This paper presents a method for recognizing various drones from images of ultra-wideband (UWB) radar range profile by using a convolutional neural network (CNN) model. CNN is a Deep learning algorithm that provides high accuracy for image recognition tasks. We investigated the recognition performance for five types of drones with different shapes, sizes, and the number of rotor blades (Matrice 600, 3DR Solo, Phantom 3, Mavic pro, and Bebop drone) and a radio-controlled flapping bird (Bionic bird). As a result, we have confirmed that our presented method can recognize each target with high accuracy of 90 % or more.

Small unmanned vehicles (UVs), which include aerial, land-based and water-based vehicles, are expected to play important roles in future society. When UV is remotely controlled via a network, a highly reliable and small transmission delay communication channel is indispensable. In terms of transmission delay, a wireless access network often becomes a bottlenecks. We aim to achieve an affordable and high quality communication channel that can be used for UV remote control. In this research, we focused on a shared wireless Local Area Network (LAN), because it can realize low cost communication, at this time. Although cost reduction could be realized by sharing, problems arise in terms of communication quality. Especially, a sudden large delays (delay spikes) are often observed in a shared wireless LAN. To solve the problem, we proposed a path switching function to use two paths on independent two wireless LANs. The function enables to switch path of the communication channel immediately after detecting an occurrence of delay spike. We implemented functions of the proposal and carried out experimental evaluations to elucidate its effectiveness. Experimental results indicate that the proposed function is effective for improving UV controllability.

This paper proposes two techniques for reducing the buffer size and computational complexity of an aggregation layer-2 switch (L2SW) in access systems by using buffer observation and multilevel dynamic bandwidth allocation (DBA). The conventional architecture for providing cousin fairness, which realizes fairness among multiple passive optical network (PON) branches, needs a huge buffer in an L2SW that depends on the number of optical network units (ONUs). Our proposal reduces the required buffer size for an L2SW that depends on the number of optical subscriber units (OSUs), which is much smaller than the number of ONUs. The proposed techniques reduce by more than two thirds the amount of unfairly distributed bandwidth caused by the lack of cousin fairness. A simulation result obtained with our proposed approach shows improved cousin fairness among multiple PON branches with a smaller buffer.

This paper proposes a sleep control function for power saving in the optical line terminal (OLT) of an Ethernet passive optical network (EPON) employing duplicated layer-2 switches (L2SWs). The basic idea is to make one of the duplicated L2SW sleep according to the amount of traffic. Furthermore, this paper proposes a novel sleep control function that uses dynamic bandwidth allocation (DBA) information. The proposed sleep control function calculates the traffic in advance from the DBA information, and switches one of the duplicated L2SW between active and sleep mode based on the accurate traffic predictions. The proposed control function provides exact predictions of the upstream traffic, thus eliminating excess latency due to prediction error. Numerical simulations show the validity of the sleep control proposal.

Recently, various architectures for future networks have been researched and discussed. In one of these approaches, we assume the deployment of an access network in which wavelength division multiplexing (WDM) and time division multiplexing (TDM) techniques will be applied to user and service multiplexing, respectively. In line with the envisioned scenario, we are studying a new access network based on a multi-stage semiconductor optical amplifier (SOA), which has a flexible transmission distance, low delay performance and low power consumption for each service. It has multi-access points supporting the dropping/adding/regenerating of signals with/without optical-electrical-optical (OEO) conversion. In this paper, we describe the configuration of this new access network. Moreover, we propose a priority control method for adding/regenerating signals designed to realize a low delay, and describe simulation results related to the number of OEO conversions. Moreover, we clarify a multi-access point traffic design for low delay performance.

Realtime video streaming is one of the most important tool for the computer supported collaborative workspace (CSCW). CSCW requires bi-directional or many-directional video exchanging. The delay or jitter caused by network quality is easily affecting application or users of CSCW. The quality of experience (QoE) of CSCW with video streaming over IP networks depends on the quality of network. It is important to consider the relationship between the QoE of video streaming and quality of service (QoS) of the network in order to achieve high quality CSCW services effectively. Then we can define the suitable parameter of networks for the applications. The goal of this research is to establish the evaluation method of the correlations between the QoE of CSCWs and QoS of networks to obtain the optimal real-time communication system design. In this paper, we propose a method to measure the correlation between the application and network QoS with precise packet monitoring environment. The result shows that micro-second resolution helps a lot to capture the precise behavior which effects the codec system's performance.

Emerging ATM-based virtual private network (VPN) services offer customers a flexible way to interconnect customer premises networks (CPNs) via high-speed links. Compared with traditional leased lines, these services allow for rapid provisioning of VPN bandwidth through cooperative control between customer and provider. Customers can dynamically renegotiate the VPN bandwidth according to their current needs, paying only for the resources they actually use. In order to meet the various requirements and demands of different classes of VPN customers, a VPN provider must provide customers with the flexibility to choose their own control schemes and objectives. The focus of this paper is on enhancing the customer's capability of controlling a VPN. First, we propose a new scheme for a broadband VPN service, which is based on the virtual path group (VPG) concept. In our scheme, the customer performs VP control operations without interacting with the VPN provider, thus enabling the following merits: (1) the customer can share bandwidth among VPs that traverse the same physical network link in the provider's domain, thus using the VPN bandwidth more efficiently; (2) customers can perform VP control operations according to their own requirements and control objectives. Second, we outline an architecture for a customer-operated control system, which utilizes a VPG-based VPN service. The system is structured into three layers of control, which execute on different time scales. The functionalities of these layers are call processing, VP control, and VPN control, respectively. Finally, we evaluate the effectiveness of the control system, with respect to VP control.

This paper proposes an implementation scheme for the self-healing function in ATM networks and assesses its performance. First, our proposed ATM self-healing scheme is described. This scheme realizes more rapid restoration of failed virtual paths than other self-healing algorithms, supports the node failure case, and minimizes the spare resources required. Next, an implementation scheme is proposed. We propose that the self-healing function be implemented as a software process, and that OAM cells are utilized for fast message transmission. Next, results of a prototype system that we implemented on an ATM cross-connect system are discussed. The fundamental characteristics of restoration performance are measured using an experimental network. Based on these results, an NE processing system analysis and computer simulation for estimating the characteristics as applied to a real-scale network are discussed. Finally, a management scheme for self-healing is proposed based on the TMN concept.

The paper presents a new ATM transport network technique that realizes the direct virtual path configuration by using path bandwidth control and the virtual path group concept. Direct virtual paths link local switches directly and enable channel set up processing to be eliminated from transit nodes. However, this configuration, which employs no toll switches, suffers from several problems such as reduced utilization of virtual path bandwidth and increased difficulty of localized network management based on network segmentation. The authors introduce virtual path bandwidth control and the virtual path group concept into ATM transport networks to realize the direct virtual path configuration in a very efficient manner. Virtual path bandwidth control enables the optimum balance between switching and transmission systems to be struck. Virtual path groups make it possible to provide a localized network management capability in a way similar to that available in a conventional network.>

Path layer technologies will play a key role in the development of a powerful and failure resilient B-ISDN. So far, they have been based on electrical technologies. This paper highlights WDM/FDM techniques and demonstrates that optical paths can greatly enhance the path layer capability and, therefore, the network performance. It is also shown that effective network failure restoration can be achieved with optical paths. The applicability of the wavelength path (WP) technique to global area networks is revealed by comparing different optical path realization techniques. WPs are applied to the national backbone network example to evaluate the required number of wavelengths, and to identify optical cross-connect node requirements. It then proposes a new optical path concept: the virtual wavelength path (VWP). In the VWP scheme, wavelengths are assigned on a link-by-link basis. In other words, the wavelength assigned to a wavelength path has only local significance. Significant benefits of the VWP such as the simplified path accommodation design within a transmission facility network and the reduced number of wavelengths needed, are elucidated. An optical cross-connect node architecture that enables the VWPs is also proposed. The architecture allows the VWP concept to be realized with commercially available optical technologies. The optical path layer concept proposed exploits and consolidates the layered transport network architecture and optical technologies, and will open up new opportunities for creating a B-ISDN that is bandwidth abundant and has a high degree of integrity.>