Question : can any n-router support g and n standards simultaneously?

hi all,
i want to upgrade my network to support n standard, i have several n-capable laptops and other network devices that are only b and g capable, such as iphones and old laptops.

my question is do i need a router with dual bands in order for all this devices to work   simultaneously on their highest performance available, i.e newer laptops will work with n connectivity and iphones will work with b connectivity, or does any router that supports b g and n standards can work will all three standards simultaneously??

thanks in advanced

Answer : can any n-router support g and n standards simultaneously?

sort of, G will connect to N and work but it does not use the entire N packet.  

"Addresses 11n APs and a mixed 11n/a/g/b environment. As in legacy mode, 11a and 11g/b clients will read the first three fields of the AP’s 11n header, while 802.11n will also parse the additional three “high throughput” fields of the full 11n header. Again, if the 5-GHz option isn’t supported in the 11n AP, there will be no backward compatibility with 802.11a. "

In short they will all work, but it's not actually g.  G can connect to N without the full speed or range.

here is an article that explanes it.
http://www.networkworld.com/newsletters/wireless/2006/0206wireless1.html?fsrc=rss-wireless