The performance analysis of distributed connection management for WDM optical networks with different nodal degrees
is proposed in this study. In our previous study, we proposed a distributed wavelength reservation scheme with switch
fabrics status. We consider the reconfiguration information of switch fabrics in the signaling protocol, which designated
as the signaling with switch fabric status (SWFS). Distributed reservation algorithms will reserve the wavelength with
minimum of reconfiguration times of OXCs along the route to shorten the connection establishment time. In this paper,
we analysis the reservation schemes with or without SWFS for FAXC or FBXC modes, especially the performance with
different nodal degrees. The simulation results indicate that schemes with SWFS have the shorter setup time, lower
switching ratio than those without SWFS. The schemes for FBXC mode have the better blocking performance than those
for FAXC mode. The switching ratio, the blocking probability and connection setup time decrease with the increase of
nodal degrees for S-RM. The increase of the nodal degree from 2 to 3 and from 6 to 7 leads to higher nodal degree gains.
A new scheme to mitigate the connection setup time overheads in distributed wavelength reservation schemes for WDM multi-fiber optical networks is proposed in this study. In this scheme, we consider the reconfiguration delay of switch fabric in distributed signaling protocols, which designated as signaling with switch fabric status (SWFS). Protocol realization selects and reserves the available wavelength that has the least switch fabric reconfiguration times along the path to shorten the connection establishment time. In this paper, we proposed four wavelength reservation schemes with SWFS for multi-fiber optical networks, which are S-FW-FF, S-FW-RF, S-RW-FF, and S-RW-RF. Simulation results indicate that schemes with SWFS have the shorter setup time, lower switching ratio as well as better blocking performance than those of without SWFS. Especially, the proposed schemes significantly reduce numbers of switch fabric that need to be reconfigured.
We introduce an intelligent optical cross connect (OXC) structure based on our lambda-group model, as well as a dynamic algorithm of configuration helpful to complicated optical traffic grooming, which presents a distinctive approach of dividing granularities into specific tunnels for effective treatment. Results and figures from experiments show that the particular channel partition not only is helpful to port reduction significantly, but also improves the channel and blocking performance for dynamic connection requests.
In this paper, a new scheme to mitigate the connection setup time overheads in distributed control schemes for wavelength-routed optical networks is proposed. In this scheme, we consider the reconfiguration delay of switch fabrics in the distributed signaling protocols, which designated as the signaling with switch fabric status (SWFS). Based on the reconfiguration information being carried by signaling messages along with wavelength availability information,
distributed wavelength assignment algorithm at the destination node will select a wavelength with the minimal switch reconfiguration delay along the lightpath to shorten average connection setup time. Simulation results indicate that the first-fit algorithm with switch status (S-FF) and random algorithm with switch status (S-RM) have the shorter setup time, lower switch ratio as well as better blocking performance than those of classic schemes. Especially, the proposed scheme significantly reduces the number of switch fabrics that need to be reconfigured. Moreover, we investigate the effect of number of add/drop ports of optical cross-connects (OXCs) on the blocking performance of the scheme. We find that when the number of add/drop ports of OXCs is larger than a base boundary, the network may achieve almost the best blocking performance of the distributed wavelength provisioning.
One of the challenges to dynamically set up a lightpath is to develop efficient control schemes in control as well as the management of the distributed-controlled optical networks. In networks with highly dynamic traffic loads, longer lightpath setup time may result in higher blocking probability and serious degradation of the network performance. In this paper, we propose a novel distributed signaling protocol designated as signaling with switching fabric status (SWFS). In this scheme, we consider the switch fabric configuration performing distributed signaling as well as routing and wavelength assignment. We forward the signaling request messages with available wavelength sets as well as the extra switching status for each wavelength at each node in the paths between the source-destination (S-D) pairs. The extra switching status indicates if the switch fabric should be reconfigured to provide internal port connection for specified wavelength at the node. When the signaling message reaches the destination, a wavelength with minimal reconfiguration times in the available wavelength set will be selected to shorten the connection establishment time. A distributed discrete event simulation platform has been developed to evaluate the performance of SWFS. The simulation results show that our proposed technology has the shorter setup time and lower blocking probability than the traditional non-optimization signaling technology.
A new flexible broadcast optical switching structure (FBOSS) using tunable optical splitter is proposed. FBOSS supports both point-to-point and point-to-multipoint (broadcasting) connections, and any input optical signal can be broadcasted to any number of output optical ports without extra optical power loss. Its flexibilities of the optical port and optical wavelength help to enhance the capability of switching.
A novel all-optical packet switching is presented. Adopting optical-controlled optical switch and multi-wavelength optical label technology, all the extraction of optical packet header, recognizing of route information and control of optical switch matrix can be processed in optical domain without O-E/E-O conversion. In this switching, the header label pulses are separated to different optical paths to control the optical-controlled optical switch matrix. According to different sequence and different wavelength of the header pulses, the different optical routes can be established, and a kind of all-optical packet switching is achieved.