5G – FROM LABORATORY TO LIVING ROOM
What is 5G?
Former FCC Chairman Tom Wheeler said “If anyone tells you that they know the details of what 5G is going to become, run the other way.” 5G, or the fifth generation mobile network, is a large undertaking intended to include many different services and modes of communicating via radio transmissions. Experts are still figuring out what 5G will be. Nevertheless, proponents speak of 5G in visionary terms:
||5G is a new kind of network: a platform for innovations that will not only enhance today’s mobile broadband services, but will also expand mobile networks to support a vast diversity of devices and services and connect new industries with improved performance, efficiency, and cost. 5G will redefine a broad range of industries with connected services from retail to education, transportation to entertainment, and everything in between. We see 5G as technology as transformative as the automobile and electricity.
5G is predicted to be at the center of intelligent platforms – both mobile platforms and fixed – that link multiple products and services, where the integrated service system is more valuable than each individual product or service. This is expected to transform many important industries, including entertainment, healthcare, transportation and financial services.
Customer Demand is Key to 5G
Steve Jobs famously said, “A lot of times people don’t know what they want until you show it to them.” Jobs was enormously successful creating new product categories like the iPod and smart phone. These products sparked vast customer demand that was not there before and cannibalized demand for existing products such as cameras.
Proponents of 5G are taking a page from Jobs’ playbook by seeking to create demand for new lifestyles with previously unheard-of 5G products and services. 5G will require massive build-out of new infrastructure, as well as expensive development of new technologies and equipment. In order to pay for all this, providers need to sell a lot of 5G products and services. Demand creation is a key component of 5G, even if it is not discussed in the 5G brochures. 5G providers need to create customer demand as much as they need to perfect the technology.
What Are The 5G Technologies?
New technologies and ways of doing things are needed in order to fulfill the promise of 5G. These include new spectrum and small cells, plus three inter-related technologies. Here is a quick summary:
- More spectrum. 5G is expected to take advantage of various types of radio spectrum, including low-band, mid-band and high-band spectrum. The Federal Communications Commission (FCC) has been allocating spectrum for 5G and advanced services in all three bands. Low-band spectrum (e.g., at 600 MHz or 900 MHz) has good, long-range propagation and does well in buildings and rain, and around plants. T-Mobile says it is using 600 MHz spectrum won at the FCC’s incentive auction to provide 4G LTE and, later, 5G. High-band spectrum (e.g., above 24 GHz) has a short propagation distance, does not do well in buildings, and gets blocked by rain and plants. However, the FCC has been allocating high-band spectrum in very large blocks, giving capacity to carry sizable amounts of data, including for video downloads or virtual reality. Verizon and AT&T are working on providing fixed 5G services using high-band spectrum.
- Small cells. Carriers will construct many new, lower power base stations, in order to help the signals get around short propagation distances, as well as blockage or fading due to buildings, trees and rain. This will form many small cells that provide pinpoint coverage. Depending on density, it could be one base station per city block or it could be many stations per block. Once again, the FCC has been doing its part by loosening restrictions on new cell sites. Nevertheless, this will represent a massive infrastructure build-out, with large capital expenditures, as well as time-consuming negotiations with owners of poles, buildings and rights of way, in order to site the base stations.
||In addition to new spectrum and small cells, a trio of technologies will work together to provide a new type of wireless service.
- Massive MIMO. MIMO stands for multiple input, multiple output. Most cellular base stations may use 12 or fewer antennas. By contrast, a 5G base station is expected to have hundreds or even thousands of antennas. This is projected to dramatically increase network capacity, which is needed to transmit the large amount of data associated with 5G, as well as facilitate beamforming (below).
- Beamforming. Cellular base stations currently broadcast their signals omnidirectionally. However, with hundreds or even thousands of antennas broadcasting at once, the signals would interfere with each other. Hence, the need for beamforming, which, in theory, would enable a base station to send a signal directly to a single end user without interfering with signals for other users. With beamforming, a massive MIMO base station would receive signals from many users, arriving at different times and from different angles. The base station would keep track of the direction and timing of arrival of each signal. Then, the base station would use signal processing algorithms to triangulate the exact location of each end user, and plot the best transmission path back to each user.
- Full duplex. Antennas are both transmitters and receivers. A basic can antenna transmit or receive, but not both at once. Currently, the solution is to have transmit and receive take turns or to put them on different frequencies. Full duplex utilizes frequency reciprocity – the ability of a radio wave to transmit data in both directions at once – to transmit and receive on the same frequency. This would use the spectrum more efficiently, further enabling carriage of large amounts of 5G data.
||Once this trio of technologies becomes commercialized, it likely would result in replacement of most or all base stations on cell towers and elsewhere, which, again, would necessitate large capital expenditures.
Are the 5G Technologies Ready Now?
The trio of technologies – massive MIMO, beamforming and full duplex – would work together and one day should provide exciting benefits. However, this technology trio is still in research and development, and is many years away from commercial deployment. For example, in a posting dated August 22, 2017, National Instruments (NI) proudly presents its “5G Massive MIMO Testbed: From Theory to Reality,” which NI describes as follows:
||Massive MIMO is an exciting area of 5G wireless research. For next-generation wireless data networks, it promises significant gains that offer the ability to accommodate more users at higher data rates with better reliability while consuming less power. Using the NI Massive MIMO Software Architecture, researchers can build Massive MIMO testbeds to rapidly prototype large-scale antenna systems using award-winning LabVIEW system design software and state-of-the-art NI USRP™ RIO software defined radios (SDRs).
The National Instruments testbed appears to be the first of its kind. Below is National Instruments’ list of open research items for Massive MIMO in 5G.
This technology needs to go through the usual research and development process: basic research, prototyping, proof of concept, pilot studies, small-scale demonstrations, larger scale projects and finally, commercialization. How long until massive MIMO, beamforming and full duplex, successfully progress through these steps to become core technologies in commercial mobile systems? This will take at least several years, perhaps longer.
When Will We Get 5G?
When proponents talk about the 5G time line, they usually reference the 3GPP and ITU schedules for when various sets of standards are scheduled to be released. Below is a typical scenario.
For the next couple of years, telecoms will be advancing 4G LTE or 4G Plus, even if they are marketing it as 5G. The core 5G standard (3GPP release 16) is expected to be ready in the year 2020. Once the 5G standard is frozen and published, chip makers would be able to produce microchips. From there, the new 5G radio equipment would be manufactured and find its way into the field.
Other timelines are important, too. As described above, the 5G technologies of massive MIMO, beamforming and full duplex, probably will not be ready for at least several years. There also is the infrastructure build-out timeline – including, eventually, a complete replacement of every cell transmitter. Further, all those new, low-power base stations could take years to put in place. Similarly, there are consumer acceptance, revenue uptake and capital expenditure timelines. How long until we get commercial mobile systems with the full suite of 5G features? We won’t hazard a guess except to note that it is still some years away, with much development work yet to be done.
2 Everything you need to know about 5G, Qualcomm
3 Five Dangerous Lessons to Learn From Steve Jobs, Forbes Magazine, Oct 17, 2011.
4 An IEEE video introduces these items.
6 Nikhil Kundargi, Ph.D., NI Massive MIMO Prototyping System, National Instruments.
7 Roadmap and Timeline