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http://hdl.handle.net/11375/7571
Title: | Wavelength division multiplexing cross connect networks |
Authors: | Ahmadvand, Nima |
Advisor: | Todd, Terence D. |
Department: | Electrical and Computer Engineering |
Keywords: | Electrical and Computer Engineering;Electrical and Computer Engineering |
Publication Date: | May-1997 |
Abstract: | <p>Fiber optic communication is only 30 years old, but it has already become one of the technologies of choice for current and future high-speed communications. Unfortunately, the enormous bandwidth available in optical fiber cannot be accessed as a single communication channel. This is because each user station typically connects tot he network through its electronic interface whose speed is limited to the maximum electronic processing speed. However, access to this bandwidth is possible using parallel channel architectures, where each channel operates at rates which are accessible to electronic processing. Currently, wavelength-division-multiplexing (WDM) is being considered for this purpose. In local and metropolitan area networks, WDM may offer increased transmission concurrency compared with conventional single-channel designs, with only modest increases in station complexity. However, because of device limitations the number of available wavelength channels may initially be less than desired. As a result, spatial reuse of wavelength channels may be required to obtain designs which will support a reasonable number of stations. One option in this case is to perform media access across a spatial wavelength cross connect. In such a system, the total capacity may be n times that of a single passive star network, where n is the number of available wavelengths.</p> <p>In this thesis, WDM cross connect networks are considered as a specific category of optical networks, which efficiently reuse the available wavelengths. The proposed networks are classified into two classes: single-hop and dual-hop.</p> <p>In the single-hop case, time slot assignment techniques are considered which can dynamically schedule communications across the wavelength cross connect network. These new scheduling techniques are developed for a high performance dynamic medium access control based on the traffic demands of the network stations. Some simple random access methods are also introduced for the cases where some higher levels of simplicity are sought. Simulation programs are used to compare different scheduling methods. The results also show that the proposed methods perform quite efficiently.</p> <p>The dual-hop class of WDM cross connect networks proposes a shared buffering scheme which simplifies network operation. These networks consist of two stages. In the first, the wavelength tunability of the user stations is used to route packets from a given local optical network (LON) to a destination LON. When packets arrive at a destination LON, they are buffered and transmitted onto the required destination wavelength. There are a number of advantages to this design including the elimination of protocols which would require both dynamic station transmitter and receiver tunability. This design also takes advantage of increasingly available commercial ATM (Asynchronous Transfer Mode) buffer/switch components. Several hybrid electro-optic options are considered. It is also shown that by using a novel optical multichannel buffering scheme, the number of required buffers can be significantly decreased.</p> |
URI: | http://hdl.handle.net/11375/7571 |
Identifier: | opendissertations/2840 3862 1412695 |
Appears in Collections: | Open Access Dissertations and Theses |
Files in This Item:
File | Size | Format | |
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fulltext.pdf | 26.38 MB | Adobe PDF | View/Open |
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