Efficiently managing route invalidation is important in Wireless Sensor and Actuator Networks (WSANs), mainly when downward traffic, from root to actuator nodes, commonly occurs. The No-Path Destination Advertisement Object (NPDAO) mechanism for route invalidation was initially proposed in RFC 6550. This approach can sometimes be inefficient, leading to stale routes, high overhead, and lower packet delivery ratios. A newer method, introduced in 2021 by RFC 9009, uses the mechanism through Destination Cleanup Object (DCO) messages for route invalidation. This paper implements DCO in Contiki-NG and compares its performance to NPDAO using the Cooja simulator. In the evaluated scenarios, the root and nodes within the tree send packets downwards to nodes that switch parent. The two route invalidation mechanisms are compared in scenarios with and without probing of the parents. The results show that in the most favourable scenario, the mechanism in RFC 9009 improves packet delivery ratio (PDR) for downward traffic from 66% (NPDAO) to 97% (DCO). Moreover, probing significantly improves network recovery times, which contributes to reliability. These findings validate and extend RFC 9009’s claims, confirming DCO’s suitability for WSANs.

The wireless deployment or configuration of devices or systems without any manual intervention is essential to increase the efficiency as it allows to automate the setup process entirely, requiring minimal or no human involvement. This concept is also called zero-touch deployment and requires a proper and efficient key management strategy when constrained devices at large scale are involved. In this paper we propose a highly efficient mutual authentication and key agreement scheme, enabling devices without pre-shared key material to get access to the system network. The proposed protocol satisfies perfect forward secrecy and resistance against ephemeral session key leakage. We also discuss its feasibility for Time Slotted Channel Hopping (TSCH) based sensor networks.

We present a novel approach to privacy preserving electronic road pricing (ERP) based on on-board units (OBUs) and zero-knowledge proofs (ZKPs), and without any need for tamper-proof elements. Since our approach issoftware-onlyandprotocol-enforced, it can be rapidly deployed on off-the-shelve or even pre-existing hardware, such as a smartphone or the on-board computer of a car. In addition, communication complexity is onlylogarithmicin function of route length, such that even for short routes the communication cost of the protocol is lower than the cost of naively transmitting the clear text route. Our implementation proves the construction to be computationally practical, especially for the verifier. Since the scheme is based on ZKPs, no unnecessary information gets leaked. At the basis of the scheme lies Bulletproofs, which is modified to provide native support for Pedersen vector commitments with logarithmic impact on proof size.

Abstract Fog computing allows to connect the edge of the network, consisting of low cost Internet of Things devices, with high end cloud servers. Fog devices can perform data processing, which can significantly reduce the delay for the application. Moreover, data aggregation can be carried out by fog devices which decrease the bandwidth needed being very important for the wireless part of the communication with the cloud servers. The edge-fog-cloud architecture is currently being rolled out for several applications in the field of connected cars, health care monitoring, etc. In this paper, we propose an identity-based, mutual authenticated key agreement protocol for this fog architecture, in which end device and fog are able to establish a secure communication without leakage of their identities. Only the cloud server is able to control the identities of device and fog. We formally prove that the session keys are also protected in the Canetti–Krawczyk security model, in which adversaries are considered to have access to session state specific information, previous session keys, or long-term private keys. The scheme is very efficient as it only utilises elliptic curve operations and basic symmetric key operations.

The joined use of cloud computing and Internet of Things (IoT) led to the definition of Cloud of Things (CoT), a powerful combination which builds on the strengths of both technologies. Active research in this field provides brand new solutions or improves the ones already in place, but it is hampered by the lack of standardization and by the heterogeneity of adopted technologies. The focus of this work is on the application of a service mesh network to include IoT edge devices in a multi-cloud cluster federation. As the adoption of multi-cloud is rising day by day, the integration of IoT applications in it will surely follow. Available solutions are often restricted to specific use cases and technologies or require IoT middleware to work. The goal of this paper is to propose an architecture which can be used to achieve connectivity, interaction and data exchange between multiple IoT edge devices hosted in distinct environments, through the realisation of a network service mesh. A logical architecture is proposed, defining the components needed, discussing potential applications. An implementation is realised to demonstrate the feasibility of the system. Measurements show that with a negligible increase of computational resources and time, the benefits of a service mesh can be extended to IoT edge devices and the applications deployed on them.

In order to design successful Internet of Things (IoT) networks, prototyping and simulation are complementary techniques. This requires that the prototypes have enough hardware resources to run the entire IoT stack. Moreover, the simulators must be fine-tunable to accurately behave like the simulated network components at all the levels of the stack. Both must have facilities for measuring and reporting performance indices without significantly perturbing normal operation. This paper describes dual motes used as hardware building blocks to build prototype networks. They fulfill the enounced requirements and allow the experimental determination of the parameters necessary for extending the study of a prototype network by means of simulations.

When looking at cloud computing, aside from the commercial solutions like Amazon Web Services and Microsoft Azure, there are also promising open source alternatives. In this paper, our hands-on experiences are summarized with consuming, deploying and managing an on-premise Infrastructure as a Service (IaaS) cloud solution based on the open source OpenStack platform in combination with Ceph as a distributed storage solution. We introduce means on how to achieve high-availability of this small-scale on-premise cloud infrastructure solution and provide network architecture and storage recommendations. Finally, performance measurements of these network and storage solutions are presented, indicating observable throughput and latency differences between the various configurations.

In 2015, the National Institute of Standards and Technology (NIST) announced Keccak as the new primitive to be used in SHA 3, not replacing but complementing SHA 2. The Keccak primitive, based on a sponge construction, has flexible parameters that can be controlled by the user to fit the needs of the application. However, the SHA 3 standard constrains and predefines the Keccak parameters to be used and thus making its use less flexible. In this paper we try to understand the influence of these parameters with respect to memory size and throughput, specifically for constrained devices used in the Internet of Things (IoT) where speed and efficiency is important. Apart from evaluations of the code on real devices, a mathematical model is also presented which helps predicting the performance of the Keccak primitive. We also compare the standard functions from SHA 2 with SHA 3 on different platforms. All implementations of SHA 2, SHA 3 and Keccak are purely written in Rust, since Rust guarantees safe memory manipulation whilst having the same performance as C. Our measurements show that for the software implementations SHA 2 is always faster than SHA 3 on all tested platforms. When only looking at the Keccak construction, Keccak- 𝑓 ⁡ [ 8 0 0 ] always outperforms other permutations based on Keccak- 𝑓 when the capacity 𝑐 stays below 276 bits. In addition, Keccak- 𝑓 ⁡ [ 8 0 0 ] has the added advantage of using less flash memory on 32-bit platforms.

Fifth generation (5G) and beyond systems require flexible and efficient monitoring platforms to guarantee optimal key performance indicators (KPIs) in various scenarios. Their applicability in Edge computing environments requires lightweight monitoring solutions. This work evaluates different candidate technologies to implement a monitoring platform for 5G and beyond systems in these environments. For monitoring data plane technologies, we evaluate different virtualization technologies, including bare metal servers, virtual machines, and orchestrated containers. We show that containers not only offer superior flexibility and deployment agility, but also allow obtaining better throughput and latency. In addition, we explore the suitability of the Function-as-a-Service (FaaS) serverless paradigm for deploying the functions used to manage the monitoring platform. This is motivated by the event oriented nature of those functions, designed to set up the monitoring infrastructure for newly created services. When the FaaS warm start mode is used, the platform gives users the perception of resources that are always available. When a cold start mode is used, containers running the application’s modules are automatically destroyed when the application is not in use. Our analysis compares both of them with the standard deployment of microservices. The experimental results show that the cold start mode produces a significant latency increase, along with potential instabilities. For this reason, its usage is not recommended despite the potential savings of computing resources. Conversely, when the warm start mode is used for executing configuration tasks of monitoring infrastructure, it can provide similar execution times to a microservice-based deployment. In addition, the FaaS approach significantly simplifies the code logic in comparison with microservices, reducing lines of code to less than 38%, thus reducing development time. Thus, FaaS in warm start mode represents the best candidate technology to implements such management functions.

Summary Consider the situation of a patient carrying a body area network with sensors measuring different body characteristics. These data should be securely sent to the cloud and only retrievable by doctors authorized by the patient. Even the cloud service provider should not be able to derive the sensible data. In order to address this problem, this paper first proposes a highly efficient certificate‐based signcryption scheme, able to execute signing and encryption in one single phase and to guarantee the link between identity and public key. We show that our proposed scheme outperforms others both in computation and communication complexity. Next, based on this primitive, a complete proxy re‐signcryption scheme is presented to be integrated in this smart body area network. The proposed schemes are based on elliptic curve operations and do not use compute intensive pairing operations, like previous proposals. We show that our scheme outperforms previous proposed proxy re‐signcryption schemes in the literature.

We propose an adaptation of the well-known Time Slotted Channel Hopping (TSCH) Medium Access Control (MAC) protocol, which was initially specified for IEEE 802.15.4 based networks, for operation over the LoRa PHY layer. Thanks to its deterministic nature, multiple concurrent communications can be handled, while reducing channel collision and ensuring reliability in a power-efficient manner. The proposed solution was implemented in the Contiki-NG operating system and tested on real motes.

A major goal of the H2020 Inter-IoT project is to provide a framework for seamless integration of different Internet of Things (IoT) platforms. To allow the Inter-IoT user to interact with those platforms, which feature their own syntax and Application Programming Interfaces (APIs), so called bridges are designed and implemented. For ensuring interoperability, semantics play a key role. The ontologies used by the different platforms need to be aligned with a central ontology. We present the features supported by Inter-IoT's Inter-MiddleWare layer and discuss the operation of a bridge towards a oneM2M based platform.

The Medium Access Control (MAC) protocol proposed by the evolving IEEE 802.15.4 standard for Low-power and Lossy Networks (LLNs) includes a multichannel mode known as Time-Slotted Channel Hopping (TSCH). TSCH, published in 2015, is part of the most recent version of the IEEE 802.15.4 standard. In this paper, we present a performance comparison between TSCH (with Orchestra scheduling algorithm) and EM-MAC, a contention-based multichannel MAC protocol for LLNs, in terms of average packet delivery ratio, power consumption and latency after network start-up phase. Results obtained from experiments on a testbed with Z1 nodes sending traffic to the sink in an environment with negligible external interference, follow the same trend as the ones obtained through a simulation study. TSCH/Orchestra outperforms EM-MAC or performs equally well for all considered loads. A point of attention though for TSCH, is the significant time required by newly joining nodes to associate to the TSCH network and to join the tree created by the IPv6 Routing Protocol for LLNs (RPL).

As part of the recent advances in the IoT world, constrained platforms featuring more than one radio interface have emerged. Typically, they combine the more classical short-range radio and the long or medium range technologies. However, their full potential is not yet exploited. The modifications to the IPv6 routing protocol for Low-Power and Lossy Networks (RPL) and the Medium Access Control (MAC) layer presented in this paper are a first step in this direction. They allow the node to automatically select the most suitable radio link if more than one is available, improving network reliability. This can be especially relevant for monitoring and smart cities applications. The solution is implemented in the ContikiOS, and tested with the Zolertia Re-mote platform, but can be extended to any platform featuring more than one radio interface. The presented testbed experiments indicate that more investigation is needed to optimally tune RPL's metrics for networks featuring nodes with dual-band communication capabilities.

To enable interoperability in the very fragmented IoT market, different integration platforms are emerging. oneM2M is one of such platforms that enables interoperability in two ways: by standardizing the HTTP, CoAP and MQTT message format as transport vehicle for oneM2M primitives, or by including custom-developed Interworking Proxy Entities (IPEs). We present an architecture that enables horizontal integration of long range low power LoRa motes that run CoAP or MQTT on a full TCP/IPv6-stack in a oneM2M framework. OneM2Ms standardized bindings are used for interoperating these disparate application layer protocols as they allow to reduce the development time of an IoT application integrated in the Internet. However, they also cause extra overhead in terms of payload size. Consequently, for LoRa motes, Time-on-Air is impacted, increasing power consumption and limiting the amount of data that can be sent over the Low Power Wide Area Network (LPWAN). Therefore, an alternative solution with reduced payload size, featuring IPEs for oneM2M, is also discussed. This paper shows that although oneM2M is a good interoperability enabler, a tradeoff exists between ease of development/deployment and the amount of useful data that can be sent over LPWANs.

Connected vehicles (CVs) are one of the critical components of intelligent transportation systems. CVs enable any vehicle to act as a smart node that collects and shares information on vehicles, roads, and their surroundings. This information can then be distributed to other vehicles via vehicle-to-vehicle (V2V) communication, and also to road users via vehicle-to-human (V2H) communication, for an improved driving experience. The information can also be forwarded toward traffic control systems via vehicle-to-infrastructure (V2I) communication, for improved traffic management and road safety. Making use of of connected vehicles in intelligent transportation systems will revolutionize the way we drive. Many issues, however, need to be resolved to achieve better performance of connected vehicles. Improvements relate to data processing and storage, the development of standards and regulations across all platforms, design and deployment of new communication protocols and system architectures, and the creation and introduction of new services and applications.

Several recent sensor platforms combine long-range and more classical short-range radio technologies. In this poster we propose some modifications to the RPL routing protocol such that it automatically selects the most suitable radio link when more than one is available. The solution has been implemented in the ContikiOS and tested on the Zolertia Re-mote platform.

New Long-Range radio technologies have recently emerged in the IoT landscape. These technologies work in the Sub-GHz bands, allowing low-power communications over long distances. They are typically based on star-topology networks, where nodes send the data directly to a base station connected to the Internet. One of such technologies is LoRa. Enabled LoRa-based multihop communications would open up new possibilities. In this paper we present a solution allowing to have multihop LoRa communications. This is done by means of a newly designed MAC protocol (RLMAC), used to select the Spreading Factor for each available neighbor. The proposed Objective Function used by RPL will therefore be able to select the routing path that minimizes time on-air. By selecting the path with the lowest time on-air, the power consumption can be decreased, enlarging network lifetime. Preliminary validation tests are also presented in the paper.

Nowadays, the transition of Wireless Sensor Networks (WSNs) to Internet Protocol version 6 (IPv6), in particular to IPv6 over Low power Wireless Personal Area Networks (6LoWPAN), is evident [1]. However, in most commonly used implementations, not all IPv6 features are available. For example, current implementations are not very optimized for multicast, despite the many benefits multicast can offer with respect to the number of radio transmissions and the amount of consumed energy. In this paper we present Bidirectional Multicast RPL Forwarding (BMRF), a new multicast protocol that combines the best features of the Routing Protocol for Low Power and Lossy Networks (RPL) multicast on the one hand and of Stateless Multicast RPL Forwarding (SMRF) on the other hand. The main features are bidirectionality and the ability to offer a choice between Link Layer broadcast and Link Layer unicast for which the threshold to decide for a mote, which link layer mode to choose, is mainly based on its number of interested children and the duty cycling rate. An implementation of BMRF is realized in Contiki. Our measurements show that BMRF, when using the optimal configuration, results in less radio transmissions, and less energy consumption, and higher packet delivery ratio compared to SMRF, often at the cost of a higher end-to-end delay.

The degree of modernization of transportation is currently an important criterion for urban development. Progress in communication techniques and networking, together with vehicle localization methods, have become the key enablers of innovative transportation systems.

In today’s Internet, the commercial aspects of routing are gaining importance. Current technology allows Internet Service Providers (ISPs) to renegotiate contracts online to maximize profits. Changing link prices will influence interdomain routing policies that are now driven by monetary aspects as well as global resource and performance optimization. In this article, we consider an interdomain routing game in which the ISP’s action is to set the price for its transit links. Assuming a cheapest path routing scheme, the optimal action is the price setting that yields the highest utility (i.e., profit) and depends both on the network load and the actions of other ISPs. We adapt a continuous and a discrete action learning automaton (LA) to operate in this framework as a tool that can be used by ISP operators to learn optimal price setting. In our model, agents representing different ISPs learn only on the basis of local information and do not need any central coordination or sensitive information exchange. Simulation results show that a single ISP employing LAs is able to learn the optimal price in a stationary environment. By introducing a selective exploration rule, LAs are also able to operate in nonstationary environments. When two ISPs employ LAs, we show that they converge to stable and fair equilibrium strategies.

In the Intelligent Distributed Environmental Assessment (IDEA) [3] system, sensors are used to measure noise and air pollution. The architecture is service-oriented, allowing application architects to combine services provided by the system platform in order to satisfy application needs. A typical user application may require a set of those services. Because of the sensor nodes' resource limitation, some services may not keep Quality of Service (QoS) levels stable over a long period, which could lead to Service Layer Agreement (SLA) violations. To maintain SLA, QoS levels must be estimated so that services can be properly invoked and combined to satisfy the user's QoS requirements. This paper proposes a novel approach to estimate QoS levels of web services. On the basis of monitored values of QoS parameters, a Naïve Bayes estimation model is developed to select the best-suited services. This paper also presents approaches adopted to monitor QoS levels of web services in the IDEA environment.

In this paper, we evaluate the suitability of the vehicular devices for supporting data storage and distribution applications. Vehicular storage systems have recently emerged as means for making the information related to the vehicular environment available to vehicular users. Information could either be collected by sensors mounted onboard vehicles or coming from the surrounding environment. Modeling a vehicular data storage and distribution system requires the introduction of a number of parameters, such as the vehicle concentration and transmission range, the value of which may determine the suitability or unsuitability of the vehicular environment for establishing a communication infrastructure with the desired quality. In this paper we show how to solve this problem by resorting to a Markovian model and some results achieved through its application.

Network-wide time synchronization is essential for schedule-based communication in multi-channel wireless sensor networks (WSN). However, broadcast communication, used by many time synchronization protocols, is not fully supported in networks of this type. This poses a difficulty in distributing the global timing information over the complete network to achieve network-wide synchronization. To overcome this problem, a time synchronization scheme is needed that uses parallel communication on multiple channels for disseminating the timing information. Located at the medium access control (MAC) layer, the scheme can obtain more precise clock offset estimation. Besides, the timing information is piggybacked on MAC layer control messages, the time synchronization scheme does not induce extra messages. Experimental evaluation results from real hardware have shown that the scheme achieves a very high accuracy with an acceptable overhead. This proves that the deployment of several proposed schedule-based multi-channel MAC protocols is practically feasible without threatening the energy consumption of the network.

The 19th IEEE LANMAN 2013 Workshop on Local and Metropolitan Area Networks has a long tradition as a leading forum for showcasing the latest technical advances in networking in the local and metropolitan areas. This year's LANMAN features the theme of seamless services, particularly within the context of recent explosion of cloud, mobile, heterogeneous, and wireless systems.

An increased bandwidth demand and the problem of interference have resulted in the advent of multi-channel protocols for Wireless Sensor Networks. In this paper, we propose a distributed contention-free multi-channel access scheme. This scheme is based on the parallel rendez-vous principle, which exploits the possibility of concurrent transmissions on different channels in the same collision domain. We describe a multi-agent learning algorithm that resolves all contention in a traffic adaptive manner. Moreover, the medium access resolution is combined with route selection in order to increase the number of parallel transmissions. The results of simulation experiments show that the proposed protocol can outperform McMAC, a state-of-the-art parallel rendez-vous protocol, in terms of throughput and latency.

Much has been written about the benefits of wireless sensors which enable measurements in harsh or hermetic environments. However, the problem concerning battery replacement is still open. This paper presents a new solution for a wireless self-powered sensors network, which allows the harvesting of energy from the action of a turbine wheel rotating in the path of a fluid stream environment. This new family of devices can find application in water/gas smart metering systems, subject of very large interest today. Furthermore, the proposed approach suggests a wireless network planning designed to eliminate problems related to a large cell radio architecture.

IPv6 over Low power Wireless Personal Area Networks (6LoWPAN) and IPv6 Routing Protocol for Low-power and Lossy networks (RPL) have accelerated the integration of Wireless Sensor Networks (WSNs) and smart objects with the Internet. At the same time, the development of the Constrained Application Protocol (CoAP) has made it possible to provide resource constrained devices with web service functionalities. CoAP is an HTTP like web transfer protocol able to extend the REpresentational State Transfer (REST) architecture to LoWPANs. The major difference between CoAP and HTTP is the different transport layer protocol (UDP instead of TCP) and the header compression which makes the packet size significantly smaller. This work provides an evaluation of CoAP compared to HTTP. The performance is evaluated in terms of mote's energy consumption and response time. The aim of the paper is to demonstrate, with a quantitative and qualitative analysis, that CoAP is more suited to REST based WSNs compared to HTTP. The results have been obtained by means of simulation as well as tests on real sensor motes.

In today's Internet the commercial aspect of routing is gaining more and more importance. Commercial agreements between ISPs (i.e. transit and peering agreements) influence the inter-domain routing policies which are now driven by monetary aspects as well as global resource and performance optimization. To allow scalability and protect business critical topology information, hierarchical routing and topology aggregation became a fundamental issue in modern inter-domain networks. In this paper, we introduce a pricing mechanism that takes into account the effects of load dependent internal costs on the domain income and allows ISPs to set link prices during the topology aggregation process. We adapt a Continuous Action Reinforcement Learning Automata (CARLA), to operate in this framework as a tool used by ISP operators to learn the best price according to the network state. The reinforcement signal is proportional only to the domain's utility (i.e. profit) and thus does not need any central authority or sensitive information exchange among domains. Simulation results show that one ISP using CARLA can significantly improve its utility compared to other ISPs that statically choose their link prices. When two ISPs employ the same CARLA they can reach an equilibrium strategy while still improving their utilities.

The use of Internet Protocol (IP) technology in Wireless Sensor Network (WSN) is a key prerequisite for the realization of the Internet of Things (IoT) vision. The IPv6 over Low power Wireless Personal Area Networks (6LoWPAN) standard enables the use of IPv6 in networks of constrained devices. 6LowPAN enables the use of Service Oriented Architectures (SOAs) in WSN. The Internet Engineering Task Force (IETF) has defined the Constrained Application Protocol (CoAP), a web transfer protocol which provides several Hypertext Transfer Protocol (HTTP) functionalities, re-designed for constrained embedded devices. CoAP allows WSN applications to be built on top of Representational State Transfer (REST) architectures. This considerably eases the IoT application development and facilitates the integration of constrained devices with the Web. This work describes the prototype design and development of a Web platform which integrates a REST/CoAP WSN with a REST/HTTP Web application and allows a user to visualize WSN measurements in the Web browser. Since the WSN Web integration relies on a non-transparent gateway/server, we also show how to provide transparent cross-protocol resource access by means of an HTTP-CoAP proxy. The paper describes the major building blocks, functionalities and the implementation approach.

The Principal Component Aggregation has recently been proposed as a versatile distributed information extraction technique for sensor networks [3]. This demonstration illustrates its use for a network-level pattern recognition task. Four different patterns, or events, may be sensed by light measurements of a network of 27 nodes. The sens measurements are fused on the fly along a routing tree up to the base station, where the monitored pattern is recognized by a prediction algorithm.

One can imagine a lot of realistic scenarios, such as home or factory automation, where a wide variety of sensors and actuators form a wireless network in order to perform various tasks. There is still a lot of work to be done to ensure scalable and reliable functionality of such a heterogeneous network. We present a MAC layer algorithm that ensures end-to-end latency requirements while minimizing maintenance. We demonstrate that our algorithm scales down the duty cycles along constrained paths in such a way that nodes with more capabilities take on more responsibility in meeting the end-to-end application constraints.

This paper presents a simple routing protocol based on topology control that improves the lifetime of a Wireless Sensor Network in the usual convergecast pattern, by allowing the nodes to choose between two predefined power-levels to forward data towards the sink. The proposed protocol takes advantage of non-homogeneous topologies, where the nodes are grouped in clouds. Nodes will only use the highest power, to establish a link, when necessary, like for bridging the distance between two clouds. Within the clouds, only low-power links are used. The underlying distributed algorithm is shown to converge and finds, for each node of the network, an efficient path to the sink, provided the network is potentially connected at the highest of the two available transmission powers. We also propose a simple routing information refreshing technique that adds robustness to the proposed algorithm.

Space and Earth monitoring is the next step for sensor networks. Distributed systems of small sensor-equipped satellites improve the cost efficiency and the missions' performance. This abstract discusses the characteristics of satellite Wireless Sensor Networks (WSNs) and the challenges they introduce.

Due to the unpredictability of IP traffic, MANs are migrating from SONET/SDH ring architectures to DWDM mesh infrastructures. Firstly, the fast advance in optical technologies has provided DWDM networks with extremely high bandwidth capability (i.e. OC-192 and OC-768). Secondly, Generalized Multi Protocol Label Switching (GMPLS) and Multilayer Traffic Engineering (MTE) paradigms have turned them into highly flexible, scalable and cost efficient infrastructures able to improve service provider's return on investment (ROI). With the GMPLS automated control plane, IP/DWDM networks can take advantage of a better integration between the electrical and optical domains and consequently of a more optimized resource usage. GMPLS enables network-state-depended dynamic routing and grooming and provides network operators with the tools to differentiate service types and increase the offered QoS. This paper discusses the benefits of GMPLS as an integrator paradigm in IP/DWDM metro infrastructures and proposes a QoS control framework which allows a network operator to accommodate MPLS/DiffServ traffic on different virtual topologies that can guarantee different QoS levels. The benefits of GMPLS/MTE and of the proposed scheme are discussed by means of simulation results.

This paper presents a modularization strategy for linear genetic programming (GP) based on a substring compression/substitution scheme. The purpose of this substitution scheme is to protect building blocks and is in other words a form of learning linkage. The compression of the genotype provides both a protection mechanism and a form of genetic code reuse. This paper presents results for synthetic genetic algorithm (GA) reference problems like SEQ and OneMax as well as several standard GP problems. These include a real world application of GP to data compression. Results show that despite the fact that the compression substrings assumes a tight linkage between alleles, this approach improves the search process.

The paper presents a testbed for native IPv6 multicast and tries to evaluate the available routing protocols such as PIM-DM and PIM-SM. From an objective perspective we can measure the join latency, as well as multicast forwarding delay, its jitter and the control overhead. Having a calibrated software tool, we can evaluate later the existing alternative solution towards IPv6 multicast: CastGate and CastGate router. The proposed enhancements are referring to PIM-SM support and to the possibility of migrating from IPv4 to IPv6 on CastGate architectures

The paper deals with the control problem of routing in packet switched networks. Using Q-learning an adaptive, distributed and autonomous routing strategy can be obtained. The objective of the Q-learner under study is to balance the load such that average packet delivery time is optimised. If pure Q-learning is applied to routing each source has to learn the expected cost for sending a message via each of its neighbours for all destinations. Since Q-learning is basically a trial and error method packets have to be sent along non-optimal paths, which artificially increases the load. To reduce this effect and to speed up the learning a variant of Q-learning has been developed. Exploration and exploitation are partially decoupled such that stabilising features can be included in the Q-learning algorithm to cope with instabilities and overhead that might be caused by the costly exploitation in search of alternative paths. In the paper the above statements are justified mathematically and supported by the results of experiments.