We present an evaluation of the Interest-based Routing Protocol (IRP), a routing strategy for Opportunistic Networks based on learning about users' real-time changing interests in different topics. We compare IRP with Social-aware Contentbased Opportunistic Routing Protocol (SCORP), which is also based on users' interest, and Epidemic. We conducted a set of experiments using real traces extracted during an academic year at MIT, and with users' real-time changing interest in receiving messages from specific topics. The results obtained show that IRP delivers more messages than the other algorithms, and also has better results in Messages Relayed, Buffer Occupancy, and Network Overhead.

We present the Interest-based Routing protocol (IRP), a new routing strategy for Opportunistic Networks based on learning about the users' real-time changing interest in different topics. IRP uses these users' interests to identify the messages' destinations, and as these destinations can change at any time, to make forwarding and delivery decisions according to it. Learning about interests at every opportunistic contact allows IRP to build a perception of the interest that may exist in the network and to use it to make forwarding decisions to relay messages when and where there is interest in a topic. This perception is also used to intelligently manage the buffer to remove only messages that have low interest when space is required. To evaluate IRP, we designed a scenario located in Barcelona. Then, we ran a set of simulations, studied the performance of our proposal and compared it with other opportunistic algorithms. In them, IRP delivered the higher number of messages and relayed the lower number.

VANETs (Vehicular ad hoc networks) are wireless and infrastructureless networks created spontaneously, and where the nodes are vehicles that move freely. In them, many conditions may affect the right operation of the packet delivery process. Many of them may be in some way expected, such as the scenario where the VANET is running or the routing protocol used. Others may not be as easily predictable, such as black hole attacks, where malicious nodes inside the network discard packets. Several research analysis have been done regarding VANETs and black hole attacks for different delivery protocols, but all of them are based on non realistic scenarios. In this paper, we analyze the performance impact of black hole attacks on VANETs in a real scenario. This is done by combining a Panama City realistic urban traffic scenario with four major routing protocols (AODV, OLSR, DSR, and DSDV) working regularly and under black hole attack, and relying on the ns-3 and SUMO (Simulation of Urban MObility) simulation tools. Finally, the simulations show that using realistic scenarios produce more accureate and closer to reality results.

We measure quality of service (QoS) in a wireless network architecture of transoceanic aircraft. A distinguishing characteristic of the network scheme we analyze is that it mixes the concept of Delay Tolerant Networking (DTN) through the exploitation of opportunistic contacts, together with direct satellite access in a limited number of the nodes. We provide a graph sparsification technique for deriving a network model that satisfies the key properties of a real aeronautical opportunistic network while enabling scalable simulation. This reduced model allows us to analyze the impact regarding QoS of introducing Internet-like traffic in the form of outgoing data from passengers. Promoting QoS in DTNs is usually really challenging due to their long delays and scarce resources. The availability of satellite communication links offers a chance to provide an improved degree of service regarding a pure opportunistic approach, and therefore it needs to be properly measured and quantified. Our analysis focuses on several QoS indicators such as delivery time, delivery ratio, and bandwidth allocation fairness. Obtained results show significant improvements in all metric indicators regarding QoS, not usually achievable on the field of DTNs.

In this paper, we use graph analysis to evaluate the network architecture of a large scale delay tolerant network (DTN) of transoceanic aircraft. At LCN (Local Computer Networks) 2014 we analyzed information propagation inside a pure opportunistic version of this network, a scenario constructed from more than 2,500 traces of transatlantic flights in which communications relied only on the sporadic contacts between airplanes. As only a small percentage of the nodes were capable of performing efficient air-to-ground communications we concluded the need to devise a more suitable network architecture by combining opportunistic and satellite communication systems. We propose a generic methodology based on graph analysis (both static and dynamic temporal) to evaluate the different ways to create this new architecture. We show the architectural combination that most improves the network delivery performance while minimizing its deployment costs.

In this paper we analyze information propagation inside a large scale delay tolerant network (DTN) of transoceanic aircraft. We characterized this network at LCN 2013, a scenario constructed from more than 2,500 traces of trans-Atlantic flights in which communications rely on the sporadic contacts between airplanes. We observe the traffic of this network and analyze how two epidemic based routing protocols behave in this scenario. We use simulations to compare their performance through metrics such as the network traffic per packet, end-to-end-delay and delivery ratio. The analysis of data propagation inside this DTN aims to evaluate the feasibility of using this network as a reliable way to deliver on-flight generated data (either from passengers or company) to the ground. This approach seeks to provide applications with a cheaper alternative to other communication systems.

Forwarding data in scenarios where devices have sporadic connectivity is a challenge. An example scenario is a disaster area, where forwarding information generated in the incident location, like victims' medical data, to a coordination point is critical for quick, accurate and coordinated intervention. New applications are being developed based on mobile devices and wireless opportunistic networks as a solution to destroyed or overused communication networks. But the performance of opportunistic routing methods applied to emergency scenarios is unknown today. In this paper, we compare and contrast the efficiency of the most significant opportunistic routing protocols through simulations in realistic disaster scenarios in order to show how the different characteristics of an emergency scenario impact in the behaviour of each one of them.

In this paper we analyze a large scale delay tolerant network (DTN) of transoceanic aircraft. We assume that each airplane in our network is equipped with a simple communication system based on IEEE802.11b/g, with a communication link of around 20 km. The characterization of this large aeronautical DTN will be used to choose routing strategies for passenger or company data, only through the contacts between airplanes, in order to use this network as a cheaper alternative to other communications systems, or as backup when no other communication systems are available. Instead of relying on synthetic data, we carry our analysis from the actual traces of 2,550 trans-Atlantic flights in the ns-3 simulator, to provide a detailed study of the network connectivity and mobility metrics (node degree, clustering, any contact time and inter any contact time). The impact of other parameters (such as radio coverage) on the network is also analyzed.

During emergency situations, the use of mobile devices and wireless opportunistic networks as a solution of destroyed or overused communication networks are vital. In these cases, the fast and reliable delivery of emergency information, together with the use of energy-efficient communication mechanisms are required. In this paper we propose PropTTR and PropNTTR, a set of forwarding mechanisms for wireless opportunistic networks in emergency scenarios that provide a high message delivery ratio together with a low energy consumption. We have set up a testbed used to compare the performance and energy-efficiency of our proposals with two other significant forwarding methods. We present the results of this analysis comparison in terms of message delivery ratio, delivery cost, latency and energy consumption, showing the improvements of our proposals.

This paper introduces a double multiagent architecture allowing the triage of victims in emergency scenarios and the automatic update of their medical condition. Gathering updated information about the medical condition of victims is critical for designing an optimal evacuation strategy that minimizes the number of casualties in the aftermath of an emergency. The proposed scheme, currently under development, combines Wireless Sensor Networks, an Electronic Triage Tag and a double multiagent system (Agilla-JADE) to achieve a low cost, no infrastructure based, efficient system.

The use of electronic devices such as sensors or smartphones in emergency scenarios has been increasing over the years with new systems taking advantage of their features: mobility, processing speed, network connection, etc. These devices and systems not only improve victim assistance (faster and more accurate) but also coordination. One of the problems is that most of these systems rely in the existence of a network infrastructures, but usually in big disasters, or mass casualties incidents, these infrastructures become saturated or destroyed by the very nature of the emergency. In this paper we present MAETT and Haggle-ETT, two applications that provide electronic triage tags (ETTs), a digital version of the classics triage tags, based on mobile agents and opportunistic networks, respectively. These systems are able to work even without network infrastructures using ad-hoc networks to forward the ETTs to a coordination point where they will be processed.

Forwarding data in scenarios without connectivity, Pocket Switched or Opportunistic networking can be difficult without a mobility model, or a history of node contacts. One of these scenarios is a disaster, where forwarding victim's medical information to a coordination point is critical for the good and fast intervention. "Time To Return" (TTR) forwarding was used in combination with mobile agents in MAETTS to provide early resource allocation during such emergencies. In this paper, we propose to apply TTR forwarding in Haggle to create an Electronic Triage Tag. This approach allows us to take advantage of short connectivity opportunities between nodes.

The information in healthcare institutions is generally managed by computer applications deployed in medical centers. Usually, each organization has its own system, which is normally proprietary and makes it difficult the exchange of information with other institutions. This chapter discusses the use of mobile agent technology [51,7] as an enabler of open distributed eHealth applications. More precisely, it describes some successful experiences based on this technology: one regarding integration of medical information, and two concerning emergency scenarios. These three successful cases can be very useful at the time of designing new eHealth systems since they have already solved many of the most common issues in this domain.

From the first steps of the mobile agent technology, the main concerns have been its security and interoperability. At the contrary, its performance has been usually relegated to a second place. The main contribution of this article is the proposal of a new agent transfer protocol, called Fragment Transfer Protocol (FrTP), for the Inter-Platform Mobility Architecture (IPMA) that improves the agent migration performance. The new protocol has been designed because a poor agent migration performance is observed in some Agent Middlewares, such as JADE, when large sized code and data agents are transferred. The reason is that the existing IPMA protocols encapsulate too much data in a single IEEE-FIPA ACL message and these Agent Middlewares do not deal well with this situation. Therefore, FrTP proposes to transfer the agent by sending its code and data split into several messages. The new protocol approach is fully compliant with the IEEE-FIPA interoperability agent standards and IPMA framework. Furthermore, it has been integrated into the IPMA implementation for JADE and it has been extensively validated through a set of performance tests carried out on different scenarios. Hence, its usage will strongly improve the performance of agents with large sized codes or data.

Mobile agents (MAs) are autonomous computing entities that dwell in agent platforms and have the ability to move to different locations as needed. They are typically composed of code, data, and a state. The performance of MA migrations is always penalized by the need of carrying these components to each visited location. In contrast to the agent data and state, the agent code is static during the whole agent life. Therefore, optimizing the agent code management, the agent migration performance can be improved. The main contribution of this article is the definition of a global cache service to efficiently and securely deal with the distribution of agent code. An implementation of the service has been developed, and its benefits have been extensively demonstrated by a set of performance tests carried out in different scenarios. Copyright © 2010 John Wiley & Sons, Ltd.

Lacking medical information about a victim in the aftermath of an emergency makes the early treatment and the efficient allocation of resources difficult. On the other hand, communication infrastructures are normally disrupted in these situations, thus hindering the gathering of the required information. This paper presents a new application of mobile agents for retrieving partial information of medical records upon request from the emergency scene. This solution fits well when mobile ad hoc networks are in use, and it is based on the asynchronous communication provided by mobile agents. By using the proposed system, it is possible to request remote hospitals for critical information about the victims, such as allergies or infectious diseases, thus facilitating more accurate diagnosis and bringing forward decision making. An implementation of the system has been developed, showing its feasibility.

The existence of heterogeneous mobile agent systems hinders the interoperability of mobile agents. Several solutions exist, but they are limited in some aspects. This article proposes a full interoperability solution, in the context of the IEEE-FIPA agent standards, composed of three parts. The first part is a simple language-independent agent interface that enables agents to visit locations with different types of middlewares. The second part is a set of design models for the middlewares to support agents developed for different programming languages and architectures. And the third part is a method based on agents with multiple codes and a common agent data encoding mechanism to enable interoperability between middlewares that do not support the same programming languages. Furthermore two agent interoperability implementations, and its corresponding performance comparison, carried out over the JADE and AgentScape agent middlewares are presented.

Mobile agents are autonomous software entities driven by a set of goals and tasks. Reactivity, social ability, autonomy, the ability to move to different network locations, and the weak agent notion of proactiveness, allow for autonomous processing of distributed information according to their environment (context awareness). Although agent mobility has been devised for homogeneous environments, deployment of agent mobility in heterogeneous environments has been hindered by the absence of a common set of interoperation rules and ontologies for different agent middlewares. In this article, an agent migration model based on the communication standards of the IEEE-FIPA organisation is proposed. The approach described encompasses the definition of several specifications to achieve interoperability in the migration process in heterogeneous environments. The model provides a basic and extensible common migration process, which is flexible enough to support different kinds of migration methods and future upgrades. It is completely independent of any specific middleware implementation.

Quick response is critical during an emergency situation. This paper describes a system based on mobile electronic triage tags that makes victim information available at the base of operations as soon as possible, thus allowing an early medical resource allocation and immediate action. The cornerstone of the system is mobile agent technology, which allows information to be transported asynchronously and reliably from terminal to terminal and not requiring any network infrastructure at all. This novel approach is ready to be used in the worst case scenario, where only small handheld devices carried by the emergency personnel are available, but also integrates well when synchronous connections are possible, for instance when a mesh network can be created. The system has been successfully implemented, showing the feasibility of the proposal. By using this low-budget system, the number of casualties during the triage stage of an emergency is expected to drop off.