Upstream  - Upstream is the transmission path from the end-user (subscriber, client site, etc.) to the central site, ISP, video on demand server, etc. Also see return path.
https://en.wikipedia.org/wiki/Upstream
https://en.wikipedia.org/wiki/Upstream_(computer_science)
Upstream/downstream

CableLabs Certified Cable Modem Project

DOCSIS Cable Modem Systems - (Data Over Cable Service Interface Specification)

Downstream (TV)

High Bit-Rate Digital Subscriber Line - (HDSL)

VSB - (Vestigial Side Band)

See the Interactive Television Institute.