5G vs. LTE: Comparing speed, spectrum and latency

The debate between 5G and LTE largely comes down to speed and spectrum. But latency and wired network implications are also important differentiators.

When gauging wireless throughput, you have to keep an open mind and accept that the speeds and feeds you ultimately get are a moving target shaped by a number of situational specifics.

In the comparatively simple realm of wired Ethernet, a 100 Mbps connection is just that. You can count on it. It's easy to talk about and easy to understand. Wireless networking is fraught with if-this-then-that nuance, and that effect only gets more pronounced when dealing with cellular networking technology. That said, we're standing on the edge of 5G's ascent to the cellular throne, and we naturally want to contrast 5G vs. LTE. Let's give it a shot, but expect caveats as we go.

First, if 5G is the latest, then shouldn't we instead compare it to 4G rather than LTE (Long-Term Evolution)? Actually, LTE is arguably the same thing as 4G -- as long as we don't split hairs. 4G is a series of "performance values up to ___" statements, and LTE falls under the 4G technical framework. LTE is the closest we'll ever get to realizing 4G's upper-end promises without actually getting there.

5G vs. LTE: Faster, but how long will it take?

One thing is clear: What 5G promises will not be achieved on day one. But 5G will start off faster than LTE, and it will only get better. LTE's best speeds top out around 100 Mbps. At its best, if we ever reach it, 5G could hit speeds of 20 Gbps. That is impressive, but the speeds supported by the first 5G networks largely remain to be seen. They will certainly be faster than 4G and are likely to be measured in hundreds of Mbps in good conditions.

Latency is another factor. It contributes to network performance, and it can make or break certain applications. LTE's latency is fairly variable across conditions and carriers. 5G's stated latency goal is in the submillisecond territory -- across the board. This, too, is impressive, but if and when this lofty latency service-level agreement can be realized for most users remains to be seen.

5G vs. LTE: Spectrum tradeoffs

One area that is easier to discuss as we contrast LTE and 5G is related to spectrum. Not only is 5G allowed to use wider channels to push more data, it will have more spectrum available to it. LTE's available licensed spectrum allocations are all under 6 GHz. 5G gets the same frequencies as LTE plus swaths way up in the tiny wavelengths between 30 GHz and 300 GHz -- the millimeter wave (MM wave) band.

More spectrum is always good, but the tradeoff here is the MM wave stuff has a much harder time penetrating solid surfaces. This means 5G requires more small cells attached to buildings and street-level poles. That's much different from the tower-centric approach LTE generally uses.

The 5G vs. LTE discussion wouldn't be complete without examining how the new standard will transform the wired network. 5G will accommodate a greater number of simultaneous devices per coverage area. More capacity and users at the network edge will be felt upstream as well, so 5G will force an evolution on the wired back end that will likely be more extensive than what underpins LTE today.

This was last published in September 2019

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