Antenna Systems & Technology - Summer 2015 - (Page 26)

GUEST COLUMN DAS and Small Cells, Revisited By John Spindler | TE Connectivity In a blog a couple of years ago, I suggested that the small cells of the day didn't offer as robust or cost-effective a solution for enterprise mobile wireless coverage as a distributed antenna system (DAS). But, small cells have advanced considerably in the past two years, so it's time to revisit our premise. Today's small cell vendors tout several attributes in their favor. Let's look at these one by one and see how DAS stacks-up. Easy Installation and Set-up - Small cells can use existing Ethernet LAN cabling. You install small cells throughout a building, connect them to Power over Ethernet (PoE), and link them to a central controller in the IT equipment room. These networks of small cells are supposed to be self-organizing, so vendor marketing information says that the individual cells are self-provisioning and coordinate with other cells and the controller automatically. DAS may require new cabling, but because all of the antennas are driven from a central point in the IT equipment room, any configuration can be done in one location. Self-Optimization - A DAS is self-optimizing by default because there's only one cell for the entire building. Small cells use coordination software and central controllers to achieve this. Ease of Use - Both small cell and DAS vendors say that their solutions offer "set it and forget it" turn-up with no maintenance. Once the system is installed and configured, it should require little effort to use. One potential issue is that any reconfigurations of the LAN infrastructure may affect performance of a small cell system, whereas DAS doesn't have this problem because it uses a separate infrastructure. Multi-Operator, Multi-Technology, Multi-Band - Two years ago small cells were single-band devices, but now they support two bands. This may be adequate for smaller buildings, but larger venues that require coverage for all bands will require multiple sets of small cells. It's easier to scale a DAS for different applications in larger buildings because you can add capacity or frequency bands at the head-end by deploying additional base stations. Backhaul Efficiency - Since each small cell has its own backhaul over the Ethernet connection, users need to make sure that backhaul is managed throughout the building. DAS is more efficient because the entire system is backhauled from one head-end location in the IT equipment room. Low Cost - Small cells have come down in price, but deploying a lot of them is still an expensive proposition. For smaller buildings, small cells may be the most economical choice, but DAS is often the best priced solution in medium- to large-sized buildings, especially with multiple bands and services. Marrying DAS and Small Cells - I believe DAS and small cells can work together, the small cell by providing the baseband signal and the DAS by distributing it throughout the building. From my perspective, it's much more efficient and scalable to cell sites within a building with a DAS, but using a small cell as the baseband unit helps optimize the deployment by right-sizing the signal source. Small cell technology has come a long way in the past two years, but fundamentally it's cleaner and more efficient to create one distribution system within a building with a DAS that can more easily migrate as user uptake and technologies change than it is to deploy multiple small cells that have edge interference issues. Small cells may be right for limited deployments in smaller buildings, but only DAS has the scalability and performance to support enterprise services. About the Author John Spindler was named vice president of Product Management for TE Connectivity's wireless business in December 2007 through the company's acquisition of LGC Wireless where he served as Vice President of Marketing. In his current role, Spindler is responsible for developing and managing an innovative wireless product portfolio for the company's Network Solutions Business Unit. For more information visit www.te.com 26 Antenna Systems & Technology Summer 2015 www.AntennasOnline.com http://www.te.com http://www.AntennasOnline.com

Table of Contents for the Digital Edition of Antenna Systems & Technology - Summer 2015

Editor’s Choice
The Future of DAS - In-Building and Dynamic Capacity
Impedance Matching is No Match for Aperture Tuning
All Band VSAT Antenna Radomes: A New Perspective
Antennas
Components/Subsystems
Software / System Design
Test & Measurement
Industry News
Marketplace
DAS and Small Cells, Revisited

Antenna Systems & Technology - Summer 2015