processor speed does not matter.
Bandwidth is the connection speed or the data rate maximum possible... e.g. 4mb conncection means dowload speeds of 900kbps-1.2mbps max
The speed of light is the limit for the transmission of information. As for the bandwidth (the number of bits per second that are transmitted), fiber optics currently exist that allow 40 Gbps; experimentally, higher bandwidths have already achieved, but this is not standardized. It is also possible to connect several of those in parallel, to achieve even higher bandwidths.
about 10Mbs.
Not Buffer like crazy in youtube.
give to examples for baseband
Bell labs has managed to break the Petabit barrier, they have achieved a speed of 15.5 Tbit/s over a single 7000 km fiber. Now one must keep in mind this was multiplexed over hundreds of channels and was a single mode cable. The maximum realistic speed application on single mode fiber cable is about 10gb speed. There are standards for 100 gigabit over multimode fiber and single mode, but those are not widely in use at the moment.
* 1000 base-tx *1000 base-sx
Yes. The iPhone 5 works well on European cellular bandwidths.
No. The iPhone 3GS is sadly a GSM only phone, so it cannot function on Sprint (or Verizon's) bandwidths.
None. A bit is a bit is a bit, and all are digital. Bandwidth identifies how much space is available for bits.
There are many types of wireless routers and bandwidths. The later the alphabet the more recent the addition. The current routers have a N designation.