Distributed Antenna Systems for Large Facility

Date Updated: July 6, 2015
Question:
We have a large conference facility with multiple rooms, and would like the ability to use any of our wireless microphones in any of the rooms. Is this feasible?
Answer:


  1. Is a distributed antenna system feasible for a very large conference center?  Yes, it is probably possible to design and engineer such a system.  


  2. It will be critically important to engage a knowledgeable and experienced RF engineer to design the antenna system.


  3. What is involved in designing a distributed antenna system?  The design process will include a detailed site survey.  At the site survey, information is gathered about the construction of the building (i.e. types of walls and materials used), RF tests may be conducted to determine transparency of walls to signals, permissible routes and distances for coaxial cables are identified, and antennas are selected to match the area to be covered.  After the site visit, detailed plans are drawn showing the overall wiring plan and all active components with their position in the network.  In addition, a frequency plan will be developed to support the needed quantity of wireless microphone channels.  The frequency plan is developed within parameters where RF bandpass filters will likely be deployed in the antenna system to minimize any chance for overload from out-of-band signals (i.e. portable two-way radios, nearby TV stations, cell phone signals, etc.).


  4. What is the cost for a large distributed antenna system?  The cost will be very high for engineering and design, material, installation labor, and on-going maintenance.  Material alone for the antenna system could be $10,000 - $20,000 in 2014 dollars.


  5. A distributed antenna system that covers such a large area will be prone to interference.  If interfering signals occur in one area of the facility, they may block desired wireless microphone signals in another part of the facility.  Trying to diagnose and locate the source of the interference may be very difficult to nearly impossible due to the size of the facility.


  6. Maintenance of a complex distributed antenna system will be quite expensive.  Troubleshooting problems will require expert knowledge and special test equipment, as well as accurate and extensive documentation.


  7. It is recommended to consider other options for planning wireless microphone coverage.  For instance, dividing the facility into four zones would vastly simplify as well as improve reliability of an antenna system.  Another option is to use portable wireless racks delivered to individual meeting rooms for specific events.  Brainstorming other options will likely be worthwhile for this project.


  8. Will Shure design the antenna system for me? While we are happy to assist a qualified engineer (see point 2, above) by reviewing designs and offering suggestions, it is not practical for Shure to provide detailed system designs for applications of this complexity. It will be necessary to engage knowledgeable experts who can conduct on-site surveys to assemble a plan.