scholarly journals Optical Space Switches in Data Centers: Issues with Transport Protocols

Photonics ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 16 ◽  
Author(s):  
Mamun Abu-Tair ◽  
Philip Perry ◽  
Philip Morrow ◽  
Sally McClean ◽  
Bryan Scotney ◽  
...  
Keyword(s):  
Optical Networks ◽  
Transmission Control Protocol ◽  
Network Capacity ◽  
Network Architectures ◽  
Control Mechanisms ◽  
Network Resource ◽  
System A ◽  
Improved Performance ◽  
Total Capacity ◽  
Detrimental Impact

A number of new architectures for data centre networks employing reconfigurable, SDN controlled, all-optical networks have been reported in recent years. In most cases, additional capacity was added to the system which unsurprisingly improved performance. In this study, a generalised network model that emulates the behaviour of these types of network was developed but where the total capacity is maintained constant so that system behaviour can be understood. An extensive emulated study is presented which indicates that the reconfiguration of such a network can have a detrimental impact on Transmission Control Protocol (TCP) congestion control mechanisms that can degrade the performance of the system. A number of simple scheduling mechanisms were investigated and the results show that an on-demand scheduling mechanism could deliver a throughput increase of more than ∼50% without any increase in total installed network capacity. These results, therefore, indicate the need to link the network resource management with new datacentre network architectures.

scholarly journals D-OLIA: A Hybrid MPTCP Congestion Control Algorithm with Network Delay Estimation

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5764 ◽  
Author(s):  
Tabassum Lubna ◽  
Imtiaz Mahmud ◽  
Geon-Hwan Kim ◽  
You-Ze Cho
Keyword(s):  
Congestion Control ◽  
Transmission Control Protocol ◽  
Network Capacity ◽  
Delay Condition ◽  
Network Delay ◽  
Trip Time ◽  
Congestion Control Algorithm ◽  
Underlying Network ◽  
Improved Performance ◽  
Single Path

With the recent evolution of mobile technology, modern devices equipped with multiple communication interfaces have become popular. The multipath transmission control protocol (MPTCP) has evolved to facilitate multiple communication interfaces through a single TCP connection for faster Internet access. MPTCP congestion control algorithms (MPTCP-CCAs) control data flow by fulfilling three design goals, i.e., ensuring improvement over single-path flows, ensuring fairness, and balancing congestion. Current MPTCP-CCAs cannot fulfill these design goals. For example, the opportunistic-linked increase algorithm (OLIA), a well-known MPTCP-CCA in load balancing, often results in low throughput because it cannot properly utilize the underlying network. In addition, the current Internet has a rapidly changing characteristic due to a large amount of short-lived traffic, making it difficult for MPTCP-CCAs to cope. An awareness of prevailing network delay conditions might help MPTCP-CCAs to utilize the network capacity fully. Therefore, we propose dynamic OLIA (D-OLIA), a hybrid MPTCP-CCA that enhances the performance of OLIA by integrating an awareness of the current network delay condition for deciding the congestion window (CWND) decrease factor. We estimate the current network delay condition, i.e., less-congested or congested, by observing the changes in the round-trip-time (RTT). Based on the estimated network delay condition, we decide the CWND decrease factor in real-time for reducing the CWND during packet loss events. We implemented D-OLIA in the Linux kernel and experimented using the Mininet emulator. The emulation results demonstrate that D-OLIA successfully estimates current network delay conditions and results in approximately a 20% increased throughput compared to the original OLIA. Compared to certain MPTCP-CCAs, it also yields a highly improved performance in terms of throughput, RTT, packet retransmissions, and fairness among the MPTCP sub-flows.

Challenges in Future Intra-Data-Center Networks and Possible Solutions

2020 ◽  
pp. 157-199
Author(s):  
Muhammad Ishaq ◽  
Mohammad Kaleem ◽  
Numan Kifayat
Keyword(s):  
Optical Networks ◽  
Data Center ◽  
Network Architecture ◽  
Power Efficiency ◽  
Current Data ◽  
Network Architectures ◽  
Data Center Network ◽  
Data Center Networks ◽  
Bandwidth Utilization ◽  
Transparent Optical Networks

This chapter briefly introduces the data center network and reviews the challenges for future intra-data-center networks in terms of scalability, cost effectiveness, power efficiency, upgrade cost, and bandwidth utilization. Current data center network architecture is discussed in detail and the drawbacks are pointed out in terms of the above-mentioned parameters. A detailed background is provided that how the technology moved from opaque to transparent optical networks. Additionally, it includes different data center network architectures proposed so far by different researchers/team/companies in order to address the current problems and meet the demands of future intra-data-center networks.

Challenges in Energy-Efficient Communications as Enablers for Green Solutions on the 5G Heterogeneous Networks

2021 ◽  
pp. 457-475
Author(s):  
Irma Uriarte-Ramírez ◽  
Norma A. Barboza-Tello ◽  
Paul Medina-Castro
Keyword(s):  
Energy Management ◽  
Heterogeneous Networks ◽  
Energy Efficient ◽  
Interference Mitigation ◽  
Interference Management ◽  
Network Capacity ◽  
Management Plan ◽  
Network Architectures ◽  
Green Communications ◽  
Radio Access

One of the most representative challenges of multi-tier heterogeneous network architectures is the interference management among different Radio Access Technologies. In this sense, in order to achieve the potential increase on network capacity forecasted for 5G, the issue of interference must be addressed. Intelligent energy management, as proposed in the growing area of Green Communications could serve as an appealing solution to the interference issue. However developing an optimal energy management plan requires the understanding of the characteristics of 5G cellular networks that could be exploited to improve energy and resources efficiency. In this work we present a study about challenges in energy-efficient communications and technologies as enablers for green solutions and how this challenges can be extended to meet those of the 5G heterogeneous networks, in order to identify possible solutions to address the energy efficiency and interference mitigation issues.

Study of the Impact of Emerging Technologies Across the Value Chain Function of Educational Technology (EdTech) Firms

2022 ◽  
pp. 221-237
Author(s):  
Som Sekhar Bhattacharyya ◽  
Ankita Walke ◽  
Yash Shah
Keyword(s):  
Value Chain ◽  
Emerging Technologies ◽  
Big Data Analytics ◽  
Secondary Data ◽  
Ease Of Use ◽  
Base Case ◽  
Content Creation ◽  
System A ◽  
Improved Performance ◽  
The Impact

Narrative technology has been a prominent feature in educational value creation. Rapid penetration of internet and better digital infrastructure resulted in adoption of emerging technologies in education sector. As business of EdTech platforms soared up, the purpose of this research was to understand the impact of emerging technologies like big data analytics, cloud-based technologies, blockchain, machine learning, artificial intelligence, augmented reality, and virtual reality on various stages of EdTech value chain. This involved content creation, content distribution, and learning plus management system. A secondary data base case study analysis was carried out of EdTech firms in India. The value factors such as cost, accessibility, ease of use, and updated content came out as main attributes impacting acceptance of EdTech platforms. The mentioned emerging technologies impacted the content creation, delivery, evaluation, and feedback stages which resulted in improved performance across these value factors with lesser associated total costs.

Challenges in Energy-Efficient Communications as Enablers for Green Solutions on the 5G Heterogeneous Networks

2017 ◽  
pp. 58-76
Author(s):  
Irma Uriarte-Ramírez ◽  
Norma A. Barboza-Tello ◽  
Paul Medina-Castro
Keyword(s):  
Energy Management ◽  
Heterogeneous Networks ◽  
Energy Efficient ◽  
Interference Mitigation ◽  
Interference Management ◽  
Network Capacity ◽  
Management Plan ◽  
Network Architectures ◽  
Green Communications ◽  
Radio Access

One of the most representative challenges of multi-tier heterogeneous network architectures is the interference management among different Radio Access Technologies. In this sense, in order to achieve the potential increase on network capacity forecasted for 5G, the issue of interference must be addressed. Intelligent energy management, as proposed in the growing area of Green Communications could serve as an appealing solution to the interference issue. However developing an optimal energy management plan requires the understanding of the characteristics of 5G cellular networks that could be exploited to improve energy and resources efficiency. In this work we present a study about challenges in energy-efficient communications and technologies as enablers for green solutions and how this challenges can be extended to meet those of the 5G heterogeneous networks, in order to identify possible solutions to address the energy efficiency and interference mitigation issues.

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