Prepare a research report that thoroughly answers the following exercise question.

Cable modems on the coaxial part of the topology of an HFC configuration shown in Figure 13.3 on page 510 are a tree structure. Cable modems with Ethernet stations resemble an Ethernet LAN. Contrast an HFC coaxial broadband LAN with a regular Ethernet LAN on:
(a) Topology
(b) Downstream protocol
(c) Upstream protocol.