Network and service providers are rapidly deploying IPTV networks to deliver a wide variety of video content to subscribers. Some video content may be protected by copyright and/or may be subject to distribution restrictions. Encryption technologies may not always be effective to manage protected video content, particularly when video content is legally decrypted upon receipt by a subscriber. This paper presents a new approach to detect if specific (or protected) downloaded video is being redistributed by a subscriber using the broadband Internet connection. The approach employs a traffic-based signature of the protected video clip. The signature which is shown to be unique is stored in a signature store. We adopt a wavelet-based analysis to match video streams captured from the network to the signatures in the store. The performance of the detection algorithm is evaluated using a large video database populated with a variety of movies and TV shows. The experiment results show that our algorithm achieves high detection rates and low false alarm rates using video clips of only a few seconds.

Progress in network technologies and protocols is paving the road towards flexible optical transport networks, in which leasable circuits could be set up and released on a short-term basis. Thus we consider it reasonable that, at least for some types of services, the holding time of connection requests can be known in advance. In this paper, we propose to exploit the knowledge of connection-holding time to improve the performance of an algorithm for shared-segment protection (SSP). For a typical US nationwide network, we compared our approach to an holding-time-unaware, but otherwise shared segmented efficient, approach, obtaining savings on resource overbuild of up to 7% for practical scenarios.

We investigate the problem of reliable multi-path provisioning of traffic in high-capacity optical backbone mesh networks, e.g., next-generation SONET/SDH networks supporting virtual concatenation (VCAT). VCAT enables a connection to be inversely multiplexed on to multiple paths. As a result, a connection can be provisioned more flexibly, and such a multi-path provisioning approach may lead to significantly improved performance over the conventional single-path provisioning approach. This multi-path provisioning approach may also be applicable to other mesh networks such as those employing optical wavelength-division multiplexing (WDM) and multi-protocol label switching (MPLS), where the bandwidth of a connection to be provisioned exceeds the available capacity on any path based on current network state. We propose effective multi-path bandwidth as the metric to provision a connection on to multiple paths while satisfying its reliability requirements (measured in terms of availability). We show that effective multi-path bandwidth provides more flexibility and lower blocking probability without the cost and complexity associated with traditional protection schemes developed for optical WDM and MPLS networks.

This paper investigates survivable lightpath provisioning and fast protection switching for generic mesh-based optical networks employing wavelength-division multiplexing (WDM). We propose subpath protection, which is a generalization of shared-path protection. The main ideas of subpath protection are: 1) to partition a large optical network into smaller domains and 2) to apply shared-path protection to the optical network such that an intradomain lightpath does not use resources of other domains and the primary/backup paths of an interdomain lightpath exit a domain (and enter another domain) through a common domain-border node. We mathematically formulate the routing and wavelength-assignment (RWA) problem under subpath protection for a given set of lightpath requests, prove that the problem is NP-complete, and develop a heuristic to find efficient solutions. Comparisons between subpath protection and shared-path protection on a nationwide network with dozens of wavelengths per fiber show that, for a modest sacrifice in resource utilization, subpath protection achieves improved survivability, much higher scalability, and significantly reduced fault-recovery time.

We propose a hybrid optical-electrical switch architecture which integrates all-optical waveband switching and electrical time-division-multiplexed (TDM) switching. By grouping pass-through traffic into wavebands and switching them all-optically, the hybrid architecture can significantly reduce the size of electrical switch and number of associated transponders. As a result, it provides tens of terabits per second switch throughput with a small footprint. The proposed architecture is capable of TDM switching, wavelength conversion, and multicasting. In this paper, we investigate the network-optimization problem with static traffic to minimize the overall network switch cost. A mathematical formulation of the optimization problem and its solutions are presented. Fast heuristic approaches for near-optimal solutions are also proposed and evaluated.

This paper investigates the problem of dynamic shared-path-protected lightpath provisioning in optical mesh networks employing wavelength-division multiplexing (WDM). We prove that the problem of finding an eligible pair of working and backup paths for a new lightpath request requiring shared-path protection under the current network state is NP-complete. We develop a heuristic, called CAFES, to compute a feasible solution and an algorithm, called OPT, to optimize resource consumption for a given solution. The merits of our approaches are that they capture the essence of shared-path protection and approach to optimal solutions without enumerating paths. We evaluate the effectiveness of our heuristics and the results are found to be promising.

We investigate the survivable traffic-grooming problem for optical mesh networks employing wavelength-division multiplexing (WDM). In the dynamic provisioning context, a typical connection request may require bandwidth less than that of a wavelength channel, and it may also require protection from network failures, typically fiber cuts. Based on a generic grooming-node architecture, we propose three approaches for grooming a connection request with shared protection: protection-at-lightpath level (PAL); mixed protection-at-connection level (MPAC); separate protection-at-connection level (SPAC). In shared-mesh protection, backup paths can share resources as long as their corresponding working paths are unlikely to fail simultaneously. These three schemes explore different ways of backup sharing, and they trade-off between wavelengths and grooming ports. Since the existing version of the problem for provisioning one connection request with shared protection is NP-complete, we propose effective heuristics. Under today's typical connection-bandwidth distribution where lower bandwidth connections outnumber higher bandwidth connections, we find the following: 1) it is beneficial to groom working paths and backup paths separately, as in PAL and SPAC; 2) separately protecting each individual connection, i.e., SPAC, yields the best performance when the number of grooming ports is sufficient; 3) protecting each specific lightpath, i.e., PAL, achieves the best performance when the number of grooming ports is moderate or small.

This study investigates the problem of fault management in a wavelength-division multiplexing (WDM)-based optical mesh network in which failures occur due to fiber cuts. In reality, bundles of fibers often get cut at the same time due to construction or destructive natural events, such as earthquakes. Fibers laid down in the same duct have a significant probability to fail at the same time. When path protection is employed, we require the primary path and the backup path to be duct-disjoint, so that the network is survivable under single-duct failures. Moreover, if two primary paths go through any common duct, their backup paths cannot share wavelengths on common links. This study addresses the routing and wavelength-assignment problem in a network with path protection under duct-layer constraints. Off-line algorithms for static traffic is developed to combat single-duct failures. The objective is to minimize total number of wavelengths used on all the links in the network. Both integer linear programs and a heuristic algorithm are presented and their performance is compared through numerical examples.