential network performance issues. Physical site surveys are typically more accurate than predictive surveys but can be more time-consuming and costly.

Survey Planning:

Survey planning is a critical step in conducting a successful site survey. This involves identifying the survey objectives, determining the survey area, and choosing the appropriate survey tools. Include the number and placement of access points, antenna types, and other network equipment required survey planning. A well-planned site survey can save time, reduce costs, and ensure optimal network performance.

Signal Strength Measurements:

Wi-Fi signal strength measurements are a critical component of a site survey. Signal strength is typically measured in dBm. Various factors affect signal strength such as distance from the source, obstacles, and interference. Therefore, take multiple signal strength measurements at different locations and heights to accurately determine the signal coverage area. Moreover, network engineers should also identify potential sources of interference that have potentially stronger signals than the planned WLAN.

Interference Identification:

Identify wireless signal interference during the site survey as it can significantly impact network performance. Interference can come from various sources, including other wireless networks, microwaves, and Bluetooth devices. Identify potential sources of interference and choose an interference free channel using spectrum analyzers and other tools.

Access Point Placement:

AP placement is a critical factor in determining network coverage and performance. Place access points strategically to provide maximum coverage and minimize signal loss. In addition, consider factors such as the building structure, obstructions, and the number of clients to determine the optimal access point placement. Carefully plan and test access point placement during the site survey as it can significantly impact network performance.

Antenna Types:

Optimize wireless coverage and performance using different antenna types. Some of the commonly used antenna types include omni-directional antennas, directional antennas, and sector antennas. Use omni-directional antennas to provide coverage in all directions. In contrast, use directional and sector antennas to provide coverage in a specific direction or area. Network engineers should choose the appropriate antenna type based on the network requirements and site characteristics.

Conclusion

Wireless site surveys are critical in designing and deploying a reliable wireless network. A CCNA candidate should have a good understanding of WLAN site survey fundamentals. Therefore, master site survey types, tools and planning, signal strength measurements, interference identification, AP placement, and antenna types before taking the CCNA exam. By considering these factors, network engineers can design and deploy a wireless network that provides optimal coverage, performance, and reliability.