While 5G technology offers enormous improvements over previous-generation licensed wireless networks, much of the impetus for pushing 5G into new frequency bands comes from old-fashioned physics, according to experts.\nIt can be difficult to nail down precisely which frequencies 5G technology will use, in part because it varies heavily across different countries and even among different carriers. There are, however, three main groupings into which most 5G frequencies will be able to fit.\nThe low end: 650MHz to 1GHz\nLower frequencies \u2013 from around 650MHz at the lowest up to around 1GHz \u2013 are particularly prized by wireless companies deploying 5G. Signals in this range propagate over relatively long distances, meaning that service providers can cover a huge area with a single access point.\n\n5G resources\n\nWhat is 5G? Fast wireless technology for enterprises and phones\nPrivate 5G can solve some problems that Wi-Fi can\u2019t\nPrivate 5G keeps Whirlpool driverless vehicles rolling\n5G can make for cost-effective private backhaul\nCBRS can bring private 5G to enterprises\n\n\nHowever, there\u2019s a serious limiting factor to 5G use in the lower range of the RF spectrum, according to Gartner analyst Bill Ray.\n\u201c[These] are very popular frequencies,\u201d he said. \u201cAnd the military and TV stations still own a lot of them.\u201d\nThat\u2019s a problem, because while the channel capacity is the same at the low end as at higher frequencies \u2013 that is to say, a 5MHz-wide channel in the 850MHz range offers the same throughput as a 5MHz-wide channel in the 2.6GHz range \u2013 the lack of available spectrum means that there simply aren\u2019t enough channels to provide the high connection speeds that 5G advertises.\n\nTo attain higher speeds, 5G uses wider channels. \u201cIn 3G, the standard transmission was 5MHz wide,\u201d Ray added. \u201cIn 5G, we\u2019re talking about slots that are 100MHz wide, so your transmission [channel] can run from 2.4 to 2.5Ghz\u201d\nThe middle: Sub-6GHz and the spectrum rush\nMuch of the performance and efficiency increases promised by 5G technology rely on parts of the spectrum that are close to Wi-Fi \u2013 the \u201csub-6GHz\u201d range between 2.4GHz and 6GHz, which is a departure for service providers used to playing slightly lower on the wireless spectrum.\n\u201cThe sub-6GHz stuff is new spectrum for them,\u201d said Patrick Filkins, a senior research analyst with IDC. \u201cIt means bigger channels and latency improvements.\u201d\nAn additional wrinkle is that there\u2019s free spectrum available in this frequency band, particularly in the citizens broadband radio service\/general authorized access (CBRS\/GAA) spectrum between 3.5GHz and 3.7GHz. This spectrum uses a system of prioritized access, with incumbents \u2013 specifically the U.S. Navy and satellite ground stations \u2013 given first dibs, but others may use the frequencies anywhere where they\u2019re not interfering with those incumbents. Needless to say, the spectrum-hungry carriers are interested.\nAs individual carriers carve out their own pieces of this valuable spectrum, 5G coverage will continue to expand, and its advantages over Wi-Fi in one particular aspect will become clearer. 5G spectrum is parceled out to one licensee per geographic area whereas Wi-Fi offers no such exclusivity; anyone can use it anywhere, setting the stage for overlapping signals and interference.\n\u201cThe way that cellular is deployed is very deterministic \u2013 one of the big benefits it has over Wi-Fi is that it\u2019s able to overcome that interference problem that Wi-Fi doesn\u2019t have a great answer for yet,\u201d said Filkins.\nThe high side: Millimeter wave\nFor all of its optimization and sophistication, 5G still requires lots and lots of bandwidth to deliver on its promises of gigabit-scale throughput. And despite the wireless industry\u2019s aggressive pursuit of bandwidth in lower frequencies, there simply isn\u2019t enough available space in the more desirable sub-6GHz and 1GHz ranges.\nEnter millimeter-wave technology, which operates at anywhere between 24GHz and 60GHz, depending on which expert you\u2019re talking to and the particular technology involved. These particularly high-frequency bands allow for particularly wide transmission channels, enabling those blazing-fast connection speeds, but there are a host of drawbacks.\n\u201cThe only good thing about [millimeter-wave] frequencies,\u201d said Ray, \u201cis that they are empty, so there\u2019s plenty of space.\u201d\nFor one thing, thanks to basic physics, signals in the millimeter-wave range simply don\u2019t propagate very far in comparison to those in lower regions of the RF spectrum, and they don\u2019t penetrate solid objects like walls and windows. This means that, to cover a given area, even within a single building, requires deploying lots and lots of access points.\n\u201cIt\u2019s not ready for enterprise deployment,\u201d said Filkins. \u201cRight now the story is that it\u2019s not robust, but it has a lot of promise.\u201d\nMillimeter-wave technology has been around for at least a decade. The unlicensed wireless world has long had the 802.11ad standard, which is, essentially, Wi-Fi operating at millimeter-wave frequencies. Qualcomm and Huawei both manufacture equipment that operates in that range, but the technology\u2019s limitations, coupled with the continued drought in endpoints that can actually take advantage of it, mean that it has remained on the sidelines.\nThat won\u2019t be the case forever, of course. Trends in the demand for wireless bandwidth suggest that there will be so much need for spectrum that millimeter-wave will be required to cope with it.\n\u201cThe rest of the world will use [millimeter-wave] eventually, they\u2019re just not using it now,\u201d said Ray.\nFor the moment, however \u2013 particularly in light of the fact that adding millimeter-wave capable antennas and modems to mobile phones and laptops boosts their per-unit costs by a hefty $20, according to Ray \u2013 millimeter-wave will remain a technology of the future.