ony technologies, and associated services and businesses developed is informative on how nascent broadband telecommunica- tions services and associated ecosystems evolve and how they may be analysed and managed. Review Questions 1. What value do switches provide in telephony? 2. What is multiplexing and why is it necessary? 3. How does a telecom engineer decide on the number of lines necessary for connecting two local exchanges? Broadband Telecommunications Technologies and Management 4. Access http://www.erlang.com/calculator/erlb/and calculate the number of necessary circuits to provide a 1% GoS for the following amount of traffic: (a) 1E (b) 5E (c) 10 E (d) 301 E (e) 120 E (f) 180 E 5. Draw the result from question 4 on a graph with offered traffic on the horizontal and required links on the vertical axis. What do you observe? Is there a business consideration? 6. How does GoS inform a government's telecommunications policy? 7. Why is telephone infrastructure provision a natural monopoly? 8. A call centrr has 60 employees on-line, each of whom make one phone call every 3 min on average, and talk on average for 2 min. Each call costs 15 c. (a) What is the total traffic in erlangs? (b) How many circuits are required for a GoS of 1%? (c) How much should the yearly (250 working days, 8 working hours a day) lease price be for the company to make a 50% saving in its telephone bills over the first 3 years? Assume the lease set-up fee of $30 000 should be paid over a period of 3 years. 9. What factors contributed to the decrease in cost of transatlantic telephony? 10. How did satellite communication impact the undersea cable telephony business? Was it complementary or competitive? 11. Undersea cables were a major infrastructural investment. How do you think these were repaired when a technical problem occurred? 12. How vertically integrated were the early telephone operators? Why? 13. What portion of early telephone operators' revenue came from provision of a 'pipe' and what portion from provision of 'content'? How do