to remove interference with military use. SAS gives DoD priority in the band, but keeps the band open for commercial users when not occupied.
This precedent may serve as a guide for future spectrum sharing between DoD and the commercial sector. By offering up its own bandwidths to share, DoD can also encourage a system of “bi-directional” spectrum sharing in which civil and federal users could access one another’s spectrum with varying prioritization. This would increase the amount of spectrum available to DoD on a secondary level, while maintaining priority access in its own bandwidths. Additionally, DoD stands to gain significant benefits from 5G development, for reasons listed at the beginning of this chapter. DoD may have some initial growing pains as it begins to share parts of the spectrum, but the net gain in capability from 5G will ultimately make up for that inconvenience. If DoD does not begin to share the sub-6 spectrum, it will increase the risk of dependence on a compromised supply chain as U.S. companies will be blocked from developing and competing their own sub-6 5G offerings, and foreign providers will increasingly embed their offerings in networks and systems globally.
Security Challenges in 5G
Supply Chain Risks
DoD is facing a future 5G environment where its supply chain will be increasingly vulnerable or compromised, from the subcomponent level to the integrated network level, as well as the services associated with each. In previous decades, DoD was able to operate on bespoke systems that fulfilled its unique requirements due to its position as a large user relative to the rest of the commercial world, but that privilege no longer exists. Commercial sector tech development and usage dwarfs that of DoD, and it is no longer practical for DoD to build and operate on siloed, bespoke systems and architecture. As a result, DoD is increasingly dependent on commercial off-the-shelf (COTS) equipment and commercial services, and the same will hold true for the future 5G ecosystem.
DoD can incorporate commercial inputs into its 5G infrastructure at four levels: the RF component, the integrated chipset, the device, and the service. RF components can include subcomponents ranging from semiconductors to switches and amplifiers. Integrated chipsets combine various subcomponents and other subsystems to interface with system components on a motherboard. Devices can range from mobile handsets to fixed computer systems, which include both the subcomponents and integrated chipsets listed above. Finally, each of these inputs comes with a set of service offerings to operate, manage and maintain them.
Commercial companies can supply any and all of the above inputs, but this comes with the risk of inadvertent or malicious security vulnerabilities that put DoD systems and networks at risk. The 5G ecosystem will especially run the risk of including security vulnerabilities if China becomes the global leader supplying 5G infrastructure from the subcomponent-level to the integrated system-level, for even if the United States limits sales of Chinese products into the United States, DoD will still have to operate on foreign networks overseas that will likely be built with a Chinese supply chain.
