Shanguo Huang

Desaturation following rapid sequence induction using succinylcholine vs. rocuronium in overweight patients

Background: Rapid sequence induction may be associated with hypoxemia. The purpose of this study was to investigate the possible difference in desaturation during rapid sequence induction in overweight patients using either succinylcholine or rocuronium.

Distributed Protocol for Removal of Loop Backs with Asymmetric Digraph Using GMPLS in P-Cycle Based Optical Networks

Pre-configured protection cycles (p-cycles) have drawn many attentions due to the fully pre-connected cyclic structures, ring-like speed, mesh-like spare capacity efficiencies and fast switching characteristics. In this paper, we propose a novel removal of loop back (RLB) approach with standard protocol extension (the flooding based distributed cycle pre-configuration (F-DCPC)) to solve the resource inefficiency issue due to long restored paths for symmetric dynamic networks. Meanwhile, distributed cycle pre-configuration (DCPC) is a representative technique for automatic p-cycle configuration. But for the mesh network topology under asymmetric service distribution, it works especially with more network convergence time and larger amount of extra controlling overhead. So in our RLB approach, F-DCPC scheme using generalized multi-protocol label switching (GMPLS) protocol to solve the problems of configurations and reconfigurations with asymmetric digraph in high-speed optical mesh networks is presented. Additionally, to describe the basic idea of traffic splitting strategy in the unidirectional resource distribution, we present the mathematic model with a heuristic algorithm to accelerate resource configuration. We evaluate the performance of F-DCPC utilizing proposed RLB approach with various classical p-cycles enumeration algorithms and allocation strategies by experimental simulations implemented in OPNET modeler, and the simulation results show the effectiveness of the proposed scheme.

Spectrum–block consumption for shared-path protection with joint failure probability in flexible bandwidth optical networks

We propose a minimum-free-spectrum-block-consumption algorithm (MFSB) for shared-path protection with joint failure probability requirements in flexible bandwidth optical networks. Compared with conventional algorithms, MFSB efficiently decreases the spectrum block consumption and achieves higher spectrum utilization.

Energy and Spectrum Efficiency with Multi-Flow Transponders and Elastic Regenerators in Survivable Flexible Bandwidth Virtual Optical Networks

Survivable energy-aware and spectrum-aware approaches (SEA/SSA) are developed to minimize energy and spectrum consumption in flexible bandwidth virtual optical networks. Simulation results show that SEA and SSA can efficiently reduce energy and spectrum consumption, respectively.

Minimum spectrum block consumption for shared-path protection with joint failure probability in flexible bandwidth optical networks

We propose a minimum-free-spectrum-block-consumption algorithm (MFSB) for shared-path protection with joint failure probability requirements in flexible bandwidth optical networks. Compared with conventional algorithms, MFSB efficiently decreases the spectrum block consumption and achieves higher spectrum utilization.

Dynamic Survivable Mapping in IP Over WDM Network

As the survivable mapping is critical in IP-over-wavelength-division-multiplexing (WDM) network to guarantee the restorability of IP layer, provisioning survivability in network with dynamic traffic is essential. However, survivable mapping problem for dynamic traffic shows more complexity than that for static traffic: 1) How to guarantee a survivable mapping since the lightpath is established and released dynamically; 2) how to make a balance between the cost of maintaining the survivable mapping and network utilization efficiency; 3) what kind of algorithm could be employed as an efficient online algorithm with acceptable computing complexity and scalability. In this paper, two schemes, dynamic routing and logical topology remapping, are proposed to keep a survivable mapping from logical topology to physical topology in dynamic traffic scenario. In addition, two different cutset-searching methods are presented in order to support the proposed online survivable mapping algorithm. At the end, a series of experiments employing regular networks and some special topologies with different connectivity have been carried out in order to evaluate the efficiency and scalability of our approach, in terms of the blocking probability, resource utilization, critical link holding time, and the restoration rate for random single failures. Generally, our results show that this new approach offers great degree of survivability for IP layer, but with acceptable resource cost and complexity.

Minimized spectrum resource consumption with rescaled failure probability constraint in flexible bandwidth optical networks

We investigate the problem of minimizing spectrum resource consumption for a set of connection requests in a flexible bandwidth optical network under the constraint that the failure probability of each connection must be below a specified threshold. To optimize the total frequency slots consumed, three schemes are proposed and evaluated: the rescaled failure-probability-aware algorithm (RFPA), the traffic cognition algorithm with rescaled failure probability (RFPTC), and an integer linear programming (ILP) model. We also introduce two traditional Dijkstras algorithms with load balancing and spectrum assignment by first fit and traffic cognition (FF_DB and TC_DB) to compare with the proposed three schemes. For static traffic in a small network, the total frequency slots consumed by the RFPA and RFPTC algorithms will approach that of the optimal ILP solution as K increases, aswellastheaveragehops (AH). Furthermore, the average rescaled failure probabilities (RFPs) of the RFPA and RFPTC algorithms are much better than thoseof the ILP solutions. Inaddition, similarly, the results of the heuristic algorithms, FF_DB, TC_DB, RFPA, and RFPTC, in the large network have the same characteristics as in the small network. For dynamic traffic in a large network, the RFPTC algorithm reduces blocking probability and makes the best use of spectrum resources compared with the other schemes, which also reflects that discontinuous spectrum fragmentation is greatly reduced by the traffic cognition method. However, both RFPTC and RFPA result in much higher average RFP but perform fewer AH compared to TC_DB and FF_DB.

k-regular and k-(edge)-connected protection structures in optical transport networks

We construct k-regular and k-(edge)-connected structures for providing protection against multiple failures in optical transport networks. It improves the spare resources efficiency without increasing the complexity of design and implementation of protection mechanisms.

Collision-aware routing and spectrum assignment in GMPLS-enabled flexible-bandwidth optical network

In a flexible-bandwidth optical network (FBON) with a generalized multiprotocol label switching control plane, the resource reservation protocol with traffic engineering extensions (RSVP-TE) is employed to establish end-to-end bandwidth variable lightpaths. The resource reservation can be blocked due to spectrum contention of different concurrent RSVP instances (called backward blocking), and it is the predominant blocking contribution when traffic load is low and arrival highly dynamic. Also, due to its flexible traffic granularity in FBON, the backward collision would happen more frequently and the collision scenario would be more complicated than that in wavelength-routed networking; thus the need for a collision evaluation and avoiding method. So, a collision-avoiding routing with maximum available spectrum allocation (SA) options and an SA scheme to search the spectrum segment with minimum collision possibility are proposed for backward blocking reduction, as well as an extension to the RSVP-TE. Simulation results show that the proposed algorithm could achieve better blocking performance through significantly reducing the backward reservation collision but with acceptable forward blocking deterioration. At the same time, with the proposed algorithm, different granularity traffic could be served more fairly in FBON.

A novel multi-fault localization mechanism in PCE-based multi-domain large capacity optical transport networks

A stateful PCE-based multi-link failure localization mechanism using fuzzy fault set is implemented in multi-domain large capacity optical networks. The novel localization mechanism has high scalability, speed and success rate compared with extended LVM protocol.