I was just wondering about today's dual-band routers. You get a 2.4 Ghz channel, and a seperate 5 Ghz channel. Could you say that a home network that uses a router like this is segmented (2 separate network segments)?
Generally you home "router" can only run 1 subnet for the lan of any kind and it will translate that to a single wan ip address. These are best called gateways. Now a true router...or a "gateway" with dd-wrt loaded on it can actually assign multiple subnets to both radio channels. It can put multiple ssid up on each and keep then separate with vlans.