Lig vir Afrika
- Authors: Lacquet, B.M.
- Date: 2008-11-03T07:11:36Z
- Subjects: Telecommunications , Optical fibres , Optical communication systems
- Type: Inaugural
- Identifier: uj:14895 , http://hdl.handle.net/10210/1445
- Description: Inaugural lecture--Dept. of Electrical Engineering, Rand Afrikaans University, 22 September 1999 , The exponential growth in the use of the Internet and the consequent growing need for higher bandwidth force the telecommunications industry to expand the laid networks at a much faster rate. Optical fibre is the only transmission medium that has the potential of unlimited bandwidth and can handle very high data rates. After a brief overview of the history of optical communications, the working of a simple fibre optic link and how a simple optical fibre channel functions will be described. This is followed by a discussion on erbium-doped fibre optic amplifiers and of wavelength-division multiplexing. These are both enabling technologies that have dramatically changed the future of optical fibre communications, from being just another communication system to one that is part of our daily lives. A brief discussion of an all-optical network and the progress that has been made in LA lightwave transmission capacity since 1980 is followed by a brief overview of the required enabling technologies at the component, materials and network levels to reach an even higher capacity and L bandwidth. These needs are motivated from a business perspective, and with the help of a roadmap for the future technological needs in optical communication systems up to 2015. The question to be asked and answered is: where does Africa stand with respect to these developments and what are we at RAU doing within the industry supported Centre for Optical Communications?
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Optimization of resources for H.323 endpoints and terminals over VoIP networks
- Authors: Nlend, Samuel , Swart, Theo G. , Clarke, Willem A.
- Date: 2011
- Subjects: VoIP Networks , Statistical multiplexing , Telecommunications
- Language: English
- Type: Conference paper
- Identifier: http://hdl.handle.net/10210/139763 , uj:15455 , S. Nlend, T. G. Swart and W. A. Clarke, "Optimization of resources for H.323 endpoints and terminals over VoIP networks," in Proceedings IEEE Africon, Livingstone, Zambia, September 13-15, 2011, published on CD (5 pages)
- Description: We suggest a method of optimizing resource allocation for real time protocol traffic in general, and VoIP in particular, within an H.323 environment. There are two options in the packet network to allocate resources: aggregate peak demand and statistical multiplexing. Statistical multiplexing, our choice for this case, allows the efficient use of the network resources but however exhibits greater packet delay variation and packet transfer delay. These delays are often the result of correlations or time dependency experienced by the system’s queue due to the variations observed in different point processes that occur at a point of time. To address these issues, we suggest a queuing method based on the diffusion process approximated by Orstein-Ulenbeck and the non-validated results of Ren and Kobayashi.
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