Spectrum sharing fundamentally is important because it can change the business model for existing and new potential providers of communications services, much as increased availability of unlicensed spectrum likewise allows incumbent and new service providers to create services and revenue streams. In other words, shared spectrum is important because it changes the value and cost of spectrum rights.

One example: AT&T might be betting that the value of a new nationwide emergency services network (FirstNet) will come largely from access to shared spectrum, not the actual operation of the network.

In the case of FirstNet, the perceived value of building and operating a network that has great potential societal value, but a questionable financial return, might be justified by access to shared spectrum, and not necessarily from revenues generated by customers of the network.

In other words, access to 20 MHz of 700-MHz spectrum, nationwide, might be enough inducement to build a network costing up to $40 billion.

 The tangible benefits might well be the use of 20-MHz of new 700-MHz spectrum, whenever the emergency services personnel are not using the network. That might be “most of the time,” as the network will rely heavily on small cells.

The thinking might well be that even if the network only breaks even, or perhaps even loses some money, the upside comes from the use of 20 MHz of shared spectrum with excellent coverage characteristics.