Telecommunication Software Applications Exam, Exams of Software Engineering

Download Telecommunication Software Applications Exam and more Exams Software Engineering in PDF only on Docsity! EE423 Telecommunication Software Applications Page 1 of 5 Semester I Examinations 2012/2013 Exam Code(s) 4BP121 4BN121 Exam(s) B.E. Degree Examination (Electronic Engineering) B.E. Degree Examination (Electronic Engineering and Computer Engineering) Module Code(s) EE423 Module(s) Telecommunication Software Applications Paper No. 1 Repeat Paper No External Examiner(s) Prof. G. W. Irwin Internal Examiner(s) Prof. G. Ó Laighin Mr. L. Kilmartin Instructions: Answer 3 questions from 4. All questions carry equal marks (20 marks). Duration 2hrs No. of Pages 5 Department(s) Electrical & Electronic Engineering Course Co-ordinator(s) Requirements: MCQ Handout Statistical Tables Yes Graph Paper Yes Log Graph Paper Other Material EE423 Telecommunication Software Applications Page 2 of 5 Question 1 (a) Describe the role of the following functions typically implemented within the Subscriber Line Interface Circuit of a local exchange in a modern Public Switched Telephony Network (PSTN): (i) Hybrid (ii) Codec (iii) Supervision [5 marks] (b) A local exchange is connected to a trunk exchange using an E1 TDM link within a telephony network. Describe the process by which a call is routed from the local exchange to the trunk exchange during the call set up phase. In addition to explaining the steps by which this route is established, your answer MUST include a diagram and explanation detailing the structure of the E1 TDM link and how the E1 link is used during the call routing process. [5 marks] (c) A client of a PSTN operator requires a service whereby subscribers could dial a single telephone number and these calls would be routed to whichever one of the client’s offices is physically located nearest to the calling party’s location. Describe how this type of service could be implemented using (i) an IN based solution and (ii) a solution solely based on number mapping\routing tables in local exchanges. Provide one relative ADVANTAGE and one relative DISADVANTAGE of implementing the service using solution (i) compared to solution (ii). [5 marks] (d) A company uses a leased line which has a bidirectional 256kbps traffic bandwidth to EXCLUSIVELY provide telephony interconnection between two sites. Assuming that standard PCM is used to encode the speech, determine the GOS delivered by this solution during the busy hour if the average number of calls is 20 calls per hour and the average call duration is 5 minutes. The company undertook a process of encouraging its employees to utilise non- telephony services (e.g. email, IM, VoIP) as a means of carrying out this type of inter-site communication. As a result, they reduced their leased line capacity to 128 kbps and they now experience a 5% GOS on this new leased line. Assuming the average call duration has remained the same, what is the new average number of telephony calls per hour going over this new leased line connection? [5 marks]