Network Virtualization such as SDN (Software Defined Network) or NFV (Network Functions Virtualization) is the important technology in the new generation network architecture. This provides flexible networking for various kinds of network usage demand. Network virtualization requires the definition of a user specific network called as “slice” and the method for programming a slice design of programmable forwarding nodes in network. The key aspect is to introduce the programmability in network. This can provide new value for users and application providers by working together with computation and peripheral technologies such as cloud computing, Internet of Things, mobile devices and so on. Also, the delivery time of a slice can be shorter than in existing network. “Programmable Network” has huge potential to change the games in creating network service. In this talk, the R&D activities of network virtualization and its programmability methods are introduced to explain how the flexibility is realized as hardware and software system. Then, we discuss how we utilize programmable network for creating network services. The several use cases such as 4K/8K contents distribution, resiliency of network system, and edge distributed computing are introduced to show the possibility of creating new value by Programmable Network. Finally, we discuss the possibility of applying EDA technologies for supporting the design flow of a user specific network in Programmable Network.

Recently, many large-scale natural disasters, such as earthquake and tsunami occur all over the world. One of the major problems after a disaster is the damage caused to the communication and power infrastructure, such as damaged base station and power grid. As a result, disaster victims are unable to communicate with outside area for an extended period of time. Therefore, it is essential to deploy a communication network, which can operate even without power supply or infrastructure. In this paper, we focus on Wireless Mesh Networks (WMNs), which consists of Solar Powered Base Station (SPBS) equipped with air interfaces. These WMNs can be promptly setup. However, because the power generated from solar panel is easily affected by weather condition, it is insufficient and unstable. Additionally, because the power consumption is affected by the distance between the SPBSs and the number of wireless links in each SPBS, it is difficult to maintain network connectivity in the WMNs that are consisted of SPBSs. Therefore, to address the network connectivity problem in the assumed network, we aim to reduce the power consumption of the wireless links by controlling the on-off cycle of air interfaces. We first analyze the network connectivity issue in disaster area and formulate this problem, and propose the on-off scheme of controlling the wireless links of air interfaces based on graph theory. Simulation results of our proposal show that our proposed scheme can ensure the network connectivity.

Wireless Data Center Network (Wi-DCN) is considered one of the most promising future data center architectures due to its low installation and management cost and high flexibility of network design. However, the existing Wi-DCN is, still, not capable of providing an efficient big data mining service such as MapReduce because its topology (i.e., Cayley graph with same degree) cannot achieve enough connectivity on the breakdown of servers and spectrum efficiency, which are important factors to improve the performance of big data mining. Therefore, in order to modify the existing Wi-DCN for big data mining, this paper proposes a spherical rack architecture based on a bimodal degree distribution that improves both failure tolerance and spectrum efficiency. Extensive computer simulations demonstrate the effectiveness of our proposed rack architecture in terms of data transmission time required for MapReduce under a failure-prone environment.

The development of technologies for realizing “Internet of Things” inspire many applications which utilize the things' network. Additionally, the ambient information of the things including various information collected via the network has attracted much attention as useful data for novel applications. By collecting the ambient information from things and constructing databases of them, it is expected to make our lives smarter and more convenient. On the other hand, to maximize the advantage of such a database, it is important to keep the information in the database as fresh as possible. However, in order to keep the freshness of the database, periodically collecting data with short interval is needed, which causes heavy traffic congestion when we use the traditional access control schemes in the existing communication network technologies. Thus, in this paper, we propose a novel access control scheme to keep the freshness of the database while avoiding traffic congestion. Additionally, an optimization to improve the efficiency of our proposed method is provided with mathematical expressions. Moreover, numerical results verify the effectiveness of our proposal.

Since communications services become much more demanded after disaster strikes, it is necessary to promptly set up a temporary communications infrastructure to provide services to those in need. The Movable and Deployable Resource Unit (MDRU) based Wireless Mesh Network (WMN) is an attractive candidate to achieving this goal. In MDRU based WMN, the MDRU is transported to the disaster affected area by either ground or air transportation like truck or helicopter. After arriving at the disaster area, it configures any remaining wireless Access Points (AP) in the area to provide connectivity services. This work provides an insight on the performance of MDRU based WMN under the situation where multiple MDRUs are deployed within close region to increase the overall coverage and performance of the network. A simulation is conducted to estimate the performance of the network under both scenarios where mesh tier operates under a single channel and where a channel assignment scheme is applied. We show that the performance of MDRU based WMN can be greatly enhanced by deploying multiple MDRUs to the area. However, since the number of available MDRUs is limited, using more MDRUs than necessary is not efficient. We discuss some of the factors that should be taken into account when selecting an appropriate number of MDRUs for a single area.

In the last decade, there has been a tremendous increase in both the number of mobile devices and the consumer demand for mobile data communication. As a general network architecture, ad hoc mobile networks are expected to offload a large amount of mobile traffic in lots of promising application scenarios. However, how to achieve a good balance between delivery performances (like delivery delay and delivery probability) and network resource consumptions (like power energy and buffer storage) remains an extremely challenging problem. In this paper, we focus on the general k-hop relay routing, which covers a lot of popular routing schemes as special cases, such as the direct transmission (k = 1), the two-hop relay algorithm (k = 2), and the epidemic routing (k = n - 1). We first develop absorbing continuous-time Markov chain models to characterize the complicated message delivery process under the general k-hop relay routing, and then conduct Markovian analysis to derive all the above important performance metrics. Finally, extensive numerical results are presented to illustrate the achievable delivery performances under the general k-hop relay and the possible performance trade-offs there.

This JSAC special issue is covering four emerging areas in communications: Area 1 - e-Health; Area 2 - Peer-to-Peer Networking; Area 3 - Vehicular Networks and Telematics Applications; and Area 4 - Social Networks. This is the first issue of a brand new series in JSAC focusing on "Emerging Technologies in Communications." These emerging technical areas were selected from ComSoc's Technical Committees and Technical Sub-Committees. (The second issue will be published later in 2013 on the following areas: Area 5 - Applications of Nanotechnologies in Communications; Area 6 - Autonomic Communications; Area 7 - Fiber Wireless Integration; and Area 8 - Nanoscale and Molecular Networking.) The papers selected are briefly summarized. For this issue, 55 regular papers were selected for publication out of 197 open-call submissions. Also included are three overview (invited) papers. It is devoted to reporting on cutting-edge research achievements covering the following four emerging technical areas in communications.

Hierarchical unstructured peer-to-peer (P2P) networks for file sharing systems such as Gnutella and Kazaa have made a tremendous achievement in the last decade. However, while these P2P networks can be tolerant to churn, i.e., the dynamics of peer participation and departure (or fault), there still remains the issue of vulnerability to Denial of Service (DoS) attacks, i.e., when the highest degree peers are removed. In order to overcome this shortcoming, we focus on a bimodal degree distribution, which is tolerant to both churn and DoS attacks. However, the network topology affects the network stability that was not taken into considered in the previous works. Therefore, we analyze the optimal network topology for DoS attack tolerance, and accordingly develop the peer joining procedure to construct and maintain the proposed network topology. Our proposed scheme is dubbed THUP (churn/DoS Tolerant, Hierarchical, Unstructured, P2P network). Performance evaluation conducted through computer simulations shows that THUP substantially improves the stability and communication efficiency compared with other existing P2P networking structures.

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.

We developed a flexible network node that is tuned for high-speed and multilayer packet manipulation. The key idea is a dynamic function assignment mechanism; each packet processing task is assigned to several processing modules in an on-the-fly manner and incoming packets are processed in them. With this mechanism, we can freely arrange the modules and add extra ones if more processing power is needed. In addition, the processing modules are realized using field programmable gate arrays (FPGAs) and micro processing units (MPUs). Thus, the functionality of each module can be dynamically changed at anytime. In this paper, the system concept and its implementation are described with an example application.

A novel distributed-resource abstraction environment is introduced. You can access any resource in a computer network as a memory mapped I/O device, as if it was attached to the local bus of your PC. This network technology gives us several benefits. From the application development viewpoint, no network-related programming is required, and we don't need to modify the applications even if the network topologies and protocols are changed. On the other hand, network maintenance and upgrading can be done anytime without worrying about the application users, because the environment completely separates or hides the network from the applications. The API (Application Program Interface), a resource abstraction mechanism, and a directory service are implemented. In addition, a reconfigurable hardware technology is adopted to perform autonomous network control using a lour layer protocol. Furthermore, we introduce a testbed that allows heterogeneous resources to be utilized, and demonstrate the feasibility of our concept using some applications.

This paper describes a project dedicated to developing an improved (in terms of usability) version of our previous telecommunication-oriented field programmable gate array (FPGA), and its applications. To achieve this goal, we adopt several challenging design strategies. First, we determine the new FPGA architecture based on a quantitative evaluation carried out to optimize the interaction between the FPGA and CAD algorithms. In addition, we create a new chip design environment that allows semi-automatic test pattern generation and cross-checking between logic and layout design. Furthermore, a dedicated CAD system is developed based on a consideration of the evaluation results and the characteristics of the FPGA. As a result of these design strategies, the FPGA and CAD system are well-balanced, and even though the FPGA has very rich routing resources, the routing process can be finished quickly without sacrificing application-circuit performance. The FPGA is applied to several reconfigurable systems for telecommunications, and is found to offer the required functions and good performance.

The paper describes a transmutable telecom system called ATTRACTOR, which uses more than 100 FPGAs, and features both reconfigurability and high performance. There are two key innovations. One is the board-level modularity concept that allows different functions to be implemented on different boards individually. The other is a high-speed serial link mechanism that provides excellent inter-board communication without sacrificing performance. Thus this system can be completely reconstructed to suit different applications by arranging different board combinations and reconfiguring each board. Using ATTRACTOR, we realized an IP packet forwarder, which is very speed-intensive telecom function, that has to decide the next-hop address of each incoming IP packet and send it out on-the-fly. It was confirmed that the function works well in a real ATM-LAN environment.

No abstract available.

This paper discusses how a distributed environment providing effortless networking can be efficiently implemented in a network system. To formalize the distributed environment, we introduce the concept of "Virtual BUS". It is similar to the concept of the computer system's bus architecture. We define user behavior as accessing the resources in a network through his/her own bus. Based on this simple formalization, we discuss the key issues in implementing distributed environments to support different requirements for realizing the quality of service desired. We implement an experimental effortless networking environment based on the Virtual BUS concept and show that the concept realizes effortless networking while guaranteeing QoS.

We have developed an architecture-oriented routing method for a telecommunications FPGA (Field-Programmable Gate Array) which has rich hierarchical routing resources. Our routing method consists of four routing procedures, each of which are related to a specific part of the routing resource architecture of the FPGA. It can accomplish routing results almost five times faster than a reference method that does not consider the routing resource architecture. The key idea in our approach is to reduce the number of possible resource candidates by referring to both the logical net structure and the FPGA resource architecture. We apply different routing algorithms according to the amount and architecture of candidate routing resources. Experiments show that our architecture-oriented method is more effective than conventional single-algorithm-based methods.

In designing FPGAs, it is important to achiev e a good balance bet w een the number of logic blocks, suc h has Look-Up Tables (LUTs), and wiring resources. It is difficult to find an optimal solution. In this paper, w e presen t an FPGA design methodology to efficiently find well-balanced FPGA architectures. The method covers all aspects of FPGA development from the architecture-decision process to physical implementation. It has been used to develop a new FPGA that can implement circuits that are twice as large as those implementable with the previous version but with half the number of logic blocks. This indicates that the methodology is effectiv e in dev eloping well-balanced FPGAs.

We propose an FPGA architecture for next generation B-ISDN telecommunications systems. Such a system requires an FPGA in which an over 10 K gates circuit can be implemented and that has a clock cycle rate of 80 MHz. While the FPGA architecture has been discussed in terms of its circuit structure, we consider the circuit structure of the FPGA with its CAD tools. We evaluate several FPGA logic-element structures with a technology mapping method. From our experiments, the multiplexer based logic-element is found to be suitable for implementing such a high-speed circuit using the BDD-based technology mapping method.

A design data management method in a distributed design environment is described. This method is based on detecting the difference between the original design data and modified design data. One of the advantages of this method is that the precise difference among versions can be identified. Exploiting this feature, the history of modifications of design data can be traced, and the required storage space can be reduced to less than that needed for previous methods. Another advantage is that efficient concurrency control is achieved by detecting the difference between design data.>

A novel approach to formal verification of computer hardware designs at a higher level of representation than the register-transfer level is presented. In this verification method, the specification of a digital system is defined as the input/output behavior of the external systems that communicate with the target system. The specification description called a cospecification and the implementation description called an FBL (functional block level) description are transformed into a hardware model representation and composed by connecting their related ports in the hardware model. Whether the design is correct or not is verified by producing state transitions of the composite system. This verification method requires only input/output relations between the cospecification description and the FBL description. This feature makes it suitable for verification of a higher-level design in which implementation details may not be explicit.>