The United States (US) Federal Communications Commission (FCC) as of 2010, defines "Basic Broadband" as data transmission speeds of at least 4 megabits per second (Mbps), or 4,000,000 bits per second, downstream (from the Internet to the user’s computer) and 1 Mbit/s upstream (from the user’s computer to the Internet). The trend is to raise the threshold of the broadband definition as the marketplace rolls out faster services.
Data rates are defined in terms of maximum download because network and server conditions significantly affect the maximum speeds that can be achieved and because common consumer broadband technologies such as ADSL are "asymmetric"—supporting much lower maximum upload data rate than download.
"Broadband penetration" is now treated as a key economic indicator. Source and for more info:http://en.wikipedia.org/wiki/Broadband_Internet_access
BROADBAND MAPS (US and UK)