The first generation (1G) of mobile communication brought us cell phones. Next, with 2G, came text messaging, followed by 3G and 4G delivery of global positioning systems, telemedicine, videoconferencing, and Bluetooth. Now 5G is set to bring us autonomous vehicles and high-precision factory automation in the next five to 10 years.
And, incredible as it may sound, sixth generation (6G) mobile communication development is already underway.
6G is an appealing concept with very ambitious goals. According to Cisco, the number of connected devices will grow exponentially to reach 500 billion by 2030, far exceeding the world’s population. That number includes vehicles, robots, drones, home appliances, displays, and the smart sensors that are installed in various infrastructures, construction machinery and factory equipment.
Avoiding congestion among all those connected machines will require faster networks. Connected mobile network elements such as augmented reality (AR) glasses, virtual reality (VR) headsets, and hologram devices using extended reality (XR) will require greater hardware computation prowess and higher transfer speeds. 5G technology will not have enough frequency bands, a sufficiently fast data rate or low enough latency to handle that 500 billion strong tide. Traffic capacity, reliability and localization precision to support hundreds of billions of devices and ensure a good user experience will also fall short.
6G will expand the availability of frequency bands to terahertz (THz) bands, above the mmWave frequency range that 5G operates in. 6G will also increase the data rate from 5G’s 20 gigabits per second (Gbps) to 1 terabit per second (Tbps). In addition, 6G will reduce the latency, or end-to-end delay, from 5G’s 1 to 5 milliseconds to less than 1 millisecond. As a result, 6G’s traffic capacity will increase from 5G’s 10 Mbps/m2 to a theoretical maximum of 10 Gbps/m2, and increase its reliability ratio from 5G’s 10-5 to 10-9.
Moreover, 6G will achieve a localization precision of 1 cm on 3D compared to 5G’s 10 cm on 2D. Furthermore, 6G innovations will create a significantly different network architecture and support different device types.
Potential 6G Applications
6G can potentially support the expansion of multiple technologies, such as artificial intelligence (AI), mixed and extended reality (the ultimate form of virtual reality technology), enhanced communications, and precision positioning with lightning speed.
Cloud-Based Artificial Intelligence
AI has reached finance, health care, manufacturing, industry, and utility networks. However, 5G won’t be able to fully support communication networks’ AI use. Implementing 6G networks will realize AI’s potential for improving performance while reducing costs. Real-time AI depends on supercomputers with machine learning capabilities. With 6G, access to AI capability in the cloud can occur in real time and be readily available to mobile or wearable devices.
Extended reality implementation
Extended reality (XR) refers to the combination of virtual reality (VR), augmented reality (AR) and mixed reality (MR). XR will have exciting applications in diverse fields such as entertainment, medicine, science, education and manufacturing. While XR has significant hardware requirements, it also demands sufficient wireless capacity. Current AR mobile display technology gets by with 5G. However, truly immersive AR using XR will require at least a tenfold increase in data rate and display points—specifications that only 6G can support. With truly immersive AR, a virtual face-to-face meeting will seem real. So much so that identifying the “person” standing in front of you as an ultra-high-definition 3D image may be next to impossible.
6G will be able to support multiple kinds of communications. For example, Big Communication wants to balance resources so that many users, in both urban and rural areas, can communicate simultaneously at a high data rate. For that kind of extensive coverage, which is dependent on extremely large bandwidth (THz waves), AI is needed to balance resources.
Another example, three-dimensional integrated communication, applies to satellites, unmanned aerial vehicles, and underwater communications. Holographic communication, also a 3D technology, manipulates light rays beamed to an object and records the resulting interference pattern. The transmitted 3D images need to be complemented with a stereo voice. The high bandwidth and reliability of 6G will enable the reconfiguration of stereo audio with the 3D images to make a hologram feel realistic. If a user can experience the hologram via touch, the hologram will feel even more real. 6G can deploy the tactile aspect of a hologram.
And in the final stage of virtual communications, all five senses will combine to make the experience completely immersive. With 6G, fully autonomous driving will finally become a reality. Vehicle-to-vehicle (V2V) communications using 6G can potentially bring the number of traffic accidents down to zero.
Lastly, 6G will enable precision localization to the centimeter level. While such accuracy is unnecessary during outdoor positioning, it will be useful for indoor localization. 6G can merge sensing and imaging in a way that enables 3D mapping of indoor surroundings.
Indoor positioning applications are abundant. For example, home health care will be able to rely on ultraprecise position monitoring so that the time, location and height of an individual’s fall is recorded and reported immediately. Caretakers will know exactly how serious a fall is, and appropriate actions can be taken right away. And possibly, before the arrival of an ambulance, a domestic robot will have already started taking care of the individual.
Challenges and Obstacles in 6G Implementation
During its implementation, 6G is likely to face even more challenges than 5G. For example, a new wireless communication will require ultra-reliable low latency communication (uLLRC) for 6G networks, along with new infrastructure to accommodate terabit speeds. Building this new infrastructure would necessitate new electronic building blocks, new materials for server cabling, and a completely different engineering and testing approach. The following are a few of the obstacles to overcome.
First, the amount of available computing power will be a significant bottleneck for the application of 6G. The growing demand for computing power is already outpacing the increase in mobile computing power. Hopefully, the advancement in renewable energy and battery technologies will be able to accommodate this.
The consistency with which 6G technology delivers various kinds of service will be critical. 6G needs to support many mission-critical tasks with a high level of reliability and enable a consistent and high data rate.
Ensuring expandable and reliable network coverage will be critical to 6G. 5G already insists on more antennae than 4G, with greater antennae density. Propagating THz bands for 6G means the antennae numbers and density must rise still further. Installing enough antennae and at the proper density for 6G will be a logistical challenge.
While a 6G base station and antennae may be more energy-efficient than 5G’s, total energy consumption may still be high, given 6G infrastructure’s overall size and density. Therefore, improving battery life or harvesting energy from the surrounding environment may reduce the environmental footprint of the 6G infrastructure.
In the age of big data, massive troves of data are increasingly attractive to hackers. Hackers can steal data for their own use or sale on the black market. Hackers can even hold the data hostage and demand a ransom. Much more data will be flowing through a 6G network at any given time and more quickly, making it easy for the hackers to steal without detection. To counter this, 6G networks must ensure data security and user privacy.
Spectrum sharing will be crucial. While more spectra will be available to 6G, demand may still be high due to the massive number of devices in the network. Also, network traffic levels tend to cluster within certain hours daily. During these times, many network operators will be competing for a limited number of spectra. Therefore, it will be essential to balance spectrum usage by various entities. The network operators need to work together to share information on spectrum access. AI can potentially be used to manage the dynamic process of spectrum sharing.
No Governing Body Behind 6G
Supported by the seven international standard organizations (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, and TTC), the 3rd Generation Partnership Project (3GPP) is the governing body behind the development of 5G specifications. But it is different for 6G. There is no such formal entity governing the technology; therefore, there is no standard to be agreed upon. Developing pre-standard technologies means that incompatibility and interoperability issues will surface when the standard becomes available.
What’s Ahead for 6G in the Next Five Years?
It takes about 10 years for a mobile communication system to reach its next generation. After many years, 5G evolution is taking place. Release 16 just came out this year. Release 17 is delayed due to the pandemic. It may be another few years before 5G finally settles down. Nonetheless, this has not stopped companies from moving forward with 6G development in hopes of winning the technology race. Some are optimistic. According to Samsung, a 6G standard could be completed as early as 2028, and mass commercialization could occur around 2030.
When 6G happens, many of us will get a taste of truly immersive reality or have our hologram taken. Extended reality and holograms will do more than entertain us; they will have applications in medicine, education, and even the military, in the form of cyber warfare.
5G implementation has not been easy. Similarly, there will likely be roadblocks on the path to implementing 6G. 5G requirements mainly focused on performance aspects, such as latency and data rate. In contrast, 6G requirements will involve network architecture and trustworthiness in addition to performance. Overcoming computation capability limits and using AI to integrate networks and rebalance resources are among 6G’s architecture demands. Its trustworthiness requirements include data security and user privacy issues. But hopefully, we can learn from 5G implementation so that we can do 6G better.
In the next five years, expect to see theoretical discussions, research, initial investment and development for 6G. While there is a lot of excitement and hype, real-world implementation will most likely be more than 10 years away.