1,182 research outputs found
Caching at the Edge with LT codes
We study the performance of caching schemes based on LT under peeling
(iterative) decoding algorithm. We assume that users ask for downloading
content to multiple cache-aided transmitters. Transmitters are connected
through a backhaul link to a master node while no direct link exists between
users and the master node. Each content is fragmented and coded with LT code.
Cache placement at each transmitter is optimized such that transmissions over
the backhaul link is minimized. We derive a closed form expression for the
calculation of the backhaul transmission rate. We compare the performance of a
caching scheme based on LT with respect to a caching scheme based on maximum
distance separable codes. Finally, we show that caching with \acl{LT} codes
behave as good as caching with maximum distance separable codes
Random Linear Network Coding for 5G Mobile Video Delivery
An exponential increase in mobile video delivery will continue with the
demand for higher resolution, multi-view and large-scale multicast video
services. Novel fifth generation (5G) 3GPP New Radio (NR) standard will bring a
number of new opportunities for optimizing video delivery across both 5G core
and radio access networks. One of the promising approaches for video quality
adaptation, throughput enhancement and erasure protection is the use of
packet-level random linear network coding (RLNC). In this review paper, we
discuss the integration of RLNC into the 5G NR standard, building upon the
ideas and opportunities identified in 4G LTE. We explicitly identify and
discuss in detail novel 5G NR features that provide support for RLNC-based
video delivery in 5G, thus pointing out to the promising avenues for future
research.Comment: Invited paper for Special Issue "Network and Rateless Coding for
Video Streaming" - MDPI Informatio
Enhancing multi-source content delivery in content-centric networks with fountain coding
Fountain coding has been considered as especially suitable for lossy environments, such as wireless networks, as it provides redundancy while reducing coordination overheads between sender(s) and receiver(s). As such it presents beneficial properties for multi-source and/or multicast communication. In this paper we investigate enhancing/increasing multi-source content delivery efficiency in the context of Content-Centric Networking (CCN) with the usage of fountain codes. In particular, we examine whether the combination of fountain coding with the in-network caching capabilities of CCN can further improve performance. We also present an enhancement of CCN's Interest forwarding mechanism that aims at minimizing duplicate transmissions that may occur in a multi-source transmission scenario, where all available content providers and caches with matching (cached) content transmit data packets simultaneously. Our simulations indicate that the use of fountain coding in CCN is a valid approach that further increases network performance compared to traditional schemes
Caching in Heterogeneous Networks
A promising solution in order to cope with the massive request of wireless data traffic
consists of having replicas of the potential requested content memorized across the
network. In cache-enabled heterogeneous networks, content is pre-fetched close to the
users during network off-peak periods in order to directly serve the users when the
network is congested. In fact, the main idea behind caching is the replacement of
backhaul capacity with storage capabilities, for example, at the edge of the network.
Caching content at the edge of heterogeneous networks not only leads to significantly
reduce the traffic congestion in the backhaul link but also leads to achieve higher
levels of energy efficiency. However, the good performance of a system foresees a deep
analysis of the possible caching techniques. Due to the physical limitation of the caches’
size and the excessive amount of content, the design of caching policies which define
how the content has to be cached and select the likely data to store is crucial.
Within this thesis, caching techniques for storing and delivering the content in
heterogeneous networks are investigated from two different aspects. The first part
of the thesis is focused on the reduction of the power consumption when the cached
content is delivered over an Gaussian interference channel and per-file rate constraints
are imposed. Cooperative approaches between the transmitters in order to mitigate
the interference experienced by the users are analyzed. Based on such approaches, the
caching optimization problem for obtaining the best cache allocation solution (in the
sense of minimizing the average power consumption) is proposed. The second part of
the thesis is focused on caching techniques at packet level with the aim of reducing
the transmissions from the core of an heterogeneous network. The design of caching
schemes based on rate-less codes for storing and delivering the cached content are
proposed. For each design, the placement optimization problem which minimizes the
transmission over the backhaul link is formulated
Efficient content delivery through fountain coding in opportunistic information-centric networks
Opportunistic networks can increase network capacity, support collaborative downloading of content and offload traffic from a cellular to a cellular-assisted, device-to-device network. They can also support communication and content exchange when the cellular infrastructure is under severe stress and when the network is down or inaccessible. Fountain coding has been considered as espe- cially suitable for lossy networks, providing reliable multicast transport without requiring feedback from receivers. It is also ideal for multi-path and multi- source communication that fits exceptionally well with opportunistic networks. In this paper, we propose a content-centric approach for disseminating con- tent in opportunistic networks efficiently and reliably. Our approach is based on Information-Centric Networking (ICN) and employs fountain coding. When tied together, ICN and fountain coding provide a comprehensive solution that overcomes significant limitations of existing approaches. Extensive network simulations indicate that our approach is viable. Cache hit ratio can be increased by up to five times, while the overall network traffic load is reduced by up to four times compared to content dissemination on top of the standard Named Data Networking architecture
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