A high-performance transport network platform

1995 ◽  
Vol 34 (4) ◽  
pp. 705-724 ◽  
Author(s):  
G. Lebizay ◽  
C. Galand ◽  
D. Chevalier ◽  
F. Barre
2020 ◽  
Vol 19 (2) ◽  
pp. 412-445 ◽  
Author(s):  
Sergej Andreev ◽  
Roman Tregubov ◽  
Alexander Mironov

The paper proposes a solution to the problem of selecting the bandwidth capabilities of digital communication channels of a transport communication network taking into account the imbalance of data traffic by priorities. The algorithm for selecting bandwidth guarantees the minimum costs associated with renting digital communication channels with optimal bandwidth, provided that the requirements for quality of service of protocol data blocks of the first, second, and k-th priority in an unbalanced in terms of priorities transport communication network are met. At the first stage of solving the problem, using the method of Lagrange multipliers, an algorithm for selecting the capacities of digital communication channels for a balanced in terms of priorities transport network was developed. High performance of this algorithm was ensured by applying algebraic operations on matrices (addition, multiplication, etc.). At the second stage of solving the problem, using the generalized Lagrange multipliers method, we compared the conditional extrema of the cost function for renting digital communication channels for single active quality of service requirements for protocol data blocks, for all possible pairs of active quality of service requirements for protocol data blocks, for all possible triples of active requirements for the quality of service of protocol data units, and so on up to the case when all the requirements for quality of service maintenance of protocol data units are active simultaniously. At the third stage of solving the problem, an example of selecting the bandwidth capabilities of digital communication channels of the unbalanced by priorities transport network consisting of eight routers serving protocol data blocks of three priorities was considered. At the fourth stage of the solution of the problem of the choice of carrying capacities the estimation of efficiency of the developed algorithm by a method of simulation modeling was carried out. To this end, in the environment of the network simulator OMNet ++, the unbalanced in terms of priority transport communication network consisting of eight routers connected by twelve digital communication channels with optimal bandwidth was investigated.


2018 ◽  
Vol 38 ◽  
pp. 04019
Author(s):  
Ya Wang ◽  
Yu Cheng ◽  
Zhi Zhao

With the rapid development of economy, the volume of transportation in China is increasing, the opening process of the market is accelerating, the scale of enterprises is expanding, the service quality is being improved, and the container multimodal transport is developing continuously.The hardware infrastructure of container multimodal transport is improved obviously, but the network platform construction of multimodal transport is still insufficient.Taking Shandong region of China as an example, the present situation of container multimodal transport in Shandong area can no longer meet the requirement of rapid development of container, and the construction of network platform needs to be solved urgently. Therefore, this paper will briefly describe the conception of construction of multimodal transport network platform in Shandong area.In order to achieve the rapid development of multimodal transport.


Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5168 ◽  
Author(s):  
Chaohui Luo ◽  
Biyun Ma ◽  
Fangjiong Chen ◽  
Quansheng Guan ◽  
Hua Yu ◽  
...  

Software-defined acoustic modems (SDAMs) for underwater communication and networking have been an important research topic due to their flexibility and programmability. In this paper, we propose a reconfigurable platform for SDAMs based on the TI AM5728 processor, which integrates dual-core ARM Cortex-A15 CPUs and two TI C66x DSP cores. The signal processing and A/D, D/A for physical-layer communication are implemented in the DSP cores. The networking protocols and the application programs are implemented in the ARM cores. The proposed platform has the following characteristics: (1) Due to the high-performance dual-ARM cores, the whole NS3 network simulator can be run in the ARM cores. Network protocols developed in a software simulation platform (e.g., NS3 platform) can be seamlessly migrated to a hardware platform without modification. (2) A new physical-layer module associated with real acoustic channel is developed, such that a data packet generated from the application layer will be transmitted through a real acoustic channel. The results of networking experiments with five nodes are presented to demonstrate the effectiveness of the proposed platform.


Author(s):  
A. V. Crewe ◽  
M. Isaacson ◽  
D. Johnson

A double focusing magnetic spectrometer has been constructed for use with a field emission electron gun scanning microscope in order to study the electron energy loss mechanism in thin specimens. It is of the uniform field sector type with curved pole pieces. The shape of the pole pieces is determined by requiring that all particles be focused to a point at the image slit (point 1). The resultant shape gives perfect focusing in the median plane (Fig. 1) and first order focusing in the vertical plane (Fig. 2).


Author(s):  
N. Yoshimura ◽  
K. Shirota ◽  
T. Etoh

One of the most important requirements for a high-performance EM, especially an analytical EM using a fine beam probe, is to prevent specimen contamination by providing a clean high vacuum in the vicinity of the specimen. However, in almost all commercial EMs, the pressure in the vicinity of the specimen under observation is usually more than ten times higher than the pressure measured at the punping line. The EM column inevitably requires the use of greased Viton O-rings for fine movement, and specimens and films need to be exchanged frequently and several attachments may also be exchanged. For these reasons, a high speed pumping system, as well as a clean vacuum system, is now required. A newly developed electron microscope, the JEM-100CX features clean high vacuum in the vicinity of the specimen, realized by the use of a CASCADE type diffusion pump system which has been essentially improved over its predeces- sorD employed on the JEM-100C.


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