CHAPTER 4: BOARD RECOMMENDATIONS FOR 5G
Board Recommendations
The Defense Innovation Board bases its recommendations on the assumption that mmWave fundamentally cannot be deployed on a large scale in the United States because of the propagation and cost limitations, and that sub-6 GHz mid-band spectrum (in the 3 and 4 GHz range) will become the global standard for broad area networks in coming years. This assumption is based on an assessment of the engineering requirements for mmWave and various studies projecting the required infrastructure and associated cost to support even a limited mmWave network. Additionally, the current financial state of U.S. providers may inhibit their ability to invest the required capex to support a mmWave network, limited or otherwise.
Recommendation #1
DoD needs to make a plan for sharing sub-6 GHz spectrum to shape the future 5G ecosystem, including an assessment of how much and which bandwidths need to be shared, within what timeframe, and how that sharing will impact DoD systems.
- DoD and the FCC must flip their prioritization from mmWave to sub-6 GHz spectrum for 5G. DoD and FCC have been prioritizing the 28 and 37 GHz bandwidths as options for 5G development, but this effort is misplaced. This study has covered the broad range of limitations associated with mmWave, and reasons why the rest of the world will adopt a sub-6 GHz 5G ecosystem. In light of this, DoD must prepare itself for that future operating environment by focusing on co-existing, if not explicitly sharing, with civil 5G operations in those bands of spectrum.
- DoD should particularly focus on the bands of the sub-6 GHz spectrum that are already being used by China. Chinese 5G systems and infrastructure operate in the 3.2-3.6 GHz range, as well as the 4.8-5.0 GHz range. As a result, the commercial world has developed semiconductors and handsets that are configured for that range, and DoD should angle for the most developed market to expedite 5G sub-6 GHz deployment in the United States. It takes approximately two years to add new frequency bands to complex multiband transceivers, and the United States would be able to avoid those two years of development by leveraging subcomponents and devices already on the market for more mature spectrum usage, such as existing Qualcomm products with functionality in the bands leveraged by China.
- As an additional consideration, DoD currently occupies ~500 MHz of space in the 4 GHz spectrum. DoD should take action to share parts of this space, given that it is a material amount of bandwidth that could make a serious impact on 5G development. 5G functions most optimally on large amounts of consecutive bandwidth, and this range could provide the real estate to drive 5G development forward.
- *For more detailed options around DoD spectrum sharing, see Classified Annex.
