F.T. Johnsen

Forsvarets forskningsinstitutt, Horten, Vestfold county, Norway

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Publications (38)14.64 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Web services can be used as a middleware for standardized, interoperable machine-to-machine communication. However, the technology has communication overhead, leading to a need to investigate ways to optimize its resource use when applying the technology in limited capacity networks. There exist several approaches to optimization, and in this paper we investigate potential gains from replacing the commonly used HTTP/TCP transport for Web services with alternative transport protocols. We study four different protocols (TCP, UDP, SCTP, and AMQP) for conveying Web services traffic, evaluating them in an emulator under typical civil and military networking conditions.
    Military Communications and Information Systems Conference (MCC), 2013; 01/2013
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    ABSTRACT: Information-centric networking is a communication paradigm where there is no focus on endpoint addressing; rather, it is an attempt to achieve efficient information dissemination by focusing on the content that is distributed. In this article we describe how information-centric networking can be leveraged in order to extend NATO core enterprise services (CES) into the tactical domain. The paradigm can be implemented using decentralized publish/subscribe along with content caching. We present our information-centric middleware, Mist, and perform a comparative evaluation with an existing framework called Haggle. Mist is tailored to mitigate challenges encountered in mobile ad hoc networks. As a proof of concept, we implement a gateway between Mist and WS-Notification, which is the standard used in the Publish/Subscribe CES. This shows that with little effort it is possible to create gateways from networks using Mist to Web services-enabled infrastructure networks, ensuring compatibility and interoperability with higher levels in the chain of command, and also with other nations.
    IEEE Communications Magazine 01/2013; 51(10):34-41. · 3.66 Impact Factor
  • F.T. Johnsen, T.H. Bloebaum
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    ABSTRACT: Using the publish/subscribe paradigm for information exchange allows for loose coupling between information sources and consumers. It also reduces network usage because it ensures that information is only transmitted when there is new information available. This is particularly useful in mobile networks, where network capacity can be low. Subscription based information exchange is often built around the concept of topics, where a consumer subscribes to the topics it is interested in. Consumers then need to be able to find out which topics are available to subscribe to, and where to subscribe to them. When using Web services, the consumer uses a discovery mechanism to find information sources, but the current standards for service discovery do not support discovery based on topics. In this paper we extend the WS-Discovery standard with a topic matching rule, which enables consumers to search for Web services providing information about a given topic.
    Wireless Communications and Mobile Computing Conference (IWCMC), 2012 8th International; 01/2012
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    ABSTRACT: In this paper, we present Mist: a reliable and delay-tolerant middleware for information dissemination between highly mobile devices. Mist provides publish/subscribe with guaranteed message delivery in fully connected networks. Through emulation we show how the middleware is effective in static networks, as well as in dynamic topologies with high mobility. We describe how Mist is able to scale using a topic routing mechanism, allowing groups of mobile units to cooperate with infrastructure-based P2P-networks. Finally, we describe recent experiments where Mist has been employed successfully in real-life deployments. The implementation of the middleware, written in Java, is released as open source.
    New Technologies, Mobility and Security (NTMS), 2012 5th International Conference on; 01/2012
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    ABSTRACT: The objective of the IST-090 group is to investigate challenges of SOA applications in disadvantaged networks. The group studies possible solutions that can improve the overall efficiency of information dissemination when facing different disruptions. This paper presents lessons learned from the real-life experiment and demonstration that was carried out by IST-090 group members during the MCC 2011 conference. We evaluated several solutions, namely the WS-DDS interface, the DSProxy, the Mist protocol, and ESBs that were used as SOA solutions enabling efficient information exchange in a disadvantaged environment. The experiment was preceded by separate tests of each solution. However, in the combined scenario, the aim was to evaluate the interoperability of these solutions and define a long-term plan for either their application in operations or for further functionality development. The paper gives an overview of the solutions we investigated, presents a rough model of the network environment used, and discusses the results observed and the lessons learned.
    Communications and Information Systems Conference (MCC), 2012 Military; 01/2012
  • M. Skjegstad, F.T. Johnsen, J. Nordmoen
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    ABSTRACT: In this paper we present our framework for emulated evaluation of service discovery protocols in mobile ad-hoc networks (MANETs). Emulation is preferable to simulation when evaluating real world software implementations, as it provides a controlled network environment without requiring modifications to the software. We base our work on the open-source simulator ns-3, which also has support for network emulation. Our own test framework consists of a set of scripts running in Linux Containers, providing a means to bootstrap and populate service discovery protocols with services and queries. Our setup allows us to perform controlled and repeatable service discovery protocol experiments in MANETs with a high degree of automation. Experiment series are set up, controlled, and statistics calculated by scripts, thus enabling complex, large, and real-time evaluations to be performed without human interaction.
    New Technologies, Mobility and Security (NTMS), 2012 5th International Conference on; 01/2012
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    ABSTRACT: We have designed and implemented a prototype system providing role based Quality of Service (QoS) for Web services in heterogeneous networks. We leverage industry standards to the fullest extent, in an attempt to bring role based QoS support to standard Web services. We have extended an existing enterprise service bus to accommodate the changes necessary for prioritization on the server side, and created a custom client library to ensure prioritization in both the request and the response of the Web services message exchange. Finally, roles are defined using Security Markup Assertion Language (SAML) tokens. Our framework has been released as open source. Our evaluation shows that the concept is viable, and that prioritization on the application level of the OSI model, combined with network level prioritization as provided by DiffServ, is beneficial in networks with low bandwidth.
    Globecom Workshops (GC Wkshps), 2012 IEEE; 01/2012
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    ABSTRACT: NATO has identified Web services as a key enabler for its network enabled capability. Web services facilitate interoperability, easy integration and use of commercial off-the-shelf components, and while request/response-based schemes have hitherto been predominant, publish/subscribe-based services are gaining ground. SOAP-based Web services, however, introduce considerable communication overhead, and optimization must be done to enable use on the tactical level. Data compression is one such optimization, and it works well for large messages. We claim that the inherent characteristics of publish/subscribe-based Web services are such that using difference-based compression will allow effective compression also for small messages. In this paper we present the design and implementation of a proof-of-concept mechanism called ZDiff, which we have tested on several types of military data formats. Together with our SOAP-based proxy system it can be used together with commercial off-the-shelf Web services software. The results show that difference-based compression outperforms traditional compression for small messages, at the same time as it never performs worse than traditional compression for larger messages.
    MILITARY COMMUNICATIONS CONFERENCE, 2012 - MILCOM 2012; 01/2012
  • MCC 2011; 10/2011
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    Trude Hafsoe, Frank T. Johnsen
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    ABSTRACT: Web services technology is becoming more widespread for military use, in addition to being common in civilian systems. This technology is defined by a number of standards, each addressing a different aspect of communication, integration and interoperability. This makes Web services highly suited for integrating civil and military systems. In a civil-military scenario, there are strict demands for security and control of information flow between systems. Web services support application level security, and in the long term, security in Web services based systems should be provided using these standards. However, current security policies often demand the use of other, existing security measures, such as the use of a so-called diode. A diode is placed between networks or domains, and ensures that information can only flow one way between these networks, for example from a civil network to a military network domain. In this paper, we investigate the use of Web services technology in networks where a data diode is in use.
    05/2011;
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    Frank T. Johnsen, Trude Hafsoee
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    ABSTRACT: The NATO Network Enabled Capabilities (NNEC) feasibility study has identified Web services as a key enabling technology for NNEC. The technology is founded on a number of civil standards, ensuring interoperability across different operating systems and programming languages. This also makes the technology a natural choice for interoperability also in multinational civil-military operations, where a large number of heterogeneous systems need to exchange information. Web services provide loose coupling and late binding, which are desirable properties in such a setting. Discovering available services in an operation is essential, and the discovery process must leverage standards to ensure interoperable information exchange. WS-Discovery is a standard for Web services discovery suited for dynamic environments and civil networks, but has high overhead and is not so suitable for tactical networks. Like the other Web services standards, it uses XML for encoding messages. In civil networks bandwidth is abundant, but in tactical networks XML may incur unacceptable overhead. However, the W3C has created a specification for efficient XML interchange (EXI), which reduces XML overhead by defining a binary interchange format. This paper investigates the performance gains (in terms of reduced bandwidth) that can be achieved by combining the WS-Discovery standard with the EXI specification.
    05/2011;
  • F.T. Johnsen, T. Hafsøe
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    ABSTRACT: Web services technology is in widespread use, but employing the technology in highly dynamic environments is a challenge. The current Web services discovery standards are tailored for use in fixed infrastructure networks and single hop ad hoc networks. They are not suitable for use in highly dynamic multi-hop mobile ad hoc networks (MANETs), such as the networks employed in search and rescue operations. In a search and rescue operation we also need to know about not only the available services, but also where the nodes participating in the operation are. In this paper we address these needs by designing an experimental Web services discovery protocol that can be used in such multi-hop MANETs. We combine service and location discovery in our novel Web services discovery protocol called SAM, which we have implemented, tested in a field trial, and released as an open source project.
    GLOBECOM Workshops (GC Wkshps), 2010 IEEE; 01/2011
  • J. Flathagen, F.T. Johnsen
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    ABSTRACT: Wireless Sensor Networks (WSNs) are expected to provide greatly enhanced situational awareness for warfighters in the battlefield. Sensors widespread in the battlefield are however, of very limited value unless the sensors are reliable during the entire operation and the information produced is accessed in a timely manner. In this paper we focus on these issues by enabling WSNs as a capability in the NATO Network Enabled Capability (NNEC) using Web services. We demonstrate that Web services is an enabling technology for information-sharing, facilitating presentation of sensed data and alarms to a battlefield management system. In addition, we show the feasibility of using a Web services approach as a query processing tool enabling multi-sensor fusion and data aggregation in the WSN domain. The networking protocols can in this way inherently adjust data-aggregation and -processing criteria according to the requirements posed by external subscriber systems. In this way, energy efficiency, which is paramount in WSNs, is optimized without sacrificing the flexibility of Web services. Our proposed methods are tested using practical experiments with TelosB sensing nodes.
    MILITARY COMMUNICATIONS CONFERENCE, 2011 - MILCOM 2011; 01/2011
  • Magnus Skjegstad, Frank T. Johnsen, Trude Hafsøe
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    ABSTRACT: This paper addresses Web services discovery in mobile service oriented systems. Our goal is to determine which Web services discovery mechanism(s) are best suited for ad- hoc networks in a search and rescue scenario. The evaluation is performed through a series of experiments, where we test open source service discovery mechanisms using two relevant topologies. The mechanisms tested include both standardized and experimental solutions. The experiments show that the experi- mental protocols are preferable to the standardized protocols in a search and rescue scenario. Index Terms—Service discovery, ad-hoc networks, Web ser- vices I. INTRODUCTION
    Proceedings of the 7th International Wireless Communications and Mobile Computing Conference, IWCMC 2011, Istanbul, Turkey, 4-8 July, 2011; 01/2011
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    ABSTRACT: Chat is becoming increasingly important in military operations. XMPP is the de facto chat protocol in use in NATO today. XMPP is intended for use in stable networks with high bit rate (e.g., LAN, Internet) and does not function well in military tactical networks where resources are scarce and disruptions are frequent. In this paper, we present our novel decentralized solution specially tailored for multi user chat in tactical mobile ad-hoc networks. Our protocol is implemented in Java, and then tested in emulated network conditions. Compatibility with XMPP is achieved through the use of a gateway, so that compatibility with existing deployed chat infrastructure is ensured. Our tests show that our chat solution has a higher message delivery rate in poor conditions than XMPP.
    01/2011;
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    ABSTRACT: Web services are in widespread use today. This paper discusses Quality of Service (QoS) concepts which are not covered by existing Web services standards, and focuses on application level solutions that will be important building blocks in the future. We implemented a QoS based admission control mechanism, which provides priority based access to the network, while at the same time avoiding overloading the limited network capacity that is available. We use cross-layer mechanisms to combine QoS mechanisms at the network layer with our Web services admission control broker. The preliminary experiments we have performed with Web services over emulated wireless links are discussed.
    01/2011;
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    M. Skjegstad, F.T. Johnsen, T. Hafsoe, K. Lund
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    ABSTRACT: Existing service discovery mechanisms for ad hoc networks are often designed with one specific network type in mind. Solutions capable of handling highly mobile nodes usually have high bandwidth requirements, particularly as the number of nodes increases. The bandwidth requirement can be reduced by locally caching state information, but this increases the risk of nodes having outdated state information when mobility is high. Some solutions avoid these two issues by tightly coupling service discovery with the routing mechanism itself. However, this requires that nodes are homogeneous on the network layer. We propose a solution that leverages the special properties inherent in broadcast-based radio networks. In such networks, every node within transmission range will hear a transmission, be it unicast or broadcast. Each node therefore aggregates relevant service information and broadcasts it at regular intervals. Unnecessary transmissions are suppressed by efficiently synchronizing local state information. In this paper, we describe the Mist-protocol, a robust and efficient adaptive service discovery protocol, that supports large, highly mobile networks consisting of heterogeneous nodes. We test the protocol in large scale simulations in both static and mobile environments. Finally, we show that it is feasible to actually implement the design by providing a proof-of-concept prototype, which has been evaluated in a small scale experiment.
    MILITARY COMMUNICATIONS CONFERENCE, 2010 - MILCOM 2010; 12/2010
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    ABSTRACT: NATO has identified Web services standards as a key enabler for interoperability between the different military systems used by various NATO nations. Compared to many civilian systems, military networks vary greatly in terms of computing resources, network bandwidth, mobility and stability, and distributed applications use several different networks concurrently or interact across them. In such dynamic and heterogeneous environments, runtime service discovery is a necessity. According to the W3C, discovery is the act of locating a machine-processable description of a Web service-related resource that may have been previously unknown and that meets certain functional criteria. In this article we present our approach to service discovery, where we combine Web services standards and proprietary solutions using our prototype interoperability gateway. This approach has been experimentally evaluated in a military experiment featuring both mobile ad hoc networks and fixed infrastructure networks, and the results show that transparent discovery between proprietary solutions and Web services discovery standards can be achieved.
    IEEE Communications Magazine 11/2010; · 3.66 Impact Factor
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    ABSTRACT: NATO Network Enabled Capability is first and foremost about achieving better interaction between the different actors involved in military operations. This implies more efficient exchange of information. Consequently, the NATO information infrastructure will consist of a federation of systems, including a plethora of different information and communication systems, as well as a mix of new and legacy systems. NATO recommends a service-oriented architecture approach based on Web services to enable such a federation. In this article we explain how the communication protocols normally used in Web services are unsuited for disadvantaged and heterogeneous networks. We then present our prototype proxy, which enables the use of standard unmodified Web services across all network types, including tactical networks with low data rates and frequent disruptions. It is designed to work with existing security mechanisms, and also offers further optimizations in the form of optional plug-ins.
    IEEE Communications Magazine 11/2010; · 3.66 Impact Factor
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    ABSTRACT: In scenarios such as search-and-rescue operations, it may be required to transmit information across multiple, heterogeneous networks, often experiencing unreliable connections and limited bandwidths. Under such conditions, Publish/subscribe-based communication, combined with store-and-forward capabilities in the network nodes, greatly improves the ability to transmit information. At the same time, it is desirable to use commercial, standards-based software as much as possible, in order to reduce both cost and development time, and to ease the interconnection of systems from different organizations. In this paper, we present our prototype middleware solution called the Delay and Disruption Tolerant SOAP Proxy (DSProxy) which adds Publish/Subscribe functionality to standard, unmodified Web services. Together with its ability to make Web services delay and disruption tolerant, the DSProxy enables SOA based on Web services in scenarios as described above. The DSProxy has been tested in field trials, with promising results.
    IEEE International Conference on Web Services, ICWS 2010, Miami, Florida, USA, July 5-10, 2010; 01/2010