Plain old telephone calls continue to be the industry's biggest revenue generator, but thanks to advances in network technology, this is changing. Telecom is growing less about voice and increasingly about video, text, and data. High-speed Internet access, which delivers computer-based data applications such as broadband information services and interactive entertainment, is rapidly making its way into homes and businesses around the world. The main broadband telecom technology, Digital Subscriber Line (DSL), has ushered in a new era. The fastest growth comes from services delivered over mobile networks. Of all the customer markets, residential and small business markets are arguably the toughest. With literally hundreds of players in the market, competitors rely heavily on price to slog it out for households' monthly checks; success rests largely on brand name strength and heavy investment in efficient billing systems. Explain