There are two frequency bands in 5G technology. The first band is known as Sub-6 GHz bands, and it works in 5G, just like it works in 4G. The transmitted frequency in this band is less than 6 GHz and the cell phone towers transmit frequency using this band spectrum.
The second frequency band creates a major difference between 5G and 4G. It is a high-frequency band with millimeter-wave (mmWave) and frequencies above 24 GHz. 5G is an ideal solution for urban areas because these high frequencies have a very large bandwidth, keeping everyone connected.
The comparison of 4G frequencies with 5G frequencies
Before 2G and 3G networks, 850 MHz and 1900 MHz frequency spectrums were used to operate the Global System for Mobile Communications (GSM) networks. The modulation method changed with the arrival of 2G and 3G networks, but mostly the same frequency spectrum was used. New frequency bands and a spectrum of nearly 2100 MHz were added with the arrival of 3G. New frequency bands and spectrum were also added with the arrival of 4G, ranging from 600 MHz to 2.5 GHz. For 5G, the frequency spectrum of sub-6 GHz ranging between 450 MHz to 6 GHz and 24 GHz to 52 GHz are the frequency ranges of mmWave. These high frequencies make the 5G frequency band very complex. All previous cellular spectrum, sub-6 GHz range and above sub-6 GHz spectrum will be included in 5G.
It will take several years for the 5G network to be fully available. Most of the 5G expectations are impossible to achieve with current technology. Only some of the 5G requirements can be met with the current technology and communication infrastructure. Due to limited technology, there are many associated challenges including cost-effective hardware.
It is not possible to replace 4G with 5G immediately, therefore, 5G and 4G will share the frequency spectrum. Time-division duplex and frequency division duplex can share the frequency spectrum. In time division duplex, there is one frequency band and a requirement to switch between uplink and downlink, according to the requirement. In frequency division duplex, there are different frequency bands, so one can be used for downlink and one for uplink without needing to switch between them. It will take nearly 10 ms to assign the bands between 4G and 5G, according to a U.S. patent assigned to AT&T.
Enhanced mobile broadband
5G aims to provide coverage everywhere in an urban area with extreme data rates. These goals differ from 4G mobile broadband. The peak downloading speed that can be provided by the current 4G network is few hundreds of megabits per second (Mbps). However, the speed reduces to 10 Mbps or less in urban areas with a latency time of more than 10 ms. 5G mobile broadband aims to provide at least 100 Mbps speed in urban areas with a latency time of 4 ms. The peak downloading speed that can be achieved with 5G is 20 Gbps. It will enable the users to instantly download a video. Apart from videos, virtual reality applications can also be used with the help of 5G in real-time.
Current cell phone architectures are not capable of supporting 5G enhanced mobile broadband. There is a need to upgrade the technology for cell phones as well as the entire cellular networking system. Some telecom companies are already working to improve cell phone technology to make them compatible with 5G enhanced mobile broadband performance.
Reliable and low latency communications
There are some applications where latency time cannot be compromised. These applications include factory automation, autonomous vehicles, emergency response and mobile healthcare. 4G is not suitable for these applications, especially with the involvement of IoT, which demands highly reliable and low latency communication between different devices and sensors, and a delay in communication could result in loss. 5G aims to provide ultra-reliable and low latency communication for such applications where a delay in communication is not acceptable.
Each time, the frequency bands and operational modes have changed with the evolution of new cellular technology and it is the same for 5G. The only difference is the number of spectrums added and the electromagnetic spectrum region in which these frequencies will propagate. There are many applications such as IoT and machine-to-machine communications that are encouraging researchers to study the 5G operating modes so that it will be able to work best on these applications. 5G is expected to become the best solution to the connectivity problems that the world is facing with 4G.