T-MPLS is regarded as one of the most important transport technologies in the next generation network, it a
connection oriented packet transport technology develop from MPLS techniques, now defined by ITU-T SG13 &
SG15. In this paper, we analyze the architecture of the transport MPLS networks, the most important building
blocks for the modular design of the common T-MPLS equipment are introduced. And based on the functional
blocks, a four-layer simulation T-MPLS node structure is developed. And the simulation environment is introduced.
Many kinds of research can be done using this T-MPLS simulation tool, such as the research of the feasibility
T-MPLS design, the inter-working between the T-MPLS and the PWE.
The paper reports a novel design for single-polarization single-mode (SPSM) operation at 1310 nm in photonic crystal fibers (PCFs), using a rectangular-lattice PCF with two lines of three central air holes enlarged. The proposed PCF, composed entirely of silica, is modeled by a full-vector finite-element method with anisotropic perfectly matched layers. Simulations show that wideband single-polarization operation can be easily realized with the proposed structure. This wideband SPSM operation, the low confinement losses, and the small effective mode area are the main advantages of the proposed fiber. The influence of varying PCF parameters on the SPSM operation is discussed, and numerical results show that the proposed fiber is a SPSM one with confinement loss less than 0.1 dB/km at wavelengths ranging from 1100 to 1460 nm and effective mode area about 4.3 µm2 at 1310 nm.
This paper focuses on the survival mechanisms against single link failure for optical QoS services in ASON (Automatically Switched Optical Network). The new protection and restoration methods and optical QoS services enabled by ASON also bring new requirements. Correspondingly, the component functions in ASON control plane, such as Connections Controller, Link Resource manager and Routing Controller are extended. According to the survival level of the QoS service requested, we divide the traffic into five types, viz. 1+1, 1:1, shared-mesh, rerouting and extra traffic. Optical QoS services and resource preemption are realized in our simulation platform. Extensive simulations are performed concerning failure localization time, failure recovery time, recovery success ratio and network resource utilization.
A distributed flexible architecture of adaptive control and service provisioning founded on automatic switched optical network is proposed in this paper. The testbed named Adaptive Multi-Service Optical Network (AMSON) has been developed for proof of the fundamental of adaptive control for intelligentized service realization and lightpath transmission.
p-cycle provides a new protection scheme which provides fast protection switching time as that in ring networks and high resource efficiency as that in mesh networks. Extensive research has shown that the concept of p-cycle can also be applied to Automatically Switched Optical Network (ASON), which is the direction of the next generation optical network. This paper proposes a novel dynamic p-cycle algorithm in ASON named Routing in Spare plus Protecting Capacity Dynamic p-cycle Algorithm (RSPC-DP). Different from traditional dynamic p-cycle algorithms, the proposed algorithm takes traffic forecast matrix into account, and it is capable of tracing the changes of network environment and dynamic traffic matrix on-line. Extensive simulation results show that the proposed algorithm outperforms the existing algorithms significantly.
We study and test several P-Cycle generation algorithms from different strategies. The basic approach of P-Cycle algorithm is to identify an elementary cycle-set firstly, and then to search for improvements on this set through different strategies to create the final P-Cycle-set with higher efficiency. The P-Cycle generation algorithms which are presented in this paper are in terms of three aspects that are elementary cycle-set generation, expansion strategies and expansion times. At last simulation and analysis with these different algorithms will be presented.
A novel wavelength availability advertisement based ASON routing protocol implementation is proposed in this paper which is derived from Open Shortest Path First protocol (OSPF) version 2. It can be applied to ASON network with a single control domain and can be easily extended to support routing in the multi-domain scenarios. Two
new types of link state advertisement (LSA) are suggested for disseminating wavelength availability and network topology information. The OSPF mechanisms are inherited to ensure that the routing messages are delivered more reliably and converged more quickly while with fewer overheads. The topology auto discovery is realized through LSA flooding interacting with auto neighbor discovery using Link Management Protocol. The new LSA formats are given and how the link state database (LSD) is comprised is described. The new data structures proposed include topology resource list, adjacency list and route table. Then we analyze the differences of ASON in link state exchange, routing information flooding procedure, flushing procedure and new resources participating, i.e. new links or nodes join in an existing ASON. The link or node failure and recovery effect and how to deal with them are settled as well. In order to adopt different Routing and Wavelength Assignment (RWA) algorithms, a standard and efficient interface is designed. After extensive simulation we give the numerical analysis and come to the following conclusions: wavelength availability information flooding Convergence Time is about 30 milliseconds and it is not affected by RWA algorithms and the call traffic load; routing Protocol Average Overhead rises linearly with the increase of traffic load; Average
Connection Setup Time decreases with the increase of traffic load because of the decrease of Average Routing Distance of the successfully lightpaths; Wavelength availability advertisement can greatly promote the blocking performance of ASON in relatively low traffic load; ASON operator can make a good trade off between the wavelength availability advertisement Protocol Average Overhead and Blocking Probability by adopting and adjusting the routing update
triggers; and the last is that wavelength availability advertisement throughout the optical network is applicable and our ASON routing protocol implementation could be applied in ASON when its scale is not too large and if the calls do not arrive and leave the network in a too frequent pace.
This paper describes our work on the key techniques in ASON control plane and introduces a practicable software simulation-based ASON network framework and node structure. The implementation methods of the control channel and the composition of the control protocol traffic flow are analyzed. Then simulation of the control channel capacity requirements in ASON under different conditions is realized. Relationship between the control channel traffic rate and the network traffic load of the ASON network is introduced. The capacity requirements of the control channel under different connection setup time limits are also analyzed. In the end the approximate equations to describe these relations are developed.
In this paper, according to the ITU-T recommendation G.8080, we present a novel architecture of RC based on the extended GMPLS, which consists of interface component, OSPF-TE component, route computation component and routing information database. The RC is emulated in the ASON simulation software developed by us, where the OSPF is extended as the routing protocol and GMPLS RSVP-TE is adopted as signalling protocol. In the simulation, the RWA scheme, the fixed shortest path routing way and first fit wavelength algorithm, is used. The simulation results of RC have been presented in terms of flooding time (FT), flooding overhead (FO) and route computing time. The FT and FO just have a very little change under different traffic load, which indicates that re-flooding is rare and the RC works efficiently.