This paper demonstrates a new RFID based health management system with a low-power ARM microcomputer. RFID cards are usually used as identification in many companies. The developed RFID cards can measure exercise quantity of office workers by deploying a low-power microcomputer and sensors. It is well known that a quantity of exercise has a strong relation with a health condition. Therefore, a quantity of exercise is a key indicator to prevent chronic diseases. The developed system employs a standardized RFID system to communicate with RFID reader/writers. Therefore, it is easy to install the developed system by updating software for RFID reader/writers in entrance gates, doors, etc. This paper demonstrates the prototype system for health management system built on a low-power ARM microcomputer.

This paper demonstrates a new ID card based momentum measurement system for office workers' health managements in companies. Our system can measure office workers' momentum with a new ID card that implements a microprocessor, sensors and a RFID tag because an amount of momentum has a relation with a health condition and it is an important indicator to prevent chronic diseases. RFID based ID cards are widely used in office buildings to manage a security control and to record working hours. Therefore, companies can install the proposed system by updating software for a RFID reader/writer in entrance gates, doors, etc. The demonstration shows a prototype system for health management system with ID card based measurement devices of momentum.

We propose the use of a mutually complementary communication protocol (MCCP) based on destination oriented directed acyclic graph (DODAG) using multi-interface communications. Recently, research on smart home is getting more active because of the public opinion on energy saving or comfortable living. The architecture of smart home includes sensor networks that are important infrastructure to collect environmental information such as temperature, humid, or brightness. The MCCP is suitable for such sensor network because of its feature, interface switching and DODAG routing. In this work, for the performance evaluation of the MCCP, we developed evaluation boards which are connected with both power line communication (PLC) and the IEEE 802.15.4 module. An experimental result shows that the DODAG routing, which we discussed in this paper, is useful for the complicated topology such as PLC/RF integrated network of the MCCP.

We describe a system that controls various devices such as sensors or home appliances in heterogeneous networks. This system can deal with unified devices by interconnecting them in networks using different communication protocols and integrating them, and it is possible to view sensing data and control home appliances with mobile devices. Moreover, as they all communicate through a Web server, it is possible to achieve a cooperative device service using the Web browsers of mobile devices. We implemented a service where a user set a value for a sensor with his/her Web browser, and when the sensor displayed its value, the Web server automatically controlled a specific appliance.

We propose a mutually complementary wireless and wired network, developed for residences, for a larger university school building. We evaluated the resulting practical, realizable communication system through simulation.

Many people in the modern world feel that they are poor at face-to-face communication.We have developed a topic-providing system that can infer daily life behavior and provides users with their conversation partner’s information, including hometown, hobbies and life log at the advent of face-to-face communication. The life logs are details about a user’s life, and are generated using Bayesian network on the basis of sensor values by our system. This system enables users to access other users’ behavior from the accumulated life logs and utilize this information to generate a topic for conversation.

This paper proposes construction technology for a Smart Tap Home Energy Management System (HEMS) that can make the energy consumption of living environment information and the consumer electronics visible using Wireless Sensor Networks (ZigBee). This technology solves the problem of the introduction cost of the HEMS spread Also, HEMS can be easily constructed in homes or the offices without modifying it to fit an existing building or consumer electronics product at all. Moreover, using the features of the ZigBee telecommunication, the technology is described that can display and analyze a detailed breakdown of the amount of electric power an hour. We developed and evaluated the proposed prototype Smart Tap HEMS for Indication. As a result, we found out how much electricity is wasted and shared the energy-saving strategy in our laboratory.

Energy consumption has been increasing over the past half century. Even though ultra-low power consuming appliances are being developed, the amount of energy consumption in homes is increasing because of various appliances being produced for ubiquitous smart home. We propose an adaptive home/building energy management system (A-HEMS/BEMS) for controlling energy consumption using the convergence of heterogeneous sensor/actuator networks. The system goes far beyond traditional auto meter reading (AMR) systems that offer only limited meter-reading functionality and provides a smart infrastructure management that brings new features and benefits to every aspect of our utilities.

Localization protocol is important for estimating node positions in a wireless multi-hop network. Routing protocol is also important for controlling paths. In previous research, localization and routing protocols have been discussed and evaluated separately. In this paper, we propose an integrated protocol for the optimized link state routing (OLSR) and OLSR based localization (ROULA). Our protocol enables simultaneous localization and routing. ROULA's localization is performed using OLSR overhead such as hello packets and routing tables. The routing overheads and the processing procedures can be efficiently integrated. We demonstrate that the integrated protocol for ROULA and OLSR enables simultaneous localization and routing.

This paper presents a novel technique for multi-hop localization by using mobility (MLM) in mixed line-of-sight/non-line-of-sight (LOS/NLOS) environments. In MLM, nodes equipped with ultra-wideband (UWB) radio first move randomly for collecting time-of-arrival (TOA) measurements and then apply a modified biased Kalman filter (MBKF) designed for mitigating NLOS errors. NLOS bias in the measurements is further mitigated by using the shortest path distance (SPD) selection. Node positions are initialized by using multidimensional scaling (MDS) and then estimated by using iterative trilateration accompanied by an error accumulation management. Our simulation results demonstrate that the positioning accuracy of MLM outperforms previous methods in obstructed building environments with a limited anchor heard (AH).

This demonstration presents the system shown in the paper accepted at CCNC 2009 [1]. By using this system, control of a network camera programmed to be activated by a sensor is possible. With mobile devices, a user can set or delete the service, which would be executed when a predefined event occurred. When a situation satisfies the predefined criteria of the program utilizing the sensor, this architecture detects it, and executes the service which is determined in advance. Precise definition of the event, which is composed of several types of sensors, is also possible. This architecture is not limited by vendor but can be adapted to many kinds of hardware. Therefore, a user can use sensors without being conscious of the difference of vendors. We demonstrate how to define an event and set the service for the defined event.

The design and implementation of home appliance control based on information from sensors is presented. In a ubiquitous networking society, there are a lot of devices connected to a network. However, many kinds of networks coexist, and they use different communication protocols. Therefore, a technology to integrate different networks is necessary to provide flexible services, which can control various devices connected to different networks where different protocols are used. At the same time, the technology of sensor networks is important in such a society. Sensors also use different protocols. Therefore, using sensing data from different kinds of sensor networks is difficult. To collect and process information from various kinds of sensors, we designed and implemented a sensor gateway. To control home appliances, protocols defined by the Peer-to-Peer Universal Computing Consortium are used in our system.

We have developed a wireless multi-hop localization game, i.e., a war game, based on a classical field game. The players use mobile game consoles with ad-hoc networking capability and play the game on a field. The fundamental concept underlying a wireless multi-hop localization game is that players on a team establish an ad-hoc network to estimate their positions and then compete for positioning accuracy with other teams by using a multi-hop localization technique. Simulation revealed that velocity and obstruction position were the key parameters in playing the war game. The simulation results demonstrated that the proposed game made a good use of the ad-hoc networking capability.

Since the Session Initiation Protocol (SIP) has been chosen by the Next Generation Network (NGN) as its standard for establishing sessions in the Internet Multimedia Subsystem (IMS), a complementary architecture based on SIP and its exten- sions would provide a tremendous opportunities for future ubiq- uitous multimedia communications. However, SIP-based end-to- end approaches require negotiation between parties, even though the transfer destination device has the same capabilities and is physically nearby. This paper addresses a delay in streaming control between networked media devices in home networks. We assume that cellular phones would act as control points (CPs) for virtual devices, and have called these networks mobile Personal Area Networks (mPANs). The architecture is based on combining the indirect approach with the SIP approach. CP can control input/output (I/O) devices for audio/video streamings within mPAN individually. With switching from end-to-end to indirection with a home gateway, the unnecessary renegotiation between parties are cut. We also added an extra handover header to reduce the delay in retrieving streaming from a device to the CP. From the experimental results, the mPAN-supported SIP User Agent (UA) dramatically reduced the transfer time between devices and the retrieval time from device to CP compared with non-supported SIP UA. Index Terms—media streaming transfer, Session Initiation Protocol (SIP), mobile personal area networks, Fixed Mobile Convergence (FMC) I. INTRODUCTION The appearance of dual-mode cellular/Wireless LAN (WLAN) mobile phones provides the potential for new IP- based multimedia communications in collaboration with long- range and short-range wireless networks. While mobile phones are improving with more enhanced capabilities for IP-based multimedia communications, they remain limited in terms of bandwidth, display size, audio quality, and computational power. At the same time, recent consumer electronics have been media devices networked through the broadband Internet access service, and they have much greater capabilities than mobile phones. Combining the advantages of both into a single virtual device complements the capabilities of mobile phones and provides seamless interaction between consumer electronics, mobile phones, and PC devices. This paper addresses a seamless streaming transfer archi- tecture to control networked media devices in home networks based on the Session Initiation Protocol (SIP) (1) and a delay in streaming control between networked media devices in the networks. We assumed that mobile phones would act as control points for aligned devices, and called these networks mobile Personal Area Networks (mPANs). Users can then seamlessly control input/output (I/O) devices in networked media devices within mPANs. Since the SIP has been chosen by the Next Generation Network (NGN) as its standard for establishing sessions in the Internet Multimedia Subsystem (IMS) and it is being deployed in hardware and software IP multimedia clients, a comple- mentary architecture based on SIP and its extensions would provide a tremendous opportunities for future ubiquitous fixed mobile convergence (FMC) multimedia communications. With wide acceptance of Voice over IP (VoIP) and expectation for rapid adoption of multimedia mobile services, the signaling efficiency in IMS has become increasingly important. Users not only expect high voice and video quality, but also high availability, speed and reliability in service invocation and execution. Motivated by the importance of signaling efficiency for SIP-based system, in this paper we propose an architecture for mPAN that is based on combining the indirect approach with the SIP approach. With the hybrid architecture, user can control I/O devices for audio/video streamings within mPAN individually, as well as the transfer time between devices and the retrieval time from device to mobile phone are reduced. The rest of the paper is organized as follows. Section II outlines related work. In Section III, we describe the features of mPAN in more detail and seamless streaming control architecture using SIP. Section IV provides the results obtained from evaluating the prototype testbed. Section V ends the paper with a brief summary and some concluding remarks.

Procedures that provide a virtual link service aggregating bandwidths of multiple physical links are called a multilink protocol. The multilink protocol enables to utilize bandwidths of multiple links flexibly and to improve reliability of communications. This paper focuses on the resequencing function needed to preserve packet sequence integrity. The resequencing is generally performed by both each link layer protocol as well as the multilink protocol. This paper shows that a problem of the head of line (HOL) blocking occurs due to the resequencing if packets of multiple IP flows are transferred over the multilink connection. To solve this problem, this paper proposes the Per- Flow ReSequencing (PFRS) scheme for the multilink protocol and evaluates its effectiveness through analysis and simulations.

Node localization obtained by estimating node positions is an essential technique for wireless multi-hop networks. In this paper, we present an optimized link state routing (OLSR)-based localization (ROULA) that satisfies the following key design requirements: (i) Independency from anchor nodes, (ii) robustness for non-convex network topology, and (iii) Compatibility with network protocol. ROULA is independent from anchor nodes and can obtain the correct node positions in non-convex network topology. In addition, ROULA is compatible with OLSR protocol, and it uses the inherent distance characteristic of multipoint relay (MPR) nodes. We reveal characteristics of MPR selection and the farthest 2-hop node selection used in ROULA, and describe how these node selections contribute to reducing the distance error for a localization scheme without ranging devices. We used a simulation to specify appropriate MPR_COVERAGE for ROULA, and give a comparative performance evaluation of ROULA for various scenarios including non-convex network topology and various deployment radii of anchor nodes. Our evaluation proves that ROULA is effective for localization in various network scenarios.

We developed the HAT (home appliance translator) and HAT-Sub to enable conventional appliances without telecommunication capabilities to connect to home networks. The demand is rising for home appliances to connect to networks so that they can be remotely controlled, however, purchasing information appliances places financial strain on users. If conventional appliances could connect to home networks, this problem would be solved. X-10 devices can do that, but they can only turn appliances on and off. HATs and HAT-Subs allow more advanced control and determine the state of a conventional appliance in more detailed by using an IR signal and supplied electricity. The user can program a VCR and adjust the temperature of a heater and remotely determine whether those tasks were correctly done by using HATs and HAT-Subs. These devices use power lines for automatic communication. Users can construct home networks more easily and cheaply, without information appliances, new communication infrastructures, or complex settings.

This paper studies the case where multiple IP flows are aggregated over a single satellite channel and an error recovery by retransmissions is performed by Selective- Repeat (SR) ARQ. We propose MQ-PFRS (Multi-QoS Per-Flow Resequencing) ARQ that provides a differentiated service for an IP flow depending on its traffic class, such as real-time traffic (ex. UDP) or non-real-time traffic (ex. TCP). MQ-PFRS ARQ eliminates interferences among IP flows by resequencing received packets independently for each IP flow. It also controls the maximum packet delay by limiting the persistency of retransmissions and the maximum resequencing time for each packet. This paper also presents the analysis of the probability distribution of real-time packet delays. Simulation results show that the delay variation of real-time traffic is effectively controlled by proposed MQ-PFRS ARQ and the results of the analysis well capture the characteristics of the packet delay distribution. This means that MQ-PFRS is effective for handling multiple classes of IP flows and quality of real-time traffic transferred by the scheme can be predicted by the analysis.

Energy efficiency has been known as the most significant problem in all facets of the wireless sensor network operations. In this paper, we propose a meta-data-based data aggregation scheme in the clustering wireless sensor networks. For all sensor nodes in the sensing range of an event can detect the event and generate the sensing data, the cluster head will receive the sensing data packets about the same event, and there is likely to be some redundancy. In our scheme, only one of the sensor nodes within the sensing range of an event in a cluster is selected to transmit the sensing data to the cluster head via the meta data negotiation. We also evaluate this scheme with the LEACH protocol. The simulation results show that the cluster protocol with our data aggregation scheme is effective in prolonging the network lifetime and supporting scalable data aggregation.

In ad-hoc multicast networks, the maintenance of the delivery tree is important. However, the cost of reconstruction of the delivery tree is very large. In this paper, we propose the method to recover the delivery tree locally and effective retransmission for the packet loss caused by disconnection of the delivery tree. A new node group named the support group is composed in surroundings of the delivery tree for a local recovery. The support group is maintained by recursive constructing in the surroundings though the member of this support group might be included in the delivery tree by a local recovery. From our simulation, the proposed method has better performance than ODMRP.

SR (selective-repeat) ARQ (automatic repeat request) is employed to recover packet errors in communication environment with long propagation delay. This SR ARQ has problems of large resequencing delay and bursty packet output due to the resequencing function. In order to solve these problems this paper proposes two types of resequencing schemes and compares the TCP throughput of the schemes by simulations, where a number of upper layer flows are multiplexed over SR ARQ performed in Layer 2.

An SR (selective-repeat) ARQ (automatic repeat request) protocol is used for effective packet error recovery on a satellite channel. This SR ARQ has a problem of large delay due to the resequencing of received packets. To mitigate this problem, the PFRS (per flow resequencing) scheme was proposed, where resequencing is performed independently for each upper layer flow, while the detection of lost packets and associated retransmissions are performed based on the whole flows multiplexed over the SR ARQ. The paper models the SR ARQ protocol, where the maximum number of retransmissions is limited, by a collection of simple stop-and-wait protocols; it shows calculation results on the delay distribution of retransmission and resequencing and proves the effectiveness of the PFRS scheme.

It is difficult to retain accessibility to data on other hosts in ad hoc networks because of disconnections caused by movements of hosts. This fact affects the practical use of ad hoc networks. When important data are operated on ad hoc networks, it is demanded to retain accessibility to the data from users even if there are disconnections between mobile hosts. Hara (2001) has proposed some methods for allocating replicas on ad hoc networks for achieving high accessibility to data objects shared by multiple hosts. The methods are based on an assumption that all hosts on the network know the probabilities of data access to each object and the probabilities do not change. In this paper, we handle a case that the probability of data access from each host change with time and its location. We propose a method to enhance the accessibility to data that are associated with locations and used frequently by hosts that are close to the location. We assume data object is accessed by geocast. Such kind of data will be used in personal navigation systems, systems handling virtual objects overlaid on to the real world like Space Tag and cooperative work for disaster relief etc.

A remote monitoring of various device distributed over wide area is strongly demanded to cut down their maintenance cost. With the introduction of wireless packet systems, the mobile remote monitoring system has started to propagate, because of a less limit to establish remote monitoring devices and its characteristic of always connectivity. Many small to medium sized corporations have been hesitating, although they understand this necessity, because of high investment costs involved in the maintenance of monitoring systems. One solution to this problem is the ASP (Application Service Provider). We developed the multi sharing mobile remote monitoring system MMRM. This paper will present the four layers object management model and the three layers application protocol stuck model that are basic design schemes of MMRM. The system structure and the function block diagram of the practical system TRM (Tokai-Remote Monitoring System) in which Toshiba Machine's TC-mini is used as a data logger will be introduced. In addition, system characteristics such as the delay period from trouble detection to sending alarm message will also be described.

In the field of mobile communication, not only has the scale of network environments increased over the last few years, but there has also been a steady increase in the diversity of mobile communication protocols and service applications due to the spread of mobile Internet applications. To enable these networks to be designed and developed efficiently, it is therefore necessary to have some way of simulating entire systems in order to evaluate different schemes, predict the traffic levels and try out alternative designs. In this study, we simulate a large-scale wide-area mobile Internet environment by allowing multiple existing simulators to cooperate with each other. Specifically, by calling a wireless data link protocol software simulator on an OPNET from an ns-2 simulator running a wide-area network simulation, we have conducted a simulated evaluation of a TCP/IP communication protocol suite including a W-CDMA environment, thereby confirming the validity of this approach.

We propose a multimedia data transmission method, Multitrack, that achieves high-speed and efficient data transmission between multiple mobile hosts and the Internet. This method enables terminals that have a low-speed link to the Internet to receive and play a high quality streaming video, and mitigates the load on the server. Multitrack is used in a cluster-type network where multiple mobile hosts are connected to each other with short-range, high-speed links. High-speed communication with hosts outside the cluster is realized by using multiple wireless links from each mobile host in the cluster and the Internet in parallel and dispersing data traffic to them. By using Multitrack, users of the hosts in the cluster can see a high quality streaming video by sharing the received multimedia data. However, because of the differences in the bandwidth and the delay, it is important to disperse traffic according to the quality of multiple links in order to offer stable multimedia data transmission. We propose an effective traffic dispersion method for this environment, and evaluate this method and other methods by simulations.

Mobile computing has become very popular. Many people can access the Internet through mobile hosts. However, wireless links used by mobile hosts have problems such as narrow bandwidth and low reliability. To offer high-speed communication on wireless links, we have proposed SHAKE (SHAring multiple paths procedure for cluster networK Environment). In SHAKE, mobile hosts that are connected by a fast local link use multiple wireless links owned by each host simultaneously to communicate with hosts on the Internet. An experimental system was implemented and evaluated. In this system, however, not only mobile hosts but also correspondent hosts on the internet require special software for SHAKE. We propose a fast WWW access method with SHAKE (Web SHAKE). The feature of Web SHAKE is that it does not require any special software on Web servers on the Internet to use SHAKE. The feature is realized by an use of HTTP proxy server that works on each mobile host. We present the result of a performance evaluation of the Web SHAKE.

Based on the existing models and methodologies for software process improvement (SPI), an evolution management framework (EMF) is proposed. This methodology uses best practices of various existing models and methodologies, extends or adapts them, and puts them into the context of embedded software engineering development environments.

The article presents a framework for algorithmic debugging of distributed programs written in procedural languages. It also gives an overview of a prototype system based on this framework and explains how to debug with this system, using an example of the dining philosophers' problem.

An optimistic consistency scheme has been established with respect to data consistency and availability in distributed systems. Wireless networks are becoming popular in data communication and suitable for data sharing among users using multicast capability, but have hidden node problems. This paper proposes a simple data coherency protocol for mobile devices that has less data traffic in data collaboration using a multicast communication feature and is capable of automatic recovery from unpredictable disconnection, such as hidden node problems, by a data versioning scheme using a version vector and update log management. We evaluated the efficiency of data sharing over multicast communication and the recovery cost from failure caused by hidden nodes and confirmed the efficiency of the protocol.

We can access Internet by carrying a portable computer and using the wireless communication. The wireless network with PHS (Personal Handy phone System) and portable cellular telephone has only rates of tens of Kbps to a few Mbps. Compared with the cable network, the transfer rate cannot generally satisfy a highly developed communication services such as large file transfer and real-time communications. This paper proposes a protocol, SHAKE, for sharing multiple paths in cluster type network that is a kind of LAN in which some mobile hosts temporarily connect mutually. SHAKE provides the functions for composing cluster type network, and dispersing traffic efficiently by measuring transfer rate and round-trip time. As a mobile host has only low transfer capacity in individual to communicate with outside, if whole capacities of other hosts which compose cluster type network are shared, we can get larger transfer capacity and satisfy the required communication services.

Mobile agent technologies are becoming popular as an efficient way to access network resources. Because an application using mobile agents has some unique problems caused by frequent creation, migration and disappearance of mobile agents, a mobile agent platform has to provide not only agents and their execution engines but some functions and mechanisms which are specialized to mobile agent systems. We discuss the practical problems occurring in mobile agent environments, that is, agent controllability, resource restrictions and security. To solve these problems, we propose a mobile agent platform, called SFM (Secured Floating Market) model. This model fulfils the agent controllability by agent control parameters and has the measures against the resource restrictions such as location of resources and agents, processing capability and condition of load. Besides, this model guarantees some suitable security strength levels for flexible execution of various services and user requirements. We implement the prototype of this model using Aglets.

Summary form only given. We present an implementation of a VOD (video on demand) system that addresses the problem of increasing video stream supply capabilities. To obtain fundamental video stream transfer characteristics on Ethernet, we first performed an experiment in which it became clear that bottlenecks of the CPU of a video server were the most serious. To solve this problem we implemented a distributed RAID4 (Redundant Arrays of Inexpensive Disks) method video server. Distributed RAID means extending the RAID method usually applied to disks to the servers, so as to achieve improvements in performance and reliability. The great advantage of this architecture is that the linear performance improvement can be achieved by adding inexpensive servers of a diffusion model.

In a distributed cooperative system, each agent has to observe its environment in order to create an adequate subgoal. The paper discusses tradeoff between cost of observation and achievement of the shared final goal of agents moving in a lattice world. The model is referred to as the restricted Tower of Babel. A cooperation mechanism called LM-DMax is evaluated through simulation against observation interval, the number of agents and moving area site. We find that the model has an optimal observation interval, an optimal area size to minimize the total cost. Then three adaptive policies which modify the observation interval of each agent are proposed. They are geometrical policy, arithmetical policy and slow-start policy. Slow-start policy shows the best result among them. Though the discussion is restricted to the specific model, it is directly applicable to a vehicle scheduling problem and a robot planning problem.

In this paper, the theoretical studies and solutions regarding problems for realizing Soft TCCS (Time Critical Communication System), residing on top of Ethernet LAN are presented. We analyze Ethernet LAN including its precise back off sequence to obtain throughput and delay characteristics in a light loaded circumstances. We also analyze the same performance characteristics effected by multi-modal condition which is the mode of transmitting both short packets for control messages and long packets for bulk data concurrently in Factory Automation system. These theoretical studies are validated through computer simulations. We end by presenting the definition of the bandwidth in Ethernet LAN and also formulae regarding its estimation needed for admission control to maintain the total load within the predetermined value.

The authors describe the design of a testing environment, called FOREST (formal environment for systematic testing), for communication systems. The proposed method integrates three major strategies: (1) the use of formal description techniques (FDTs), for their formal semantics, which makes them unambiguous; (2) a stepwise approach to generate appropriate test cases for different test stages; and (3) the systematic support of the testing process, from test development to test execution. FOREST consists of four major subsystems. TENT (test sequence generation tool) is a subsystem that generates test cases from the formal specification of the behavior of a given protocol. APRICOT (ASN.1 pre-compiler, coder and test-debugger) is a subsystem that generates test data from the protocol data structures definition. TESPEC (test specification editor) is a tool producing some test specification based on a standardized formalism. The last subsystem, TEXEC (test executor), is a test execution system which consists of an upper tester and a lower tester, and a simulator of the communication medium.>

The testing environment FOREST (formal environment for systematic testing), which uses formal description techniques systematically, has been developed. FOREST generates the TTCN format test sequence from the specification described in SDL. Furthermore, FOREST generates the test data from the protocol data definition described in ASN.1. By using the FOREST system, the test specification and test execution and test report description are achieved systematically. Therefore, the cost of the testing phase of OSI upper layer software development is reduced. In particular, the facility for test sequence generation of FOREST realizes high coverage with a reasonable cost. The facility can efficiently check protocol specifications. The effectiveness of the approach is demonstrated by an application to the test design for the CCR protocol.>