Smartphone System-Level Design: So What?

5G calls for new thinking about smartphone design

There are a lot of buzz words in mobile and even more in mobile chipsets. Phrases such as integration, optimization, efficiency and system performance get used so widely that their real meaning and importance tend to get lost or misunderstood. This is perhaps not surprising given the volume of competing marketing messages and the complexity of chipset design.

Nonetheless, it’s important to understand that not all phones are created equal. All smartphones have the basic elements in common: modem, transceiver, CPU, GPU and an abundance of RF components. But in the same way that a car’s design has a direct impact on its performance, the same is true in a smartphone. A car demands the careful balancing of several elements, starting from the chassis and including the engine, the transmission and so on. The interrelationship of these parts is all-important.

Smartphone Design

A smartphone is no different, and it’s a major reason why Qualcomm recently decided to acquire the remaining interest in RF360 Holdings. Its joint venture with TDK was established on the basis that the complexities of 5G would need a very different approach to smartphone design. The introduction of TDD as well as FDD frequencies, huge variation in wavebands from sub-6 GHz to millimetre wave, wider channel bandwidths and the need from day one to scale across more than 20 operators and 20 manufacturers entailed a very different, system-level approach.

This is in stark contrast to how smartphone design worked in the early days of 4G. A manufacturer would pick the various elements needed, from the modem to the antenna, from a range of suppliers. This provided the advantage of choice and flexibility, but as complexity increased, those benefits began to be outweighed by the challenges.

Integrating and optimizing various components into a system becomes ever more complicated and expensive. In a smartphone market in which design cycles, time to market and margins are everything, and competition cutthroat, it’s a gamble for manufacturers unless they have clear scale and the required RF expertise.

The System-Level Advantage

Here the advantages of a modem-RF system come to the fore. Manufacturers can select a chipset platform and supporting RF components such as filters, power amplifiers, multiplexers and antenna tuners knowing they’re fully compatible and highly optimized. Moreover, the system-level approach provides significant performance advantages. Throughput, coverage, form factor, power consumption and thermals are all directly affected by a device’s efficiency in managing the enormous complexity between the modem and the antenna. These efficiencies are why most products using Snapdragon 855 have also featured Qualcomm’s RF front-end solutions.

We’re still in the early days of 5G, and the competitive landscape has not yet settled. The entrance of new suppliers of 5G chipsets at a wider range of prices is inevitable as manufacturers seek to spur competition and bring down cost. Early 2020 will see far wider experimentation. However, the introduction of products featuring a broader range of silicon is also likely to see the gulf widen in terms of the performance, efficiency and feature set of 5G smartphones.

A Two- and Three-Tier 5G Device Landscape

We predict that a two-tier 5G smartphone market will begin to appear in 2020, with a noticeable gap in performance and feature set between devices. This could develop into three tiers in 2021 as 5G devices targeting lower price bands demand preconfigured modem-RF systems to meet design and cost requirements.

But it’s unlikely to be sustainable. If there’s been one constant in the smartphone market over the last 10 years it’s been steady consolidation thanks to increasing complexity, the need to invest huge sums in research and development and the knock-on effect that has on profitability. The gap between winners and losers becomes wider.

The transitions to 3G and 4G were catalysts that dramatically changed the market structure. Now, 5G requires a very different approach to chipset and RF system design that’s very likely to have a fundamental impact on smartphone performance, quality and ultimately the chipset supply landscape.

CCS Insight will be exploring several RF system technologies in more detail in the coming months. Stay tuned.

A version of this article was first published by FierceWireless on 1 October 2019.