Kai frowned. “So one bad layer breaks the whole stack?”
“More like a tower of translators,” Lena said. “Each layer talks only to the one above and below it. The radio doesn’t know about music; it just flips frequencies. The L2CAP doesn’t know about security; it just chops data. But together, they form a reliable chain from your Spotify playlist to your ears.” bluetooth stack
Lena patched a single line in the HCI driver — a buffer overflow fix. Then she recompiled the stack. Kai frowned
He paired his phone. The earbuds connected. One minute passed. Then five. Then thirty. Crystal-clear audio. The radio doesn’t know about music; it just
“Yes. And in our case,” Lena pointed at a red line, “the HCI — Host Controller Interface — is corrupted. It’s the translator between the chip’s firmware and the phone’s operating system. Ours keeps mistranslating ‘start streaming’ as ‘reset pairing.’”
She showed the pairing handshake — a rapid dance of temporary keys, link keys, and encryption requests. “That’s layer three. Ours fails here 20% of the time. Why? Because our stack’s Security Manager uses an outdated key storage method.”