2,783 research outputs found
Smart PIN: utility-based replication and delivery of multimedia content to mobile users in wireless networks
Next generation wireless networks rely on heterogeneous connectivity technologies to support various rich media services such as personal information storage, file sharing and multimedia streaming. Due to users’ mobility and dynamic characteristics of wireless networks, data availability in collaborating devices is a critical issue. In this context Smart PIN was proposed as a personal information network which focuses on performance of delivery and cost efficiency. Smart PIN uses a novel data replication scheme based on individual and overall system utility to best balance the requirements for static data and multimedia content delivery with variable device availability due to user mobility. Simulations show improved results in comparison with other general purpose data replication schemes in terms of data availability
Cooperative Caching and Transmission Design in Cluster-Centric Small Cell Networks
Wireless content caching in small cell networks (SCNs) has recently been
considered as an efficient way to reduce the traffic and the energy consumption
of the backhaul in emerging heterogeneous cellular networks (HetNets). In this
paper, we consider a cluster-centric SCN with combined design of cooperative
caching and transmission policy. Small base stations (SBSs) are grouped into
disjoint clusters, in which in-cluster cache space is utilized as an entity. We
propose a combined caching scheme where part of the available cache space is
reserved for caching the most popular content in every SBS, while the remaining
is used for cooperatively caching different partitions of the less popular
content in different SBSs, as a means to increase local content diversity.
Depending on the availability and placement of the requested content,
coordinated multipoint (CoMP) technique with either joint transmission (JT) or
parallel transmission (PT) is used to deliver content to the served user. Using
Poisson point process (PPP) for the SBS location distribution and a hexagonal
grid model for the clusters, we provide analytical results on the successful
content delivery probability of both transmission schemes for a user located at
the cluster center. Our analysis shows an inherent tradeoff between
transmission diversity and content diversity in our combined
caching-transmission design. We also study optimal cache space assignment for
two objective functions: maximization of the cache service performance and the
energy efficiency. Simulation results show that the proposed scheme achieves
performance gain by leveraging cache-level and signal-level cooperation and
adapting to the network environment and user QoS requirements.Comment: 13 pages, 10 figures, submitted for possible journal publicatio
Pricing and Resource Allocation via Game Theory for a Small-Cell Video Caching System
Evidence indicates that downloading on-demand videos accounts for a dramatic
increase in data traffic over cellular networks. Caching popular videos in the
storage of small-cell base stations (SBS), namely, small-cell caching, is an
efficient technology for reducing the transmission latency whilst mitigating
the redundant transmissions of popular videos over back-haul channels. In this
paper, we consider a commercialized small-cell caching system consisting of a
network service provider (NSP), several video retailers (VR), and mobile users
(MU). The NSP leases its SBSs to the VRs for the purpose of making profits, and
the VRs, after storing popular videos in the rented SBSs, can provide faster
local video transmissions to the MUs, thereby gaining more profits. We conceive
this system within the framework of Stackelberg game by treating the SBSs as a
specific type of resources. We first model the MUs and SBSs as two independent
Poisson point processes, and develop, via stochastic geometry theory, the
probability of the specific event that an MU obtains the video of its choice
directly from the memory of an SBS. Then, based on the probability derived, we
formulate a Stackelberg game to jointly maximize the average profit of both the
NSP and the VRs. Also, we investigate the Stackelberg equilibrium by solving a
non-convex optimization problem. With the aid of this game theoretic framework,
we shed light on the relationship between four important factors: the optimal
pricing of leasing an SBS, the SBSs allocation among the VRs, the storage size
of the SBSs, and the popularity distribution of the VRs. Monte-Carlo
simulations show that our stochastic geometry-based analytical results closely
match the empirical ones. Numerical results are also provided for quantifying
the proposed game-theoretic framework by showing its efficiency on pricing and
resource allocation.Comment: Accepted to appear in IEEE Journal on Selected Areas in
Communications, special issue on Video Distribution over Future Interne
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