From "4G+5G" to "5G+5G": Dual SIM dual standby evolves quickly

Driven by market demand and the country's "new infrastructure" policy, China's 5G network construction is entering an explosive period in 2020. According to experts' predictions, the total scale of China's 5G base stations may exceed 600,000 in 2020, achieving coverage of prefecture-level cities in China. At the same time, 5G terminals are also developing very rapidly. 5G mobile phones priced under 2,000 yuan have appeared on the market, laying the foundation for the popularization of 5G mobile phones. According to data recently released by the China Academy of Information and Communications Technology, a total of 81 5G mobile phones were launched in China in the first five months of 2020. In May, domestic 5G mobile phone sales accounted for 46.3% of the total mobile phone shipments in the same period. It is estimated that the total shipments of 5G mobile phones in 2020 will exceed 200 million units.

Looking at the existing 5G mobile phones on the market, support for 5G NSA/SA modes is already standard, and support for multiple frequency bands is becoming more and more comprehensive. However, in terms of the dual-SIM dual-standby function that people are accustomed to, most only support "4G+5G", which seems a bit too conservative. In fact, in the "China Mobile 5G Mobile Phone Product White Paper" released on November 20 this year, although China Mobile mentioned the two dual-SIM modes of "4G+5G" and "5G+5G", it clearly stated that it recommends "5G+5G" dual-SIM products. Obviously, "4G+5G" will only be a temporary transition strategy, and the overall trend of 5G mobile phones must be "5G+5G" dual-SIM dual-standby.

Indispensable dual SIM dual standby

Dual SIM dual standby means that a mobile phone can be inserted with two SIM cards and use two numbers at the same time. This technology first appeared in China in 2006. At that time, China Unicom had two mobile communication networks, GSM and CDMA. In order to attract users to choose CDMA services, it jointly launched the so-called "dual-mode dual standby" mobile phone that can insert two SIM cards at the same time with some mobile phone manufacturers.

Later, people found that this technology was very practical. First, one mobile phone can be used with two numbers, saving the cost and trouble of carrying two mobile phones; second, the two numbers can have different usage occasions and are clearly distinguished; third, new packages have preferential prices and people are reluctant to discard the old numbers, so a mobile phone with two SIM cards and dual standby is undoubtedly the best solution.

As a result, dual SIM dual standby has become a standard feature of mobile phones in the domestic market. Of course, dual SIM dual standby is no longer a feature exclusive to the Chinese market, and mobile phones sold overseas also basically have dual SIM dual standby.

Currently, dual-SIM dual-standby functions require chip support, so what kind of dual-SIM dual-standby functions mobile phones on the market have are actually determined by mobile phone chip manufacturers. At this stage, 5G SoC chips launched by mainstream chip manufacturers mostly support "4G+5G" dual-SIM dual-standby, including Qualcomm's Snapdragon 865, Snapdragon 765G, Huawei's Kirin 990 5G, Kirin 985, Kirin 820. Currently, only MediaTek's Dimensity 1000+, Dimensity 820, Dimensity 800U, Dimensity 700 and other Dimensity series 5G chips support "5G+5G" dual-SIM dual-standby.

"4G+5G" dual-card dual standby means that the phone can only access 5G services for one card, and the other card can only use 4G services, while "5G+5G" can use 5G services for both cards. In the early stages of 5G business development, there were no 5G signals in many places, and "4G+5G" was undoubtedly a very realistic countermeasure, and consumers basically had no concerns. However, judging from the country's support for the "new infrastructure" and the active actions of operators, the widespread coverage of 5G networks is expected to achieve great results in the next two years, which means that "4G+5G" will soon be eliminated, and "5G+5G" is the general trend.

Gradual development has become the rule

In the history of mobile phone development, transitional dual-SIM dual-standby such as "4G+5G" is not an isolated case. In fact, every time mobile communication technology is updated, cross-generation dual-SIM dual-standby models will appear. For example, at the beginning of 3G commercial use in China, switching to 3G packages required replacing SIM cards and mobile phones, while "2G+3G" dual-SIM dual-standby allowed many consumers to use high-quality 3G packages while continuing to use old 2G cards. In the 4G era, the connotation of dual-SIM dual-standby is richer, with a variety of transitional solutions such as "2G+4G" and "3G+4G", each with its own applicable population. In this way, it is not surprising that "4G+5G" dual-SIM dual-standby plays a leading role in the current 5G mobile phone market.

The reason for the emergence of the transitional dual-SIM dual-standby function is due to both user demand factors and technical and cost reasons.

In terms of technology, at the beginning of the upgrade from 2G to 3G and 3G to 4G, the overall technical performance of mobile phone chipsets could not keep up, and each card slot could not be compatible with two-generation cards, so it could only be a combination of "2G+3G" and "3G+4G". Later, with the continuous improvement of mobile phone chipset technology, dual-SIM dual-standby full network access became the mainstream of the market. From a cost perspective, transitional dual-SIM dual-standby chips appeared earlier and were lower in cost, so mobile phone manufacturers were also happy to use them to design a new generation of models to seize the market. The popularity of "4G+5G" mobile phones is also based on the same reason.

However, transitional solutions cannot last long after all. "5G+5G" that can bring consumers greater freedom is the general trend. In fact, chips and mobile phones that support dual 5G standby are already on the market. Most of the existing 5G mobile phones on the market use Qualcomm and Huawei's 5G SoC chips, so they only support "4G+5G", while MediaTek's Dimensity 5G chips launched from last year to this year mostly support "5G+5G" dual-card dual standby. It can be expected that with the large-scale mass production and listing of terminals equipped with MediaTek Dimensity chips, more and more 5G mobile phones that appear after the second half of 2020 will have dual 5G functions.

Advantages of Dual 5G

Although the "5G+5G" dual-SIM dual-standby system appeared relatively late on the market, on the one hand, the two cards can freely choose 4G or 5G services, which can completely replace the "4G+5G" solution. On the other hand, both cards can use 5G services, which provides a better user experience. Therefore, it will not affect its development potential at all.

For example, there are differences in the key areas of 5G network construction of the three major domestic operators, and the quality of 5G signals in different areas will be high or low. Users can purchase SIM cards and 5G packages from different operators, and switch to the 5G SIM card of the operator with the strongest signal, so that they can get the best 5G experience anytime and anywhere. In addition, early 4G voice calls could only fall back to 2G/3G bearer, which had a great impact on user experience. Later, operators began to consider directly providing quality-guaranteed voice services (VoLTE) on 4G networks, but the call quality was still not good enough. 5G is also considering the same problem (VoNR), and has higher requirements for the quality of voice calls. Therefore, dual 5G allows both SIM cards to use high-quality VoNR services, which fully surpasses the "4G+5G" solution.

In addition, in the 5G era, more and more industries will seek to use 5G networks for digital transformation. Industrial manufacturing, urban management, public safety, park inspections, logistics and transportation, news media and other fields may require employees to use 5G cards to complete various tasks. At the same time, in daily life, browsing high-definition videos, doing live video broadcasts, and experiencing VR/AR games also require high-speed 5G networks. These applications are obviously not suitable for mixing with work content. On the other hand, as 5G and industry applications continue to move towards in-depth integration, some industries’ work 5G cards may not be able to access external resources, and personal 5G cards cannot access internal corporate resources. At this time, only "5G+5G" dual-card dual-standby can allow users to balance work and life.

Nowadays, communication technology is advancing rapidly. The 5G R16 version standard is expected to be determined in the near future. The low latency and high reliability of 5G networks will further stimulate the enthusiasm for application innovation in all walks of life. In such an environment, the market demand for 5G terminals with stronger performance and flexibility will become more urgent. "4G+5G" is obviously unable to adapt to the new situation. In the "China Mobile 5G Mobile Phone Product White Paper", it is clearly recommended to focus on the development of dual-card mobile phones that support NR/TD-LTE/LTE FDD/WCDMA/GSM. This is an urgent demand from operators and the market. With many advantages and superior performance, products such as dual 5G SoC chips and mobile terminals will inevitably quickly occupy the mainstream of the market.