Content Offloading Research Articles

Federated learning empowered mobility-aware proactive content offloading framework for fog radio access networks

Proactive content caching has emerged as a promising solution to cope with exponentially increasing mobile data traffic. The popular user contents can be cached near the network edge for faster retrieval and processing. Current state-of-the-art approaches adopt a centralized model training mechanism that requires high communication and data exchange overheads to predict content popularity. Moreover, these approaches fail to deal with the dynamicity of the environment since they do not take into account the users’ mobility information and are unable to incorporate content offload timings. In this paper, we address these limitations by proposing a novel federated learning-based Mobility and Demand-aware Proactive Content Offloading (MDPCO) framework. MDPCO exploits distributed learning strategies and capitalizes on users’ mobility and demand information for proactive content offloading. Extensive simulations are carried out to validate the efficacy of MDCPO against local and cloud-based models. Our proposed model yields an average performance improvement of 6.7% in comparison to the cloud-based model. Furthermore, with the increase in the number of fog servers, the MDPCO achieves a 9.8% higher data offloading ratio and 1.18% increase in the downlink rates while being more energy-efficient than cloud-based approaches.

An energy efficient and scalable endpoint linked green content caching for Named Data Network based Internet of Things

Technology and applications of Internet of Things (IOT) is expanding. Large number of smart devices with networking capabilities, often called endpoints are part of IOT networks. These endpoints are typically resource constrained in terms of battery power and this impacts the endurance of IOT applications in operational field. Therefore, energy effciency of IOT networks is important. This paper employs content caching mechanism of Named Data Network (NDN) as leverage to propose a novel Endpoint Linked Green Content Caching scheme to reduce energy consumption in NDN based IOT network architectures. We implement a novel threshold based content offloading mechanism where endpoints can adapt to increase in content request rate in real time, conserve energy and collect metadata required to maintain the freshness of transient data. The proposed scheme achieved reduction in network energy consumption in the range of 30%–57% and reduction in response time for content request in the range of 35%–75% when compared with different existing schemes. The strategy performed consistently when the number of nodes in the network was scaled.

Joint Power and Subchannel Allocation for Distributed Storage in Cellular-D2D Underlays.

Wireless distributed storage is beneficial in the provision of reliable content storage and offloading of cellular traffic. In this paper, we consider a cellular device-to-device (D2D) underlay-based wireless distributed storage system, in which the minimum storage regenerating (MSR) coding combined with the partial downloading scheme is employed. To alleviate burdens on insufficient cellular resources and improve spectral efficiency in densely deployed networks, multiple storage devices can simultaneously use the same uplink cellular subchannel under the non-orthogonal multiple access (NOMA) protocol. Our objective is to minimize the total transmission power for content reconstruction, while guaranteeing the signal-to-interference-plus-noise ratio (SINR) constraints for cellular users by jointly optimizing power and subchannel allocation. To tackle the non-convex combinational program, we decouple the original problem into two subproblems and propose two low-complexity algorithms to efficiently solve them, followed by a joint optimization, implemented by alternately updating the solutions to each subproblem. The numerical results illustrate that our proposed algorithms are capable of performing an exhaustive search with lower computation complexity, and the NOMA-enhanced scheme provides more transmission opportunities for neighbor storage devices, thus significantly reducing the total power consumption.

Cooperative content offloading scheme in air-ocean integrated networks

Cooperative content offloading scheme in air-ocean integrated networks

Blockchain-Inspired Secure Computation Offloading in a Vehicular Cloud Network

With the emergence of computation-intensive vehicular applications, computation offloading based on mobile-edge computing (MEC) has become a promising paradigm in resource-constrained vehicular cloud networks (VCNs). However, when doing computation offloading in a VCN, malicious service providers can cause serious security concerns on the content offloading. To address that in this article, a blockchain-based secure computation offloading scheduling scheme is proposed. It embraces the blockchain-based trust management paradigm and smart contract-enabled deep reinforcement learning (DRL) algorithm. As for the trust management, the long-term reputation and short-term trust variability are jointly considered. Specifically, a novel three-valued subjective logic (3VSL) scheme is adopted to obtain a more comprehensive reputation, and the statistics of behavioral transitions can provide a short-term trust variability to timely capture the malicious behaviors. In addition, to securely update, validate, and store the trust information, we propose a hierarchical blockchain framework that comprises vehicular blockchain, roadside unit (RSU) blockchain, and cloud blockchain. Furthermore, a smart contract-enabled DRL algorithm is proposed to implement the secure and intelligent computation offloading scheduling in a VCN. Simulations are conducted to verify the effectiveness of the proposed scheme.

DAGIoV: A Framework for Vehicle to Vehicle Communication Using Directed Acyclic Graph and Game Theory

Data sharing and content offloading among vehicles is an imperative part of the Internet of Vehicles (IoV). A peer-to-peer connection among vehicles in a distributed manner is a highly promising solution for fast communication among vehicles. To ensure security and data tracking, existing studies use blockchain as a solution. The Blockchain-enabled Internet of Vehicles (BIoV) requires high computation power for the miners to mine the blocks and let the chain grow. Over and above, the blockchain consensus is probabilistic and the block generated today can be eventually declared as a fork and can be pruned from the chain. This reduces the overall efficiency of the protocol because the correct work done initially is eventually not used if it becomes a fork. To address these challenges, in this paper, we propose a Directed Acyclic Graph enabled IoV (DAGIoV) framework. We make use of a tangle data structure where each node acts as a miner and eventually the network achieves consensus among the nodes. A game-theoretic approach is used to model the interactions between the vehicles providing and consuming offloading services. The proposed model is proven to be highly scalable and well suited for microtransactions or frequent data transfer among the nodes in the vehicular network.

Social Community-Aware Content Placement in Wireless Device-to-Device Communication Networks

In this paper, a novel framework for optimizing the caching of popular user content at the level of wireless user equipments (UEs) is proposed. The goal is to improve content offloading over wireless device-to-device (D2D) communication links. In the considered network, users belong to different social communities while their UEs form a single multi-hop D2D network. The proposed framework allows us to exploit the multi-community social context of users for improving the local offloading of cached content in a multi-hop D2D network. To model the collaborative effect of a set of UEs on content offloading, a cooperative game between the UEs is formulated. For this game, it is shown that the Shapley value (SV) of each UE effectively captures the impact of this UE on the overall content offloading process. To capture the presence of multiple social communities that connect the UEs, a hypergraph model is proposed. Two line graphs, an influence-weighted graph, and a connectivity-weighted graph, are developed for analyzing the proposed hypergaph model. Using the developed line graphs along with the SV of the cooperative game, a precise offloading power metric is derived for each UE within a multi-community, multi-hop D2D network. Then, UEs with high offloading power are chosen as the optimal locations for caching the popular content. Simulation results show that, on the average, the proposed cache placement framework achieves 12, 19, and 21 percent improvements in terms of the number of UEs that received offloaded popular content compared to the schemes based on betweenness, degree, and closeness centrality, respectively.

Cooperative Crossing Cache Placement in Cache-Enabled Device to Device-Aided Cellular Networks

In cache-enabled device-to-device (D2D) -aided cellular networks, the technique of caching contents in the cooperative crossing between base stations (BSs) and devices can significantly reduce core traffic and enhance network capacity. In this paper, we propose a scheme that establishes device availability, which indicates whether a cache-enabled device can handle the transmission of the desired content within the required sending time, called the delay, while achieving optimal probabilistic caching. We also investigate the impact of transmission device availability on the effectiveness of a scenario of cooperative crossing cache placement, where content delivery traffic can be offloaded from the local cache, a D2D transmitter’s cache via a D2D link, or else directly from a BS via a cellular link, in order to maximize the offloading probability. Further, we derive the cooperation content offloading strategy while considering successful content transmission by D2D transmitters or BSs to guarantee the delay, even though reducing the delay is not the focus of this study. Finally, the proposed problem is formulated. Owing to the non-convexity of the optimization problem, it can be rewritten as a minimization of the difference between the convex functions; thus, it can be solved by difference of convex (DC) programming using a low-complexity algorithm. Simulation results show that the proposed cache placement scheme improves the offloading probability by 13.5% and 23% compared to Most Popular Content (MPC) scheme, in which both BSs and devices cache the most popular content and Coop. BS/D2D caching scheme, in which each BS tier and user tier applies cooperative content caching separately.

Edge-CoCaCo: Toward Joint Optimization of Computation, Caching, and Communication on Edge Cloud

With the development of recent innovative applications (e.g., augmented reality, natural language processing, and various cognitive applications), more and more computation-intensive and rich-media tasks are delay-sensitive. Edge cloud computing is expected to be an effective solution to meet the demand for low latency. By the use of content offloading and/or computation offloading, users' quality of experience is improved with shorter delay. Compared to existing edge computing solutions, this article introduces a new concept of computing task caching and gives the optimal computing task caching policy. Furthermore, joint optimization of computation, caching, and communication on the edge cloud, dubbed Edge-CoCaCo, is proposed. Then we give the solution to that optimization problem. Finally, the simulation experimental results show that compared to the other schemes, Edge-CoCaCo has shorter delay.

Bus-based content offloading for vehicular networks

Vehicular ad hoc networks (VANETs) represent the promising technologies for comfort driving and infotainment applications which rely heavily on the content offloading. Due to the rapid change of network topology and intermittent connection, it is a big challenge to satisfy the content requests from multi-sedans at the same time. This paper proposes a bus-based content offloading (BBCO) algorithm which aims to maximize the volume of offloaded content from bus to sedans while the offloading opportunity fairness of each sedan is also taken into consideration. By predicting the number of buses which the sedan would encounter in its future path and estimating the transmission rate, the BBCO algorithm schedules the content offloading service for sedans slot by slot to maximize the offloaded content volume and guarantee the offloading opportunity fairness. The effectiveness of the proposed algorithm is evaluated by extensive simulations.

Integrity-Oriented Content Offloading in Vehicular Sensor Network

In this paper, an integrity-oriented content offloading ( ICO ) problem with variable modulation and coding schemes is proposed for relay-assisted vehicular sensor network. To accurately describe the link duration properties, a finite-state Markov chain-based model is built by jointly considering the mobility and radio propagation characteristics. Considering the ICO problem is NP-hard, our solution divides it into two offloading sub-problems with direct link and relay-assisted path, respectively. These two sub-problems are solved heuristically, and the corresponding results are combined to achieve a near-optimal result as the ICO scheme. While the analytical model is validated by Monte Carlo simulations and chi-square goodness fit test, the performance of our proposed ICO scheme is verified through simulations and comparisons, showing that our ICO solution can reduce the integral content offloading time compared with two other selected schemes and an upper performance bound.

SCORE: Exploiting Global Broadcasts to Create Offline Personal Channels for On-Demand Access

The last 5 years have seen a dramatic shift in media distribution. For decades, TV and radio were solely provisioned using push-based broadcast technologies, forcing people to adhere to fixed schedules. The introduction of catch-up services, however, has now augmented such delivery with online pull-based alternatives. Typically, these allow users to fetch content for a limited period after initial broadcast, allowing users flexibility in accessing content. Whereas previous work has investigated both of these technologies, this paper explores and contrasts them, focusing on the network consequences of moving towards this multifaceted delivery model. Using traces from nearly 6 million users of BBC iPlayer, one of the largest catch-up TV services, we study this shift from push- to pull-based access. We propose a novel technique for unifying both push- and pull-based delivery: the Speculative Content Offloading and Recording Engine (SCORE). SCORE operates as a set-top box, which interacts with both broadcast push and online pull services. Whenever users wish to access media, it automatically switches between these distribution mechanisms in an attempt to optimize energy efficiency and network resource utilization. SCORE also can predict user viewing patterns, automatically recording certain shows from the broadcast interface. Evaluations using our BBC iPlayer traces show that, based on parameter settings, an oracle with complete knowledge of user consumption can save nearly 77% of the energy, and over 90% of the peak bandwidth, of pure IP streaming. Optimizing for energy consumption, SCORE can recover nearly half of both traffic and energy savings.