 you think this has changed in recent years? 14. What was the importance of AT&T's technological leadership in its early history? How did it impact the business in later years? Was there anything AT&T could have done? 15. How successful do you think the Bell break-up model was? Can this have some implica- tions for the eventual privatisation of NBN Co? 16. A company's 100 salespeople on average make one phone call every 5 min, and each call lasts on average 3 min: (a) What is the total phone traffic generated by this company in erlangs? (b) If each call costs 10 C on average, what is the daily (8 h) telephone bill? (c) As the company telecom manager you have found the following two lease options. Which one of the two will you choose and why? Clearly show your assumptions and work. Option 1 Option 2 Set-up cost ($) 10000 Set-up cost ($) 25 000 20 lines/year ($) 75000 25 lines/year ($) 80000 40 lines/year ($) 135000 50 lines/year ($) 140000 Each extra 20 lines/year ($) 40000 Each extra 25 lines/year ($) 50000 17. How did the leasing business change the telecommunication operator business ecosystem? Voice Communications 18. What are the strengths and weaknesses of an operator with its own infrastructure com- pared with a virtual network operator? 19. Perform a value analysis on a leased phone service. 20. What do you see as policy implications in forcibly breaking up telephone monopolies such as that of AT&T in the United States? References [1] Huurdeman, A.A. (2003) The Worldwide History of Telecommunications, Wiley Interscience. [2] Illustrated London News (1872) Cited in http://www.educationscotland.gov.uk/scotlandshistory/ makingindustrialurban/alexandergrahambell/index.asp, accessed 23 October 2015. [3] The US National Archives.http://commons.wikimedia.org/wiki/File:Photograph_of_Women_Working_at_a_ ll_System_Telephone_Switchboard_(3660047829).jpg#mediaviewer/File:Photograph_of_Women_ Working_at_a_Bell_System_Telephone_Switchboard_(3660047829).jpg,a accessed 20 August 2015. [4] Angus, I. (2001) An Introduction 