Heuristic algorithm for allocation of wavelength convertible nodesand routing coordination in all-optical networks

It is true that in all-optical networks, network performance can be improved by wavelength conversion. However, the switching node with wavelength conversion capability is still costly, and the number of such nodes should he limited in the network. In this paper, a performance optimization problem is treated in all-optical networks. We propose a heuristic algorithm to minimize an overall blocking probability by properly allocating a limited number of nodes with wavelength conversion capability. The routing strategy is also considered suitable to the case where the number of wavelength convertible nodes are limited. We validate the minimization level of our heuristic algorithm through numerical examples, and show that our algorithm can properly allocate nodes with conversion and decide routes for performance optimization     

Designing and experimentally demonstrating automatic OPS/OCS/OpenFlow network control driven by ChoiceNet provider

Interconnection between our existing optical packet and circuit integrated network (OPCInet) and an ecosystem for network service provisioning named ChoiceNet enables network service providers to provide diverse services and realize control driven by the providers. In this paper, we design and implement control interfaces for the interconnection, which enables each ChoiceNet provider to explicitly control both OPCInet- and OpenFlow-based networks by use of a single common interface with proprietary/easily modifiable message formats for all control functions. We construct an experimental setup between the USA and Japan, and demonstrate that the OPCInet and an OpenFlow-based network placed in Japan are successfully controlled by request from the ChoiceNet provider installed in the USA. We also show that the time required to complete Telnet access to the OPCInet C-plane for each control is no more than 150 ms over the long distance from the USA to Japan.     

Demonstration of 100 Gbps optical packet switching using header processor based on 48-bit longest prefix matching

Wire-rate packet processing and its energy saving for over 100 Gbps speed of line are major issues to be resolved in optical packet switching (OPS) networks. For that purpose, we newly develop a high-speed, deterministic-latency electronic header processor based on longest prefix matching (LPM) for searching optical packet destination addresses (OP-DAs). This paper reports the successful experimental results of electronic header processing based on LPM search of up to 48 bits and optical switching of 100 Gbps optical packets by the use of the header processor. We demonstrate 48-bit LPM-capable optical packet switching. We also demonstrate IP packet transfer and 32-bit LPM-capable optical packet switching. In the latter demonstration, the 32-bit OP-DA of optical packets is directly copied from the 32-bit destination address of Internet Protocol version 4 (IPv4) packets. This result indicates that OPS networks can be deployed with electronic IP networks by the use of integrated network operation between OPS and IP networks.     

High-speed buffer management for 40 gb/s-based photonic packet switches

We develop a method of high-speed buffer management for output-buffered photonic packet switches. The use of optical fiber delay lines is a promising solution to constructing optical buffers. The buffer manager determines packet delays in the fiber delay line buffer before the packets arrive at the buffer. We propose a buffer management method based on a parallel and pipeline processing architecture consisting of (log/sub 2/N+1) pipeline stages, where N is the number of ports of the packet switch. This is an expansion of a simple sequential scheduling used to determine the delays of arriving packets. Since the time complexity of each processor in the pipeline stages is O(1), the throughput of this buffer management is N times larger than that of the sequential scheduling method. This method can be used for buffer management of asynchronously arriving variable-length packets. We show the feasibility of a buffer manager supporting 128 /spl times/ 40 Gb/s photonic packet switches, which provide at least eight times as much throughput as the latest electronic IP routers. The proposed method for asynchronous packets overestimates the buffer occupancy to enable parallel processing. We show through simulation experiments that the degradation in the performance of the method resulting from this overestimation is quite acceptable.     

ID/Locator Split-Based Distributed Mobility Management Mechanism

We have designed the heterogeneity inclusion and mobility adaptation through locator ID separation (HIMALIS) architecture to support mobility natively in the New Generation Network. This paper proposes a new distributed mobility scheme in the HIMALIS architecture for supporting seamless mobility for the host moving across access networks of different network-layer protocols. The proposed scheme also supports mobility of an access network. It includes a signaling procedure to redirect downstream traffic from the previous gateway (or previous access router) to the new gateway (or new access router) to minimize the service disruption or packet losses during a handover. The performance results obtained from a testbed implementation in Linux validate the effectiveness of the proposal. The results demonstrate that it can achieve seamless (no packet loss) handovers if overlapped wireless access networks are available.     

Using ring samples to evaluate the processing characteristics in high-pressure torsion

An Al–3% Mg–0.2% Sc alloy was processed by high-pressure torsion (HPT) using samples in the form of solid disks and rings. Following HPT, all values of the measured Vickers microhardness fall onto a single curve when plotted against the equivalent strain, such that there are increasing values of hardness at the lower strains and hardness saturation above equivalent strains of ～40. This saturation level is independent of the number of revolutions and the applied pressure. The grain size following HPT is ～220 nm, and tensile tests show that the material is superplastic at a testing temperature of 573 K.     

Endoscopically guided balloon dilatation of benign esophageal strictures in 6 cats and 7 dogs

Benign esophageal strictures in 6 cats and 7 dogs were treated with endoscopically guided balloon dilatation. Six of 13 had a history of anesthesia within 3 weeks prior to the onset of signs; 8 animals had a single stricture, and 5 had multiple strictures, for a total of 19 strictures. Four of the 19 strictures were in the upper esophagus, 11 were in the middle esophagus, and 4 were in the lower esophagus. The luminal diameters ranged from 1 to 18 mm, with a mean of 5.1 mm. Twelve animals survived the immediate postprocedure period and had a total of 50 dilatation procedures performed; the mean number of procedures per animal was 4.2 (range, 2 to 8). Complications included mild bleeding and tearing (11 of 13), moderate bleeding (1 of 13), and esophageal perforation (1 of 13). The cat with the perforation was subsequently euthanized. Follow-up information was available on the 12 remaining animals; 9 were known to be alive 6 to 59 months (mean, 28.2 months) after dilatation. Two were euthanized, 1 for persistence of signs and the other for unrelated causes. One animal died of possible aspiration pneumonia. Three of 13 animals had complete and 9 had partial resolution of signs. Of the 9 animals with partial resolution, 7 were substantially better with dietary modification, 1 was moderately better, and 1 had minimal improvement. Eleven of 13 animals (85%) had a successful outcome with moderate to complete resolution of signs. Thus, it is concluded that endoscopically guided balloon dilatation is an effective and relatively safe treatment for benign esophageal strictures in dogs and cats.     

Primary obsessional slowness: long-term findings

BACKGROUND: The purpose of this work is to analyze the fertility of the hydatid cysts from ovine, animal species of great epidemiological interest in the hydatid disease, and the ability of the gerbil (Meriones unguiculatus) as model experimental for the study "in vivo" of this hidatyd disease as preliminary phase of therapeutic studies. METHODS: It has been carried out a study of the fertility and viability of hydatid cysts from lungs and livers of ovine from Castilla and Leon by examination and evaluation of parameters among these is the production of a secondary hydatid disease in laboratory animals. RESULTS: The total cystic index was 8.57 cysts by infested ovine (5.97 cysts by infested lung and 5.57 cysts by infested liver). The fertility percentage obtained in hydatid cysts from ovine with "in vitro" viables protoescoleces was 43.97% being 43.02% a pulmonary cysts and 46.16% in hepatic cysts. The viability of protoscoleces was demonstrated by production of a secondary hydatid disease in 100% of gerbils infested. CONCLUSIONS: It is emphasized the validity of the criteria used to study the viability "in vitro" of the protoescoleces from hydatid cysts of origin ovine. The secondary hydatid produced in gerbil leads us to consider them as experimental animal for investigation "in vivo" of hydatid disease of origin ovine.