🛰️ STCPv3 is being built satellite-first.
Satellite communication makes one design constraint impossible to ignore:
Every bit on the wire costs.
Bandwidth is limited. Airtime matters. Radio transmission consumes energy. On constrained and long-distance links, protocol overhead that looks insignificant on Ethernet can become something worth eliminating.
That principle has become a major design driver for STCPv3:
Transmit as little as possible while keeping the protocol useful.
STCPv3 already uses a compact 17-byte wire header. Now v3 adds another tool specifically suited to constrained links: optional automatic payload compression.
Compression is controlled per socket. An application can enable or disable it and define a payload-size threshold for when compression should be attempted.
And there is an important rule:
If compression does not make the payload smaller, STCP sends the original payload instead.
In other words, compression is there to save bytes — not simply to say that compression is enabled.
The first full compression interoperability tests are now passing across Linux and Raspberry Pi with both STCP-TCP and STCP-UDP.
The latest test run produced:
16 / 16 payloads compressed successfully
98,816 bytes → 1,156 bytes
97,660 bytes avoided on the wire
98.83% payload reduction
0 compression errors
0 decompression errors
The payload in this functional test is intentionally highly compressible. 98.83% is therefore not a claim about the compression ratio of arbitrary real-world traffic. Real-world savings depend entirely on the data being transmitted.
What the test demonstrates is that STCPv3 can automatically compress suitable payloads, transport them and reconstruct the original data correctly end-to-end.
And the complete STCPv3 regression suite remains green:
Linux / Raspberry Pi ✅
Zephyr / nRF9151 ✅
CoAP ✅
MQTT ✅
P2P 3-node ✅
Next comes benchmarking with different payload types and frame sizes to quantify the benefit under more realistic traffic patterns.
The direction for STCPv3 is very clear:
Satellite-first networking.
17-byte wire header.
Optional automatic payload compression.
Compression only when it saves bytes.
Linux, Raspberry Pi and embedded Zephyr targets.
CoAP, MQTT and P2P interoperability.
For terrestrial broadband, a few unnecessary bytes may not matter much.
On a satellite link, I want STCP to treat every one of them as something worth avoiding. 🛰️
#STCP #STCPv3 #Satellite #SatelliteIoT #IoT #EmbeddedSystems #Networking #Rust #Zephyr #nRF9151 #LowPower #Compression
