The 5G specification sets a goal of zero latency for the connection from the wireless device to the cellular tower. We’ll have to wait to see if that can be achieved, but obviously the many engineers that worked on the 5G specification think it’s possible. It makes sense from a physics perspective – a connection of a radio signal through air travels for all practical purposes at the speed of light (there is a miniscule amount of slowing from interaction with air molecules). This makes a signal through the air slightly faster than one through fiber since light slows down when passing through fiberglass by 0.83 milliseconds for every hundred miles of fiber optic cable traversed.
This means that a 5G signal will have a slight latency advantage over FTTP – for the first few connection from a customer. However, a 5G wireless signal almost immediately hits a fiber network at a tower or small cell site in a neighborhood, and from that point forward the 5G signal experiences the same latency as an all-fiber connection.
Most of the latency in a fiber network comes from devices that process the data – routers, switches and repeaters. Each such device in a network adds some delay to the signal – and that starts with the first device, be it a cellphone or a computer. In practical terms, when comparing 5G and FTTP the network with the fewest hops and fewest devices between a customer and the internet will have the lowest latency – a 5G network might or might not be faster than an FTTP network in the same neighborhood.
5G does have a latency advantage over non-fiber technologies, but it ought to be about the same advantage enjoyed by FTTP network. Most FTTP networks have latency in the 10-millisecond range (one hundredth of a second). Cable HFC networks have latency in the range of 25-30 ms; DSL latency ranges from 40-70 ms; satellite broadband connections from 100-500 ms.
Verizon’s claim for improving the gaming or stock trading connection also implies that the 5G network will have superior overall performance. That brings in another factor which we generally call jitter. Jitter is the overall interference in a network that is caused by congestion. Any network can have high or low jitter depending upon the amount of traffic the operator is trying to shove through it. A network that is oversubscribed with too many end users will have higher jitter and will slow down – this is true for all technologies. I’ve had clients with first generation BPON fiber networks that had huge amounts of jitter before they upgraded to new FTTP technology, so fiber (or 5G) alone doesn’t mean superior performance.
The bottom line is that a 5G network might or might not have an overall advantage compared to a fiber network in the same neighborhood. The 5G network might have a slight advantage on the first connection from the end user, but that also assumes that cellphones are more efficient than PCs. From that point forward, the network with the fewest hops to the Internet as well the network with the least amount of congestion will be faster – and that will be case by case, neighborhood by neighborhood when comparing 5G and FTTP.
Verizon is claiming that the improved latency will improve gaming and stock trading. That’s certainly true where 5G competes against a cable company network. But any trader that really cares about making a trade a millisecond faster is already going to be on a fiber connection, and probably one that sits close to a major internet POP. Such traders are engaging in computerized trading where a person is not intervening in the trade decision. For any stock trades that involve humans, a extra few thousandths of a second in executing a trade is irrelevant since the human decision process is far slower than that (for someone like me these decisions can be measured in weeks!).
Gaming is more interesting. I see Verizon’s advantage for gaming in making game devices mobile. If 5G broadband is affordable (not a given) then a 5G connection allows a game box to be used anywhere there is power. I think that will be a huge hit with the mostly-younger gaming community. And, since most homes buy broadband from the cable company, lower latency with 5G ought to be to a gamer using a cable network, assuming the 5G network has adequate upload speeds and low jitter. Gamers who want a fiber-like experience will likely pony up for a 5G gaming connection if it’s priced right.