 been of great value throughout the ages: from preservation of holy texts, to maintenance of transactional integrity. Information theory pre- dicts the transport capacity of a telecommunications channel. Channel coding realises this by creating mathematical relationships between data bits and redundancy bits. The structure thus developed allows a receiver to detect anomalies, and possibly correct errors. The extent of such error detection and correction is a function of the complexity of the code and ultimately the Shannon limit. Broadband Telecommunications Technologies and Management Review Questions What was the value of error detection to ancient scribes, and how are the techniques they developed applicable to present day digital telecommunications? 2. How does error correction happen in everyday communication? 3. Give an example of an error detection mechanism. What is the metric of interest in such a process? 4. Why are there different length CRC codes? What is the advantage of a longer code? What is the principle behind FEC coding? Give an example of an FEC code and explain how this principle is used. 6. What is the Shannon limit and what is its importance? 7. What is BLER and does it compare with BER? Which of the two is of greater importance to digital telecommunications? 8. What is rate matching and why is it used? 9. List two applications where turbo codes are used. 10. List two applications where LDPC codes are used. 11. Why does error correction decoding occur before error detection decoding? 12. What do business value error detecting codes bring to telecommunications? 13. What do business value error correcting codes bring to telecommunications? References [1] Johnson, P. (1993) A History of the Jews, Phoenix, cited in http://en.wikipedia.org/wiki/Scribe, accessed 21 August 2015. [2] Hamming, R.W. (1950) Error detecting and error correcting codes. Bell System Technical Journal. [3] 3GPP Standards 25.212 Series. http://www.3gpp.org/DynaReport/25212.htm, accessed 21 August 2015. [4] Metcalfe, R.M. and