4 ms·

LTE total latency is 20-50 ms, and you compare this to the marketing "air link only" 5G latency of 1 ms. It's apple and oranges ;) FYI, the air link latency fo

by yaantc 2y ago

LTE total latency is 20-50 ms, and you compare this to the marketing "air link only" 5G latency of 1 ms. It's apple and oranges ;) FYI, the air link latency for LTE was given as 4-5 ms. FDD as it's the best here. The 5G improvement to 1ms would require features (URLLC) that nobody implemented and nobody will: too expensive for too niche markets. The latency in a cellular network is mostly from the core network, not the radio link anymore. Event in 4G. (telecom engineer, having worked on both 4G and 5G and recently out of the field)

porridgeraisin 2y ago
Always been interested in this stuff. Where would you recommend a software/math guy learn all this stuff? My end goal is to understand the tech well enough to at least have opinions on it. How wifi works would be great as well if you're aware of any resources for that.
- yaantc 2y ago
  It's a good but hard question... Because cellular is huge. In a professional context, nobody knows it all in details. There are specializations: core network and RAN, and inside RAN protocol stack vs PHY, and in PHY algos vs implementation, etc. You can see all the cellular specs (they're public) from there: https://www.3gpp.org/specifications-technologies/specifications-by-series https://www.3gpp.org/specifications-technologies/specificati... 5G (or NR) is the series 38 at the bottom. Direct access: https://www.3gpp.org/ftp/Specs/archive/38_series https://www.3gpp.org/ftp/Specs/archive/38_series It's a lot ;) But a readable introduction is the 38.300 spec, and the latest edition for the first 5G release (R15, or "f") is this one: https://www.3gpp.org/ftp/Specs/archive/38_series/38.300/38300-fj0.zip https://www.3gpp.org/ftp/Specs/archive/38_series/38.300/3830... It's about as readable as it can get. The PHY part is pretty awful by comparison. If you have a PHY interest, you'll need to look for technical books as the specs are quite hermetic (but it's not my field either).
  - porridgeraisin 2y ago
    Forgot to get back to you on these.. thanks for the links!

by yaantc 2y ago

porridgeraisin 2y ago

Always been interested in this stuff. Where would you recommend a software/math guy learn all this stuff? My end goal is to understand the tech well enough to at least have opinions on it. How wifi works would be great as well if you're aware of any resources for that.

yaantc 2y ago
It's a good but hard question... Because cellular is huge. In a professional context, nobody knows it all in details. There are specializations: core network and RAN, and inside RAN protocol stack vs PHY, and in PHY algos vs implementation, etc. You can see all the cellular specs (they're public) from there: https://www.3gpp.org/specifications-technologies/specifications-by-series https://www.3gpp.org/specifications-technologies/specificati... 5G (or NR) is the series 38 at the bottom. Direct access: https://www.3gpp.org/ftp/Specs/archive/38_series https://www.3gpp.org/ftp/Specs/archive/38_series It's a lot ;) But a readable introduction is the 38.300 spec, and the latest edition for the first 5G release (R15, or "f") is this one: https://www.3gpp.org/ftp/Specs/archive/38_series/38.300/38300-fj0.zip https://www.3gpp.org/ftp/Specs/archive/38_series/38.300/3830... It's about as readable as it can get. The PHY part is pretty awful by comparison. If you have a PHY interest, you'll need to look for technical books as the specs are quite hermetic (but it's not my field either).
- porridgeraisin 2y ago
  Forgot to get back to you on these.. thanks for the links!