Efficient shared segment protection in optical networks

This thesis introduces a new shared segment protection scheme that ensures both node and link protection in an efficient manner in terms of cost. Although the segment protection scheme exhibits an interesting compromise between link and path protection schemes and attempts to encompass all their advantages, it has been much less explored than the other protection approaches. The proposed work investigates two different Shared Segment Protection (SSP) schemes: Basic Shared Segment Protection (BSSP) and a new segment protection, called Shared Segment Protection with segment Overlap (SSPO). For both BSSP and SSPO schemes, we propose two novel efficient and scalable ILP formulations, based on a column generation mathematical modeling. SSPO offers more advantages over BSSP as it ensures both node and link protections, in addition to shorter delays. It is not necessarily more expensive while BSSP ensures only link protection. Indeed, depending on the network topology and the traffic instances, it can be shown that neither of the two SSP schemes is dominant in terms of cost. The mathematical models have been solved using column generation techniques. Simulations have been conducted to validate the two segment protection models and to evaluate the performance of the two segment protection schemes under different traffic scenarios. In addition, we have estimated when an additional cost (and how much) is needed in order to ensure node protection

A New Framework for Efficient Shared Segment Protection Scheme for WDM Networks

International audienceThis work introduces a new shared segment protection scheme that ensures both node and link protection in an efficient manner in terms of cost and bandwidth, while taking full advantage of the optical hop endpoints of the primary logical hops (induced by the routing) without adding extra ones for protection. As opposed to the link or path protection schemes, the segment protection scheme has been less studied although it offers an interesting compromise between those two protection schemes, attempting to encompass all their advantages. We investigate two different Shared Segment Protection (SSP) schemes: Basic Shared Segment Protection (BSSP) and Shared Segment Protection with segment Overlap (SSPO), and propose a design of 100% single segment protections. In SSPO, we study the extra protection capabilities, node failure and dual link failure survivability, offered by the single 100\% single segment protection. For both BSSP and SSPO schemes, we propose two novel efficient ILP formulations, based on a column generation mathematical modeling. While (SSPO) offers the advantage over (BSSP) to ensure both node and link protection, it is not necessarily much more costly. Indeed, depending on the network topology and the traffic instances, it can be shown that none of the two SSP schemes dominates the other one. Therefore, the SSPO protection scheme should be favored as it offers more protection, i.e., it adds the node protection to the link protection at the expense of a minor additional cost

COMPARISON OF HIGHLY SENSITIVE CRP AND SERUM CREATININE AS AN EARLY MARKER OF RENAL IMPAIRMENT

failure patients of both sexes not yet treated by dialysis and 50 age and sex matched healthy subjects were included in the study as case (Group-II) and control (Group-I) respectively. In this study, mean serum HS CRP concentration of CRF patients (50.938 ±38.88)mg/l found to be significantly elevated in comparison to control (1.12±.29mg/l). In CRF patients, serum HS CRP found to show a strong negative correlation with creatinine clearance and a strong positive correlation with blood urea, serum creatinine. This study shows an inverse linear relationship between HS CRP and CCRin contrast to the inverse curvilinear relationship found to exist between serum creatinine and creatinine clearance. Regression analysis between CCR and HS CRP shows a rise of HS CRP Y one unit (mg/l) is accompanied by creatinine clearance to be decreased by 0.44ml/min. Mean serum HS CRP concentration in chronic renal failure increases significantly. Early phase of decreased CCR can not be detected by the serum creatinine because serum creatinine does not increase until there is significant fall ( 30 ml/min) of creatinine clearance. In contrast to this serum HS CRP begins to rise from the very beginning of the fall of creatinine clearance. So the early phase of decreased creatinine clearance could be detected by simultaneous rise of serum HS CRP