While there will eventually be much more to 5G than just faster download speeds for our smartphones, the truth is, that’s what most people are interested in right now.
That’s good, since it’s really all that the first deployments of 5G have to offer. The early efforts are laser focused around what the telecom industry confusingly calls eMBB, short for Enhanced Mobile Broadband.
So, the obvious question is, how much better and how much faster will 5G data connections actually be than the 4G LTE Advanced Pro connections that most people have now? Not surprisingly, as with most things 5G, the answer is a complicated “it depends.”
It turns out there are quite a few factors that influence the speed of a wireless connection, including the amount of bandwidth allocated for each connection channel between the smartphone’s modem and the telco carrier’s cellular network infrastructure.
Another factor is the type of 5G signals being used—millimeter wave (mmWave) or sub-6 Additionally, one must consider things like the number of channels that can be combined, how the signals are transmitted, the types of compression technology used, and much more.
While the full details can quickly become overwhelming, it is useful to understand at least some of the basic principles behind these technologies, as well as the buzzwords for specific capabilities and how these technologies all work together to create a fast, reliable wireless 5G connection.
The most important factor in the speed of a 5G cellular connection (or, for that matter, any wireless connection) is the width of the individual channel used to connect between a device and a network. Think of it as the width of a pipe.
The wider the pipe, the more data that can pass through it.
These chunks of radio spectrum, measured in MHz, are the base unit that determines how much information can be delivered through a single connection at the same time, otherwise known as the amount of throughput.
For 4G LTE networks, the channels could range from 1 MHz up to 20 MHz, but with 5G, individual channels can be as wide as 100 MHz—theoretically offering up to five times the bandwidth of a 4G connection.
In fact, this one difference in the 5G NR (New Radio) standard is probably the most important reason that 5G networks can be faster than 4G ones.
What isn’t widely understood is the fact that the width of individual transmission channels is strongly influenced by the frequencies on which they are transmitted, but is not determined by the frequency. What that means is that, all things being equal, 10 MHz of bandwidth at 600 MHz provides the same level of data throughput (i.e., speed) as 10 MHz of bandwidth at 39 GHz.
However, there’s a big historical influence on the width of channels that were allocated to certain frequencies—particularly in the lower ranges, such as under 2 GHz.
In the early days of spectrum allocation (the process of assigning the exclusive use of certain frequencies for certain applications or to certain companies), many of the lower frequencies were the first to be allocated, because they were easier to transmit.
Many of the first wireless applications had very small bandwidth demands, so the size of the allocation “chunks” for channels at different frequencies was quite small. Unfortunately, that historical legacy maintains a strong influence on channel size for lower bandwidth frequencies.
As 5G was developed, one of the core ideas was to increase the width of channels in order to be able to increase the overall potential speed of the network. In part, this was possible because none of the historical channel size limitations were in place for previously unused frequencies like mmWave.
"There’s much more to the potential speed of a connection than just the bandwidth of a single channel Modern cellular network connections combine several different channels together in various different ways"
But there’s much more to the potential speed of a connection than just the bandwidth of a single channel.
Modern cellular network connections combine several different channels together in various different ways (several of which can be combined together for even more throughput!).
Carrier Aggregation, or CA, is a technology that lets telecom companies leverage the different sets of frequencies that they each own into a more robust offering.
Think of it like a highway, where cars in a single lane represent the bytes of data transferred over a single channel, but all the vehicles across a multi-lane highway combine to describe the total potential throughput of the road.
With 4x Carrier Aggregation, you can combine four of these lanes into a single unified connection. What’s particularly important to note is that you can even combine “lanes” from very different parts of the radio spectrum. So, for example, you can combine a range of 10MHz from the 600 MHz frequency band along with 100 MHz of spectrum from the 39 GHz frequency to get a combined data speed that’s faster than both individually. Not surprisingly, you can also combine batches of frequencies that sit right next to each in the frequency spectrum.
In 5G Non-Standalone (NSA) networks ,you can also do the equivalent of Carrier Aggregation across 4G and 5G channels at different frequencies.
The technology that enables this is called Dual Connectivity, and like CA, it combines the bandwidth of the two together.
Yet another technology available for 5G networks called Dynamic Spectrum Sharing (DSS) lets you do the same thing on 4G and 5G signals that broadcast at the same frequency.
Because the only frequencies that are used for both 4G and 5G are below 3 GHz, DSS only works with sub-6 frequencies and is not used for mmWave.
There is a bit of overhead associated with DSS such that you lose a bit of the combined bandwidth total. Nevertheless, DSS is a very important technology, because it provides both an easy way for carriers to “turn on” 5G services using their existing 4G frequencies and lets them combine the usage of the two to improve throughput.
One important point to note is Dual Connectivity will not work on Standalone 5G networks (DSS does) because as the name implies, these networks will not have any connections or dependences on 4G networks. While there are other factors that may influence throughput when 5G SA networks launch, practically speaking, this does mean 5G SA networks could be a bit slower than 5G NSA networks in certain situations.
In 5G (both NSA and SA), you can also leverage Concurrent Carriers, or CC, which are conceptually similar to CA across a continuous range of frequency bands. For sub-6 5G service, you can combine up to two 100 MHz channels to get a maximum of 200 MHz of bandwidth, whereas mmWave supports up to 8CC for 800 MHz.
This, combined with the fact that the millimeter wave frequencies are far more likely to use the full 100 MHz potential per channel (whereas many sub-6 5G frequencies have channels that are much smaller than 100 MHz), is why mmWave 5G service has been so much faster than sub-6 5G in the first real-world tests. Of course, that faster speed also carries with it a significantly shorter range, which is why both mmWave and sub-6 frequencies have important roles to play in 5G.
At present, none of the telco networks support more than 4CC, or 400 MHz, of bandwidth for mmWave, but modems like Qualcomm’s X55 support the maximum, meaning there will eventually be even faster mmWave performance.
Other factors that influence the speed of wireless data connections include transmission technologies like MIMO (Multiple Input, Multiple Output), which allows signals to be sent over multiple antennas inside a device simultaneously instead just of one at a time.
With 4G, it’s possible to do 4x4 MIMO, which, as its name implies, allows four simultaneous connections to occur.
A new capability for 5G is called Massive MIMO, and it can support up to 100 simultaneous connections by targeting a radio transmission beam in a specific direction.
For mmWave frequencies, Massive MIMO is enabled through a technology called beam forming which, as its name suggests, can create very tightly targeted beams of radio signal thanks to the use of many tiny, steerable antennas.
An important data compression technology that’s used in many smartphones is called QAM (quadrature amplitude modulation) and the latest version of it is QAM 1024.
While it’s easy to forget, cellular connections are actually based on analog waveforms, and QAM technology provides a very sophisticated way to encode more bits of data into an analog radio frequency signal.
Another point to remember about all these technology factors is that they can be cumulative, but they aren’t always. You could have a connection that supports Dual Connectivity and Massive MIMO but only 256 QAM, etc.
The number of possibilities quickly becomes overwhelming, even for telco equipment makers, so the industry tried to simplify things on the 4G side through the creation of what are called LTE Categories, which combine features like the number of channels of Carrier Aggregation, the amount of MIMO, and the type of QAM into a single category rating that’s typically shortened to Cat, such as Cat 24.
The category numbers are used by both devices like smartphones and network infrastructure equipment to quickly identify what set of features each end of the connection has in order to optimize the connection with whatever technologies are available. Interestingly, the 3GPP has chosen not to continue the categories with 5G, so there are currently no 5G categories.
The final thing to compare when thinking about network performance is the efficiency of the signal and transmission system of each of the cellular network “G” standards.
In a simple comparison of 4G signals and 5G signals being broadcast at the same frequency, the difference in data throughput with all other factors being equal is very modest between the two “G’s”.
The 5G connection will be faster because of more efficiency in the encoding and transmission of 5G signals (thanks to enhancement built into the 5G NR, or New Radio, standard), but the difference will only be in the 5-10% range for 5G over 4G.
As with most all wireless technologies, all the capabilities described above have to be supported both on the device and within the cellular network to which it’s connecting in order to work. In the case of the device, many of these capabilities are determined by the specific type of modem built into the phone and the features it offers.
While most people don’t bother diving into anywhere near this level of detail on smartphone modem specs, modem capabilities can be very important, particularly for 5G.
In situations where the technologies aren’t supported—such as in remote areas that may not have updated network infrastructure equipment installed—they’re simply not used for that particular session. As you move to different locations throughout the day, and therefore switch your cell connection from one tower to another (a pretty magical part of cellular networks that’s very easy to overlook), you may find your connection speeds improving, some of which could be due to the use of these different technologies.
If you’re curious to know how fast your connections are throughout the day, you’ll definitely want to download a handy utility called SpeedTest onto your mobile phone.
It provides a very simple way to see both the download and upload speeds of your connection at any given time and in any given location.
What you’ll quickly discover is that it can vary quite a bit from location to location because of all the factors discussed here, as well as many more, such as how busy the network is and potential interference.
Also, remember that the specifications for smartphones and their key components typically are best-case scenarios. In the real world, actual results can be very different and almost always lower.
Finally, to get back to the original question posed in the title, at the present time, we should see 5G speeds in the 400-500 Megabit per second (Mbps) range for sub-6 5G service and over 1.5 Gigabits per second (Gbps) for mmWave, when the services are available.
That’s significantly faster than the 35 Mbps average across the US right now for 4G services, so it’s easy to see why people are excited about the speeds that 5G can offer.
source: forbes
