Antenna Systems & Technology - Winter 2016 - (Page 20)

GUEST COLUMN DAS Anywhere and Everywhere By Robert Salutric | CommScope Beyond office buildings and stadiums, distributed antenna systems (DAS) are called upon to deliver wireless coverage and capacity in many different environments. In this column, I'll look at some unique environments and the attributes and deployment procedures that have adapted DAS for these applications. Cruise Ships - A ship's steel construction makes it difficult to propagate a wireless signal, so these DAS solutions are usually very dense, with lots of antenna placements. In addition, steel walls and ceilings limit where you can run cable and deploy antennas. DAS products with thinner and more flexible cabling are easier to use in a ship. Another issue is multi-frequency support: most cruise ships migrate from ocean to ocean as the seasons change, and the DAS has to be able to support correct services in different parts of the world, which means that it must support more than one frequency and be modulation agnostic. Finally, cruise ship DAS often require the ability to turn various antennas on or off to block cell phone coverage during stage shows or while the ship is in port, for example. Plants - Manufacturing plants for auto, aviation, and other industries present unique challenges. Some plants cover millions of square feet, so the DAS should support transport architecture that can reliably distribute signals over long distances without the need for patching, splicing, or thick cabling. Another issue is interference: plasma welders throw off a lot of electromagnetic radiation, which can interfere with DAS frequency propagation. The DAS engineers must be sure to locate remote antennas far enough away from such equipment to avoid interference, and that often involves using high-power remote units to increase coverage area or a low power system with digital transport to carry the signal further. One area of special concern is in paint rooms, where high temperatures might fry a ceiling-mounted DAS antenna. In these situations, engineers place the DAS antennas outside the room. Semiconductor plants and other venues feature clean rooms that are off-limits to DAS installers. In these instances, engineers design the DAS so coverage comes from antennas adjacent to these areas. Nuclear plants can emit a lot of radiation that can really mess with signal propagation from a DAS. The answer here is to use high-power remote units that can be placed outside radiation-prone areas. Hospitals - Like semiconductor manufacturing plants, hospitals have restrictions on entering operating rooms, but they still want coverage in those rooms. To address this, DAS installers place antennas in the interstitial space above the operating room ceilings. Hydroelectric Dams - Hydroelectric generators also throw off a lot of electrical interference, so DAS engineers use high-power remote units and place them well away from such machinery. Historical Buildings - Many historical buildings have restrictions on what you can do with walls or ceilings, and it may be necessary to hide remote units inside furniture or closets to avoid disrupting the building's overall look and feel. In these cases, DAS engineers use low or high-power remote units inside closets. A DAS 1. 2. 3. that supports these unusual locales will have several key attributes. It will use thin, flexible cabling It will have a management system that allows certain antennas to be turned off at will. It will offer both high-power and low-power remote units that link to the same host unit, so designers can choose the best approach for the venue. 4. And it will use a transport technology (such as digital transport over optics) to eliminate limits on how far the DAS can reach. With the right attributes, DAS products can support wireless services wherever wireless services are needed... everywhere! About the Author Robert Salutric is a senior product manager for the wireless business unit of CommScope. He has spent his entire 25-year career in engineering and marketing for telecommunications companies. Robert is responsible for directing indoor wireless product definition and lifecycle management. www.commscope.com 20 Antenna Systems & Technology Winter 2016 www.AntennasOnline.com http://www.commscope.com http://www.AntennasOnline.com

Table of Contents for the Digital Edition of Antenna Systems & Technology - Winter 2016

Contents
Editor’s Choice
Configurable Robotic Millimeter-Wave Antenna Facility
Antennas
Bringing Live Events to the Television Screen
Components/Subsystems
Software / System Design
Test & Measurement
Industry News
Marketplace
DAS Anywhere and Everywhere

Antenna Systems & Technology - Winter 2016