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161.
In optical Wavelength Division Multiplexing (WDM) networks, different protection schemes have been proposed in the literature,
namely, dedicated protection and shared protection. Shared protection techniques significantly reduce the required spare capacity
by providing the same level of availability as dedicated protection. However, current mission critical applications (which
heavily depend on the availability of communication resources) require connection availability in the order of 99.999% or
higher, which corresponds to a downtime of almost 5 min a year on the average. Therefore, in order to satisfy a connection
serviceavailability requirement defined by the users Service Level Agreement in a cost-effective and resource-efficient way,
network operators need a systematic mechanism to evaluate the network availability under multiple failure scenario to ensure
that current network configuration can meet the required availability degree; otherwise, a network upgrade is required. Unfortunately,
under multiple failure scenario, traditional availability analysis techniques based on reliability block diagrams are not
suitable for survivable networks with shared spare capacity. Therefore, a new concept is proposed to facilitate the calculations
of network availability. In this paper, we propose an analytical model for evaluating the availability of a WDM network with
shared-link connections under multiple link failures. The analytical model is also verified using Monte Carlo simulation.
The proposed model significantly contributes to the related areas by providing network operators with a quantitative tool
to evaluate the system availability and, thus, the expected survivability degree of WDM optical networks with shared connections
under multiple link failures. 相似文献
162.
163.
Pandey Swarnima Siddiqui Mohd Adnan Azim Afzal Sinha Neeraj 《Magma (New York, N.Y.)》2023,36(4):659-669
Magnetic Resonance Materials in Physics, Biology and Medicine - An early metabolic signature associated with the responsiveness to treatment can be useful in the better management of septic shock... 相似文献
164.
Menas Ebrahim Eissa Mohamed Abdel Azim Mohamed Maher Ata 《International Journal of Communication Systems》2023,36(13):e5517
The number of internet users and connected devices has dramatically expanded due to the recent technological boom and the benefits that the internet of things offers to ease our lives. Network scheduling, quality of service, resource allocation, and security issues are now being addressed via software-defined networking (SDN). SDN has several benefits over traditional networks, including global centralized control, managing network traffic, and separating the forwarding and control plane. The work done in this paper aims to design and implement a traffic-aware routing framework based on routing optimization presented as an integer linear programming (ILP) to improve heterogeneous traffic flows' quality of service (QoS) in a simulated SDN environment. With the knowledge that the routing problem is a nondeterministic polynomial-time-hard problem, the proposed scheme aims to decrease the computational routing time to make the ILP-based routing system more suitable for real-time processing. The simulation results illustrate that the proposed framework reduces the computational time by 23% and 49% for Abilene and Goodnet topology, respectively. Additionally, with 1000 flows in the network, the suggested scheme reduces the number of network flows that violate the QoS by 9% and 22% (with Abilene topology) and 16% and 51% (with Goodnet topology) as compared to the existing shortest path delay and sway methods, respectively. 相似文献
165.
Liton Chandra Paul Himel Kumar Saha Tithi Rani Rezaul Azim Mohammad Tariqul Islam Md Samsuzzaman 《International Journal of Communication Systems》2023,36(1):e5357
A semi-circular patch antenna (SCPA) is designed for WiMAX and WiFi-5/6 communications. The footprint of the proposed SCPA is only 30 × 40 × 1.575 mm3, which is composed of a semi-circular patch and a partial ground plane. The main strength of this work is that the estimated wide dual-frequency span of 2.39–3.75 GHz and 5.39–7.18 GHz are contributed with two sharp resonances at 2.77 and 6.46 GHz, respectively. The proposed SCPA has been practically tested after fabrication. The measured results confirm that the designed antenna achieved the bandwidth necessity for WiMAX 1.5 (2.5–2.69 GHz), WiMAX 2 (3.4–3.6 GHz), WiFi-5 (5.15–5.85 GHz) and WiFi-6 (5.925–7.125 GHz). In the two resonance frequencies of 2.77 and 6.46 GHz, the designed antenna achieved a gain of 2.558 and 4.109 dB, respectively. In addition, the SCPA also manifests good radiation properties and achieves an average efficiency of more than 90%. A professional version of the 3D electromagnetic simulator is utilized to examine the effect of diffident parameters and model the tested antenna. 相似文献