The explosive growth of modern short-video platforms like WeChat Channels — approaching 1.4 billion monthly active users (MAU) while serving over one billion queries per second (QPS) — has exposed fundamental limitations in conventional content delivery network (CDN) architectures, particularly their inability to handle highly dynamic content popularity patterns. The traditional cache-centric approach proves to be catastrophic when faced with ephemeral content exhibiting a "million-item waist" distribution. This phenomenon results in severe cache pollution (manifesting as 5–40% origin miss ratios) and introduces prohibitive back-to-origin bandwidth costs. Our TritonFlow overcomes these challenges by introducing access point scheduling as a novel origin traffic compensator, which reduces the operational cost of back-to-origin fetches by enhancing CDN cache affinity. Through analysis of production traces (peak >1B QPS), we demonstrate that TritonFlow reduces scheduling fluctuations by 96% and decreases back-to-origin traffic caused by non-compulsory cache misses by 35%, all while maintaining sub-200ms fetch latency.

Enhancing the quality of experience (QoE) in interactive video streaming (IVS) remains a persistent challenge due to the need for ultra-low latency and rising bandwidth demands. Conventional algorithms, whether rule-based or learning-based, are obsessed with achieving tight coupling between encoding and sending bitrate adaptations for low-latency guarantee. However, our measurement studies reveal alarming harms of tight coupling in suppressing throughput, encoding bitrates and smoothness, as application- and transport-layer bitrate adaptations inherently have different mechanisms and goals. To tackle this problem, we propose Octopus, the first loosely coupled cross-layer bitrate adaptation algorithm for IVS to maximize QoE. Instead of blind synchronization, Octopus promotes mutual cooperation and independence between encoding and sending bitrate adaptations by integrating a multi-head network with shortcut connections and auto-regressive action modules. Additionally, based on meta-imitation reinforcement learning, we design a network condition-aware online adaptation scheme that enables the loosely coupled policy to swiftly adapt to diverse and dynamic wireless networks. We implement Octopus on a testbed, a microcosm of real-world deployment, with transceiver pairs running WebRTC on the WeChat for Business dataset. Results show that Octopus outperforms state-of-the-art algorithms, either improving bitrates by 37.1%, or optimizing stalling rate and smoothness by 54.1% and 9.2%, or achieving all-around improvements.

Low-latency interactive video streaming services critically depend on robust congestion control algorithms (CCA). However, existing CCAs often exhibit frequent self-induced oscillations from unconstrained probing, causing periodic heavy queuing and degrading the user experience. We propose Themis, a novel end-to-end CCA designed to achieve stabilized near-zero queuing delay with high bitrate. By precisely quantifying the trade-off between bitrate and queuing delay within a utility feedback mechanism, Themis effectively controls the amplitude and frequency of probing while ensuring fairness. In parallel, Themis incorporates the awareness of the queuing state through an adaptive-pacing method, combined with utility feedback to guide a three-phase bitrate adjustment strategy. This enables rapid and stable convergence to the optimal utility. We implemented Themis in QUIC, evaluated it on the Mahimahi and conducted a 90-day large-scale A/B test in a real-world network. Compared to state-of-the-art CCAs, Themis effectively suppresses self-induced oscillations, increases the average frame bitrate by 66.8%, and reduces the average frame delay by 13.5%, demonstrating a superior trade-off between high bitrate and low queuing delay.

Maximizing quality of experience (QoE) for interactive video streaming has been a long-standing challenge, as its delay-sensitive nature makes it more vulnerable to bandwidth fluctuations. While reinforcement learning (RL) has demonstrated great potential, existing works are either limited by fixed models or require enormous data/time for online adaptation, which struggle to fit time-varying and diverse network states. Driven by these practical concerns, we perform large-scale measurements on WeChat for Business’s interactive video service to study real-world network fluctuations. Surprisingly, our analysis shows that, compared to time-varying network metrics, network sequences exhibit noticeable short-term continuity, sufficient for few-shot learning requirement. We thus propose Fiammetta, the first meta-RL-based bitrate adaptation algorithm for interactive video streaming. Building on the short-term continuity, Fiammetta accumulates learning experiences through offline meta-training and enables fast online adaptation to changing network states through few gradient updates. Moreover, Fiammetta innovatively incorporates a probing mechanism for real-time monitoring of network states, and proposes an adaptive meta-testing mechanism for seamless adaptation. We implement Fiammetta on a testbed whose end-to-end network follows the real-world WeChat for Business traces. The results show that Fiammetta outperforms prior algorithms significantly, improving video bitrate by 3.6%-16.2% without increasing stalling rate.

An important issue in an edge computing (EC) network is to increase the utilities of the end users concurrently accessing the computation resources. In this paper, we consider the task offloading in EC-enabled networks where the end users efficiently utilize the dispersed computation and communication resources in a multi-path multi-hop manner. We propose a binary optimization framework that generalizes multi-hop wireless EC task offloading as jointly making decisions of server selecting and traffic routing in networks of arbitrary topology (JoSRAT). We further develop an approximation algorithm JoSRAT that enables for a fully distributed implementation together with the worst-case performance guarantees. Interestingly, our proposed distributed algorithm achieves nearly optimal in the numerical evaluations, significantly outperforming the worst-case guarantees. The proposed algorithm also outperforms a widely-used heuristic, i.e., First Fit, in terms of computational time complexity, indicating the superior capability of the proposed framework.

In-network caching constitutes a promising approach to reduce traffic loads and alleviate congestion in both wired and wireless networks. In this article, we study the joint caching and routing problem in congestible networks of arbitrary topology (JoCRAT) as a generalization of previous efforts in this particular field. We show that JoCRAT extends many previous problems in the caching literature that are intractable even with specific topologies and/or assumed unlimited bandwidth of communications. To handle this significant but challenging problem, we develop a novel approximation algorithm with guaranteed performance bound based on a randomized rounding technique. Evaluation results demonstrate that our proposed algorithm achieves near-optimal performance over a broad array of synthetic and real networks, while significantly outperforming the state-of-the-art methods.

Recently, many applications (e.g., wearable cognitive assistance) with the devices of Internet of Things (IoT) (e.g., Apple Watch and Google Glass) have been fast developed. However, the current Internet may not be suitable for the future IoT applications due to the limited capabilities of the data caching and content processing services with the existing Internet architecture. In this paper, we extend the named data networking and develop the object-oriented network (OON) as a novel Internet architecture to implement both the native data caching and content processing in the network layer. The datagrams with processable payloads as well as the cached contents are both referred to as the operable objects in OON for abstraction. With the proposed OON architecture, operable objects can be processed and transmitted by forwarding them to the subroutines of content processing programs and the interfaces of content deliveries, respectively, according to the proposed naming rules. For performance evaluation, we implement the dynamic adaptive multimedia streaming application atop the proposed OON architecture in ns-3. Our simulation results show that the proposed OON architecture can effectively increase the potential quality of experience for mobile users.

The traffic of the base station can be offloaded by content sharing through device-to-device (D2D) communications if popular on-demand contents have been cached in user devices. In D2D content sharing, the receiving user gains benefit by obtaining contents while the transmitting user has to consume the transmission energy. However, users are selfish and have no obligation to help others. To motivate user involvement in D2D content sharing, we propose an energy-aware incentive mechanism where the key idea is that physically neighboring users can form a collaborative group. In a collaborative group, a user obtains contents from other users while consuming energy on providing contents to other users. We model the problem as a coalition formation game with non- transferable utility. To solve the problem, we also propose an algorithm which is proved to be of convergence and stability. Finally, simulation results show that our proposed mechanism has significant performance gains compared with two baseline schemes.

Device-to-device (D2D) communication is known as a promising way to cope with the growing mobile video traffic, which may suffer from the short duration caused by the limited energy supply. In this paper, we propose a practical D2D cooperation framework based on distributed optimization to extend the video transmission duration. In the multi-path multi-hop D2D communication scenario, we effectively schedule the routes and video traffic workloads to avoid low-battery D2D outages due to non-uniform energy consumption. Specifically, we formulate the D2D cooperation as a consensus problem among the network operator and cooperative devices, and then solve it in a flexible distributed fashion. Numerical results show that the proposed framework could reach the optimality quickly in time division duplex communication systems and significantly increase the duration of the cooperative video transmission.