how many bits per second can the first node communicate to the last?
• if node i transmits to node i+1, node i+1 cannot be transmitting to node i+2 • if node i transmits to node i+1, node i-1 cannot be transmitting to node i • if node i transmits to node i+1, node i-2 cannot be transmitting to node i-1 • so with one-directional transmission, at most 1/3 of the links can be active at any given time.