The radio waves that carry wireless network traffic are affected by many different characteristics as they travel across an area. Building materials, antenna placement, power levels and many other characteristics can alter the flow, or propagation, of wireless signals. Learn how different conditions affect wireless signal propagation, including antenna types and beamforming, site surveys and antenna placement, and power level controls.
- [Voiceover] The radio waves that carry wireless network traffic are affected by many different characteristics as they travel across an area. Building materials, antenna placement, wireless power levels and many other characteristics can alter the flow, or propagation, of wireless signals. First, there are many different types of wireless antennas that may be used. While many organizations use the simple antennas built into wireless access points, there are other options available.
There are two basic categories of antenna. The basic antennas used with wireless access points are known as omnidirectional antennas. They transmit radio waves in a doughnut-shaped pattern. The short, stubby pole-like antennas attached to wireless access points are known as rubber ducks and are examples of omnidirectional antennas. Antennas that send that wireless signal in almost every direction. In some cases network administrators may wish to point a wireless signal in a specific direction.
Such as when they're creating a point to point network between two buildings. The use of a directional antenna greatly increases the range of the network by focusing the power in a single direction. The antenna shown here is an example of a directional antenna. 802.11ac networks include a new technology known as beamforming. With beamforming, the access point uses multiple antennas that look like simple omnidirectional antennas to detect the location of a device connecting to the access point, and then steer the signal in the direction of the device.
You can think of beamforming as a virtual directional antenna that can shift as needed based upon device location. Placing antennas in access points in a facility is a highly specialized area of networking. Many different characteristics of a building will affect wireless signal propagation and engineers must take those into account to prevent dead spots while also ensuring that physically adjacent access points don't interfere with each other.
While it is possible to sketch out diagrams and place access points based upon a theoretical design, the best way to place wireless access points is to conduct a wireless site survey that uses specialized hardware and software to measure signal strength and provide optimal wireless signal coverage in a building. Finally, network engineers have the ability to manipulate the power levels transmitted by each access point to tweak coverage and prevent interference. These power levels may be manually adjusted, or automatically managed by wireless controllers.
Learn about communication and networking best practices, including TCP/IP networking, network security devices, and secure network design and management. Instructor and cybersecurity expert Mike Chapple also includes coverage of converged protocols, network encryption, and wireless networking. You can find Mike's companion study books for this series at the Sybex test prep site and review the complete CISSP Body of Knowledge at https://www.isc2.org/cissp-domains/default.aspx.
- IP addressing
- Switches and routers
- Content distribution networks
- Designing secure networks
- Specialized networking
- Managing secure networks
- Working with virtualized networks like SDNs
- Detecting and preventing network attaches
- Transport encryption
- Wireless networking
- Host security