Each of these radio links serves a vital purpose, and leaving one out of the mix would shortchange the operational team. Yet each radio literally carries a cost in size, weight, and spare battery needs. The problem is further complicated as new requirements and links are added to the list.
The solution is obvious, at least on "paper": a universal full-duplex radio module which can be used across all platforms and dynamically reconfigured in the field as needed. The "one-radio" goal would lessen the load, provide flexibility and versatility, be efficient and so provide longer operating life from a single set of batteries, and thus provide significant SWaP (size, weight, power) advantages. That was the underlying premise of programs such as the JTRS (Joint Tactical Radio System) and software-defined radio (SDR) efforts.
But making the "universal" radio concept into a reality has proven harder than envisioned. While Moore's law has driven the availability of the high-performance, lower-power processors (including FPGAs) which are needed, providing the suitable integrated analog front end (AFE) has been much more difficult. The demands on this functional block--which resides between the antenna and the processor and is the interface between the real-signal world and the digital world--are complex, varied, and stringent.
Until recently, a practical AFE for this type of versatile radio required an array of overlapping parallel channels, each designed to cover a particular segment of the RF spectrum and with bandwidth matched to the intended signal format. This approach, while doable, is costly in terms of final PC board footprint, weight, power, and dollar cost.