5G Might Have a Radically Different Architecture

Many mobile service provider executives now believe 5G might feature the use of multiple air interfaces, and might have a radically different architecture, as well.

Some 26 percent of respondents think it is “very likely” that incompatible 5G systems will emerge for different use cases, including multiple air interfaces.

About 23 percent of survey respondents think it is “unlikely” or “very unlikely” there will be incompatible radio interfaces, but the majority are uncertain.

Close to half of respondents--47 percent-- expect 5G to have a “substantially different” system architecture than the traditional cellular network. An additional 27 percent believes “a radically different” system architecture is the only way to deliver 5G.

That is because 5G is seen as a major transformation that may go beyond the radio access network (RAN) and rely on changes in the core of the network.

Software Defined Networks (SDN) and Network Functions Virtualization (NFV), for example, are seen as core network features 5G uses “natively.”

You won’t be surprised that mobile service provider executives around the world expect coming fifth generation mobile networks (5G) will use multiple low-band and high-band frequencies.Given the diversity of mobile spectrum already in use in various regions, that should come as no surprise, especially as older networks are decommissioned and spectrum is repurposed to support 5G.

A survey of 58 mobile operator executives suggests that operators lean towards use of  low-band spectrum. The sub 5 GHz bands were ranked as “critical” by around 30 percent of respondents compared to 21 percent for 5-30 GHz and 13 percent for millimeter wave.

Asian operators rank the 60 GHz to 90 GHz band as more “critical” (36 percent) for 5G than either North American (10 percent) or European (seven percent) operators.

But 50 percent of European respondents rank 1 GHz to 5GHz as “critical,” compared to about 29 percent of Asian respondents.

In North America, about 18 percent of respondents deemed the 1 GHz to 5 GHz bands as “critical.”

Operators also expect more overlap between 4G and 5G services than between 4G and 5G technology.

About 59 percent of respondents expect substantial overlap between 4G Advanced and 5G use cases and only a small minority (10 percent) think there will be “very little” or “no overlap.”

Some 39 percent of respondents  think there will be “substantial overlap in technology” between 4G and 5G. About 44 percent of respondents  think there will be “some overlap, but not substantial.”

Asked to rank different technologies, operators are clear that 5G system performance will primarily be driven by higher density networks built using small cells.

Massive MIMO(Multiple-Input and Multiple Output) also is seen as a key technology ingredient.

Device-to-device communications also are viewed as important, implying greater 5G use of ad hoc and mesh networks.

Desire for a new waveform, in fourth place, could speak to the need for low-power IoT capabilities, and for long-range coverage services deployed in the lower bands.

The survey results are based on responses from 58 mobile operator executives about expected 5G attributes. The study was conducted by Gabriel Brown Senior Analyst, Heavy Reading, with support from the Telecommunications Industry Association and Interdigital.