Alternative routing and zone-based spectrum assignment algorithm for flexgrid optical networks

Abstract

In optical flexgrid networks, the optical spectrum can be allocated at a much finer granularity than it can be in fixed-grid WDM networks and variable spectrum widths can be assigned to the lightpaths according to the transmission rates, leading to more efficient spectrum usage. However, the dynamic establishment and tear down of lightpaths yields to the fragmentation of the spectrum with increase in blocking of connections, mainly connections demanding large spectrum widths. This paper proposes a novel algorithm that introduces a zone-based assignment policy together with an alternative path routing mechanism based on the maximum capacity available. Results derived via simulation using different topologies and considering connections requests from 40Gbps to 1000Gbps, show that the proposed algorithm leads to blocking ratio consistently lower than those given by traditional approaches. It also reduces the blocking ratio of high rates connections, in some cases, by a factor of six.

Dynamic spectrum and core allocation with spectrum region reducing costs of building modules in AoD nodes

“…The repeated setups and release of connections requiring non-uniform bandwidths fragment the spectrum resources and degrade the performance of optical networks. Reference [4] proposes zone-based spectrum assignment reducing spectrum fragmentation in EONs, but the authors do not consider SDM technology. Novel transmission devices based on the SDM technology are also important because they can expand fiber capacity beyond the physical limit of conventional single-mode, single-core fibers [5].…”

Priority realloc: um mecanismo para alocação de rotas e recursos em redes EON.

“…Gbps each resulting in a link capacity of 4,000 Gbps. Each channel (wavelength) occupies 100 GHz [92] and each link comprises 4,000 GHz. The bandwidth requirement considered in the simulations were 10, 40 and 100 Gbps non-uniformly distributed as depicted in Table 7.1.…”

Priority realloc : a threefold mechanism for route and resources allocation in EONs

“…Gbps each resulting in a link capacity of 4,000 Gbps. Each channel (wavelength) occupies 100 GHz [93] and each link comprises 4,000 GHz. The bandwidth requirement considered in the simulations were 10, 40 and 100 Gbps non-uniformly distributed as depicted in Table 7.1.…”

“…A 4,000 GHz link in an EON comprises 320 FSs of 12.5 GHz each [93] Due to the fact that the minimum resource requirement in an EON is 1 FS, scenarios EON 1 and EON 2 may suffer discrepancy relating to the WDM scenario. The minimum resource requirement in the WDM network is 10 Gbps that would be equivalent to 10 GHz and not 12.5 GHz as afforded by 1 FS.…”