ogue systems. From a business viewpoint, the marketing efforts of both camps worked to create an ecosystem of equip- ment manufacturers and operators which increased the overall value proposition for new operators. This was particularly important for the CDMA camp as they did not have the same extent of policy support as GSM, which had the backing of the European community. The CDMA camp is believed instead to have benefited from US government support and its influence on its allied countries. To close the loop, it is interesting that both GSM and CDMA benefited from national and regional government policies which funded or encouraged their technological developments. This entire episode compares with the development of the 2G Japanese PDC stan- dard, which similar to both GSM and CDMA provided multiple capacity improvement compared with the 1G analogue systems. Indeed PDC produced even higher capacity improvements (at the expense of voice quality) compared with both GSM and CDMA. The business ecosystem was similarly successful, although it was created mostly Information Theory within Japan. International expansion of the technology was however unsuccessful as no other country adopted PDC. While technically a success as it continued to be used for some two decades, it has now been discontinued. Case Study Questions Why did user capacity matter in the comparison between 2G and 1G standards? What was a good metric to compare different 2G standards? Is this still a relevant metric? What challenges did the CDMA camp face in marketing its technology? How are the information theory principles helpful in separating fact from marketing hype? How did the global extent of GSM/CDMA adoption help shape the present day mobile standards? Review Questions 1. What is the entropy of a source which outputs, every second, one of 5 possible messages, a, B, 8, 8 and K with probability of ipa=1/2,p,=1/4,p,= = = 1/8, P = 1/16 and p = 1/16? Suggest a coding method for this system. What is the source information rate? 2. Find a 100% effi