Millimeter-wave (mmWave) radio is a key building block in 5G and beyond cellular networks. However, mmWave channels are very sensitive to environmental conditions and depend on Line-of-Sight  connections to provide very high data rates. Achieving reliable, consistent communication — i.e., a steady link rate together with low delay — over mmWave links is therefore a challenging problem. The goal of this work is to explore the use of predictive control to manage and simultaneously use multiple available mmWave paths to achieve reliable consistent communication by means of a multipath proxy. We investigate transient solutions of Markov Modulated Fluid Queues (MMFQ) to model the short-term evolution of the proxy’s packet queue, consistent with the use of Markovian models to capture the behavior of mmWave channel blocking. We propose a combination of models that can be solved using newly proposed matrix-analytic techniques in a timely enough manner for use in real-time control. This gives us a prediction, over a short time horizon, of either proxy queue distributions or probabilities of reaching particular proxy buffer levels. Thus, it enables the proxy to make preemptive path decisions in order to maintain a desired Quality of Service. A proof-of-concept simulation study demonstrates the efficacy of our proposed MMFQ-based predictive approach over both static and purely reactive control approaches. Further, we explore the potential benefits of a hybrid approach to path management, combining both predictive and reactive control. This can allow the controller to cater for unforeseen events that cannot be forecast by the predictive controller, mitigating the resulting extra queuing and corresponding delay spikes.

Reliable consistent communication over millimeter-wave (mmWave) channels is a challenging problem due to their sensitivity to blocking of Line of Sight connections. Even though mmWave is a key building block in 5G and future generation cellular networks, making solutions to this problem space important. Our aim is to use predictive control to manage and simultaneously use multiple available mmWave paths to achieve reliable consistent communication (i.e. steady transmission rate with low delay) with a multipath proxy. To this end we investigate transient solutions of Markov Modulated Fluid Queue models (MMFQ), apt because the mmWave blocking has been modeled with Markovian models. We propose a combination of models that can be solved using newly proposed matrix analytic techniques in a timely enough manner for use in real-time control. This gives us a prediction of either proxy queue distributions or probabilities of reaching proxy buffer levels over a short time horizon, enabling the proxy to make preemptive path decisions to maintain a desired Quality of Service. A proof of concept simulation study demonstrates the efficacy of our proposed MMFQ-based predictive approach over either static or purely reactive control approaches.

Abstract—Most Internet hosts today support multiple access technologies and network interfaces. Multipath transport protocols, like MPTCP, are being deployed (e.g., in smartphones), allowing transparent simultaneous use of multiple links. Besides providing increased resilience to link failures, multipath trans- ports may better exploit available (aggregate) capacity across all interfaces. The safest way to ensure fairness is to assume that any subflows of a multipath end-to-end connection may share bottleneck links, but knowledge of non-shared bottlenecks could allow multipath senders to exploit more capacity without being unfair to other flows. The problem of reliably detecting the existence of (non)-shared bottlenecks is not trivial and is compounded by the fact that bottlenecks may change due to traffic dynamics. In this paper we focus on practical methods to reliably group flows that share, possibly dynamic, bottlenecks online and in a passive manner (i.e., without injecting measurement traffic). We introduce a novel dynamic clustering algorithm that we apply to update our previous shared bottleneck flow grouping (SBFG) method standardized by the IETF, based on delay statistics. We also adapt an offline SBFG method based on wavelet filters to enable it for online operation. These SBFG methods are evaluated by a simple testbed, rigorous simulation and real-world Internet experiments in a testbed comprised of multihomed hosts. Our results suggest that there is no clear winner, and selection of the “best” SBFG method will have to consider tradeoffs regarding accuracy, lag, and application requirements.

Abstract—5G mmWave technology promises capacities 10 to 100 times that of 4G. However, mmWave links are very sensitive to having direct line of sight between sender and receiver, with dramatically fluctuating capacities due to transient blocking and shadow fading, which can substantially degrade TCP performance. TCP-splitting proxies (SPEPs) are often used to improve TCP performance over wireless links. We investigate current operator SPEPs (used in 4G LTE networks) under mmWave-like dynamics using the MONROE testbed. We introduce a mmWave emulation model for an urban canyon scenario, and use it to evaluate how current operational SPEPs impact the performance. Our results from experiments including four operators and three countries, indicate that SPEPs will be even more important for 5G mmWave than they are in LTE. Current 4G SPEPs provide significant, though not optimal, benefits under mmWave-like conditions, allowing them to be utilized as the network transitions to 5G technology.

This video is directed at decision makers in Network operators and equipment manufacturers. It contains a to-the-point explanation of some key technologies that needs to go into the Internet to reach the next evolutionary step.

Active Queue Management (AQM) design has again come into the spotlight of network operators, vendors and OS developers. This reflects the growing concern and sensitivity about the end-to-end latency perceived by today's Internet users. CoDel and PIE are two AQM mechanisms that have recently been presented and discussed in the IRTF and the IETF as solutions for keeping latency low. To the best of our knowledge, they have so far only been evaluated or compared against each other using default parameter settings, which naturally presents a rather limited view of their operational range. We set thus to perform a broader experimental evaluation using real-world implementations in a wired testbed. We have in addition compared them with a decade-old variant of RED called Adaptive RED, which shares with CoDel and PIE the goal of ``knob-free'' operation. Surprisingly, in several instances results were favorable towards Adaptive RED.