Recently, the open radio access network (O-RAN) architecture has been expected to enhance both the openness of network components and the intelligence of control functions as a promising RAN architecture for Beyond 5G (B5G)/6G networks. Meanwhile, the power consumption of base stations (BSs) in RAN is a serious problem that needs to be addressed owing to the recent increase in service types such as 4G-LTE, 5G, and local 5G, and it will be more remarkable in the future B5G era. However, a conventional RAN experiences energy wastage because it turns on the power of all BSs at all times, even in coverage areas that accommodate a small number of mobile terminals and low traffic. The O-RAN Alliance discusses the energy savings of BSs, but its standard specification lacks sufficient discussions on concrete models and protocols to realize highly energy-efficient power-on/off management of BSs. On the other hand, terrestrial network (TN) and non-terrestrial network (NTN) convergence has recently been considered in both academic research and standardization as an emerging technology for B5G networks. However, utilizing NTN capacities for BS power-on/off control of TN in the standard O-RAN architecture remains uninvestigated, although it has the potential to achieve higher energy efficiency. This study proposes a novel energy-efficient power management architecture for O-RAN BSs. The proposed power management architecture extends the traditional standard O-RAN architecture such that the pedestrian flow analytics results and NTN capacities can be effectively utilized to obtain a higher energy-saving effect for O-RAN BSs. Consequently, the proposed power-on/off control reduces the power consumption of O-RAN BSs while maintaining the continuity of communications, bitrate, and other metrics. We performed numerical calculations using real datasets of pedestrian flows in regional mesh areas. As a result, we proved that the proposed architecture reduces power consumption by up to 40% when the NTN can accommodate UEs’ traffic of approximately 400 Mbps. In addition, we implemented pedestrian flow analytics and power control functions in the controllers. We verified the feasibility of the functions by demonstrating the power-on/-off of an O-RAN BS using a mobile network testbed.

Running IoT applications on edge computing infrastructures has the benefits of low response times and efficient bandwidth usage. System verification on a testbed is required to deploy IoT applications in production environments. In a testbed, Docker containers are preferable for a smooth transition of tested application programs to production environments. In addition, the round-trip times (RTT) of Docker containers to clients must be ensured, according to the target application's response time requirements. However, in existing testbed systems, the RTTs between Docker containers and clients are not ensured. Thus, we must undergo a large amount of configuration data including RTTs between all pairs of wireless base station nodes and servers to set up a testbed environment. In this paper, we present an edge computing testbed system with simple application programming interfaces (API) for testbed users that ensures RTTs between Docker containers and clients. The proposed system automatically determines which servers to place Docker containers on according to virtual regions and the RTTs specified by the testbed users through APIs. The virtual regions provide reduced size information about the RTTs in a network. In the proposed system, the configuration data size is reduced to one divided by the number of the servers and the command arguments length is reduced to approximately one-third or less, whereas the increased system running time is 4.3s.

In this paper, a Proof-of-Concept (PoC) architecture is constructed, and the effectiveness of mmWave overlay heterogeneous network (HetNet) with mesh backhaul utilizing route-multiplexing and Multi-access Edge Computing (MEC) utilizing prefetching algorithm is verified by measuring the throughput and the download time of real contents. The architecture can cope with the intensive mobile data traffic since data delivery utilizes multiple backhaul routes based on the mesh topology, i.e. route-multiplexing mechanism. On the other hand, MEC deploys the network edge contents requested in advance by nearby User Equipment (UE) based on pre-registered context information such as location, destination, demand application, etc. to the network edge, which is called prefetching algorithm. Therefore, mmWave access can be fully exploited even with capacity-limited backhaul networks by introducing the proposed algorithm. These technologies solve the problems in conventional mmWave HetNet to reduce mobile data traffic on backhaul networks to cloud networks. In addition, the proposed architecture is realized by introducing wireless Software Defined Network (SDN) and Network Function Virtualization (NFV). In our architecture, the network is dynamically controlled via wide-coverage microwave band links by which UE's context information is collected for optimizing the network resources and controlling network infrastructures to establish backhaul routes and MEC servers. In this paper, we develop the hardware equipment and middleware systems, and introduce these algorithms which are used as a driver of IEEE802.11ad and open source software. For 5G and beyond, the architecture integrated in mmWave backhaul, MEC and SDN/NFV will support some scenarios and use cases.

We introduce the design and deployment of the latest version of the VNode infrastructure, VNode-i. We present new extended VNode-i functions that offer high performance and provide convenient deep programmability to network developers. We extend resource abstraction to the transport network and achieve highly precise slice measurement for resource elasticity. We achieve precise resource isolation for VNode-i. We achieve coexistence of high performance and programmability. We also enhance AGW functions. In addition, we extend network virtualization from the core network to edge networks and terminals. In evaluation experiments, we deploy the enhanced VNode-i on the JGN-X testbed and evaluate its performance. We successfully create international federation slices across VNode-i, GENI, and Fed4FIRE. We also present experimental results on video streaming on a federated slice across VNode-i and GENI. Testbed experiments confirm the practicality of the enhanced VNode-i.

The deployment of hybrid wide-area OpenFlow networks is essential for the gradual integration of OpenFlow technology into existing wide-area networks. Integration is necessary because it is impractical to replace such wide-area networks with OpenFlow-enabled ones at once. On the other hand, the design, deployment, and operation of such hybrid OpenFlow networks are often conducted intuitively without in-depth technical considerations. In this paper, we systematically discuss the technical aspects of the hybrid architecture for OpenFlow networks based on our experience so far in developing wide-area hybrid OpenFlow networks on JGN2plus and JGN-X, which are nation-wide testbed networks in Japan. We also describe the design and operation of RISE (Research Infrastructure for large-Scale network Experiments) on JGN-X, whose objective is to support a variety of OpenFlow network experiments.

Testbeds play a key role in the advancement of network science and the exploration of new network architectures. Because the scale and scope of any individual testbed is necessarily limited, federation is a useful technique for constructing testbeds that serve a wide range of experimenter needs. In a federated testbed, individual facilities maintain local autonomy while cooperating to provide a unified set of abstractions and interfaces to users. Forming an international federation is particularly challenging, because issues of trust, user access policy, and local laws and regulations are of greater concern that they are for federations within a single country. In this paper, we describe an architecture, based on the US National Science Foundation's GENI project, that is capable of supporting the needs of an international federation.

IEEE 802.15.4 based devices are a key component for mobile and pervasive computing. However, their small dimensions and reduced resources, together with the intrinsic properties of wireless communication, make it difficult to evaluate such networked systems through real-world trials. In this paper we present an emulation testbed intended for the evaluation of IEEE 802.15.4 networked systems. The testbed builds on the generic framework of the wireless network testbed QOMB, and adds IEEE 802.15.4 network, processor and sensing emulation functionality. We validated the testbed through a series of experiments carried out both through real-world trials in a smart home environment, and through emulation experiments on our testbed. Our results show that one can accurately, and in real time, execute IEEE 802.15.4 network applications on our testbed in an emulated environment that reproduces closely the real scenario.

This position paper outlines the author's view on architectural directions and key technology enablers for the future mobile Internet. It is pointed out that mobile and wireless services will dominate Internet usage in the near future, and it is therefore important to design next-generation network protocols with features suitable for efficiently serving emerging wireless scenarios and applications. Several key requirements for mobile/wireless scenarios are identified - these include new capabilities such as dynamic spectrum coordination, cross-layer support, disconnection tolerant routing, content addressing, and location awareness. Specific examples of enabling technologies which address some of these requirements are given from ongoing research projects at WINLAB. Topics covered briefly include wireless network virtualization, the cache-and-forward (CNF) protocol, geographic (GEO) protocol stack, cognitive radio protocols, and open networking testbeds.

Network virtualization has become a common research topic that many researchers consider a basis for defining a new generation network architectures. In this paper, we attempt to clarify the concept of network virtualization with its brief history, to introduce the benefit of network virtualization for the future network, to posit our strong belief in that the future network should adopt a form of a meta-architecture that accommodates multiple competing multiple architectures, and to identify challenges to achieving this architecture.

Building an experimental network within a testbed has been a tiresome process for experimenters, due to the complexity of the physical resource assignment and the configuration overhead. Also, the process could not be expedited across testbeds, because the syntax of a configuration file varies depending on specific hardware and software. Re-configuration of an experimental topology for each testbed wastes time, an experimenter could not carry out his/her experiments during the limited lease time of a testbed at worst. In this paper, we propose the AnyBed: the experimental network-building system. The conceptual idea of AnyBed is "If experimental network topologies can be portable across any kinds of testbed, then, it would expedite building an experimental network on a testbed while manipulating experiments by each testbed support tool". To achieve this concept, AnyBed divide an experimental network configuration into the logical and physical network topologies. Mapping these two topologies, AnyBed can build intended logical network topology on any PC clusters. We have evaluated the AnyBed implementation using two distinct clusters. The evaluation result shows a BGP topology with 150 nodes can be constructed on a large scale testbed in less than 113 seconds.

Aiming at actual evaluation of IMT-Advanced system performance using field tests, this paper develops an IMT-Advanced testbed system with a transmission bandwidth of 100 MHz. Taking into account recent advances in research and development of an IMT-Advanced system, orthogonal frequency division multiplexing (OFDM) with multiple-input multiple-output (MIMO) are also promising technologies in IMT-Advanced. In addition, in order to meet the requirements for IMT-Advanced, the system seems to have a bandwidth of about 100 MHz with the aid of MIMO transmission. The developed system is based on the above more reliable prediction compared with previous studies, and the goals of this development are to provide a more realistic transmission performance, judgment criteria for operators introducing new air interfaces, and to explore new applications. This paper also presents the experimental results of rotational OFDM (R-OFDM) and twin turbo (T2) decoder implemented in the testbed and demonstrates that our proposals are better than the conventional schemes in actual radio transmission. Both physical layer technologies have been proposed by the authors, however, the previous works are only predicated on computer simulation. In this paper, the proposals are experimentally evaluated by distorting the transmitted signal on radio waves with a fading simulator and additional noise generator. When the packet error rate performance is measured, the measurement results are verified to be in good agreement with the simulation results. The experimental results also demonstrate that the R-OFDM can reduce the required carrier to the interference power ratio (CIR) of OFDM by about 1.1 dB in single-input single output (SISO) multi-path fading channel. In addition, it becomes clear that the T2 decoder is better than the turbo decoder in error correction, and the required CIR reduction achieves about 0.8 dB in SISO AWGN channel. The throughput performances are also measured with different modulation and coding conditions, and the measured forward throughput in the SISO AWGN channel achieves up to 373.6 Mbps. In addition, by use of 22 MIMO transmission, the measurements results substantiate that throughput of 512.7 Mbps can be realized even in the multi-path fading condition.

This paper presents a wireless burst modulation/ demodulation method for narrowband ubiquitous communication systems. This method especially suits those systems, whose traffic is especially dominated by short frame bursts. The proposed modulation method provides a preamble-less frame structure with training symbols, which improves both transmission efficiency and burst synchronization performance. Moreover, the proposed demodulation method achieves superior burst synchronization performance in low carrier-to-noise power ratio (CNR) environments by applying a synchronization method that includes symbol timing recovery, slot synchronization, carrier frequency correction and channel tracking. In addition, this paper presents the result of experiments on hardware prototypes of the proposed modulator and demodulator. The basic operation and practical performance of the proposed method is confirmed through testbed studies.

The cognitive radio system consists of multiple wireless access systems that cover overlapping areas and cognitive terminals that use one or more of the wireless access systems simultaneously. In this paper, we describe the system architecture of a platform for load balancing and throughput enhancement with cognitive radio system. In our platform, each terminal, which can access multiple radio systems, operates with a single local IP address. Based on our platform, we have developed both simulator and testbed system. Through the simulation of and the testing of a testbed system, we prove that systems load balance was achieved between WiMAX and wireless LAN, and total user throughput was increased with the proposed platform. Moreover, load balance to satisfy both real time service and best effort service. These results demonstrate the platform described in the paper can achieve a convergence with plural wireless systems.

The cognitive radio system consists of multiple wireless access systems that cover overlapping areas and cognitive terminals that use one or more of the wireless accesses simultaneously. In this paper, we describe the architecture of the cognitive radio system and the inter-system handover protocols. In the architecture, each cognitive terminal, which can access multiple radio systems, operates with a single local IP address. The control sequence and packet format are designed to achieve fast handover among the radio systems. Based on the architecture, we have developed a testbed system. On this system, we demonstrate that data can be delivered continuously and radio systems can be switched correctly without any packet loss. In addition, we present the result of the evaluation of the end-to-end latency on the testbed system. These testbed results demonstrate the system architecture described in the paper can achieve a cognitive radio system.

Intermittent periodic transmit (IPT forwarding) has been proposed as a highly efficient packet forwarding method for wireless multihop networks. With IPT forwarding, packets are intermittently transmitted by a source node and each relaying node forwards a relaying packet immediately after receiving it. The frequency reuse space attained by this scheme is proportional to the given transmit period and if the transmit period is adequately chosen, interference between adjoining nodes in transmission can be removed. The IPT forwarding evaluations conducted to date have assumed that the transmission conditions were ideal. However, actual conditions are clearly more complex. In this paper, we develop testbeds of wireless multihop node and study the feasibility of IPT forwarding in a large-scale building with 4 stories. Each node is equipped with 802.11b wireless interface in the Ad-Hoc mode and proprietary protocols for IPT forwarding that we developed for these experiments.

We study the configuration issue of three-stage multi-granularity optical cross-connects (MG-OXC) for the dynamic traffic model in all-optical networks. From the single node point of view, we propose a configuration algorithm to configure different granularity cross-connects for arrival sub-requests with different traffic types and bandwidths. The performance of the configuration algorithm is evaluated by simulation and, furthermore, is validated by experiment based on our flexible Multi-functional Optical Switching Testbed (MOST).

The need for responsive, flexible agents is pervasive in many application domains due to their complex, dynamic, and uncertain nature. Dynamic Adaptive Autonomy allows Sensible Agents to reorganize themselves during system operation to solve different problems in the face of these complex and dynamic environments. This paper presents both functional and implementation architectures for Sensible Agent systems. The functional architecture supports concepts from the distributed computing community by separating internal agent functionality into a discrete set of modules whose interactions are formally specified using the Interface Definition Language (IDL) from the Common Object Request Broker Architecture (CORBA). These four modules are: (1) Perspective Modeler--which contains the agent's explicit model of its local, subjective view of the world, (2) Autonomy Reasoner--determines the appropriate decision-making framework for each of the agent's goals, (3) Action Planner--interprets domain-specific goals, plans to achieve these goals and executes the generated plans, and (4) Conflict Resolution Advisor--identifies, classifies, and recommends possible solution strategies for resolving conflicts between this agent and other agents. The implementation architecture has been realized in a testbed that promotes (1) language and platform independence, (2) parallel development, (3) rapid integration of evolving representations and algorithms implementing agent functionality, (4) repeatable experimentation and testing, (5) environment and agent visualization, and (6) inter-domain application portability. The testbed uses the Inter-Language Unification (ILU) ORB from Xerox to provide the CORBA layer of inter-module and inter-agent communication. A three-dimensional visualization of the domain is provided with a CORBA-connected Virtual Reality Modeling Language (VRML) model while low-level data collection is accomplished using a CORBA-connected Java application. The combination of a distributed functional architecture with a distributed implementation architecture provides a high level of flexibility, visualization ability and experimental fidelity for evaluating the performance of Sensible Agents in complex, dynamic and uncertain environments.

This paper first proposes an object-oriented service network model, which is composed of application, server and resource object groups, from both viewpoints of rapid and smooth introduction and effective execution of the next generation IN services. The paper also, proposes a testbed system, which is referred to as "To-be-IN (Testbed on Object-oriented and B-ISDN Environment for IN)", for evaluating network architecture based on the proposed model. Using the testbed, several technical issues can be solved such as object-oriented realization of IN services, a provision of distribution transparent environment and a transition strategy from today's IN network. The testbed system is constructed on a currently available computing environment in which a distribution transparency mechanism is added. This system provides Service Creation Environment (SCE) for a purpose of achieving seamless software transfer from a development phase to an operation phase in the object-oriented service network model. The paper finally summarizes some results of an experimental implementation of the system.