It is difficult to repair the power and cost of 5G technology.

Source：Updated：2018-03-26 08:22:28

How will 5G technology be popularized and what problems will be solved on the road ahead?

The pace of 5G is getting closer and closer, but not everywhere, and it won't come out of nowhere, and it's not the fastest version of the technology that comes first. What is likely to happen is that 5G will first be completed in densely populated metropolitan areas, starting in 2020 or 2021 and gradually gaining popularity over the next decade.

Just as today's smartphones leapfrog 2G, 3G and 4G LTE 3G, 5G is unlikely to replace 4G LTE altogether. Backward compatibility is an important consideration for all of these criteria. The frequency of 5G signals is very high, the highest frequency can reach 300 GHz, while 4G LTE is 2. 6 GHz band. Improve the bandwidth can increase the density of the data, so the increase of frequency makes 5 g signal can carry more data, but also means higher frequency signals are more susceptible to trees, buildings, and human interference, we can stop the millimeter wave signal your body also.

"5G technology needs to overcome several major challenges: return, addressing and spectrum," James Faucette, executive director of Morgan Stanley, said in a recent speech. "To use 5G, you have to deploy hundreds of times more base stations. The frequency of 5G is much higher than the previous wireless standard, and when it reaches millimeter-wave frequency, the 5G signal can barely cover a single room. The unpredictability of signals and how far they can transmit is a big problem.

Map 1 spectrum range.

None of this has stopped the development of 5G, but they certainly have influenced the promotion of 5G technology. The first form of the 5G terminal may be a wireless set of devices, essentially wireless. The millimeter-wave signal can't be worn through the window, so it needs an antenna. So many Repeaters and small base stations have to be deployed, and the installation sites of these devices need to pay rent, which can bring considerable financial pressure to operators.

FIG. 2 5G technology acceptance curve.

Prepare for 5G
This year's winter Olympics in pyeongchang, South Korea, partly revealed the promise of 5G technology. Everything from virtual reality to 8K video, which does not require special 3D glasses, supports the effect of the increased bandwidth of the quasi-5g technology. Samsung has even provided SmartSuits for skateboarders who can use sensors to draw body positions and send vibration signals to wearables.

But the application that really drives the demand for 5G technology is self-driving cars.

"5G represents the basic technology needed for autonomous driving experience," said Steven Liu, vice President of marketing at the company. "Autonomous driving technology needs more communication between vehicle (V2V) and vehicle - infrastructure communication (V2I, V2X), means the car need to deploy will continue to increase the number of radar system, involving technology including identification of collision avoidance radar, GPS, parking signal and traffic dispatch vehicles gesture sensor etc.

These systems will be combined with existing systems, including the comfort control system, information entertainment systems, monitoring temperature, tire pressure, and the motor monitoring subsystem for regulating gases. Used for long-distance transport trucks need curve of load balancing, load transfer and shear system, the system must work together to ensure that the goods are not damaged during the transit, as well as the container is stable in the entire road trip. 5G communication is critical for these systems to perform their respective operations correctly.

In fact, 5G is so important to assisted driving and autonomous driving that it can change the design of electronic devices used by these vehicles. But how the car electronics eventually evolved depends in part on which side of 5G technology and parts suppliers are prepared.

"With the advent of electric cars and ADAS, 4G / 5G could become the mainstream standard for automotive communications," said Mike Rosa, director of strategy and technology marketing for the 200mm device product division of applied materials. "Use as the investment of 5 g technology, the electronic devices may reduce inside the car, because the cloud storage more, of course the cloud will not handle all affairs, but the amount of processing can be done in the cloud, and then through the 5 g link provide service to the car."

Two kinds of technology
There are two options for 5G technology. One is the sub-6 GHz band, which is slightly improved on 4G LTE, while the other USES a frequency of more than 24GHz, and the final form is millimeter-wave technology. In general, the ability to transmit data faster and to transmit more data at a faster rate increases as the frequency increases.

On the other hand, as the frequency increases, so does the signal propagation distance. As a result, more Repeaters and base stations need to be deployed. This of course is a good news for the semiconductor industry, but it also means that 5 g technology of launch time is longer than previous generations of mobile communication technology, because need more time to deploy 5 g communication more infrastructure as needed.

"The frequency of 5G is very high, the noise is lower, and it can lead to new applications," said Jamie Schaeffer, director of the project at grosfield 22FDX. "From a base station point of view, you need a digital front end with a data converter. And 5G phones need to integrate the front-end module and realize low power consumption. For applications such as facial recognition, 5G technology in the 24 GHz-40 GHz band is the best solution.

The 5G devices can use beam forming and beam tracking technology and large-scale MIMO (multi-input and multi-output) technology to piece together multiple sets of split signals.

There is a technical trade-off behind all of these. As the frequency increases, the thickness of the film used in RF filtering becomes smaller, which creates another problem.

"In 2-2," says Rosa of applied materials. At the frequency of 5 GHz, the thickness of the front-end RF film (usually the aluminum nitride film) is usually about 1 micron. As the frequency gets higher and higher, the film becomes thinner and thinner. The current process is difficult to control the stress uniformity on the 8-inch and 12-inch wafers.

So it increases the scandium doping process, but it also has limits. Eventually you will find that you need to reverse the way these films are developed, and now they are generated by sputtering. In the short term, it doesn't seem like a big deal, but over time, we need to find alternatives to deposit thinner films.

Even thin film materials can change. For example, it is now widely believed that lithium niobate could replace aluminum nitride because it doubles the efficiency of electromechanical coupling. Now most RF switching devices are implemented using silicon germanium, but in the base station, on the one hand, the need to increase the power to bring more signal drive to more Repeaters, on the other hand also need to deal with the electricity cost of power itself, so may be gan to replace silicon germanium.

Other technical issues
It's not just the base stations that need to solve the power problem, but when the 5G phones are dropped, they run out of battery power faster than they do in the efficient service area.

"End user equipment antenna needs to be done a lot of work, so that when you pick up the equipment can be used directly," the national instruments software defined radio department senior product marketing manager Sarah Yost said. "The industry is still trying to figure out how to create efficient beam patterns for all of these antennas. If there are 8 to 64 channels on the phone, the number of beam patterns will be very large. You may have 12 send patterns and 12 receive modes, all of which may vary in magnitude.

This makes it very time-consuming to test the 5G chips using today's devices and methods. "Today, the test time is millisecond," Yost said. "If you need to test all these beam patterns and more capabilities, the test time will be extended by 2,500 times. The test of these chips is essential, but now you need to use different test methods, and we are now testing the air test method.

A large scale MIMO test platform developed by Bristol university and lund university.

The advantage of this approach is that it can continuously test chips to optimize signals, but in the field of testing, this is a new concept. "The advantage of this approach is that you can upgrade it to a modular platform to track changes in the standard," Yost said. "It makes the platform part of the real network, allowing you to make phone calls in the design process as early as possible."

This method can be combined with some external system level tests to speed up testing and built-in self-testing.

Plan for change.
The current design level is not so clear. Too many unknowns make it difficult to optimize the design of chips. As a result, flexibility is required both at the architectural level and in the structural layout, and flexible at the logical level of programmability.

"People are wondering if they need a bigger control system," says Sundari Mitra, chief executive of NetSpeed Systems. "This requires a fundamental change in the architecture level, which requires more dynamic computing, which means that the complexity of these designs will improve. You can't use a traditional system architecture to put it together in a 5G system, because 5G requires heterogeneous computing, and it's not just a single processor that needs access to memory.

In any sense, 5G itself is a disruptive technology. However, when combined with other disruptive technologies such as self-driving technology, the unknown will increase significantly.

Ty Garibay, chief technology officer at ArterisIP, said: "when a car enters the autopilot mode, 5G connectivity will always be required. These cars produce terabytes of data per hour. Some of the data will be processed in the terminal chip, and the other data will be processed in the cloud after being forwarded. 5G will be the key to the forwarding data. The challenge is to bring together different types of processing and I/O, which is a big problem for anyone.

Unlike previous generations of mobile communication technologies, the adoption of 5G is likely to be a long-term evolution of multigenerational technology. So, while 5G will be available in the near future, it could take decades to reach 5G phones and base stations outside the city. In fact, there is debate about whether the technology is universal.

"If you look at what's now called a 5G system, they're just prototypes," said Mike Fitton, senior director of strategic planning and business development at Achronix. "That's why they all use programmable logic. Standards are changing, and some different application scenarios are emerging. So you need to build some programmability in ASIC.

The same is true of 3G and 4G, where the early market was almost entirely based on the FPGA, which was replaced by ASIC in order to reduce costs and power consumption. The same is true of 5G, but it takes longer. The first phase of its evolution will be UHF and then millimeter wave. So, the market is going to be, in the 4G ocean, 5G is just beginning to emerge as an island, and then slowly expanding its sphere of influence.

But it is not clear when 5G will break out. Geoff Tate, chief executive of Flex Logix, says the industry's interest in eFPGAs has increased because of the uncertainty. "With the advent of 5G, there is an increasing interest in embedded FPGA," he said. The base station has power limitation.

If you don't use SerDes, you can save a lot of power. Power saving is important because performance requirements are higher and higher. What's more, 5G needs to deploy more base stations, and now there is about one base station per half mile, but the deployment density of 5G will be even greater. A large base station will follow many small base stations, which will require more power.

This bodes well for embedded programmable devices, because they are more flexible than ASIC, and they are smaller and less powerful than the vertical FPGA.

Fitton, of Achronix, points out that the next revision of the 5G specification, the revised version 16, adds some extra features. "You will find that these new features are very suitable for the application of the Internet of things. The Internet of things requires super-reliable, low latency features, and 5G will lead to new applications."

Technology evolution
From a higher perspective, from the initial release of 5G to the future iteration of the technology, the 5G ecosystem has a lot of changing components. In fact, it's like managing a 3D matrix that changes over time, and the various parts of the matrix are in different stages of research, development, and even definition.

"In 5G, you can mix analog, digital and RF systems together," says Ranjit Adhikary, vice President of marketing at ClioSoft. "Once you start using this technology, some bugs are hidden in IP migration, and after a while, no one can figure out why they're doing something. People change jobs in different companies, and a lot of IP knowledge is gradually disappearing.

Adhikary says that with the evolution of 5G technology, IP development, optimization and description will also be affected. "5 g don't have much to a third party IP right now, but we must ensure that, when released a new version of the 5 g technology level in the system level, all elements can be tracked, including script and procedures.

The evolution of 5G technology will start with a cable modem, because its protocols and specifications change so fast that it is hard to track it in a few months. What's more, there are so many companies around the world that you have to track which version of IP is being developed and which version of the third-party IP is being used. How do you ensure that everyone using this IP can use the correct IP if the new version is specified?"

conclusion
The uncertainty between the multiple markets and technology are intertwined, puts forward the more about the future will be how to use the 5 g, 5 g when commercial, eventually need to spend much money and other resources.

"All these markets have additional request for life, cost, and in the future to realize automatic electric control, they will still be on the system design and manufacture of a significant challenge," Liu said of umc.

5G is one of the key challenges in these technological shifts, but it remains to be seen how hard it will be and when it will be commercially available.