Parametric Protocol-Driven Agents and their Integration in JADE

Abstract. In this paper we introduce "Template Global Types" which extend Constrained Global Types to support a more generic and modular approach to define protocols, meant as patterns of events of a given type. Protocols can be used both for monitoring the behavior of distributed computational entities and for driving it. In this paper we show the potential of Template Global Types in the domain of protocol-driven intelligent software agents. The interpreter for "executing" Template Global Types has a very natural implementation in Prolog which can easily implement the transition rules for moving from one state to another one, given that an event has been perceived (in case of monitoring) or generated for execution (in case of protocol-driven behavior). This interpreter has been integrated into the Jason logic-based agent framework with limited effort, thanks to the native support that Jason offers to Prolog. In order to demonstrate the flexibility and portability of our approach, which goes beyond the boundaries of logic-based frameworks, in this paper we discuss the integration of the protocol-driven interpreter into the JADE agent framework, entirely implemented in Java

Dynamic Selection of Network Protocols for Group Communications in Mobile Ad-hoc Networks

This thesis addresses the topic of dynamically selecting protocols at various levels of network stacks in challenged environments, speci cally those with message loss, long-term fragmentation, and high mobility, in an e ort to meet the demands of group-based messaging applications. Currently, developers select protocols based on a static set of assumptions about the underlying network and application requirements. This thesis introduces a method of sensing the network state, merging this with similar information from peers, and dynamically changing the underlying protocols. This alleviates the need for developers to select protocols and instead assert message requirements. Further, since application instances are involved in group communications, they likely act as such from a mobility perspective, causing di erent portions of the network to have drastically di erent properties. For example, there may be clusters of nodes in certain locations, but minimal connectivity between them. The proposed solution allows systems to adapt to these situations as protocols may be interchanged at any time, allowing the best to be used in any given scenario. The thesis rst establishes a formal de nition of the problem space, and then proposes a solution utilizing Markov Random Fields to classify the network. This classi cation is then used to dynamically select the protocols utilized by the network stack. The Dynamic Protocol Selection Middleware (DPSM) is introduced as the implementation of this approach. Using this middelware, the e ectiveness of the approach is tested in both random group environments and real-world scenarios. In general, DPSM delivered at least as many messages as any statically selected protocol, while delivering substantially more messages in many scenarios with only modest increases in overhead or latency.M.S., Computer Science -- Drexel University, 201

Dynamic Protocol Selection in Open and Heterogeneous Systems

International audienceThis paper addresses the problem of dynamic protocol selection in open and heterogeneous multi-agent systems (MAS) for collaborative task performance. Protocols are interaction patterns which help agents coordinate their activities. Usually, agent designers select the protocols to be used for collaborative task performance. In open and heterogeneous MAS, such selection may lead to protocol mismatch at run time. Protocol selection mismatch may in turn result in a collaborative task not being performed, although it could have been performed had the protocols been selected properly. Our solution to this problem is to enable agents to dynamically select protocols. We first study the characteristics of protocols and the descriptions of collaborative tasks. Using these characteristics and descriptions, we devise mechanisms that enable agents to dynamically select protocols when they have to perform a task in collaboration. In this work we relax some restrictive assumptions made in prior work on protocol selection, and which may hinder collaborative task performance. In particular, we do not assume that agents trust one another. Additionally, because there is no protocol specification standard, we allow several protocol specification formalisms to coexist. Our method allows agents to select their protocols locally and individually, yet coordinate their selection with other agents' selections based on message exchange flows. Since the selection is performed locally, some errors may occur in the process. Our mechanisms provide means for detecting such errors and overcoming them. As we show, the complexity of our solution is empirically sufficiently low for practical use, and the level of success in coordinated protocol selection is very high