The Infrastructure Challenges of 5G – Frequency
There is a tremendous amount of excitement surrounding 5G and for very good reason. The new wireless network promises 100 times better capacity than 4G and brings with it faster download speeds and much lower latency.
The 5G we’re talking about is the actual fifth-generation wireless standard the industry is currently working on. It will require new hardware radios on cell site locations that support 5G, and it will not work with existing phones. A software update on today’s 4G LTE enabled phones will not simply upgrade it to 5G. 5G is truly the next generation of mobile communication and has the power to disrupt just about any industry.
Like any new technical advancement, 5G comes with some significant challenges and costs.
One of the challenges associated with 5G has to do with radio frequencies, particularly in the US.
Low-band frequencies (<1Ghz) can travel long distances and penetrate buildings but can only carry a limited amount of data. Mid-band frequencies (1Ghz – 6Ghz) can also travel fairly long distances but can carry a lot more data than low-band. Mid-band is quite appealing for 5G and is the frequency range used in today’s WiFi and some 4G. High-band frequencies (24Ghz – 100Ghz) can carry a substantial amount of data, but due to their shorter wave-length, travel shorter distances and are more susceptible to buildings and trees blocking the signal.
In the US, the wireless operators bid for available frequencies which are controlled by the FCC. In 2019, the FCC concluded three high-band auctions for licenses in the 24Ghz, 28Ghz, 37Ghz, 39Ghz and 47Ghz frequencies. As a result, early 5G rollouts in the US will mostly be in the high-band frequency offering fast downloads but limited coverage.
To combat the challenges associated with the high-band frequency, wireless operators in the US will need to build out a large number of nodes or “small cells” to ensure a blanket of 5G coverage. It’s estimated that over 800,000 small cells will be needed for 5G to be realized.
Within the wireless industry, mid-band 5G is being regarded as the “sweet spot” for the balance between 5G coverage and performance, assuming users are within a couple of miles of the cell site. Some US wireless operators will also leverage low-band frequency for their 5G signal providing broader coverage. The downside with the low-band 5G is it won’t be anywhere near as fast as mid-band or high-band 5G, and will likely be subject to LTE-like latency.
Unlike in the US, European wireless operators have more access to the mid-band range in the frequency spectrum. This access allows them to build 5G networks that balance higher data speeds with reasonable coverage with less need for small cells.
As two of the major advantages of 5G are greater speed and reduced latency, it’s likely we’ll see a multi-pronged approach from the wireless operators for 5G. The low-band will be used as a blanket for broad coverage, especially in more rural areas; available mid-band will be used for everyday 5G and high-speed service such as home broadband; and some high-band for high-capacity and ultra-fast download speeds in dense urban areas. Not all operators have the same mix of frequencies between low-band, mid-band, and high-band, and therefore their 5G rollouts will be different.
With all the excitement surrounding 5G, let’s not forget that 4G will continue to be the primary wireless network in the US for the next five years. Wireless operators will continue to enhance their LTE networks while they simultaneously invest in 5G buildouts.
While 4G and 5G networks are vastly different from one another, one commonality is they both require real estate for the cell sites. Additional cell sites are being developed for the continued expansion of 4G LTE networks, and 5G will require many more cell sites, especially within metro areas. A combination of towers, rooftop antennas, indoor and outdoor systems, and small cell solutions will need to be developed and optimized for 5G to become a reality.