Sharing is hard...
Upstream Transmission
- Amplify 5-42 MHz frequencies
- Tight quarters! Just below Analog TV channels
- Very vulnerable to ingress noise (radio, pagers, appliances)
- Channel signaling uses TDMA
- sharing/collisions mediated using Ethernet MAC
- Upstream data rates of 320 Kbps -10 Mbps
“Downstream channels over a CATV system
look like a water distribution system…
Upstream channels more closely resemble
a sewer system” … Kim Maxwell