Antenna Systems & Technology - Fall 2013 - (Page 12)
Managing Distributed Antenna Systems (DAS)
Effectively and Efficiently
By Ben Stump, Senior Vice President and Chief Technology Officer • Westell Technologies
Distributed Antenna Systems (DAS) have become more common for expanding the wireless coverage area and capacity of a network, especially in high traffic locations such as
stadiums, campuses, airports and train stations. From one piece of hardware in a shopping mall closet to a motor speedway or stadium where hundreds of antennas are used to provide coverage to every area of the complex, a DAS network can be large or small but is critical to extending and
ensuring network availability. Adding to the popularity and complication of a DAS is multi-tenant arrangements – having multiple service providers utilizing different standards (GSM, W-CDMA, etc.) and spectrum
in a single DAS environment.
The DAS Management Challenges
DAS networks can involve complexity for both the owner of the DAS (often a tower operator or facility
owner) and the service providers who sublet space and capacity from the owner. For example, most distributed antenna systems today are not being monitored for quality and availability. If an issue arises,
service providers usually find out when a customer complains about intermittent or lost communication
connections. Finding the problem can be time-consuming because it isn’t known where in the system the
problem exists. With an antenna, expansion unit, host unit (head end), or even which sector has the issue.
Fine tuning of a DAS network is challenging because it is often conducted when there is limited or no load
on the system. When the network is finally exercised and stressed with a significant number of users, the
owner/operator needs to understand how the system is performing, not just if it is functioning or not. Any
problems need to be easily identified, both in terms of location and potential issue, and network and sector
saturation must be avoided in order to maintain coverage and satisfied customers.
DAS networks range dramatically in configuration and size and leverage expandable amounts of hardware
that have their own set of fault and performance information. While it might be possible to directly monitor
every single alarm, this can quickly become unrealistic and overwhelming. To worsen the potential situation, in many systems, there are numerous ways to receive the same type of information, which often
means receiving duplicate information.
Understanding if and when a DAS reaches saturation is critical. Is the entire system and each sector sized
appropriately? In today’s environment, it is common to just monitor the utilization of the overall DAS, and
if a problem occurs, then a technician would need to look at not only the head end unit but also the antennas in each sector to pinpoint the problem and take corrective action. This could take hours if there are
many sectors in the DAS network.
Comprehensive DAS Management
A comprehensive DAS management solution provides the technology required for monitoring the DAS
infrastructure to obtain critical information about the health of the system, remotely. The operational
status of the deployed infrastructure is available at all times, and when issues arise, alarms automatically notify the relevant personnel for further investigation, and in many situations, the issues can be
A DAS management solution provides equipment monitoring to collect alarms and key performance indicators to verify the operational status of the distributed antennas. Quality monitoring provides an operational
view of the subscribers’ user experience, and the information can be provided as key performance indicators and troubleshooting data. Finally, test results are stored to ensure network integrity measurements
such as connectivity, data throughput, and signal strength.
Antenna Systems & Technology Fall 2013
Table of Contents for the Digital Edition of Antenna Systems & Technology - Fall 2013
Exponential M2M Market Growth Calls for Innovative RF and Antenna Solutions
Managing Distributed Antenna Systems Effectively and Efficiently
Millimeter Wave Antenna Radome Systems for Satellite on the Move Applications
Test & Measurement
Antenna Systems 2013: Conference Preview
Addressing Customer Requirements in Public Safety Antennas
Antenna Systems & Technology - Fall 2013