Moving computing components from headsets to cloud servers is a promising approach to increasing headsets' lifespan and comfort for Extended Reality (XR) users. However, latency is an unavoidable challenge for XR services due to longdistance transmission, especially when haptic feedback (usually requires 1 ms latency) is involved. To address this challenge, we leverage the Latent Diffusion Model (LDM) to propose a novel transmission architecture, which can accurately generate the future potential haptic feedback from current or previous video frames. Moreover, we also introduce an acceleration architecture to accelerate the haptic feedback generation process. The simulations indicate that the lifespan of headsets can be tripled by moving computing resources to the cloud. In addition, our proposed architecture can accurately generate future potential haptic feedback at least 170 ms before contact, which can satisfy the 1 ms latency requirement of haptic feedback.

With the increasing demands placed on geographically distributed Data Centers (DCs), recent studies have focused on optimizing performance from the perspective of both cloud providers and customers. These studies address a variety of goals, such as minimizing transmission time, reducing resource usage, and optimizing network costs. However, many existing models for workload transfers operate using a uniform time-slot approach, which limits their flexibility in handling variable data transfer requests with different deadline requirements. This lack of adaptability can negatively impact the quality of service for users. Additionally, these models often overlook the potential benefits of incorporating multiple data sources, which can lead to sub-optimal transmission times. To overcome these limitations, this paper introduces TCOMS, a Time-slot-aware, COst-effective, and Multi-Source-aware method for file transfers tailored specifically for geo-distributed DCs, leveraging a multi-source and dynamic time-slot strategy to accelerate transmission and enhance service quality. The proposed model identifies the optimal sources, paths, and time slot lengths required to efficiently transmit workloads to their destinations while minimizing costs. Initially, we introduced a Mixed Integer NonLinear Programming (MINLP) model and subsequently linearized it within our framework. Given the NP-hard nature of the proposed model, its applicability is limited in large-scale environments. To address this issue, we developed an efficient heuristic algorithm that can derive near-optimal solutions in polynomial time. The simulation results demonstrate the effectiveness of the proposed TCOMS model and the heuristic algorithm in terms of the reduction in cost and transmission time for file transfers between geographically distributed DCs.

Haptic data compression has gradually become a key issue for emerging real-time haptic communications in Tactile Internet (TI). However, it is challenging to achieve a trade-off between high perceptual quality and compression ratio in haptic data compression scheme. Inspired by the perspective of embodied AI, we propose a cross-modal haptic compression scheme for haptic communications to improve the perception quality on TI devices in this paper. Since multimodal fusion is routinely employed to improve the ability of system in cognition, we assume that haptic codec is guided by visual semantics to optimize parameter settings in the coding process. We first design a multi-dimensional tactile feature fusion network (MTFFN) relying on multi-head attention mechanism. The MTFFN extracts the multi-dimensional features from the material surface and maps them to infer the coding parameters. Secondly, we provide second-order difference and linear interpolation to establish an criterion for the determination of optimal codec parameters, which are customized by the material categories so as to give high robustness. Finally, the simulation results reveal that our compression scheme can efficiently make a personalized codec procedure for different materials, obtaining more than 17% improvement in terms of compression ratio with high perceptual quality at the same time.

With the continuous evolution of networking technologies, multi-modal services that involve video, audio, and haptic contents are expected to become the dominant multimedia service in the near future. Edge caching is a key technology that can significantly reduce network load and content transmission latency, which is critical for the delivery of multi-modal contents. However, existing caching approaches only rely on a limited number of factors, e.g., popularity, to evaluate their importance for caching, which is inefficient for caching multi-modal contents, especially in dynamic network environments. To overcome this issue, we propose a content importance-based caching scheme which consists of a content importance evaluation model and a caching model. By leveraging dueling double deep Q networks (D3QN) model, the content importance evaluation model can adaptively evaluate contents' importance in dynamic networks. Based on the evaluated contents' importance, the caching model can easily cache and evict proper contents to improve caching efficiency. The simulation results show that the proposed content importance-based caching scheme outperforms existing caching schemes in terms of caching hit ratio (at least 15% higher), reduced network load (up to 22% reduction), average number of hops (up to 27% lower), and unsatisfied requests ratio (more than 47% reduction).

Data centers have undergone significant expansions in recent years, as cloud service providers seek to improve the quality of service and reduce operational costs. Cloud providers are investing heavily in inter-data center wide-area networks, which help to transport traffic between geographically distributed data centers. However, efficient workload management in complex large-scale networks with a dynamic environment is challenging. In this regard, researchers have developed various solutions to address different challenges for data transfer in inter-data center networks. In this paper, we present a comprehensive review of recent strategies and optimization schemes proposed in the literature to optimize data transfer in geographically distributed data centers. This review paper examines the challenges of data delivery and classifies recent existing solutions for addressing the issues based on communication patterns, objectives, proposed communication frameworks, and evaluation methods. In this study, we provide valuable insights into the current challenges and identify several promising research directions that require significant research endeavors in the future. The findings of this study are useful for researchers and practitioners interested in optimizing data transfer in inter-data center networks.

The Internet of Things (IoT) has already emerged as one of the most popular directions in today’s information and communication technology (ICT) domain. With its advancement over different application areas, such as smart home, smart healthcare, industry 4.0, etc., a huge amount of data has been generated by billions of IoT devices, which aggravates the shortcomings of the network layer (IP)-based networks, such as limited expressiveness of IP addressing, inefficient support for mobility, and in-network caching. Building IoT on top of information-centric networking (ICN) is believed to be a promising solution to tackle the above challenge, especially the in-network caching of ICN can significantly benefit IoT in terms of reducing data and saving IoT devices’ energy. However, caching IoT data is more challenging than caching traditional Internet content, e.g., video, because IoT data are usually valid within a certain period of time, and IoT devices are typically constrained with battery. Hence, in this survey, we first review the current implementation proposals of ICN-based IoT (ICN-IoT). Next, we present the conventional caching decision policies and replacement policies which could be adopted to mitigate the aforementioned challenges, e.g., reducing IoT traffic, saving energy, and reducing data retrieval latency. Further, since leveraging machine learning (ML) techniques have the potential to further improve the caching efficiency by dealing with uncertainties, e.g., predicting unknown information, adaptively interacting with the environment, we also demonstrate the recently proposed ML-based caching schemes for ICN-IoT. In addition, we outline the open research issues and point out the future opportunities of caching in ICN-IoT.

Advanced network technologies and ubiquitous connected devices are boosting the development of the Internet of Things (IoT) at an unprecedented pace. However, as most of the connected IoT devices are battery powered, the energy consumption issue has become the bottleneck of the IoT’s development. Caching is a promising approach to reducing the energy consumption of the battery-powered devices since the requested data packets can be retrieved from intermediate nodes in the network, e.g., routers, instead of from the remote battery-powered IoT devices, which allows the IoT devices to spend more time in the sleep mode. To realize in-network caching and overcome the IP-based networks’ inefficiency support for IoT, building IoT over information-centric networking (ICN) is a promising approach advocated by researchers. However, existing works in this area assume the network environments are static, which hinders the development of existing approaches in the real dynamic network environments. In this article, we leverage the deep$Q$-networks (DQNs) to propose an intelligent caching scheme (named as iCache) that can automatically adjust the caching nodes’ caching parameters to make caching decisions for the dynamic network environments. Extensive evaluations were conducted and the results show that the proposed iCache outperforms the existing approaches in terms of the total energy consumption (e.g., more than 29% reduction compared to the caching transient data (CTD) caching scheme) and the average number of hops (e.g., more than 20% reduction compared to the CTD caching scheme).

The considerable increase of multimedia services, such as video-on-demand (VoD) services, is a significant contributor to the total Internet traffic. Software-defined networking (SDN) and information-centric networking (ICN) are two promising technologies that can be combined to facilitate video delivery and to reduce network delays. In this paper, we first formulate the caching decision problem as a 0-1 integer linear programming (ILP) problem. Second, in contrast to existing approaches that solve the formulated ILP problem by assuming all future video requests are known, we consider the impact of the time scale, which transforms the static 0-1 ILP problem into a dynamic problem. By solving the dynamic 0-1 ILP problem, we find more accurate optimal solutions compared to existing approaches. Third, since the formulated 0-1 dynamic ILP problem is NP-hard, we leverage the in-network caching of ICN and the global view of the SDN controller to propose a novel SDN-based caching decision policy. Finally, extensive evaluations are performed, and the results demonstrate that the proposed SDN-based caching decision policy provides solutions that are close to the optimum in substantially less computation time. The SDN-based caching decision policy also outperforms existing practical ICN caching decision policies in terms of the cache hit ratio and the average number of hops, which are directly related to the video delivery latency. Moreover, the SDN-based caching decision policy can substantially reduce the number of generated and broadcasted interest packets, which is a shortcoming of the current ICN.

Since multimedia services will become fundamental in the upcoming 5G networks, how to improve the user quality of experience (QoE) is becoming a major challenge. In this paper, we integrate the concept of Information-Centric Networking (ICN) to the infrastructure of 5G networks. Due to the in-network caching feature of ICN, proactive caching can be beneficial in 5G networks. More precisely, this paper introduces a novel proactive caching approach (called smart caching) which leverages the non-negative matrix factorization (NMF) technique to predict the future ratings of user preferences on all videos for 5G-ICN networks. To solve the shortcoming of the NMF technique that generates inaccurate predictions for high rated but unpopular videos, we also take video historical popularity into consideration. Thus, the user future demands can be predicted based on the user preferences (i.e. the predicted ratings) and the historical popularity of videos. Simulation results show that the proposed smart caching outperforms existing approaches in terms of hit ratio, average video retrieval delay, and user satisfaction.

As devices for the Internet of Things (IoT) are typically battery-powered, energy efficiency is a major challenge for IoT networks. In this paper, we leverage the in-network caching of Information-Centric Networking (ICN) to propose a novel cooperative caching scheme, based on the IoT data lifetime and user request rate, to improve the energy efficiency of IoT networks. By caching IoT data at different nodes (such as content routers, base stations, etc.), IoT devices can stay in sleep mode for a larger portion of time and therefore reduce the overall energy consumption. With the help of an auto- configuration mechanism, the proposed IoT data Lifetime-based Cooperative Caching (LCC) scheme can dynamically adapt to the change of request rate. Extensive evaluations were performed and the simulation results show that LCC outperforms existing schemes in terms of total energy consumption reduction (up to 40%) and the reduction in the average number of hops traversed along the path (up to 20%), which is also directly related to the response time. Keywords- Internet of Things (IoT), Cooperative Caching, Information-Centric Network (ICN).

Information centric networking (ICN) is one of the emerging Internet paradigms proposed to overcome the shortcoming of the current host-centric Internet. With ubiquitous in-network caching, ICN can facilitate content delivery and reduce network delay. In this paper, we propose a novel collaborative caching scheme based on routers' position to cache popular videos on the edge routers which are closer to users. A priori knowledge of videos' popularity is not required as the proposed scheme adapts itself to the user requests. The benefits of our proposed approach are: light-weight, short content delivery time, and reduced network usages and publisher load. We use a simple topology to show how the proposed scheme works. Then, we use a realistic topology with real data traces to evaluate the performance of the proposed scheme. Simulation results show that our scheme outperforms existing schemes in terms of average number of hops and reduced publisher load ratio for both scenarios.