Will Spectrum Sharing Increase the Demand for Small Cell Backhaul?
The scarcity of access spectrum is a widely debated topic. According to the President's Council of Advisors on Science and Technology (PCAST), scarcity is a byproduct of the complex licensing scheme which is based on clearing government held spectrum that has only been utilized by Federal users for use in commercial operations using an auction process. The solution they stress lies in making spectrum available for shared as opposed to exclusive use. Hence, the recommendation was made to set aside 1,000 MHz of U.S. government held spectrum for shared use.
But how do we make spectrum sharing a reality? Two key trends are highlighted in PCAST’s report: small cells and interference mitigation technology.
I see this development from different perspectives.
First, there’s no doubt on how government policy shapes technological developments. WiFi is a case in point: allocating spectrum for unlicensed applications spurred a large technological evolution in wireless communications. In fact, WiFi has implemented many technologies ahead of access spectrum technologies such as OFDM and MIMO. Enacting the shared spectrum use model can provide major impetus for small cell deployments in addition to the development of a host of radio techniques (cognitive radio, interference mitigation technologies, etc.)
Second, shared spectrum would revolutionize the way wireless networks are designed. The idea of having a network of small cell base stations operating in a wide allocation of spectrum and capable of allowing coexistence between different users through a host of interference management technologies is very different from today’s networks.
Third, there would undoubtedly be a need for new business models for wireless network operation that will redefine the value chain in the wireless industry.
But to make all this reality, there are a host of technical and economic problems to solve. Small cell deployments in large volumes can only happen when the business case is feasible and for this, the backhaul challenge needs to be addressed. The pressure to solve the small cell backhaul challenge has been the growing demand for mobile data services. Spectrum sharing policies would further stimulate the demand for cost effective small cell backhaul solutions.