LAUSR

5G systems have started field trials, and deployment plans are being formulated, following completion of comprehensive standardization efforts and the introduction of multiple technological innovations for improving data rates and latency. Similar to earlier terrestrial wireless technologies, build-out of 5G systems will occur initially in higher population density areas offering the best business cases while not fully addressing airborne and marine applications. Satellite communications will thus continue to be indispensable as part of an integrated 5G/satellite architecture to achieve truly universal coverage. Such a unified architecture across terrestrial and satellite wireless technologies can ensure global service, support innovative 5G use cases, and reduce both capital investments and operational costs through efficiencies in network infrastructure deployment and spectrum utilization. This article presents an architectural framework based on a layered approach comprising network, data link, and physical layers together with a multimode user terminal. The network layer uses off-the-shelf building blocks based on 4G and 5G industry standards. The data link layer benefits from dynamic sharing of resources across multiple systems, enabled by intersystem knowledge of estimated and actual traffic demands, RF situational awareness, and resource availability. Communication resource sharing has traditionally comprised time, frequency, and power dimensions. Sharing can be enhanced by leveraging dynamic knowledge of communication platform location, trajectory, and antenna directivity. Logically centralized resource management provides a scalable approach for better utilization of spectrum, especially in higher bands that have traditionally been used by satellites and now are also being proposed for 5G systems. Resource sharing maximizes the utility of a multimode terminal that can access satellite or terrestrial RF links based on specific use cases, traffic demand, and QoS requirements.