A Novel Segmentation and Feedback Model for Resolving Contention in Optical Burst Switching

A novel segmentation and feedback model (SFM) applied to resolve contention is proposed. Simulation and performance analyses show that the SFM effectively avoids contentions in optical burst switching (OBS). The long delay time of deflection routing and the immature technology of wavelength converters and optical buffers are not deployed in the SFM. The SFM does not only realize fast switching but also allows preemption by higher priority bursts.     

A novel optical burst switching scheme—logical cascaded private subnet with start wavelength assignment policy

Many recent studies have convincingly demonstrated that network traffic exhibits a noticeable self-similar nature, which has a considerable impact on network performance, and most studies of optical burst switching (OBS) networks are under a fundamental assumption that full wavelength conversion is available throughout the network. In practice, however, economic and technical considerations are likely to dictate a more limited and sparse deployment of wavelength converters in the optical network. Therefore, we present a novel scheme for OBS networks, called logical cascaded private subnet (LCPN) with start wavelength assignment policy. We define the concept of canoe relative to cluster in self-similar traffic, and introduce a new device named payload segregator at the edge node as a gateway to the core node in OBS Networks. According to the changes in the edge node framework, we put forward the concept of cluster private subnet and canoe private subnet in the core node correspondingly. A new start wavelength assignment policy is proposed for the absence of (full) wavelength conversion capabilities in the core node of OBS Networks. The performance study indicates that, our new scheme is robust under self-similar traffic and wavelength continuity constraint.     

Time-Space Label Switching Protocol (TSL-SP)—A New Paradigm of Network Resource Assignment

In this paper we propose a new protocol called time-space label switching protocol (TSL-SP) in optical burst switching (OBS), and define the terms time-space label (TSL) and time-space routing (TSR). An important concept of response time is introduced in the time label mechanism. The TSL-SP is a new technology that can quickly and efficiently forward data with a label on the optical networks. A two-dimension label switched path (TD-LSP) can be set up, that is maintained and deleted by the TSL-SP. For clearly illuminating the operation principles of the TSL-SP, we propose a new approach of orthogonal time-space coordinates in which the vertical coordinate is the space label and the horizontal coordinate is the time label. The proposed TD-LSP can dramatically reduce the routing failure probability and greatly improve the link network efficiency compared with other signaling protocols. Moreover, we define the time-space label control plane that can achieve the higher efficiency. When the TSL-SP is applied to networks, switching performance can be improved by two orders compared to the switching performance with the conventional OBS signaling protocols. The fundamental goal of TSL-SP is to band the signaling and routing functions together closely. Also, the TSL-SP can reduce the complexity of the network, support automatic service offering, and provide traffic engineering.     

相干光纤通信系统中的偏振分集接收机的实验研究

本文讨论了相干光纤通信系统中的偏振分集接收机的基本原理,并在实验中首次实现了基于偏振分集的偏振不敏感接收。在调制信号为137.2MHz和146.0MHz正弦波的情况下,得到了很好的与信号偏振面无关的解调信号。这一结果正在应用于1.5μm波段140Mb/s FSK相干光纤通信系统之中。     

SRS效应在双向波分复用系统中的单向等效

对在双向传输波分复用情况下系统中的受激喇曼散射（SRS）效应进行了研究。对在不含放大器以及包含级联EDFA等情况下受激喇曼散射对双向系统的影响进行了理论及模拟分析，通过对照单向系统的对应性能，发现双向系统中的SRS效应的端特性可以通过一个对应的单向系统进行等效，从而使我们可以以较少的工作量对双向系统进行细致、准确、简洁的分析。     

A novel distributed scheduling approach powered by central databases in optical burst networks

In terms of the growth rate, network capacity is slower than network traffic. To solve the mismatch between them, utilization of available capacity can be maximized to provide “best-fit” service for emerging applications (e.g., eBanking, Peer-to-Peer (P2P) file exchanges, etc.). To satisfy such a requirement, we propose a three-dimensional label scheduling algorithm (TD-LSA), which is a distributed scheduling approach powered by central databases. In the proposal, all connections are provisioned in three dimensions (i.e., space, time and wavelength) in a distributed way and uniquely identified by three-dimensional labels. And in this way a three-dimensional connection is more robust than a single-dimensional connection because the three-dimensional approach can avoid potential scheduling conflicts as much as possible by using central databases in a network. Thus, the central databases can reduce bandwidth consumption and offer “best-fit” service for three-dimensional connections. Furthermore, in order to further reduce bandwidth consumption and to match with a priority of traffic, K-least hop first path (K-LHPF) and a rescheduling mechanism are applied to our proposal. Simulation experiments demonstrate that our proposal achieves the expected performance gain against existing alternates.

红外成像检测中一种新型噪声抑制方法的理论模拟

根据线性微分方程的特点及两个合理的近似,提出了一种新的用计算机辅助去除红外成像检测中高功率噪声的方法,仿真结果表明方法有良好的抑制噪声效果。     

沿传输方向浓度渐变掺铒光纤放大器的模型

提出了两种掺铒浓度渐变的分布式光纤放大器（ｄ－ＥＤＦＡ）模型：沿传输方向，掺杂浓度单调线性下降与掺杂浓度线性由大到小，由小到大两次变化的ｄ－ＥＤＦＡ，用传输方程研究了不同渐变系数下，ｄ－ＥＤＦＡ的各种特性。     

高性能法布里—珀罗腔的研究

可调谐法布里－珀罗腔可用于频分复用，波分复用以及光孤子通信系统之中，是一种重要的光学器件。本文从原理上分析了制造性能优良的法布里－珀罗腔所应考虑的各种因素，结合两种先进的制腔方法，即腔外匹配和腔内加光阑法，解决了制做过程中所遇到的技术问题，制成的腔具有较高的性能。