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In this paper, we present algorithms that compute the routing and wavelength assignment (RWA) for scheduled lightpath demands in a wavelength-switching mesh network without wavelength conversion functionality. Scheduled lightpath demands are connection demands for which the setup and teardown times are known in advance. We formulate separately the routing(More)
Multi-granularity switching optical crossconnects (MG-OXCs) are optical switches able to switch wavelengths, to aggregate (disaggregate) wavelengths into (from) groups of wavelengths called wavebands, and to switch wavebands. MG-OXCs are interesting from an economic point of view since they can potentially reduce the cost of transporting traffic by(More)
In this paper we investigate the problem of routing a set of lightpath demands for which the set-up and tear-down dates are known. We call this type of requests Foreseeable Lightpath Demands or FLDs. In a transport network, FLDs correspond, for example, to clients’ requests for pre-provisioned bandwidth capacity such as fixed-bandwidth pipes for bulk data(More)
We present new search algorithms to detect the occurrences of any pattern from a given pattern set in a text, allowing in the occurrences a limited number of spurious text characters among those of the pattern. This is a common requirement in intrusion detection applications. Our algorithms exploit the ability to represent the search state of one or more(More)
We present a pattern matching approach to the problem of misuse detection in a computer system, which is formalized as the problem of multiple approximate pattern matching. This permits very fast searching of potential attacks. We study the probability of matching of the model and its relation to the filtering efficiency of potential attacks within large(More)
We present RWA algorithms for a new class of traffic model where, besides the source, destination and size (number of lightpaths) of the traffic demands, their set-up and tear-down dates are known. They are called Scheduled Lightpath Demands (SLDs). We model the RWA problem as a spatio-temporal combinatorial optimization problem and provide two solution(More)
Multicommodity flow models are commonly used to formulate the logical topology design (LTD) problem and the lightpath routing (LR) problem as mixed integer linear programming (MILP) problems. In general, MILP formulations are intractable even for relatively small networks due to the combinatorial complexity of the problem. In this paper we propose(More)
In this article we assess the economic gain obtained by introducing multi-granularity switching optical cross-connects (MG-OXCs) in an optical transport network. An MG-OXC is an equipment able to switch wavelengths, to aggregate (disaggregate) wavelengths into (from) groups of wavelengths called wavebands and to switch wavebands. We evaluate the economic(More)