Distributed Antenna Systems as a Revenue Source for Community Fiber-Optic Deployment

Going from a traditional cellular topology to a Distributed Antenna System (DAS) has some key advantages. Because the antenna locations are unrelated to the base-station location, they offer far more control of cell size and shape. That, in turn, leads to more optimal radio use. In addition, equipment for multiple base-stations can be hoteled for easy maintenance and consolidated backhaul. The ability to have many small antenna locations can also benefit system reliability. An individual failure will have less impact and the systems needed for small area coverage are far less complex than those needed to provide large area coverage.

Unfortunately, achieving the distances between base-station and antenna needed for efficient outdoor coverage requires a great deal of fiber-optic interconnect. Installing miles of fiber to replicate the coverage of a typical macrocell is an expensive prospect. For this reason, most DAS systems have been implemented as in-building projects. Only very large subterranean systems for public works projects have used multiple-mile fiber runs and these tend to be more expensive than a traditional macrocellular deployment covering the same area above ground. From a total cost of ownership perspective, without the cost of a dedicated fiber network, DAS would generally prove less expensive than a traditional deployment.

A potential solution to this underlying weakness of DAS is the Community Fiber-Optic Network (CFN) projects that are growing in popularity. Whether being built by an RBOC like Verizon or SBC, or by an underserved community itself, these networks entail a fiber deployment of a density never before seen. A very dense fiber network with many nodes is the perfect backbone for an outdoor DAS. By renting part of someone else’s network rather than building his own, a potential DAS builder has eliminated the major economic stumbling block for the project.

The gains of a DAS/CFN partnership are not one-sided. The economic stumbling block faced by a potential CFN builder is the uncertainty of relying on many small churn-prone customers as the primary revenue source. By signing up a DAS as a customer, the CFN has gained the churn-proof equivalent of hundreds of residential customers. Now, the CFN has a far better chance of making or beating time to payback projections.

This basic concept of a CFN leasing dark fiber for use in a DAS can be taken a step farther by incorporating the concept of Neutral Hosting into the CFN. In this model, the DAS becomes an integral part of the CFN rather than just an adjunct to it. Not only does the CFN operator provide client carriers with equipment to transform their traditional network into a DAS, or build a new network with a DAS topology, but also makes available hotel and remote antenna locations. Ideally these locations are part of the infrastructure used to create the CFN or are already owned by the CFN operator. A further evolution of this concept uses software-defined base-stations to allow the Neutral Host to offer a completely turnkey solution, using generic equipment at the hotels, to the carriers. When considering how many potential clients a Neutral Host DAS could have, remember that this solution is applicable to any wireless carrier, not just mobile telephony companies.

While DAS and CFN is a match made in heaven, the two must still find a way to come together. The simplest cases involve wireless carriers soliciting CFN operators for fiber to use in constructing their own DAS or the CFN operators soliciting carriers to rent their fiber for that same reason. The case of the CFN operator becoming a Neutral Host is more complicated, but also a much larger business opportunity. Then, there is the case of a third-party renting fiber to, become in turn, a Neutral Host. In any case, making the deal happen requires the right expertise – expertise that neither a wireless carrier nor a CFN operator is likely to possess. Clearly, finding the right partner to aid in the identification and evaluation of potential opportunities is key. Stratum Broadband specializes in finding the right solution for each client’s needs.