The integration of edge computing with 5G networks is crucial to meeting the demands for low latency, and efficient resource utilization in modern applications. This paper introduces SR4MEC, an innovative architecture that leverages Segment Routing (SR) to provide scalable and dynamic access to edge-hosted services in 5G networks. The SR-based user plane is integrated seamlessly with the 5G core network, thanks to an abstraction layer and new control plane elements managing the bindings and the states pushed at the ingress nodes of the SR domain. The proposed solution enhances flexibility in accessing service instances at the network edge by relying on policies mapping services and regions to specific edges, while addressing key requirements such as compatibility with 5G control plane, operator control, and runtime updates. An open-source prototype demonstrates the effectiveness of SR4MEC to connect a user equipment to an edge when establishing the PDU session, and to dynamically switch edge without breaking the session.

Header compression is an essential tool for the proper functioning of certain sensor networks. Their energy and throughput constraints have necessitated the adaptation of existing technologies. Thanks to compression, current or future protocols can run on Internet of Things (IoT) networks. However, this requires a human expertise to adapt to each protocol. The deep learning toolbox is now mature enough to provide the right tools to perform compression on any type of data. In this paper, we propose a new architecture, called Deep Compression Header (DCH), based on deep learning models for the compression of different header protocols. Based on a training period, DCH can perform compression and decompression directly on the IoT device. Our innovative approach allows for fine-grained understanding and compression without making prior assumptions about the traffic. A comparison with current network compression methods allows us to show that our approach provides promising results.

Traffic generation is an important tool for many data network activities such as simulation, planning and provi-sioning. Such a generation could be based on theoretical models when available; however, we believe that mimicking ground truth traffic previously collected is a much more generic solution. It provides a comprehensive tool to accommodate the various characteristics of current or future communication systems (IoT, 5G service models,…). The Deep Learning toolbox is now mature enough to provide the right tools to capture and reproduce the multi-scale factors of network traffic. In this paper, we propose a new architecture, called NeC-STGen, based on Deep learning models such as: Variational Autoencoders (VAE) and Recurrent Neural Network (RNN) for the generation of various network traffic. NeCSTGen can generate live traffic that accurately reproduces the original behaviour at the packet, flow and aggregate levels. Our approach allows an innovative fine-grained understanding and generation without the need to understand, in depth, how the protocol to be generated works. Our reproducible architecture generates data that can be exported in a. pcap file to be used for any purpose.

We present SmartPhOx, a pure camera-and-flashlight smartphone-based pulse oximetry solution. We build on the ratio-of-ratios (RR) method and linear regression, an elegant approach resting on the Beer-Lambert law and landing itself to efficient smartphone implementations. However, its implementations without specialized hardware have so far proved to be unsuitable for clinical use, in particular due to the instability of the RR measurements. We use an empirical study to shed light on the reasons why and propose using the very RR measurements to filter RR measurements – a new paradigm we call the Meta-Region of interest (Meta-ROI). We design a complete-system architecture, including a novel data structure for storing and RR values in the time and space dimensions and an efficient algorithm for identifying Meta-ROI. Results from an Android implementation of SmartPhOx with the participation of 37 volunteers show that it is the first pure camera-and-flashlight solution to meet the FDA requirement for Root Mean Square Error (RMSE).

Data flow management has become a key network activity, strengthening the need for efficient data flow classification tools. However, pervasive encryption of communication has dramatically jeopardised the legacy tools. Recent advances in Deep Learning offer a wide variety of architectures that seem relevant for this purpose. These architectures are based on different data representations as input of their classification process. In this paper, we show the need for a deeper understanding of the features used by Deep Learning models to perform such classification. Our objective is to exploit this knowledge for defining a better data processing so that the chosen architecture will significantly improve the classification process. We will show that some information carried by packet headers need to be analyzed through a separate process. This analysis highlight that current Deep Learning approaches in the literature fail to classify encrypted flows in practice. We therefore propose a new modular Deep Learning architecture called Servername Protocol Packet Network (SPPNet) to overcome this drawback. We will show by a proof of concept that SPPNet allows to perform real-time network flow classification at packet level.

With the recent integration of Non Terrestrial Networks (NTNs) into 3GPP Release 17, 5G networks are expected to benefit from the NTN large coverage area. This integration will help mobile terrestrial networks reach a worldwide coverage. However, this ultimate ubiquity also comes with its set of challenges to overcome. One of the main issues is the seamless integration of NTNs into the existing mobile network standard. In this paper, we propose a comprehensive architecture integrating NTNs as slice-aware backhaul links. This architecture remains fully compliant with the 3GPP standard. For this purpose, we propose an end-to-end slice model integrating NTNs and 5G networks. Then, we implement this model on a 5G-satellite testbed, adding new functional components to interconnect both networks at the control and data plane levels. Lastly, we evaluate the performances of our method using the aforementioned testbed by monitoring each slice and their related Quality of Service requirements.

Named Data Networking (NDN), an Information-Centric Network (ICN) architecture, is based on caching, multipath and multi-producers retrieving. These properties provide new opportunities for a single user to increase its Quality of Experience (QoE). However, handling multiple flows, each of them having its own multiple paths, is more complex. To tackle this challenge, we highlight three main principles a solution should include. Nodes should cooperate, supervise their output queues and, eventually, wisely manage the multipath capacities of NDN. These three elements are the core of our proposition: Cooperative Congestion Control (CCC). More than a solution, CCC is proposed as a framework where each principle could be implemented in multiple ways. The ultimate objective is to fairly distribute the flows on the network and maximize QoE of users. We choose basic algorithms in order to evaluate the overall framework. We evaluate our solution with simulations and compare their results with a theoretical model.

Unmanned Aerial Vehicles (UAVs) can be a cost saving and easy to deploy solution to implement a temporary network infrastructure. They can act as access points in scenarios such as emergency situations, special events, or specific area monitoring. Two main deployment families can be found in the literature. The first one, the location-based family, is based on the fundamental assumption that the network user positions are known. We do believe that this could not suit the most general scenarios. On the other hand, the location-independent family can not be as efficient as the first one. The main idea in this paper is to introduce a new crowd-based family, based on a probabilistic knowledge of user positions. We then propose a self-deployment method built on a Coulomb's law analogy where users and UAVs act as electrical charges. Short range interactions are implemented through network sensing, while long range ones use a crowd-based approach. Some numerical results are depicted, showing the performance of this self-deploying mechanism as well as a comparison with a well-known clustering algorithm.

The return link of broadband satellite systems has recently received more attention due to the spread of multi-beam antennas which enable spatial frequency reuse, and thus increase drastically the number of users that can potentially be served by one satellite. While interference isolation has so far been the way to go, with regular four-color frequency reuse scheme, there is a growing interest in densifying the frequency usage as is being done in cellular networks. In this paper, we address the return link radio resource allocation challenges, from spectral resource allocation to user scheduling, including modulation and coding scheme (MODCOD) selection. Our contributions highlight the potential gains of a two-color scheme and shed light on several levers to reap its benefits through interference management. We first consider the possibility to use a two-color scheme, while keeping the MODCOD selection and the scheduling local to each beam and we show that even though it yields a potential performance gain (+16%) with respect to the state of the art (SoA) (based on four colors), it is not viable due to a very high-block loss rate. Therefore, we propose a simple-yet fast and efficient-coordinated MODCOD selection process that alleviates the need of estimating interference and reduces drastically decoding failures. This coordination step offers significant gains (+58%) over the SoA, while leaving the per beam scheduler unchanged. Finally, we formulate a joint user scheduling and MODCOD selection problem across all beams and propose an offline heuristic to solve it efficiently. We obtain a 83% gain with respect to the SoA, but with higher computational complexity. Still, it confirms the great potential of coordinated scheduling.

High throughput satellites have proven to be an excellent solution to provide Internet services to white spots or to complement other existing infrastructures. With the use of multi-beam antennas, the same frequency may be reused dozens of times across a single satellite coverage area, increasing the system capacity and profitability. Legacy frequency reuse patterns such as uncoordinated 4-color scheme ensure interference isolation at the expense of important capacity reduction, using only one fourth of the operator's share in the scarce Ka band. Thus, to increase the per-beam available bandwidth, it is necessary to look for more aggressive and efficient Frequency Reuse schemes, generating higher Co-Channel Interference which has to be analyzed and handled. In this paper, we focus on the DVB-RCS2 return link of a multi-beam satellite and investigate the possibility of reaching the upper bound of a coordinated 2-color system capacity through the use of Interference-aware User Scheduling techniques. We first formalize the problem as an Integer Linear Program and study the impact of greedy simplifications on the optimality and processing times of our optimization models.

Unmanned Aerial Vehicles (UAVs) can be a solution for deploying temporary networks by serving as Access Points to users on the ground. The aim is to provide multiple communication services (voice, data, video, etc.) over a specific area. The network must be deployed quickly for a relatively short period (emergency situations, sporting events, etc.), in the case of cellular network overload or blackout. A Flying Ad-Hoc Network will be deployed to cover all the potential users. The objective of this paper is to investigate the impact of drone replacement due to the limitation of battery lifetime. A constraint for this kind of network is service continuity. For this purpose, an adaptation for the routing mechanism is proposed, to overcome the loss of connectivity observed in the simulations. In the beginning, a state of the art on use cases employing drones is given, followed by a description of our scenario. Thenceforth, the system is described as well as the deployment mechanism and the induced connectivity loss. In the end, we present a way to adapt the routing scheme so that the network remains connected when a node is replaced due to energy level reasons.

Depending on the congestion level and the network characteristics (e.g., buffer sizes, capacity of the bottleneck, deployment scenario, etc.) a fixed Initial Window (IW) would be either too conservative or too aggressive. This results in low usage of the network resource or damaging high congestion level. This paper presents a sender-side only modification to the slow-start of TCP, SmartIW, that bypasses the limitations and potential issues of a fixed IW. The Round Trip Time (RTT) is estimated during the establishment of the connection and further exploited by SmartIW to pace the transmission of an adequate number of packets during the first RTT. Our simulation results show that, since the IW has been set in adequacy with the available network information, larger IW can be transmitted without increasing the congestion level of the network. SmartIW eventually reduces the RTT dependence of the slow start stage to fairly provide significant performance improvements whatever the network characteristics (RTT and congestion level).

Sensor Networks can be envisaged to monitor mobile systems. Nevertheless, new challenges appear from mobility such as delay and connectivity disruptions. These challenges can be tackled by the Delay/Disruption Tolerant Networking architecture. However, implementing DTN mechanisms on sensors require to select the schemes which propose an efficient use of the memory. Our scheme, FREAK, aims at providing high performance with low-memory usage. This scheme relies on the mean frequency of past encounter with the base station. Transmissions are driven by this metric. The FREAK solution is keen because we assume that future can be predicted from the past events. The acknowledgements effects on performance is analysed. We run simulations using mobility quota-based mainstreammodels and real traces. FREAK is compared to several replication and quota-based mainstream DTN solutions and achieves quite better performance in realistic scenarios.

The evolution of satellite communication towards packet-based communication and the adoption of modern physical layer techniques, such as Adaptive Coding and Modulation, raise new issues, brought by this variability, for scheduling algorithms. This paper addresses the problem of GSE packets scheduling over DVB-S2 with QoS support by adopting a utility-based scheduling strategy. Utility functions are considered as a mean to encompass parameters from several layers into a single scheduling process. By making use of a first-order approximation, a low complexity scheduling algorithm is derived from the utility functions optimization problem, adaptable to a wide range of functions. The algorithm determines the characteristics of the next BBFrame to be send, and which GSE packets it should contain. We focus particularly on delay as a joint metric to represent QoS requirements, and assess the performance of our algorithm and the relevance of our assumptions using comparative simulations.

The mobile context of Mobile Wireless Sensor Networks (MWSN) limits the existence of a direct route from source to destination. A Disruption Tolerant Networking (DTN) architecture fits the requirements for such a context where messages need to be stored, carried and forwarded. For this kind of DTN applications, the goal is to achieve a high delivery ratio at low transmission cost with the lowest latency. Some DTN routing protocols use this ACK information to decrease the number of useless transmissions. Nevertheless in memory-constrained environments, the proportion of memory allocated to ACKs is a problem to study. This paper focuses on the use of acknowledgements (ACKs). We model the network with a Markov chain, to study the effect of ACKs on buffer time occupancy. Finally, an extensive set of simulations is run to analyse the influence of the memory proportion allocated to ACKs, on the performance.

In this paper, we consider the problem of IP packet scheduling over a GSE/DVB-S2 satellite link. Scheduling flows with QoS requirements has been widely addressed in the mobile field, especially in LTE and WiMAX, with emphasis on fairness, efficiency and dynamic adaptation to transmission conditions. We focus on the well-known empirical scheduling rules known as PF, M-LWDF and EXP-PF for both QoS and MODCOD scheduling, and present how they were adapted to GSE/DVB-S2 encapsulation. Some of the challenging issues yielded by DVB-S2 are tackled, such as joint scheduling of both QoS and MODCODs, concatenation of numerous user packets into one BBFrame and fairness issues introduced by the scheduling algorithm, especially when dealing with various transmission scenarios. We show the potential of our scheduling algorithm using several simulations.

With a vast majority of Internet connections shorter than 10 segments, designing a new fast start-up TCP mechanism is a major concern. While enlarging the Initial Window (IW) up to 10 segments is the fastest solution to deal with a short-lived connection in uncongested networks, numerous researchers are concerned about the impact of the large initial burst on congested networks.

Satellite Digital Video Broadcasting is deeply changing : the next generation is dedicated to packet based communications and introduces (like many modern physical layers : WiMax, hsdpa, ...) fade mitigation techniques leading to variable throughput. Such tremendous changes need to be taken into account and the scheduling entity needs to be revisited. The purpose of this paper is to investigate utility function based algorithms. Such techniques have already been studied but never within this context. Dvb-s2 frames can encapsulate numerous ip packets, can offer variable payload length as well as variable transmission time, because of acm techniques. A more general approach is needed to encompass theses properties. As a consequence, the number of solutions among which a scheduler has to find the better is increased. We will then show that the algorithm implemented is an important issue.

With most internet connections being short-lived (i.e. 10 segments), it is very tempting to enlarge the TCP Initial Window (IW). This would save two of the three RTTs needed to transfer most of the web pages through a legacy slow start. However it has been demonstrated that the bursts created by a larger IW greatly impair global performance. An intuitive solution is the TCP Pacing. By spreading the transmission over the whole RTT, Pacing smoothes the bursts and delays the congestion. While postponing congestion provides good performance for short-lived connections, it could significantly deteriorate global network performance insofar as the reaction to congestion is also delayed. This paper analyzes the weaknesses of large IW and TCP Pacing and proposes a fast Start-Up mechanism to speed up short-lived connections while preserving long-term connections. Extensive simulations and analysis demonstrate that our solution is as efficient as a larger IW would be in an uncongested network and better than current mechanisms in congested environments.

Content distribution over ad-hoc networks has been widely studied and numerous solutions can be adapted to VANETs (vehicular networks). VANETs, however, can also benefit from an infrastructure in order to improve the efficiency of any content dissemination technique, while allowing more transmissions resources to be available for safety applications. Unfortunately, so far, no such solution has been proposed. In this paper, we introduce the use of an 802.11p infrastructure based on Road Side Units (RSU) for downloading data (eg a map) to vehicles on a highway. At the application level, the main challenge is then how to deliver data to a large number of moving receivers with limited connectivity. While broadcasting data through each RSU should efficiently provide the cars with most of the data, one could believe that some specific transmissions based on vehicles needs could help to reach full downloads. Using simulations, we observed however that the best performances are achieved by a pure broadcasting system.

Both WSNs (Wireless Sensor Networks) and observation satellites are able to get measurements from a geographic area. To interconnect these technologies, we propose to use a store-carry-and-forward architecture relying on the DTN (Disruption and Delay Tolerant Networking) Bundle Protocol. This architecture aims at being generic, so it is application-agnostic and suits a wide range of scenarios. WSN may collect sporadically large data volume while terrestrial stations communicating with Low Earth Orbit (LEO) satellites have to endure long link disruptions when the satellite is not in the line of sight. These sporadic growths within the WSN coupled with the large latency on satellite links require to schedule data to provide quality of service to several flows. We propose a scheduling policy based on deadline of Bundles and compare it with classical DTN solutions.

Initially deployed for TV broadcasting, geostationary satellite networks and DVB standards have become mature technologies for IP communications. Also used to interconnect wide IP networks, dynamic IP routing is required in geostationary mesh satellite networks. Nevertheless, terrestrial IP routing protocols are not optimized for satellite networks. Especially, as far as BGP operates over TCP at transport layer, it does not provide any multicast support and is not optimized for natural broadcast properties of satellite systems (e.g. DVB-S2), involving a significant amount of overhead and important complexity at the satellite terminal side. To integrate and interconnect satellite systems to the IP world, the use of BGP (as EGP) is required. Therefore, this paper analyzes the different ways to deploy BGP in DVB-S2/RCS networks and the opportunity to take advantage of a reliable multicast transport layer. A light, multicast and reliable mechanism to transport BGP4 is proposed and compared to the existing solutions.

Inter-vehicular communications are considered to be an efficient proactive approach for reducing the number and the consequences of road accidents. After a series of remarkable standardisation efforts, one of the last points needing to be addressed in order for safety vehicular networks to become a reality is the scalability problem of the CSMA-based medium access control layer. With node densities that can range from very sparse to several hundred contending stations, the MAC protocol needs the capacity to adapt to the state of the vehicular network without compromising the performance of the safety applications. While previous studies focused on individual mechanisms for data rate selection or transmission power control from a global point of view, this paper proposes a complete congestion control framework aiming to increase the message reception probability in the immediate neighbourhood under heavy congestion conditions. We propose a new concept for physical carrier sensing, which takes into account the location of the transmitter, and we combine it with transmission power control and a recently proposed backoff mechanism to obtain an important improvement over the original protocol. Several implementation problems are discussed, showing the feasibility of the solution using existing hardware, and a simulation study confirms the performance of this enhanced channel access method.

Contention-based protocols for Medium Access Control (MAC) in Vehicular Ad-Hoc Networks (VANET) are currently under development in several standardization organizations. The availability and maturity of the IEEE 802.11 technology makes it the first choice for the future vehicle-to-vehicle communications. At the same time, safety applications in a vehicular environment are expected to intensively use broadcast messages. However, the IEEE 802.11 standard has not been designed for broadcast communication and a number of problems arise from this. In this paper, we analyze the impact of the minimum Contention Window (CW) on the MAC layer performance in a realistic vehicular environment and we propose a simple solution for adapting CW to the network density in order to improve the reception probability of broadcast messages.

Adding communication capabilities to vehicles and road infrastructure has become a major goal in the intelligent transportation systems industry. The IEEE 802.11p amendment has specially been conceived for the Wireless Access in Vehicular Environments (WAVE) architecture. In this paper we study the performance of this standard by the means of extensive simulations and we argue that the current version of the protocol can not cope with high vehicular densities. We propose a simple but efficient modification of the back off mechanism which has an important impact on the quality of communications on the control channel.

Enhancing road safety using vehicle-to-vehicle communication has become an important goal for the automotive industry. A lot of effort has been put in the design of an efficient medium access control protocol, capable to function correctly even under heavy congestion. The solutions proposed so far focus on data rate or transmission power control. In this paper, we argue that the most important parameter for congestion control in vehicular ad hoc networks is the carrier sense threshold. We support this theory with analytical and simulation results and we demonstrate that the optimal threshold depends on the vehicular density. Furthermore, we propose an adaptive mechanism for physical carrier sense control and analyse its performance, showing an important increase in message reception probability.

The medium access control protocol of a future vehicular ad-hoc network is expected to cope with highly heterogeneous conditions. An essential parameter for protocols issued from the IEEE 802.11 family is the minimum contention window used by the backoff mechanism. While its impact has been thoroughly studied in the case of wireless local area networks, the importance of the contention window has been somehow neglected in the studies focusing on vehicle-to-vehicle communication. In this paper we show that the adjustment of the minimum contention window depending on the local node density can notably improve the performance of the IEEE 802.11 protocol. Moreover, we compare through simulation in a realistic framework five different methods for estimating the local density in a vehicular environment, presenting the advantages and the shortcomings of each of them.

The use of inter-vehicle communication is considered the next step to be taken in order to reduce the number of traffic accidents. The design of a versatile and efficient protocol that would manage the access to the control channel reserved for safety applications would represent a significant progress towards a generally accepted technology. However, the solutions proposed hitherto rarely took into account the broadcast nature of the messages produced by the safety applications. Furthermore, the specific properties of periodic vehicular beaconing are yet to be considered by any technical committee or research study. We present the specificities of this type of messages and discuss their impact on the performance of the medium access control layer, using both analytical and simulation tools.

Vehicular Ad-Hoc Networks (VANET) aim to increase security in the current transportation system by the means of wireless communication between vehicles and between vehicles and road infrastructure. In order to realize this goal, the Medium Access Control (MAC) protocol has to be highly reliable and has to assure a certain fairness between the nodes. In this paper, we make an in-depth analysis of the properties required from a MAC protocol in a VANET context. We then use these properties to compare the performance of two MAC protocols, one based on Carrier-Sense Multiple Access and the other using Time Division Multiple Access techniques in the case of a "heartbeat" application.

The Return Channel for Satellite (DVB-RCS) standard has become a mature technology for Internet communications via satellite access networks. Because of the propagation delay, as well as the expensive and scarce resources, the QoS support has to be optimized and harmonized. Indeed, it is provided at different independent layers (mainly layer 2,3 and application level) which are potentially either redundant or inconsistent. This paper suggests optimizations (between layer 2 and 3) for the resource sharing based on traffic contracts and using cross layer mechanisms. The traffic contracts are mainly used to perform a prediction of the incoming traffic evolution in order to reduce the effects of the transmission delay. In addition, a way to coordinate layer 2 and 3 schedulers is introduced. A first performance assessment of the proposed mechanisms in a DVB-RCS context shows that the layer 3 delays (introduced by queuing) are significantly reduced.

Initially designed for TV broadcasting, DVB standard families have become mature technologies for Internet communications via satellite access networks. A generic encapsulation protocol is therefore required for the forward link, the return link, and for mesh satellite systems. Moreover, because of the cost and the scarcity of resources, this should be as efficient and light as possible. The GSE (Generic Stream Encapsulation) protocol enables efficient transport of any protocol, originally designed for DVB-S2, that is to say on Quasi Error Free (QEF) forward links of satellite systems. This paper addresses limitations in GSE for the return link context and examines the requirements for an encapsulation mechanism for satellite systems using multiple access. This includes the return link but also mesh satellite systems and any satellite systems that uses multiple access. This paper also analyses approaches to derive requirements and provides a first analysis of these requirements.

Until now, the interaction and the handover between the satellite and wireless radio networks of next generation has not yet taken into account because of the wide difference of operation between the two networks; and the difference of their protocol stacks structures. In this context, we propose an interaction model between a network based on wireless radio technology: the mobile WiMAX, and a spatial network based on satellite broadcasting and return of data: DVB-S/RCS. We suggest also to use the multi-homing protocol: MSCTP to provide the vertical handover for Mobile Terminals that are moving between the two networks. And we propose finally a new DVB-S/RCS protocol stack amended and based on MSCTP and IP protocols to be more interactive with the mobile WiMAX and the end users exchanging IP traffic. In this model we try to ensure good QoS for video streaming traffic; and we will show some experimental results of our vertical handover model using Network Simulator (ns2).

In order to offer a better QoS during L2 handover of a mobile station, we propose in this paper to compare the performance of the two L2 HO techniques: Soft and Hard handover for different types of traffic with same architecture IEEE 802.16e in an urban area (City).

Satellite digital video broadcasting is deeply changing: the next generation is dedicated to packet based communications and introduces (like many modern physical layers: WiMax, HSDPA, ...) fade mitigation techniques leading to variable throughput. Such tremendous changes need to be taken into account and introduce the need for a scheduling entity. This paper investigates the opportunity to implement classical scheduler techniques tailored to suit fade mitigation techniques. With the help of a dedicated encapsulation scheme allowing fragmentation and concatenation, we show that stability can be achieved even at high load with basic algorithms. We then show that reclassification (an opportunity that can be described as a side effect of fade mitigation techniques) induces a significant improvement on the system performance.