Building Network Resilience into Antennas

Phillip Sorrells - 11-5-13--thumb Philip Sorrells March 27, 2013

Winter weather conditions again made headlines in most northern hemisphere countries. Blizzards with high quantities of snow and powerful winds attract particular attention. Most people worry about how such severe weather will impact their personal lives, such as travel times to work or the closing of their children’s schools. These same people will also take their wireless phone networks for granted, assuming services will continue uninterrupted.

I think that is high praise for the quality and reliability of most cell sites and their RF equipment. It is typically only the worst climatic events—tornados, hurricanes, tsunamis, floods, etc.—that cause severe damage and long power outages that knock out large swaths of wireless networks. But wind, rain, sleet, snow, sun exposure and extreme temperatures beat up installed RF infrastructure on a daily basis. These less dramatic but cumulatively significant weather conditions can lead to cell site failure or serious disruptions.

During the Salt Fog Test, the product is exposed to repetitive cycles for 240 hours. The simulated conditions meet the test standard of ETS 300 019-1-4 class 4.1E.

Water can leak into transmission lines and connectors, interfering withRF signals. Antenna mounts can rust and wither leading to poorly aligned equipment, or in the worst case scenario, antennas falling off towers. High winds can push rain and sleet into sensitive RF equipment, causing distortion and poor network performance. I wrote in a previous blog about the areas that are among the most susceptible at cell sites. Here I would like to highlight what we do within CommScope to create high quality Andrew base station antennas (BSAs) since these are among the most critical RF Path components.

We conduct about 15 separate reliability tests on all families of Andrew BSAs, including the Argus antenna portfolio. These tests include high and low temperature, humidity, vibration, salt fog corrosion, driven rain and high wind exposure. We measure electrical performance pre- and post-test to ensure weather conditions do not cause degradations.

In terms of surviving severe weather conditions, we test Andrew BSAs to withstand winds of at least 250 kilometers per hour (155 miles per hour)—the highest sustained wind speeds in Category 4 hurricanes. Each new antenna design is tested with simulated wind load forces applied to its front, side and back surfaces with antennas mounted and tilted as customers would install them. This testing assures us that our antennas can withstand severe winds without damage, rotation or change in downtilt.

Our antennas are also designed to survive extreme rain, temperature and other environmental conditions for the life of their expected deployment. Part of building wireless network resilience is being able to trust the RF equipment you install, now and years down the road. That’s why we place so much importance on testing every antenna family.

For an overview of our BSA environmental product testing equipment and standards, check out thistechnical publication. You can also view thiswhite paperto learn more about wind loading and testing.

Let me know in the Comments section what weather related issues you have experienced when it comes to RF equipment and cell sites.

About the Author

Phillip Sorrells - 11-5-13--thumb

Philip Sorrells

Philip Sorrells is vice president of strategic marketing for CommScope, a global leader in infrastructure solutions for communications networks. He is responsible for marketing strategy, linking key trends in the industry into marketing strategies for telecommunications networks.  Mr. Sorrells has 20 years of experience in the telecom industry with Allen Telecom, Andrew Corporation and CommScope, having spent 10 years prior with Texas Instruments. He has led the wireless industry in adopting many antenna system innovations—including remote electrical tilt (RET) technology for network optimization—and pioneering the concept of “agile networks,” which formed the basis for current initiatives in self-organizing networks. Mr. Sorrells has three patents related to antenna systems and holds a Bachelor of Science degree in engineering from Texas Tech University.