Hi! I want to write today some of the tips I have gathered around setting up an outdoor point to point wireless deployment. It is one of the most frequently asked questions from my customers and Cisco partners so I wanted to summarize few tips I've learned over the years.
- Site survey is key to reveal existing environment challenges such as interferences, mounting locations, Fresnel zone and cabling/wiring. This is a key step in order to identify proper mounting location of an AP and the antennas, and routing cables.
- Choosing the right type of antenna in order to provide best gain possible between the point to point link. Narrow-beam/highly directional antennas are generally recommended to span the wireless mesh link over longer distances.
- You can use a free space path loss calculator for an estimate but validating is key since there are many factors such as external environment, weather, objects in the path can interfere with the signal.
- Line of sight is recommended to maximize the signal between two APs. Remember, visual line of sight is different than RF line of sight due to Fresnel zone. Think of Fresnel zone as an ellipse encompassing the visual line of sight, representing the natural curvature of earth.
- Weather can degrade wireless performance in a wireless point to point link due to loss when RF signal passes through rain, snow, fog, and humidity.
Other general recommendations
- Mount the AP in a secure, sturdy location to prevent damage or theft due to harsh outdoor environments.
- Ensure the AP and antenna are designed for outdoor use with temperature range and humidity levels in mind. With Cisco APs, you can check data sheets for this information.
- If you are using a POE injector, ensure it is weather proof or securely located inside an enclosure.
- Outdoor wireless performance can be very difficult to predict. Ensure we set the right expectation and apply design principles in order to deliver the outcome.
- Example - running a validation survey to ensure the performance meets the application and business requirements.
- Consider running multiple AP gateways if you are looking for high availability in case one of the AP gateway goes down. However, some disruption of the traffic during the failover events will be experienced.