5G Networks Spectrum

The next generation of mobile broadband will have to share the spectrum with the current generation, and both of them must follow the laws of physics that govern how far a signal can travel and how much data it can carry.

The standard for 5G networking (5G NR, New Radio is the official name of the standard) is designed not only for using spectrum bands below 3 GHz (low-band frequencies), where most mobile communications happen today. It also makes use of spectrum bands between 3 GHz to 6 GHz (mid-band frequencies) and even new classes of bands previously thought unsuitable for mobile communications, such as bands above 24 GHz (mmWave frequencies).

Spectrum Bands

These are the different spectrum bands that the next generation of mobile broadband is planning to use. In figure 1, you can see how the FCC in the USA is planning the spectrum subdivision for 5G.

mmWave frequencies

mmWave stands for millimeter-wave. These frequencies are located above 24 GHz reaching up to 72 GHz, which is above Extremely High Frequency’s lower boundary. At those frequencies, data can be sent with fiber-optic speeds and latency, in controlled environments, speed rise to 1.2 Gbps with latency from 9 to 12 milliseconds. But not everything is good news; data can’t travel very far, only 300 meters of distance in a direct line of sight from the transmitter to the receiver, trees, and walls are significant obstacles. In order to use these frequencies, a bigger density of cells is needed, and that means more money.

mid-band frequencies

These frequencies are the most widely deployed, including WiFi networks. Data speed acquired with these frequencies is usually 100-400 Mbps. Frequencies deployed are from 2.4 GHz to 4.2 GHz. These frequencies have a better reach. There is no need for a high density of cells. Many areas can be covered simply by upgrading existing towers, which lowers the cost.

low-band frequencies

These frequencies offer a similar capacity to advanced 4G. Frequencies deployed are from 600 MHz to 850 MHz and deliver less than 100 Mbps. The performance will improve, but cannot be much higher than good 4G in the same spectrum.

Spectrum Sharing

The 5G specification aims to use spectrum sharing, so at least if not all of the three bands can be used at the same time according to the environmental situation.

US carriers are deploying 5G networks using mmWave frequencies in highly populated areas, where cell density can be high and using low- and mid-band frequencies to extend the 5G network to rural or less crowded areas. This spectrum usage brings another problem; 5G capable hardware must be compatible with all the bands. Till now, each manufacturer adopted a particular band, making the devices obsolete when using carriers with any of the other two deploys.

Some Comparisons

There are several differences between 4G networks and 5G networks:

• 5G is a unified platform that is more capable than 4G. While 4G LTE focused on delivering much faster mobile broadband services than previous generations, 5G is designed to be a unified, more capable platform that will improve not only mobile broadband but also support new services such as mission-critical communications and the massive IoT. As said before, 5G will also natively support all spectrum types (licensed, shared, unlicensed) and bands (low, mid, high), a wide range of deployment models (from traditional macro-cells to hotspots), as well as new ways to interconnect (such as device-to-device and multi-hop mesh).
• 5G is faster than 4G: 5G will be significantly faster than 4G, delivering up to 20 Gbps peak data rates and 100+ Mbps average data rates.
• 5G has more capacity than 4G: 5G will support a 100x increase in traffic capacity and network efficiency (theoretical numbers).
• 5G has lower latency than 4G: 5G has significantly lower latency to deliver more instantaneous, real-time access: a 10x decrease in end-to-end latency down to 1ms (theoretical numbers).