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by matt4711 2926 days ago
From the first link: "Comparing OFDM to LTE today we find a better scalability to a much lower latency (an order of magnitude lower round-trip time [RTT] than LTE today) in OFDM."

Doesn't LTE already have quite good latency properties?

3 comments

As I understand it, not good enough for "vehicular communication, industrial control, factory automation, remote surgery, smart grids and public safety applications" [1]. A lot of the improvement is down to the frame structure (i.e., how user and training data are distributed in time and frequency). See "Frame structure" in [1].

[1] https://www.ericsson.com/en/ericsson-technology-review/archi...

It depends on what you mean by "good". With 5G NR it will at least be possible to get to .5 ms or less.

https://www.edn.com/electronics-blogs/5g-waves/4460346/5G--T...

One data point: LTE gives me 65-90ms ping RTT in reasonable non-crowded indoor conditions. Subjectively, working interactively via LTE is totally fine for me. Compare that to UMTS (3G T-Mobile DE) where I think RTT was more like 350ms and working interactively is a pain.
Anything >10ms can be noticeable if you have a lot of requests or symmetric applications.

But I find reliability the far bigger problem with LTE than performance if everything goes right. Not sure how 5G will perform there.