One of the hottest areas of focus for the communications engineering community these days is the ongoing and future deployment of 5G services at the cell site end – be this for new sites, or for modifications to existing ones. Through the successive generations of cellular wireless, e.g. 1G, 2G, etc., increasing user demand for data has driven the need to assign additional frequency bands to accommodate the higher amount of user traffic, as well as by other means such as using higher spectrally efficient communications means, cell splitting, etc.
Of particular interest in the case of the release and build of fifth generation, 5G, services, is the use of three generally described frequency bands – low, mid and high bands. I’ve also seen the assignments of bands 1, 2 and 3 used for these bands, just in case you run into them. In general terms, these bands correspond to frequencies of below 1 GHz, 1 to about 6 GHz and then greater than 6GHz. In this way, the low band accommodates the 600, 700, 800 and 900 MHz bands in use for cellular type communications and the mid band encompasses the 1800, 1900, 2100, 2300, 2500 MHz and broadly 3 and 4 GHz bands. The high band covers the more recently released frequency assignments described operating at millimeter wave band frequencies, e.g. 26, 28 and 39 GHz bands – as well as others. The bands referred to here take into account that different global regions, countries can use different frequency bands for cellular services – so, for example, we don’t see the 900 MHz band, i.e. 870 to 960 MHz, used for cellular services in the US.
For additional information, many readers will have seen the acronym 3GPP. 3GPP stands for 3rd Generation Partnership Project and it includes a number of standards organizations that develop regional and global protocols for mobile communications. In more recent standards releases, they refer to two frequency ranges, i.e. FR1 – Frequency Range 1 covers frequency bands below 6 GHz; likewise Frequency Range 2, FR2, covers assignments above 6 GHz.
Many folk will have followed and even been part of the big buzz about C band. So where does this fit into what’s been described above? Well, we’ll need a separate blog to describe that one but suffice it to say that the term C band can cover a multitude a frequency bands depending on context. At its most fundamental level, the term C band has its origins in definitions created by the IEEE (Institute of Electronics and Electrical Engineers) and was taken to mean the frequency band 4 to 8 GHz.