This course is a prerequisite for Digital Communication II (Part II), Distributed Systems (Part II and Diploma) and Security (Part II).
The aims of this course are to develop an understanding of communications
networks from a wide perspective, within a framework of principles rather than
technologies or architectures. Technologies and architectures will, however,
be used as examples and motivation.
Two example systems: Ethernet and the telephone system: basic
operation; common issues; differing constraints; differing approaches.
Partitioning the problem.
Abstraction, service versus implementation; layering as a
restricted form of abstraction; motivation for layering; the channel
as an abstraction; layered channels.
Emphasis on the service provided by physical channel; limitations:
noise, attenuation. Channel capacity (bandwidth). Modulation
techniques for digital systems.
Coding as a general concept: modulation as a form of coding,
A/D,D/A, error correcting and detecting codes, other forms of coding,
relation to layering.
Basic definitions, FDM, synchronous and asynchronous TDM. Circuit
switching, packet switching, ATM. Shared media networks with particular
emphasis on media access control. Packet scheduling. Non orthogonal
multiplexing. Multiplexing and channel characteristics.
Switching and routing.
Introduction from LAN perspective (repeaters, bridges, routers).
Fundamental view of switching extended to telephone network,
connectionless versus connection oriented.
Protocols and state.
Imperfect view of state at far end of channel. ARQ as an example
of an error control protocol; sliding window ARQ as an example of a
flow control protocol; flow control in general: X.25 as an example.
Naming, addressing and routing.
Service access points, binding. Hierarchical versus flat address
spaces. Routing classifications and algorithms.
Internet architecture, context of development, addressing and routing,
transmission control protocol (TCP), higher layer protocols, evolution.
Role of standards, dynamics of standards process, standards
At the end of the course students should
be able to analyse a communication system by separating out the
different functions provided by the network
understand that there are fundamental limits to physical transmission
understand the general principles behind multiplexing, addressing,
routing and stateful protocols as well as specific examples of each
understand what FEC is and how CRCs work
be able to compare communications systems in how they solve
have an informed view of the internal workings of the Internet
* Peterson, L.L. & Davie, B.S. (2003). Computer networks: a systems approach. Morgan Kaufmann (3rd ed.).
Comer, D. & Stevens, D. (1995). Internetworking with TCP-IP, vol. 1 and 2. Prentice-Hall (3rd ed.).
Schwartz, M. (1987). Telecommunication networks: protocols, modeling and analysis. Addison-Wesley.