A Conversion Protocol for 2W Telephone Signal over Ethernet in a Private PSTN

In this paper, we proposed a protocol to convert 2W telephone analog signals to Ethernet data in a private PSTN 2W tactical voice system. There are several kinds of operational problems in the tactical telephone network where 2W telephone copper lines are installed hundreds of meters away from the PBX in a headquarter site. The reason is that it is difficult to install and maintain the 2W telephone copper cable in severe operational fields and to meet safety and stability operational requirements of the telephone line under lighting and electromagnetic environments. In order to solve these challenging demands, we proposed an efficient method that the 2W analog interface signals between a private PBX system and a 2W telephone is converted to Ethernet messages using the optical Ethernet data communication network already deployed in the tactical weapon system. Thus, it is not necessary to install an additional optic cable for the ethernet telephone line and to maintain the private PSTN 2W telephone network. Also it provides safe and secure telecommunication operation under lightning and electromagnetic environments. This paper presents the conversion protocol from 2W telephone signals over Ethernet interface between PBX systems and 2W telephones, the mutual exchange protocol of ethernet messages between two converters, and the rule to process analog signal interface. Finally, we demonstrate that the proposed technique can provide a feasible solution in the tactical weapon system by analyzing its performance and experimental results such as the bandwidth of 2W telephone ethernet network and the transmission latency of voice signal, and the stability of optic ethernet voice network along with the ethernet data network.

Fault Diagnosis Knowledge Reasoning of Switching Network in Distributed Generation Based on Petri Net

Telephone network based on IMS technology has been widely applied in power production and dispatching communication, especially in distributed power stations. Analysis and positioning failure of IMS network is arduous, because it’s dependent on IP data communication network. In this paper, we first introduced IMS switching network architecture and distributed generation communication network architecture, analyzed and summarized all kinds of network malfunction. Combining typical IMS network fault connection relations, we introduced an improved Petri net fault handling model and reasoning method. The diagnosis and positioning results could reflect the defects of equipment logic functions. This method on fault diagnosis and location of substation network has been proved to be effective through practical application.

Special Issue on “Graph Algorithms and Applications”

The mixture of data in real life exhibits structure or connection property in nature. Typical data include biological data, communication network data, image data, etc. Graphs provide a natural way to represent and analyze these types of data and their relationships. For instance, more recently, graphs have found new applications in solving problems for emerging research fields such as social network analysis, design of robust computer network topologies, frequency allocation in wireless networks, and bioinformatics. Unfortunately, the related algorithms usually suffer from high computational complexity, since some of these problems are NP-hard. Therefore, in recent years, many graph models and optimization algorithms have been proposed to achieve a better balance between efficacy and efficiency. The aim of this Special Issue is to provide an opportunity for researchers and engineers from both academia and the industry to publish their latest and original results on graph models, algorithms, and applications to problems in the real world, with a focus on optimization and computational complexity.

Access Point Placement Optimization for a CBTC System Wireless Data Communication Network

Radio-based Communication-Based Train Control (CBTC) systems are widely utilized in major urban centers around the world to improve capacity, performance, and safety of public rail transportation systems. The system primary functionalities are performed based on the wireless mobile communication media, through which wayside-onboard communication data links are established. The focus of the presented research is to improve the performance of the CBTC wireless network by providing an efficient framework for placement optimization of the wayside transceivers aiming to maximize the radio coverage. The QoS-oriented convex optimization cost function is based on a heuristic model of radio wave propagation in the tunnel environment. The optimization engine uses the robust, efficient, and well-behaved Nelder-Mead algorithm. Furthermore, to provide reliable means for verification, numerical results are compared with measured data produced through an empirical site survey process performed for an actual CBTC system deployment.

Performance Evaluation of a Hybrid Buffer-Based Optical Packet Switch Router

Recently, in the present day’s data center systems an explosive growth has been observed in data traffic, which restricts the speed of exiting data communication network. To solve such problem, fiber optical-based optical communication system is preferred choice. In this paper, an arrayed waveguide grating (AWG)-based optical packet switch is presented in which priority among packets is implemented effectively. This switch is a recirculating loop buffer-based switch in which a hybrid buffering (optical + electrical) technique is used for storing packets into the buffer. The power budget analysis of switch is presented in various conditions, when packet passes through the optical or electronic buffers. Comparison of optical and electronic buffering is done in terms of power required for the correct operation of the switch. In this paper, a comparison is performed between our proposed switch with recently published switch designs. The result presented in this paper clearly reveals that the performance of our proposed switch is far better than other previously published switch architecture. The major beauty of our proposed switch is that in this design priority among packets implemented effectively.