The Bright Future of Distributed Antenna Systems

As mobile data usage ramps up and the march toward 4G continues, carriers continue to increase their network footprints and ease congestion on their towers. Distributed antenna systems — or DAS — will play a key role in this, as the technology enables operators to offer better coverage and network capacity without having to build new towers or acquire more spectrum.

A DAS comprises multiple small antennas in a specific area. Deployments serve two purposes: to fill in holes where coverage is weak (in buildings and densely populated areas) and to boost capacity of traditional networks (in high-traffic areas). The space initially gained traction in brick-and-mortar locations. The real growth area for DAS, though, is outdoors, where line-of-sight antennas are often placed atop utility poles in areas where building a new tower simply isn’t feasible. The antennas are then connected via fiber to a base station hub. The role of DAS has expanded beyond specific use-cases (like in-building deployments) to become a complementary — but important — part of traditional tower build-outs.

The growing importance of DAS’s role in the mobile world was underscored again last week when Crown Castle completed its $115 million acquisition of NewPath Networks from Charterhouse Group, a private equity firm. While Crown Castle has limited experience with DAS, the move is an undeniable expansion of the Houston-based company’s traditional business of owning and operating cell towers. Meanwhile, Chicago-area company ExteNet scored a $128 million investment earlier this year, the largest deal in mobile over the past four quarters. San Jose’s NextG Networks, which has raised more than $560 million since 2008, in February announced DAS site number 5000. And Tyco said DAS was a key factor in its move to acquire ADT Telecommunications for $1.25 billion.

DAS is especially attractive to service providers with limited spectrum looking to accelerate their network deployments.  MetroPCS, for example, has used DAS as it builds out its network in urban areas like Boston, New York and Philadelphia, where towers are already crowded. Tier-one operators are also joining the DAS bandwagon: American Tower last month said it had built out an outdoor DAS network in Michigan for T-Mobile USA and Verizon Wireless is embracing the stuff as it prepares to bring its 700 MHz LTE network online.

Indeed, the deployment of 4G networks is expected to spur carrier demand for DAS. LTE and WiMAX networks will deliver faster speeds, which will increase demand — and will further highlight problems related to limited capacity. Carriers are looking to address those problems by employing a vast array of tools, from better compression technologies to metered pricing models to offloading technologies such as Wi-Fi, femtocells and now DAS. Investors are increasingly pouring money into DAS.

The DAS market faces challenges, of course: Because three to five nodes are required to equal the coverage one traditional cellular site can provide, DAS networks are generally more expensive to build. And regulatory challenges involving zoning and rights of way can vary from one community to the next, requiring DAS vendors to adapt deployments on a case-by-case basis. Those hurdles are mitigated though, by the fact that multiple carriers typically use the same DAS networks, lowering operators’ costs of deploying and maintaining the systems.

While DAS networks are still limited to specific locations in the U.S., the technology will become more commonplace over the next few years. DAS is certainly no silver bullet for operators struggling to provide quality service to as many users as possible, but it is becoming an important tool alongside femtocells and other non-cellular technologies. For consumers, that means better reception without the need for more unsightly cell towers. And for players in the space, it means more funding and more consolidation are surely on the way.

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Question of the week

How important will DAS be to carriers as they roll out their 4G networks?