The top international vendors have risen to the challenge and are all pursuing technologies that can offer ever faster and cheaper fixed and wireless network solutions based upon Internet protocol (IP). High-speed, broadband fixed, 3G and now Long Term Evolution (LTE) networks (commonly known as "fourth generation" or "4G") have enabled the progressive development of increasingly "smarter" phones and terminals and a growing environment of applications and services. Research companies such as NPD3and IDC4 are reporting that some 50 per cent (around 900 million) of all mobile phones sold in 2013 have been smart phones.