angelo germoni - Academia.edu (original) (raw)

Papers by angelo germoni

In this paper we evaluate the impact that physical impairments have on the resource consumption i... more In this paper we evaluate the impact that physical impairments have on the resource consumption in Wavelength Division Multiplexing (WDM) networks where bandwidth utilization is optimized performing an Optical Time Division Multiplexing (OTDM). In particular we propose two modified heuristics to solve the problem of Routing and Wavelength Assignment (RWA) in OTDM/WDM networks where physical impairments are taken into account. In literature this RWA problem is referred to as S-RWA (Super- Lightpath RWA) because Super-Lightpath must be routed. If D is the OTDM multiplexing degree, a Super-Lightpath is able to carry all connections from a single source node to D different destinations using the D time-slot carried out on each wavelength. The effectiveness of the technique is evaluated on the COST 266 physical topology and when random logical topologies with several connectivity degrees are considered. The RWA problem under physical impairments has been solved versus D and . The resource consumption is characterized by the average number n of wavelengths used and the number nSL of Super-Lightpath routed. When a heuristic optimizing the number of links occupied for each Super-Lightpath is used, we have obtained for D==16 (n, nSL)=(24.3, 26) and (n, nSL)=(18.9, 145) when an S-RWA problem with and without physical impairments is solved respectively. The increase in number of Super-Lightpath was expected because the routing with physical impairments leads to shorter Super-Lightpath so much more of them are needed to solve S-RWA problem. On the contrary the lower number of wavelengths is explained with a better distribution of the Super-Lightpaths on physical topology when physical impairments are taken into account. In fact when they are not considered, Super- Lightpaths are longer, it is more probable that two Super-Lightpaths have at least one link in common and so a greater number of wavelengths are needed

A packet forwarding node of a transport network performs a first packet forwarding mode in which ... more A packet forwarding node of a transport network performs a first packet forwarding mode in which received packets are processed and forwarded on a per-packet basis. The forwarding node performs a second packet forwarding mode when the node identifies a group of consecutive packets. The group of packets are destined for the same destination node of the transport network. The second packet forwarding mode comprises determining a forwarding treatment for the group of packets and forwarding the group of packets with the determined treatment. The forwarding is performed without processing the headers of at least some of the packets in the group. The group of consecutive packets is identified by a control packet preceding the group or by inter-packet signalling which indicates that the packet before the inter-packet signalling and the packet after the inter-packet signalling are to be treated as part of the same group. Packets which are determined to be received on transit channels can be forwarded without processing headers of individual packets

2008 4th International Telecommunication Networking Workshop on QoS in Multiservice IP Networks, 2008

AbstractA Multi-fiber all-optical switch which employs wavelength converters with fixed input wa... more AbstractA Multi-fiber all-optical switch which employs wavelength converters with fixed input wavelength is presented. Being the converters tuned over a fixed input wavelength, each one is shared by channels on the same wavelength, so the resulting architecture is called ...

Journal of Optical Communications and Networking, 2009

2009 11th International Conference on Transparent Optical Networks, 2009

In this paper we propose a technique to support Quality of Service for Bufferless Optical Packet ... more In this paper we propose a technique to support Quality of Service for Bufferless Optical Packet Switches (OPS) equipped with shared Wavelength Converters (WC). The WCs sharing is fully, that is all of the arriving packets share the same pool of WCs. The QoS, expressed in terms of Packet Loss Probability, is differentiated by giving the packets different priorities in

An architecture is proposed for a wavelength division multiplexed (WDM) optical packet switch equ... more An architecture is proposed for a wavelength division multiplexed (WDM) optical packet switch equipped with both limited range wavelength converters (LRWCs) and shared full range wavelength converters (FRWCs). The FRWCs are used to overcome the performance degradation in terms of packet loss probability due to the use of LRWCs only. A probabilistic model is proposed to dimension the number of

An optical packet switch that shares both limited range and full range wavelength converters for ... more An optical packet switch that shares both limited range and full range wavelength converters for contention resolution is proposed with the aim to guarantee an high conversion cost saving. To optimally dimension the number and the conversion range of the wavelength converters, an analytical model, validated by simulation, is introduced to evaluate the packet loss probability of the switch. Numerical

In this paper we propose a new solution for the Routing, Wavelength and Time-Slot Assignment (RWT... more In this paper we propose a new solution for the Routing, Wavelength and Time-Slot Assignment (RWTA) problem in a dynamic scenario. The novel aspect of this paper is that we consider nodes performing Time-slot Add-Drop directly in optical domain. The Add-Drop capabilities allow for a better network utilization in terms of blocking probability. In particular we define two heuristics, the

Selected Topics on Optical Amplifiers in Present Scenario, 2012

Journal of Networks, 2012

Journal of Lightwave Technology, 2008