Synchronization-induced congestion is a critical performance bottleneck in modern distributed machine learning (ML) training, where simultaneous gradient exchanges create bursty traffic patterns. Existing solutions, both reactive and proactive, struggle to balance throughput and latency in the presence of synchronized flows. We propose DeSync, a proactive traffic shaping scheme that introduces structured random delay to de-synchronize communication rounds. Evaluations with DCQCN, HPCC, DCTCP, and TIMELY demonstrate that DeSync significantly improves FCT, job completion times, and congestion metrics, enhancing existing CC mechanisms without specialized hardware.

Infrastructure-assisted autonomous driving has emerged as a pivotal technology to overcome the challenges posed by occlusions and limited fields of view for individual vehicles. Vehicles can fuse perception information from the infrastructure with their own in real-time, thereby enhancing their perception ability. However, our real-world experiments demonstrate that such an approach could introduce artifacts such as ghost objects, resulting in unsafe and unreliable planning outcomes. Besides, the system integration complexity and communication overhead are typically considerable, posing challenges to practical deployment. Therefore, we propose VI-Planning, an innovative infrastructure-assisted system that effectively optimizes autonomous vehicle planning in real time. The core idea of VI-Planning is to leverage the scene-level future occupancy grid maps constructed by the infrastructure as future drivable area references to directly optimize planning outcomes of autonomous vehicles. Since VI-Planning operates only at the autonomous vehicle's final output stage, without modifying the vehicle's underlying system architecture, it can be plug-and-play for most autonomous driving systems, whether they are modular or end-to-end architectures. Moreover, VI-Planning employs a novel bitwise encoding mechanism to efficiently compress these maps, enabling practical transmission. We implement VI-Planning end-to-end on a real-world testbed. The results of closed-loop and open-loop experiments indicate that VI-Planning can achieve real-time planning optimization (62.54 ms on average) and 817 × data transmission efficiency compared to the state-of-the-art baseline. A video demo of VI-Planning on our real-world testbed is available at: https://youtu.be/DXl5BhDEvFQ.

We propose VI-Planning, an innovative system that leverages the scene-level future occupancy grid maps predicted by the infrastructure as future drivable area references to directly optimize the planning trajectories of autonomous vehicles in real time. Since VI-Planning operates only at the autonomous vehicle's final output stage, without modifying the underlying system architecture, it can be plug-and-play for most autonomous driving systems. Moreover, VI-Planning employs a novel bitwise encoding mechanism to efficiently compress these maps, enabling practical transmission. The experimental results demonstrate that VI-Planning can achieve real-time planning optimization with extremely low bandwidth consumption, significantly enhancing the driving safety of autonomous systems. The source code and video demonstration of VI-Planning are available on GitHub: https://github.com/YANG-Deep/VI-Planning.

We propose VI-Planning, an innovative system that leverages the scene-level future occupancy grid maps predicted by the infrastructure as future drivable area references to directly optimize the planning trajectories of autonomous vehicles in real time. Since VI-Planning operates only at the autonomous vehicle's final output stage, without modifying the underlying system architecture, it can be plug-and-play for most autonomous driving systems. Moreover, VI-Planning employs a novel bitwise encoding mechanism to efficiently compress these maps, enabling practical transmission. The experimental results demonstrate that VI-Planning can achieve real-time planning optimization with extremely low bandwidth consumption, significantly enhancing the driving safety of autonomous systems. The source code and video demonstration of VI-Planning are available on GitHub: https://github.com/YANG-Deep/VI-Planning.

Video streaming systems are critical for intelligent applications to transmit video data from end devices to servers for real-time analysis. In contrast to traditional human-centric streaming systems, which prioritize user-perceived metrics, machine-centric streaming systems are designed to continuously provide fresh and accurate information for analytics purposes. Although numerous studies have investigated policies to optimize streaming performance, most of them employ the segment-by-segment streaming framework from human-centric systems. Through comprehensive theoretical analysis and experimentation, we uncover that the segmented streaming approach is sub-optimal for machine-centric streaming systems compared to the straightforward frame-by-frame streaming approach. Furthermore, instead of relying on conventional frame-level metrics, we introduce a novel metric called the Age of Semantic Information (AoSI) to evaluate the performance of analytics-oriented streaming systems. This metric balances the quantity and timeliness of the semantic information. Consequently, we propose a compression ratio adaption method tailored to optimize AoSI performance for frame-by-frame streaming systems. This method leverages a deep learning (DL)-based predictor to discover the dynamic, latent relationships between compression and inference accuracy. Evaluated on actual streaming prototypes and real-world datasets, our method significantly surpasses both segmented and frame-by-frame baseline methods in terms of worst-case and average AoSI performance.

Unmanned aerial vehicles (UAVs) play a critical role in disaster response, swiftly gathering information from various points-of-interest (PoIs) across extensive areas. The freshness of this information is measured by the age of information (AoI), representing the time since the latest information acquisition of a specific PoI. However, devising AoI-minimizing routes for UAVs in obstructed post-disaster environments poses unique challenges that have yet to be fully overcome. Obstacles, like post-disaster barriers, can impede direct flight paths between PoIs, and limited battery life requires energy-conscious route planning. Additionally, existing solutions fail to universally minimize varying data freshness requirements. This research addresses the AoI-driven UAV travel problem, seeking to establish periodic routes that optimize AoI metrics while considering energy and general graph constraints. We develop a learning-based algorithm to enhance the current route iteratively, utilizing guidance from a deep reinforcement learning (DRL) agent and executing a series of operations to potentially decrease AoI while adhering to topological and energy constraints. The algorithm is validated on real post-disaster datasets, demonstrating significant improvements in various AoI metrics compared to other learning-based approaches. Furthermore, our algorithm outperforms approximation algorithms and can approach the global optimum when tailored to existing AoI-minimizing problems.

Information freshness, measured by the Age-of-Information (AoI) metric, is a crucial aspect of conventional network systems. However, the emergence of the Artificial Intelligence of Things (AIoT) introduces unique requirements for assessing information freshness, rendering the traditional AoI definition inadequate. This is because the traditional AoI metric operates under the presumption that each data packet bears equal significance. In contrast, AIoT systems must prioritize the transmission of event summaries from smart IoT devices. To promptly capture events as they occur at the sources, we propose a novel information freshness metric called Age of Event (AoE). Subsequently, we thoroughly investigate the problem of AoE-minimizing transmission scheduling. This issue presents a formidable challenge because the event occurrence pattern can be unpredictable, and more crucially, the base station only becomes aware of these occurrences post-transmission. In response, we formulate algorithms and conduct a theoretical analysis applicable to scenarios characterized by complete, zero, or partial knowledge of event occurrences. Evaluations performed on a real traffic event dataset reveal that even in the absence of complete knowledge, our algorithms exhibit competitive performance when compared against the clairvoyant benchmark and markedly outperform AoI baselines.

In many IoT applications, information needs to be gathered from multiple heterogeneous sources to the base station for real-time processing and follow-up actions. Undoubtedly, information freshness, measured by age of information (AoI), is critical in taking responsive actions. Recent studies have taken AoI into the consideration of transmission scheduling over wireless channels. However, existing studies on guaranteeing AoI either assume error-free wireless channels or priorly known link reliability, which is unrealistic. In this paper, we tackle the AoI-guaranteed transmission scheduling problem over an unreliable channel with the aim of throughput maximization, which is modelled as an AoI-Guaranteed Multi-Armed Bandit (AG-MAB) problem. Since the problem has not been studied in the literature even for the oracle case with given link reliability, we first propose an optimal stationary randomized sampling (SRS) policy for the oracle case. For the AG-MAB problem with unknown link reliability, we propose learning algorithms that meet the AoI requirements with probability 1 and incur sublinear regret compared to Oracle SRS, which can also detect the unsatisfiability of the AoI constraint and switch to the fallback policy promptly with guaranteed accuracy. Numerical results show that our algorithm outperforms the AoI-constraint-aware baselines on throughput with per-source AoI requirement guaranteed.

Unmanned Aerial Vehicle (UAV) swarm offers extended coverage and is a vital solution for many applications. A key issue in UAV swarm control is to cover all targets while maintaining connectivity among UAVs, referred to as a multi-target coverage problem. With existing dynamic routing protocols, the flying ad hoc network suffers outdated and incorrect route information due to frequent topology changes. This might lead to failures of time-critical tasks. One mitigation solution is to keep the physical topology unchanged, thus maintaining a fixed communication topology and enabling static routing. However, keeping physical topology unchanged may sacrifice the coverage. In this article, we propose to maintain a fixed communication topology among UAVs, which allows certain changes in physical topology, so that to maximize the coverage. We develop a distributed motion planning algorithm for the online multi-target coverage problem with the constraint of keeping communication topology intact. As the communication topology needs to be timely updated when UAVs leave or arrive at the swarm, we further design a topology-management protocol. Experimental results from the ns-3 simulator show that under our algorithms, UAV swarms of different sizes achieve significantly improved delay and loss ratio, efficient coverage, and rapid topology update.

In the past decade, unmanned aircraft systems (UASs) have been widely used in various civilian applications, most of which involve only a single unmanned aerial vehicle (UAV). In the near future, more and more UAS applications will be facilitated by the cooperation of multiple UAVs. In such applications, it is desirable to utilize a general control platform for cooperative UAVs. However, existing open-source control platforms cannot fulfill such a demand because (1) they only support the leader-follower mode, which limits the design options for fleet control, (2) existing platforms can support only certain type of UAVs and thus lack compatibility, and (3) these platforms cannot accurately simulate a flight mission, which may cause a big gap between simulation and real-world flight. To address these issues, we propose a general control and monitoring platform for cooperative UAS, namely, CoUAS , which provides a set of core cooperation services of UAVs, including synchronization, connectivity management, path planning, energy simulation, and so on. To verify the applicability of CoUAS, we design and develop a prototype in which an embedded path planning service is provided to complete any task with the minimum flying time while considering the network connectivity and coverage. Experimental results by both simulation and field test demonstrate that the proposed system is viable.