a) Correct. Dual-band measure two sets of frequencies. I have set a different SSID to each set of frequencies.
b) Yes. The 2.4/5.0 refers to the frequency band, not the transfer speed.
c) Typically, you want want to set a 11n only AP, and a 11g only AP. From what I read, if you have legacy (i.e. 11g) devices on the same AP and your AP is set to 11g/n, then there is some penalty on the other 11n devices.
d) Not any more. In the early days, turning on WEP slows down the 11b speeds, but that no long happens (unless we have a very poor implementation).
In response to
a) Logically speaking, even though I set dual bands (2.4GHz and 5GHz), we're talking about both bands still go thought 1 WAN port. So where is the advantage? By implementing dual bands, we're sort of doing "load balancing" right?
c) So which standard should I set? Leave it as "n", or AUTO or [your suggestion]? If I leave it at "n" will legacy devices have problems connecting, or will the "n" devices see a performance impact? Or should I set SSID1 as "n" and SSID2 as "g". Then devices like in DLINK IP cam, Smart TV etc how do I know if they have "n" implementation? MacBook Pro etc? Can I then say, that in terms of speed, "n" is faster than "g", is faster than "b"?
Out of curiosity, what do you or anyone reading this post, understand from this statement from the Samsung SmartTV manual (esp the last para, so WPA2 AES is OK??):
"This TV supports the IEEE 802.11a/b/g and n communication protocols. Samsung recommends using IEEE 802.11n. When you play the video over a IEEE 802.11b/g connection, the video may not play smoothly.
Most wireless network systems incorporate a security system that requires devices that access the network through an access point or wireless router (typically a wireless IP Sharer) to transmit an encrypted security code called an access key.
If Pure High-throughput (Greenfield) 802.11n mode is selected and the Encryption type is set to WEP, TKIP or TKIP AES (WPS2Mixed) for your wireless router, Samsung TVs will not support a connection in compliance with new Wi-Fi certification specifications."