Clean energy is the key starting to be used as to solve the climate change or global warming problems. However, having intelligent, sustainable, and robust systems is a global challenge, specifically for renewable energy grid connected systems. One of the most important aspects is investigating the changes in load demand and electricity prices over the project lifetime and the possible impact on the system's performance. This paper continued work on a previous study and illustrates the importance of sensitivity analysis and system flexibility for RE systems connected to utility grid. Net present cost (NPC), levelized cost of energy (LCOE), system environmental impacts were investigated using HOMER software to do the analysis of this study. The simulation results showed that changes in load demand and electricity prices can have a significant impact on system's performance and integration to the power systems.

The Internet protocol (IP) plays a dominant role in current networking technologies and the wavelength division multiplexing (WDM) technology provides tremendous bandwidth. The IP-over-WDM is becoming the right choice for next-generation Internet networks where optical burst switches (OBS) is a promising technique to bridge the gap between IP and WDM. However, traditional OBS scheduling algorithms either have low computational complexity with high burst dropping probability or high computational complexity with low burst dropping probability. A critical design issue in OBS is how to reduce burst dropping probability as a result of resource contention using a high performance scheduling algorithm. In this paper, we present an ultra-fast scheduler which integrates the merits of both low computational complexity and low burst dropping probability. The key idea is to maintain all scheduled data bursts and void intervals in a binary representation. Then, fast hardware logic operations are performed to schedule incoming data bursts without the need to traverse and search all scheduled bursts in all channels. The new approach provides an effective optical burst switching for variable-length bursts with low computational complexity compared to existing scheduling algorithms.

Optical burst switching (OBS) is a promising technique for next-generation optical switching networks. In traditional OBS, an entire burst is discarded when all output wavelengths are engaged at the arrival instant of the burst. A critical design issue in OBS is how to reduce burst dropping probability as a result of slow scheduling reservation or resources contention. This paper proposes a hardware-based slotted wavelength assignment pipeline (SWAP) scheduler which integrates the merits of both low computational complexity and low burst dropping probability. The key idea is to maintain all scheduled data bursts and void intervals within a scheduling time window in binary vectors. Scheduling of incoming data bursts is performed using fast hardware operations without the need to search lookup tables for void intervals on output wavelength channels. The design has been verified using Verilog HDL simulation models. The performance has been evaluated for 1 Tbps switch using Poisson traffic arrivals.

Modular adders are widely used in Residue Number System arithmetic. Their performance is restricted due to the hardware implementation complexity. In this work, we investigate the design of a redundant modulo number system and present hardware architecture for performing the redundant modulo 2 n -1 addition with a constant time feature using the Binary Signed Digit Number (BSDN) System. We developed a set of logical equations that describe the BSDN full adder operation and later used it as a building block to construct the redundant modulo 2 n -1 adder. The proposed architecture has a constant delay equals to the delay of one BSDN FA and an area equals to n * (BSDN FA area), where n is the word length. We also presented a strategy to improve the design by considering the different combinations of the operands.

Optical burst switching (OBS) is a promising technique for next-generation optical switching networks which attempts to address the problem of efficiently allocating resources for bursty traffic. In traditional OBS, an entire burst is discarded when all output wavelengths are engaged at the arrival instant of the burst. A critical design issue in OBS is how to reduce burst dropping probability as a result of resource contention. This paper proposes new core node architecture to provide a combined impact for an effective scheduling algorithm that improves burst loss rate and utilization in OBS switches. The new design provides an effective optical burst switching for variable-length bursts with low complexity compared to several existing scheduling algorithms. A combined contention resolution approach of wavelength reassignment capability and limited delay is used.

It has been demonstrated that advertising the availability of wavelength and converter resources in all-optical DWDM transport networks with sparse wavelength conversion capabilities can drastically improve the blocking performance of these networks thus achieving better usage of the network resources. An important aspect with consequences in network performance is when to originate the wavelength-availability and converter-availability link state advertisements (LSAs). Frequent link-state advertisements could overwhelm the network control plane with many update messages that need to be processed. On the other hand, delaying these advertisements could result in inaccurate link-state information thus degrading the network blocking performance. In this paper, we propose two different link-state update policies to advertise the availability of wavelength and converter resource in all-optical DWDM transport networks with sparse wavelength conversion capabilities. The first one is very simple and serves as our base policy for comparison. The second policy, which is very efficient in handling the dynamic nature of all-optical DWDM networks with different degrees of wavelength conversion, reduces the number of LSAs considerably while maintaining the call blocking probability.

In this paper, we propose a novel routing framework for all-optical dense wavelength-division-multiplexing transport networks with sparse wavelength conversion capabilities. The routing framework includes an integer linear programming formulation to handle the static lightpath establishment problem and a novel open shortest path first protocol extension that advertises the availability of wavelength usage and wavelength conversion resources. Our routing framework addresses the limitations of the extensions presented in the literature because it also includes: 1) an efficient flooding protocol that is suitable for the dynamic nature of these networks and 2) an efficient route and wavelength computation engine that minimizes connection costs without hindering the blocking probability.

This work focuses on the routing and wavelength assignment (RWA) problem in all-optical DWDM networks with sparse wavelength conversion (SWC) capabilities. By sparse wavelength conversion, we mean that nodes within the optical network domain might or might not support optical wavelength conversion. For these nodes that support optical wavelength conversion, the number of wavelength converters might be limited. As such, optical lightpaths might or might not be able to find the wavelength conversion resources that might be needed for it to be established. In this work, we present the RWA problem in all-optical WDWM networks with sparse wavelength conversion capabilities (RWA-SWC). We also provide integer linear programming (ILP) formulation for static lightpath establishment (SLE) in all-optical networks with sparse wavelength conversion capabilities. Finally, we propose a new opaque extension to the OSPF routing protocol to advertise wavelength usage and converter availability throughout the optical network domain.

IPSec provides two types of security algorithms, symmetric encryption algorithms (e.g. data encryption standard DES) for encryption, and one-way hash functions (e.g., message digest MD5 and secured hash algorithm SHA1) for authentication. This paper presents performance analysis and comparisons between these algorithms in terms of time complexity and space complexity. Parameters considered are processing power and input size. The analysis results revealed that HMAC-MD5 can be sufficient for the authentication purposes rather than using the more complicated HMAC-SHA1 algorithm. In encryption applications, authentication should be combined with DES.

The toolkit for routing in optical networks (TRON) is a freely available library developed to facilitate research experiments on OSPF-based routing protocols for optical networks. Currently, TRON supports the lightwave-OSPF routing protocol, which is our adaptation of the optical extensions to OSPF proposed in the Internet drafts of Kompella et al and Wang et al. TRON is implemented in C++ using the component architecture for simulating network objects (CASiNO). TRON software can be used in either simulation or emulation mode. In this paper, we describe lightwave-OSPF and the architecture of the TRON software.