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An Emission and Discard Priority Scheme for Optical Burst Switched Networks
Optical burst switching (OBS) is a promising technology designed to meet the growing demands for internet handwidth and better Quality of Service (QoS). This technology provides all optical and high speed switching to overcome the bottleneck of electronic routers in the core network. In this thesis,...
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| Format: | Thesis |
| Language: | English |
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Department of Electrical Engineering
2024
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| _version_ | 1867613295234514944 |
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| access_status_str | Open Access |
| author | Acquaah_PEK |
| author2 | H. Anthony Chan |
| author_browse | Acquaah_PEK H. Anthony Chan |
| author_facet | H. Anthony Chan Acquaah_PEK |
| author_sort | Acquaah_PEK |
| collection | Thesis |
| description | Optical burst switching (OBS) is a promising technology designed to meet the growing demands for internet handwidth and better Quality of Service (QoS). This technology provides all optical and high speed switching to overcome the bottleneck of electronic routers in the core network. In this thesis, I describe several critical issues that affect OBS networks. I highlight the need to resolve contention efficiently and cost-effectively to improve QoS in OBS networks. Techniques to resolve contention include wavelength conversion, deflection routing, optical buffering, and burst segmentation. Amongst these techniques, deflection routing is the most cost-effective because it requires no extra hardware and offers high throughput at low loads. However, deflection routing has shortcomings such as high burst loss at high loads and a high number of late packet arrivals, which hinder its performance. Hence, the aim of our study is to reduce the number of late packet arrivals due to burst deflections and to increase the efficiency of deflection routing. For this purpose, we propose an emission and discard priority (EDP) scheme. The EDP scheme assigns emission and discard priorities to bursts based on their QoS requirements. This type of burst differentiation allows routers to deflect bursts selectively and efficiently in the core network. Through simulations, I compare the performance of the deflection with EDP scheme, the no-deflection (drop policy) scheme. and the deflection scheme. I show that the deflection with EDP scheme has a higher throughput than the no-deflection scheme. and a higher throughput than the deflection scheme for loads L ~ 0.7 . Furthermore, I shm' that the deflection with EDP scheme has a lower proportion of late packet arrivals than the deflection scheme at all loads. As a result, the deflection with the EDP scheme outperforms the deflection scheme in terms of goodput for L ~ 0.7. Although the deflection scheme has higher goodput than the deflection with EDP scheme at low loads (L < 0.7), the iii deflection with EDP scheme performs fewer burst deflections, with a minimal loss in goodput. Hence, the deflection with EDP scheme has a higher goodput per deflection ratio, and is therefore more efficient than the deflection scheme without EDP. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/39902 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:33:51.607Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2024 |
| publishDateRange | 2024 |
| publishDateSort | 2024 |
| publisher | Department of Electrical Engineering |
| publisherStr | Department of Electrical Engineering |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/39902 An Emission and Discard Priority Scheme for Optical Burst Switched Networks Acquaah_PEK H. Anthony Chan Electrical Engineering Optical burst switching (OBS) is a promising technology designed to meet the growing demands for internet handwidth and better Quality of Service (QoS). This technology provides all optical and high speed switching to overcome the bottleneck of electronic routers in the core network. In this thesis, I describe several critical issues that affect OBS networks. I highlight the need to resolve contention efficiently and cost-effectively to improve QoS in OBS networks. Techniques to resolve contention include wavelength conversion, deflection routing, optical buffering, and burst segmentation. Amongst these techniques, deflection routing is the most cost-effective because it requires no extra hardware and offers high throughput at low loads. However, deflection routing has shortcomings such as high burst loss at high loads and a high number of late packet arrivals, which hinder its performance. Hence, the aim of our study is to reduce the number of late packet arrivals due to burst deflections and to increase the efficiency of deflection routing. For this purpose, we propose an emission and discard priority (EDP) scheme. The EDP scheme assigns emission and discard priorities to bursts based on their QoS requirements. This type of burst differentiation allows routers to deflect bursts selectively and efficiently in the core network. Through simulations, I compare the performance of the deflection with EDP scheme, the no-deflection (drop policy) scheme. and the deflection scheme. I show that the deflection with EDP scheme has a higher throughput than the no-deflection scheme. and a higher throughput than the deflection scheme for loads L ~ 0.7 . Furthermore, I shm' that the deflection with EDP scheme has a lower proportion of late packet arrivals than the deflection scheme at all loads. As a result, the deflection with the EDP scheme outperforms the deflection scheme in terms of goodput for L ~ 0.7. Although the deflection scheme has higher goodput than the deflection with EDP scheme at low loads (L < 0.7), the iii deflection with EDP scheme performs fewer burst deflections, with a minimal loss in goodput. Hence, the deflection with EDP scheme has a higher goodput per deflection ratio, and is therefore more efficient than the deflection scheme without EDP. 2024-06-19T07:07:45Z 2024-06-19T07:07:45Z 2007 2024-06-18T13:15:32Z Thesis / Dissertation Masters Masters http://hdl.handle.net/11427/39902 eng application/pdf Department of Electrical Engineering Faculty of Engineering and the Built Environment |
| spellingShingle | Electrical Engineering Acquaah_PEK An Emission and Discard Priority Scheme for Optical Burst Switched Networks |
| thesis_degree_str | Master's |
| title | An Emission and Discard Priority Scheme for Optical Burst Switched Networks |
| title_full | An Emission and Discard Priority Scheme for Optical Burst Switched Networks |
| title_fullStr | An Emission and Discard Priority Scheme for Optical Burst Switched Networks |
| title_full_unstemmed | An Emission and Discard Priority Scheme for Optical Burst Switched Networks |
| title_short | An Emission and Discard Priority Scheme for Optical Burst Switched Networks |
| title_sort | emission and discard priority scheme for optical burst switched networks |
| topic | Electrical Engineering |
| url | http://hdl.handle.net/11427/39902 |
| work_keys_str_mv | AT acquaahpek anemissionanddiscardpriorityschemeforopticalburstswitchednetworks AT acquaahpek emissionanddiscardpriorityschemeforopticalburstswitchednetworks |