Spectrum sharing in the 3.5 GHz band

By: Patrick Welsh

You only need to take a look around you to see that wireless Internet traffic is skyrocketing. The statistics bear this out— CTIA, the wireless association, revealed in their annual survey that U.S. wireless providers handled 3.2 trillion megabytes of data traffic in 2013 – that’s a 120% increase over 2012. This exponential growth is one reason why companies like Verizon have pushed so hard for policymakers to identify new spectrum to meet consumer needs. Bringing new spectrum to market will help the wireless industry increase broadband speeds, which will fuel innovation.

As we have noted many times, Verizon continues to support auctioning spectrum for flexible, exclusive use. This approach has proved extremely successful and has made the U.S. the world leader in deploying next generation wireless networks. But reallocating and clearing spectrum is not always possible. For example, some government operations cannot be moved to new frequencies because alternative spectrum is unavailable or costs are prohibitively expensive. In those cases, we need another approach. That’s why Verizon is encouraging new research into and testing of different ways to allow commercial and government users to have shared access to spectrum when it cannot be cleared.

The FCC is exploring these approaches too. A good example is its proceeding on the 3.5 GHz band. The government currently operates military radar in the 3.5 GHz band. These operations cannot easily be moved to different frequencies. Building on recommendations by President Obama’s Council of Advisors on Science and Technology (PCAST), the FCC is proposing making this 3.5 GHz band available for commercial use on a shared basis.

This spectrum could then be used by the wireless industry to increase network capacity in high-demand areas like stadiums, college campuses, or airports.

Verizon and the wireless industry are moving aggressively to make this a reality. Yesterday, Qualcomm, Verizon, and Ericsson filed applications with the FCC to conduct field trials with spectrum-sharing technology in the 3550-3650 MHz band at several potential locations. The trials will combine the 3.5 GHz spectrum configured as LTE supplemental downlink with Verizon’s existing LTE network to enable the addition of 3.5 GHZ capacity to an existing lower band coverage network. These trials are constructed to evaluate the benefits of adding 3.5 GHz spectrum to Verizon’s network with a specific focus on understanding the propagation characteristics of 3.5 GHz spectrum in a real-world environment. Later this month, Verizon, Qualcomm, Ericsson, and iconectiv will conduct lab testing of Authorized Shared Access/Licensed Shared Access technologies at Ericsson’s facilities in Plano, TX to demonstrate how spectrum sharing can complement Verizon’s LTE network while protecting government operations from harmful interference. Authorized Shared Access / License Shared Access utilizes many of the spectrum sharing techniques under review by the FCC.

In today’s environment of sky-rocketing demand for wireless broadband, we need to actively explore all possibilities for opening up new sources of spectrum. We expect that these trials and field tests will help make sharing spectrum with federal government users a reality.

About the author(s): 
Director of federal regulatory affairs at Verizon