The 5G icon on your phone tells you almost nothing
Full bars, 5G on the display, and the stream will not hold 3 Mbps. The indicator was never a promise about upload, and upload is the only figure that matters to you.
The icon reports which network technology your phone attached to. That is the whole claim.
It says nothing about which band, how much of it you get, how many people share the cell, or what the site's backhaul can carry.
Bands decide almost everything
| Band type | Reach | Speed |
|---|---|---|
| Low band, under 1 GHz | Miles, through buildings | Often no faster than good 4G |
| Mid band, 1 to 6 GHz | Around a mile | The useful one. Most real gains live here. |
| High band, millimetre wave | A street corner, line of sight | Very fast, and gone when you turn around |
All three light the same icon. A phone on low band 5G can be slower than the 4G it replaced.
Networks are built for downloading. Upload is a fraction of download and it varies more. A connection that tests at 200 down may give you 8 up, and 8 is the number your stream lives on.
Why it collapses at events
A cell is shared. Put ten thousand people in a stadium and the capacity divides among them. Your signal strength stays perfect while your throughput falls to nothing, because strength and capacity are different things.
This is the failure that surprises people most. Every indicator on the phone looks healthy.
What to check instead of the icon
- Upload, more than once. Run it several times across a few minutes. One test says nothing about consistency.
- The band. Field test screens and diagnostic apps show the actual band. Learn which bands your carrier uses where you work.
- Latency under load. A link with good throughput and terrible latency under load will still break a stream.
- Time of day. Test at the hour you will broadcast, not at breakfast.
Building around it
Bond more than one carrier, not more than one SIM on one carrier. Four modems on the same network in the same cell share the same congestion and the same outage.
Then set your bitrate against the worst upload you measured, not the best. The best number is the one that makes a demo look good. The worst is the one that decides whether the stream survives.
Sources
- 3GPP, mobile standards organisation
- SRT protocol, latency and buffer guidance
- BELABOX/srtla, source and README
The Rig Wire reports on streaming technology from public documentation, source repositories and vendor releases. We did not bench-test what is described here. When we have tested something, we say so.