This paper studies dynamic dedicated protection with waveband switching to survive single-fiber link failure in optical networks. By considering the add/drop ports and switching ports consumption, we propose two heuristics named Extended Sub-path Grooming Dedicated Protection (ESGDP) and Extended End-to-end Grooming Dedicated Protection (EEGDP) based on Waveband Layered Auxiliary Graph (WLAG) since the grooming, routing and waveband assignment problem is the NP-hard. Simulation results show that ESGDP has lower blocking probability while EEGDP consumes fewer ports.

In order to save the switching ports and the cost of Multi-Granularity Optical Cross-Connect (MG-OXC), the waveband switching technique was proposed to groom multiple wavelength-level traffic to a few waveband tunnels to be switched by a few switching ports in MG-OXC. At the same time, protection for fibers is very important to ensure the service continuity since each wavelength carries a lot of traffic. Although existing works have addressed the waveband switching protection, most of them separately considered only the dedicated protection or shared protection in static demand scenario and did not deeply analyze and compare the dedicated protection and shared protection in dynamic demand scenario. Therefore, in this paper, we deeply study the consumptions of wavelengths in fibers and ports in MG-OXCs for Waveband Shared Protection (WSP) and Waveband Dedicated Protection (WDP) in dynamic demand scenario, and propose the port-cost calculation and update methods based on a new waveband layered auxiliary graph that is developed based on MG-OXC structure. In simulations, we compare WSP, WDP, traditional end-to-end waveband shared protection and traditional end-to-end waveband dedicated protection. Simulation results show that the shared protection has smaller port-cost, better wavelength utilization efficiency and lower blocking probability than the dedicated protection with the same waveband switching policy, and the sub-path waveband switching has bigger port-cost, better wavelength utilization efficiency and lower blocking probability than the end-to-end waveband switching with the same backup wavelength assignment policy.

In this paper, we study the protection problem with shared backup wavelength in waveband switching networks and propose a new Dynamic Waveband Shared Protection (DWSP) algorithm based on Waveband Layered Auxiliary Graph (WLAG) to survive the single-fiber link failure with considering the consumption of all-optical switching ports and add/drop ports. Simulation results show that DWSP obtains better performances than previous algorithm.

In this paper, we investigate the waveband switching technique and consider the problem of reducing the number of ports in optical cross-connects in wavelength-division-multiplexing optical networks. The basic idea of waveband switching is to bind several wavelengths into one waveband which can be switched by only one port so that the switches in conventional wavelength routed networks can be reduced and the cost of optical cross-connects can be saved. Since the traditional waveband switching schemes are the simple shortest route approach and the obtained paths may not be the optimal disposals for merging waveband, we propose a new heuristic waveband switching routing method. In our proposed method, we use the k-shortest path algorithm and the rerouting approach to optimize the number of ports in optical cross-connects. Simulation results show that, compared with the traditional algorithm that does not consider the waveband switching technique, the performance improvement of our proposed method is significant and promising.

In this paper, we study the waveband switching technique in WDM optical networks and propose a novel Routing Algorithm based on Integrated Auxiliary Graph (RAIAG) to save the switching ports in optical cross-connect. The IAG is compared of the single virtual topology layer and multiple waveband-plane layers, and it can well solve the problem of routing and waveband assignment. In RA-IAG, we use the waveband sub-path grouping scheme that performs better than other waveband grouping schemes. For each demand, RA-IAG first computes the single-hop or multi-hop route on virtual topology layer. If the route cannot be found on virtual topology layer, RA-IAG then computes the hybrid multi-hop route on jointing virtual topology layer and waveband-plane layers. Simulation results show that RA-IAG can obtain better performance than previous algorithm.

The structure of IP/MPLS over optical networks has become the trend for new generation backbone transport networks since the technology of general multi-protocol label switching (GMPLS) can realize the seamless converage between IP and optical networks. At the same time, due to the high-speed transmission rate of each wavelength in optical networks, survivability is a very important issue and has been studied all through these years. Therefore, in new generation GMPLS based networks, it is very necessary to investigate the multi-layer survivable algorithms. In this paper, we comprehensively review the existing survivable algorithms in multi-layer networks and analyze the shortages of current researches. Based on previous studies, we prospect challenges and propose new solutions of designing efficient survivable algorithms to well guide the future work of researchers in multi-layer networks.

This paper investigates the technique of waveband switching and considers the problem of reducing the number of ports in optical cross-connects in WDM optical networks. Based on previous studies, this paper proposes a new heuristic, in which the k-shortest path algorithm and rerouting scheme are used to optimize the number of ports. Simulation results show that the performance of proposed scheme can be significantly improved.

Since the lack of source IP address checking in today’s Internet makes it easy for the attackers to spoof the source address, the mechanism of Source Address Validation Architecture (SAVA) is proposed for building effective source-address validation to ensure that packets forwarded hold authentic source addresses. In this paper, we study the routing selection in partial deployment of SAVA nodes in the trustworthy Internet. We propose and compare three routing algorithms, i.e., Shortest-Path Algorithm (SPA), SAVA based Shortest-Path Algorithm (SSPA), and SAVA based Shortest-Path Algorithm with Load Balancing (SSPALB). Beside analytical results, we run simulations which met our expectations.

This paper investigates the problem of survivability in WDM optical networks, and proposes a new algorithm named Mixed Sub-Path Protection (MSPP) for protecting the single-link failure. MSPP computes one working path and one link-disjoint protection path (or two sub-protection paths) with considering the load balanced routing and restoration time constraints for each connection request. Simulation results show that compared with the traditional algorithms DSPP and DPP, MSPP can obtain lower blocking probability as the restoration time can be satisfied.