The promises of multipath transport are to aggregate bandwidth, improve resource utilisation and enhance reliability. In this article, we demonstrate that the way multipath coupled congestion control is defined today leads to a suboptimal resource utilisation when network paths are disjoint, i.e., they do not share a bottleneck link. With growing interest in standardising Multipath QUIC (MPQUIC), we have implemented the practical Shared Bottleneck Detection (SBD) algorithm from RFC8382 in MPQUIC (MPQUIC-SBD). Through extensive experiments, we evaluate MPQUIC-SBD in the context of video streaming with various Adaptive Bitrate (ABR) algorithms, addressing both ABR classes of rule- and learning-based solutions. We demonstrate that MPQUIC-SBD accurately detects shared bottlenecks over 90% of the time, depending on the ABR algorithm, as the size of the video segments increases. In non-shared bottleneck scenarios, when MPQUIC-SBD detects that its QUIC subflows do not share the same network resources, it decouples their congestion windows accordingly, enabling video throughput gains of up to 37% compared to MPQUIC. These gains translate directly into improved video quality metrics, including higher bitrate, better resolution and reduced buffering, resulting in an enhanced quality of experience for users.

Abstract Augmented and Mixed Reality (AR/MR) technologies enhance the human perception of the world by combining virtual and real environments. With the increase of mobile devices and the advent of 5G, this technology has the potential to become part of people’s life. This article aims to evaluate the impact of 5G and beyond mobile networks in the future of AR/MR. To attend to this objective, we surveyed four digital libraries to identify articles and reviews concerning AR/MR use based on mobile networks. The results describe the state-of-the-art of mobile AR/MR applications and the benefits and challenges of the technology. Finally, after the review, we propose a roadmap concerning AR/MR hardware and software development to run applications supported by future mobile networks.

The promises of multipath transport is to aggregate bandwidth and improve resource utilisation and reliability. We demonstrate in this paper that the way multipath coupled congestion control is defined today RFC6359 leads to a sub-optimal resource utilisation when network paths are mainly disjoint, i.e., they do not share a bottleneck. With growing interest to standardise Multipath QUIC (MPQUIC), we implement the practical shared bottleneck detection (SBD) algorithm from RFC8382 in MPQUIC, namely MPQUIC-SBD. We evaluate MPQUIC-SBD through extensive emulation experiments in the context of video streaming. We show that MPQUIC-SBD is able to correctly detect shared bottlenecks over 90% of the time as the video segments' size increase depending on the Adaptive Bitrate (ABR) algorithm. In non-shared bottleneck scenarios, MPQUIC-SBD results in video throughput gains of more than 13% compared to MPQUIC, which directly translates into better video quality metrics.

Interpath contention is a phenomenon experienced in a MultiPath TCP (MPTCP) connection when its subflows dispute resources of shared bottlenecks in end-to-end paths. Although solutions have been proposed to improve MPTCP performance in different applications, the impact of interpath contention on the multipath performance is little understood. In this paper, we evaluated such phenomenon experimentally in disjoint paths-an ordinary multipath scenario where subflows dispute bottlenecks of paths physically disjointed in a connection. Under several path conditions determined from emulations of capacity, loss, and delay of bottlenecks, we analyzed the influence of MPTCP mechanisms such as packet scheduling, congestion control, and subflow management. Differently from other studies, we observed that the very first influence was caused by the current subflow manager, full-mesh, with dichotomous impact on the multipath performance when establishing several subflows per disjoint path. Experimental results showed that contention among subflows can lead to positive (goodput improvement) or negative (goodput degradation) impacts according to the bottleneck conditions. In certain conditions, simply establishing subflows in single-mesh, with at most one subflow per disjoint path, could avoid interpath contention while improving goodput significantly, by doubling the performance of full-mesh under different conservative congestion controls.

Vehicular CrowdSensing (VCS) is an emerging solution designed to remotely collect data from smart vehicles. It enables a dynamic and large-scale phenomena monitoring just by exploring the variety of technologies which have been embedded in modern cars. However, VCS applications might generate a huge amount of data traffic between vehicles and the remote monitoring center, which tends to overload the LTE networks. In this paper, we describe and analyze a gEo-clUstering approaCh for Lte vehIcular crowDsEnsing dAta offloadiNg (EUCLIDEAN). It takes advantage of opportunistic vehicle-to-vehicle (V2V) communications to support the VCS data upload process, preserving, as much as possible, the cellular network resources. In general, it is shown from the presented results that our proposal is a feasible and an effective scheme to reduce up to 92.98% of the global demand for LTE transmissions while performing vehicle-based sensing tasks in urban areas. The most encouraging results were perceived mainly under high-density conditions (i.e., above 125 vehicles/km2), where our solution provides the best benefits in terms of cellular network data offloading.

Unlike giant clouds, small cloud providers (SCPs) focus attention on offering personalized services to better fit business needs of regional customers. However, SCPs exploit such a business niche with no massive computing infrastructure. To ensure well provisioned resources, capacity planning and resource management are pivotal tasks. To this end, this paper describes a regression-based resource estimation method for selecting and provisioning virtual machines (vms) with minimal configurations to meet tenants' web application workloads in SCP. From hundreds of http workload tests performed with dozens of vm configurations on the SCP's virtualization platform, a non-linear regression model was obtained to estimate not only CPU demands, but also amount of RAM required to handle workloads in different scales. A resource utilization improvement was verified from a case study of a tenant's web application monitored for a month in an SCP. According to the observed workload, estimated configurations have indicated that resources were overprovisioned for the tenant's vm, so that the underutilized residual resources could provision, at least, a new vm for all the monitoring time.

Several existing IP mobility solutions use invasive approaches, when adjustments in legacy protocols from the TCP/IP stack are necessary, or rely on specific network infrastructures. We devised an architecture to handle mobility using a Session-based Mobile Socket Layer (SMSL). With no need for software adaptation in the core of the network or adjustment on the TCP/IP stack, SMSL operates only at the end systems involved in the communication, being fully transparent to neighboring Transport and Application layers. The session scheme allows mobility awareness for TCP-based applications that require resilience to failures, delays, or disconnection. A general-purpose API extended from the Socket and implemented in GNU/Linux provides session services, such as tracking mobile peers, detecting disruptions, and suspending and resuming sessions with efficiency, security, and reliability. In this paper, we present the entire session support system as a mature work of research achieved with advances made in our previous study. The results of experiments in real and emulated test environments demonstrate efficiency. SMSL introduces little overhead, with a mean goodput degradation of 6.9% compared to an application implemented on top of the standard TCP/IP stack. Disruptions are detected in microseconds and suspended sessions resume in milliseconds for single-homed mobile nodes.

Current ubiquitous computing technologies provide access to customized, contextual, and location-based services. Device mobility, however, is frequently associated with communication delays, link disruptions due to signal loss, and changes in IP address. As a result, connection-oriented applications may fail and node location strategies should not rely on node addresses. In this paper, we propose the use of communication sessions to create mobility-aware applications that do not break with transmission delays or disruptions. The concept of these communication sessions is embedded in the basic network socket API functions and operates transparently with the applications. Sessions provide application level support to keep track of the location of peer nodes, to detect connection disruptions, and to suspend and resume transmissions. Experiments show our approach offers superior performance of the general IP layer mobility solution, with no need to implement or adapt software at the core network infrastructure.