2,243 research outputs found
Popularity-based video caching techniques for cache-enabled networks: a survey
The proliferation of the mobile Internet and connected devices, which offer a variety of services at different levels of performance is a major challenge for the fifth generation of wireless networks and beyond. Innovative solutions are needed to leverage recent advances in machine storage/memory, context awareness, and edge computing. Cache-enabled networks and techniques such as edge caching are envisioned to reduce content delivery times and traffic congestion in wireless networks. Only a few contents are popular, accounting for the majority of viewers, so caching them reduces the latency and download time. However, given the dynamic nature of user behavior, the integration of popularity prediction into caching is of paramount importance to better network utilization and user satisfaction. In this paper, we first present an overview of caching in wireless networks and then provide a detailed comparison of traditional and popularity-based caching. We discuss the attributes of videos and the evaluation criteria of caching policies. We summarize some of the recent work on proactive caching, focusing on prediction strategies. Finally, we provide insight into the potential opportunities and challenges as well as some open research problems enable the realization of efficient deployment of popularity-based caching as part of the next-generation mobile networks
Proactive multi-tenant cache management for virtualized ISP networks
The content delivery market has mainly been dominated by large Content Delivery Networks (CDNs) such as Akamai and Limelight. However, CDN traffic exerts a lot of pressure on Internet Service Provider (ISP) networks. Recently, ISPs have begun deploying so-called Telco CDNs, which have many advantages, such as reduced ISP network bandwidth utilization and improved Quality of Service (QoS) by bringing content closer to the end-user. Virtualization of storage and networking resources can enable the ISP to simultaneously lease its Telco CDN infrastructure to multiple third parties, opening up new business models and revenue streams. In this paper, we propose a proactive cache management system for ISP-operated multi-tenant Telco CDNs. The associated algorithm optimizes content placement and server selection across tenants and users, based on predicted content popularity and the geographical distribution of requests. Based on a Video-on-Demand (VoD) request trace of a leading European telecom operator, the presented algorithm is shown to reduce bandwidth usage by 17% compared to the traditional Least Recently Used (LRU) caching strategy, both inside the network and on the ingress links, while at the same time offering enhanced load balancing capabilities. Increasing the prediction accuracy is shown to have the potential to further improve bandwidth efficiency by up to 79%
A Bayesian Poisson-Gaussian Process Model for Popularity Learning in Edge-Caching Networks
Edge-caching is recognized as an efficient technique for future cellular
networks to improve network capacity and user-perceived quality of experience.
To enhance the performance of caching systems, designing an accurate content
request prediction algorithm plays an important role. In this paper, we develop
a flexible model, a Poisson regressor based on a Gaussian process, for the
content request distribution.
The first important advantage of the proposed model is that it encourages the
already existing or seen contents with similar features to be correlated in the
feature space and therefore it acts as a regularizer for the estimation.
Second, it allows to predict the popularities of newly-added or unseen contents
whose statistical data is not available in advance. In order to learn the model
parameters, which yield the Poisson arrival rates or alternatively the content
\textit{popularities}, we invoke the Bayesian approach which is robust against
over-fitting.
However, the resulting posterior distribution is analytically intractable to
compute. To tackle this, we apply a Markov Chain Monte Carlo (MCMC) method to
approximate this distribution which is also asymptotically exact. Nevertheless,
the MCMC is computationally demanding especially when the number of contents is
large. Thus, we employ the Variational Bayes (VB) method as an alternative low
complexity solution. More specifically, the VB method addresses the
approximation of the posterior distribution through an optimization problem.
Subsequently, we present a fast block-coordinate descent algorithm to solve
this optimization problem. Finally, extensive simulation results both on
synthetic and real-world datasets are provided to show the accuracy of our
prediction algorithm and the cache hit ratio (CHR) gain compared to existing
methods from the literature
A Feature-Based Bayesian Method for Content Popularity Prediction in Edge-Caching Networks
Edge-caching is recognized as an efficient technique for future wireless
cellular networks to improve network capacity and user-perceived quality of
experience. Due to the random content requests and the limited cache memory,
designing an efficient caching policy is a challenge. To enhance the
performance of caching systems, an accurate content request prediction
algorithm is essential. Here, we introduce a flexible model, a Poisson
regressor based on a Gaussian process, for the content request distribution in
stationary environments. Our proposed model can incorporate the content
features as side information for prediction enhancement. In order to learn the
model parameters, which yield the Poisson rates or alternatively content
popularities, we invoke the Bayesian approach which is very robust against
over-fitting.
However, the posterior distribution in the Bayes formula is analytically
intractable to compute. To tackle this issue, we apply a Monte Carlo Markov
Chain (MCMC) method to approximate the posterior distribution. Two types of
predictive distributions are formulated for the requests of existing contents
and for the requests of a newly-added content. Finally, simulation results are
provided to confirm the accuracy of the developed content popularity learning
approach.Comment: arXiv admin note: substantial text overlap with arXiv:1903.0306
A Transfer Learning Approach for Cache-Enabled Wireless Networks
Locally caching contents at the network edge constitutes one of the most
disruptive approaches in G wireless networks. Reaping the benefits of edge
caching hinges on solving a myriad of challenges such as how, what and when to
strategically cache contents subject to storage constraints, traffic load,
unknown spatio-temporal traffic demands and data sparsity. Motivated by this,
we propose a novel transfer learning-based caching procedure carried out at
each small cell base station. This is done by exploiting the rich contextual
information (i.e., users' content viewing history, social ties, etc.) extracted
from device-to-device (D2D) interactions, referred to as source domain. This
prior information is incorporated in the so-called target domain where the goal
is to optimally cache strategic contents at the small cells as a function of
storage, estimated content popularity, traffic load and backhaul capacity. It
is shown that the proposed approach overcomes the notorious data sparsity and
cold-start problems, yielding significant gains in terms of users'
quality-of-experience (QoE) and backhaul offloading, with gains reaching up to
in a setting consisting of four small cell base stations.Comment: some small fixes in notatio
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