164 research outputs found
Cache replacement for transcoding proxy caching
© 2005 IEEE.In this paper, we address the problem of cache replacement for transcoding proxy caching. First, an efficient cache replacement algorithm is proposed. Our algorithm considers both the aggregate effect of caching multiple versions of the same multimedia object and cache consistency. Second, a complexity analysis is presented to show the efficiency of our algorithm. Finally, some preliminary simulation experiments are conducted to compare the performance of our algorithm with some existing algorithms. The results show that our algorithm outperforms others in terms of the various performance metrics.Keqiu Li, Keishi Tajima, Hong She
Coordinated en-route transcoding caching for tree networks
©2004 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.As transcoding caching is attracting an increasing amount of attention, it is important and necessary to find methods to distribute multiple versions of the same media object in the Internet. In this paper, we first present a mathematical model for the problem of optimally determining the locations in which to place multiple versions of the same media object in tree networks such that the specified objective is achieved. This problem is formulated as an optimization problem. Second, we propose a low-cost dynamic programming-based solution for solving this problem, by which the optimal locations are obtained. Finally, we evaluate our model on different performance metrics through extensive simulation experiments and compare the results of our model with those of existing models that consider transcoding caching either on a path or at individual nodes only.Keqiu Li, Hong She
Mobile-Based Video Caching Architecture Based on Billboard Manager
Video streaming services are very popular today. Increasingly, users can now
access multimedia applications and video playback wirelessly on their mobile
devices. However, a significant challenge remains in ensuring smooth and
uninterrupted transmission of almost any size of video file over a 3G network,
and as quickly as possible in order to optimize bandwidth consumption. In this
paper, we propose to position our Billboard Manager to provide an optimal
transmission rate to enable smooth video playback to a mobile device user
connected to a 3G network. Our work focuses on serving user requests by mobile
operators from cached resource managed by Billboard Manager, and transmitting
the video files from this pool. The aim is to reduce the load placed on
bandwidth resources of a mobile operator by routing away as much user requests
away from the internet for having to search a video and, subsequently, if
located, have it transferred back to the user.Comment: 8 pages, 1 figure, GridCom-201
Coffee: Cost-Effective Edge Caching for 360 Degree Live Video Streaming
While live 360 degree video streaming delivers immersive viewing experience,
it poses significant bandwidth and latency challenges for content delivery
networks. Edge servers are expected to play an important role in facilitating
live streaming of 360 degree videos. In this paper, we propose a novel
predictive edge caching algorithm (Coffee) for live 360 degree video that
employ collaborative FoV prediction and predictive tile prefetching to reduce
bandwidth consumption, streaming cost and improve the streaming quality and
robustness. Our light-weight caching algorithms exploit the unique tile
consumption patterns of live 360 degree video streaming to achieve high tile
caching gains. Through extensive experiments driven by real 360 degree video
streaming traces, we demonstrate that edge caching algorithms specifically
designed for live 360 degree video streaming can achieve high streaming cost
savings with small edge cache space consumption. Coffee, guided by viewer FoV
predictions, significantly reduces back-haul traffic up to 76% compared to
state-of-the-art edge caching algorithms. Furthermore, we develop a
transcoding-aware variant (TransCoffee) and evaluate it using comprehensive
experiments, which demonstrate that TransCoffee can achieve 63\% lower cost
compared to state-of-the-art transcoding-aware approaches
Transcoding proxy placement in en-route web caching
Copyright © 2004 IEEEWith the rapid growth of audio and video applications on the internet, caching media objects in transcoding proxies has become an important research topic in recent years. In this paper, we address the problem of finding the optimal locations for placing fixed number of transcoding proxies among the nodes in a network such that the specified objective is achieved. We present an original model for this problem, which makes transcoding proxy placement decisions on all the en-route nodes along the routing path in a coordinated way. In our model, proxy status information along the routing path of requests is used for optimally determining the locations for placing fixed number of transcoding proxies. We formulate this problem as an optimization problem and the optimal locations are obtained using a low-cost dynamic programming-based algorithm. We implement our algorithm and evaluate our model on different performance metrics through extensive simulation experiments. The implementation results show that our model significantly outperforms the random algorithm which places transcoding proxies among the nodes in a network randomly.Keqiu Li, Hong She
Hit Ratio Driven Mobile Edge Caching Scheme for Video on Demand Services
More and more scholars focus on mobile edge computing (MEC) technology,
because the strong storage and computing capabilities of MEC servers can reduce
the long transmission delay, bandwidth waste, energy consumption, and privacy
leaks in the data transmission process. In this paper, we study the cache
placement problem to determine how to cache videos and which videos to be
cached in a mobile edge computing system. First, we derive the video request
probability by taking into account video popularity, user preference and the
characteristic of video representations. Second, based on the acquired request
probability, we formulate a cache placement problem with the objective to
maximize the cache hit ratio subject to the storage capacity constraints.
Finally, in order to solve the formulated problem, we transform it into a
grouping knapsack problem and develop a dynamic programming algorithm to obtain
the optimal caching strategy. Simulation results show that the proposed
algorithm can greatly improve the cache hit ratio
Cooperative Multi-Bitrate Video Caching and Transcoding in Multicarrier NOMA-Assisted Heterogeneous Virtualized MEC Networks
Cooperative video caching and transcoding in mobile edge computing (MEC)
networks is a new paradigm for future wireless networks, e.g., 5G and 5G
beyond, to reduce scarce and expensive backhaul resource usage by prefetching
video files within radio access networks (RANs). Integration of this technique
with other advent technologies, such as wireless network virtualization and
multicarrier non-orthogonal multiple access (MC-NOMA), provides more flexible
video delivery opportunities, which leads to enhancements both for the
network's revenue and for the end-users' service experience. In this regard, we
propose a two-phase RAF for a parallel cooperative joint multi-bitrate video
caching and transcoding in heterogeneous virtualized MEC networks. In the cache
placement phase, we propose novel proactive delivery-aware cache placement
strategies (DACPSs) by jointly allocating physical and radio resources based on
network stochastic information to exploit flexible delivery opportunities.
Then, for the delivery phase, we propose a delivery policy based on the user
requests and network channel conditions. The optimization problems
corresponding to both phases aim to maximize the total revenue of network
slices, i.e., virtual networks. Both problems are non-convex and suffer from
high-computational complexities. For each phase, we show how the problem can be
solved efficiently. We also propose a low-complexity RAF in which the
complexity of the delivery algorithm is significantly reduced. A Delivery-aware
cache refreshment strategy (DACRS) in the delivery phase is also proposed to
tackle the dynamically changes of network stochastic information. Extensive
numerical assessments demonstrate a performance improvement of up to 30% for
our proposed DACPSs and DACRS over traditional approaches.Comment: 53 pages, 24 figure
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