2 research outputs found
Optimizing Joint Probabilistic Caching and Communication for Clustered D2D Networks
Caching at mobile devices and leveraging device-to-device (D2D) communication
are two promising approaches to support massive content delivery over wireless
networks. The analysis of such D2D caching networks based on a physical
interference model is usually carried out by assuming that devices are
uniformly distributed. However, this approach does not fully consider and
characterize the fact that devices are usually grouped into clusters. Motivated
by this fact, this paper presents a comprehensive performance analysis and
joint communication and caching optimization for a clustered D2D network.
Devices are distributed according to a Thomas cluster process (TCP) and are
assumed to have a surplus memory which is exploited to proactively cache files
from a known library, following a random probabilistic caching scheme. Devices
can retrieve the requested files from their caches, from neighbouring devices
in their proximity (cluster), or from the base station as a last resort. Three
key performance metrics are optimized in this paper, namely, the offloading
gain, energy consumption, and latency
Optimized Caching and Spectrum Partitioning for D2D enabled Cellular Systems with Clustered Devices
Caching at mobile devices and leveraging device- to-device (D2D)
communication are two promising approaches to support massive content delivery
over wireless networks. The analysis of cache-enabled wireless networks is
usually carried out by assuming that devices are uniformly distributed,
however, in social networks, mobile devices are intrinsically grouped into
disjoint clusters. In this regards, this paper proposes a spatiotemporal
mathematical model that tracks the service requests arrivals and account for
the clustered devices geometry. Two kinds of devices are assumed, particularly,
content clients and content providers. Content providers are assumed to have a
surplus memory which is exploited to proactively cache contents from a known
library, following a random probabilistic caching scheme. Content clients can
retrieve a requested content from the nearest content provider in their
proximity (cluster), or, as a last resort, the base station (BS). The developed
spatiotemporal model is leveraged to formulate a joint optimization problem of
the content caching and spectrum partitioning in order to minimize the average
service delay. Due to the high complexity of the optimization problem, the
caching and spectrum partitioning problems are decoupled and solved iteratively
using the block coordinate descent (BCD) optimization technique. To this end,
an optimal and suboptimal solutions are obtained for the bandwidth partitioning
and probabilistic caching subproblems, respectively. Numerical results
highlight the superiority of the proposed scheme over conventional caching
schemes under equal and optimized bandwidth allocations. Particularly, it is
shown that the average service delay is reduced by nearly 100% and 350%,
compared to the Zipf and uniform caching schemes under equal bandwidth
allocations, respectively