Courses » Digital Switching - I

Digital Switching - I


The course will introduce the learners to basics of digital telephony. It will start with crossbar switch and move to theory of switches. Towards end, packet switching basics will be looked into.


Students, Teachers, Professionals, Trainers, Leaders, Employers


UG/PG: Both UG and PG

PREREQUISITES: Preferably should have done Basics of Digital Communications, and Digital Communication Networks.

INDUSTRY SUPPORT: There is no industry support. The course will be useful to the people from telecom industry.


Prof. Yatindra Nath Singh was born in Delhi, India. He did his B.Tech Electrical Engineering from REC Hamirpur (Now NIT Hamirpur), and M.Tech in Optoelectronics and Optical Communications from IIT Delhi. He was awarded Ph.D for his work on optical amplifier placement problem in all-optical broadcast networks in 1997 by IIT Delhi. In July 1997, he joined EE Department, IIT Kanpur. He was given AICTE young teacher award in 2003. Currently, he is working as professor. He is fellow of IETE, senior member of IEEE and ICEIT, and member ISOC. He has interests in telecommunications' networks specially optical networks, switching systems, mobile communications, distributed software system design. He has supervised 11 Ph.D and more than 115 M.Tech theses so far. He has filed three patents for switch architectures, and have published many journal and conference research publications. He has also written lecture notes on Digital Switching which are distributed as open access content through content repository of IIT Kanpur. He has also been involved in opensource software development. He has started Brihaspati (brihaspati.sourceforge.net) initiative, an opensource learning management system, BrihaspatiSync – a live lecture delivery system over Internet, BGAS – general accounting systems for academic institutes.


Week 1  : Introduction, Basic signaling, Strowger exchange, crossbar, crossbar operation algorithm.
Week 2  : Call congestion and time congestion; Lee’s approach, Karnaugh’s approach
Week 3  : Strictly Non-blocking networks, Rearrangeably non-blocking networks; Clos Network;  Paull’s matrix; Clos theorem; Strictly non-blocking for f-way multicasting.
Week 4  : Slepian Duguid theorem, its proof; Paull’s theorem; Recursive construction; Crosspoint complexity for rearrangebly and strictly non-blocking networks
Week 5  : Cantor network; proof; Wide-sense non-blocking network – example network and proof.
Week 6  : Packet Switching, Buffering strategies, Input Queued Switch, Output Queued switch
Week 7  : Banyan Networks, Delta Network, Shufflenet as Delta network – proof.
Week 8  :Buffered Banyan network (buffering at each switching element), Computional analysis.


1. Y.N.Singh, NPTEL Video lectures on Digital Switching.
2. Y.N.Singh, Working Lecture notes on Digital Switching – http://brihaspati.nmeict.in/ guest enabled course on EE629 Digital Switching in IIT Kanpur area.
3. Mischa Shwartz – Communication Networks: protocols, modeling and analysis. 
4. Various research papers as documented in Working lecture notes.

  • The exam is optional for a fee.
  • Date and Time of Exams: April 28 (Saturday) and April 29 (Sunday) : Afternoon session: 2pm to 5pm
  • Exam for this course will be available in one session on both 28 and 29 April.
  • Registration url: Announcements will be made when the registration form is open for registrations.
  • The online registration form has to be filled and the certification exam fee needs to be paid. More details will be made available when the exam registration form is published.


  • Final score will be calculated as : 25% assignment score + 75% final exam score
  • 25% assignment score is calculated as 25% of average of  Best 6 out of 8 assignments
  • E-Certificate will be given to those who register and write the exam and score greater than or equal to 40% final score. Certificate will have your name, photograph and the score in the final exam with the breakup.It will have the logos of NPTEL and IIT  Kanpur. It will be e-verifiable at nptel.ac.in/noc.