28 research outputs found
Modeling and Analysis of Content Caching in Wireless Small Cell Networks
Network densification with small cell base stations is a promising solution
to satisfy future data traffic demands. However, increasing small cell base
station density alone does not ensure better users quality-of-experience and
incurs high operational expenditures. Therefore, content caching on different
network elements has been proposed as a mean of offloading he backhaul by
caching strategic contents at the network edge, thereby reducing latency. In
this paper, we investigate cache-enabled small cells in which we model and
characterize the outage probability, defined as the probability of not
satisfying users requests over a given coverage area. We analytically derive a
closed form expression of the outage probability as a function of
signal-to-interference ratio, cache size, small cell base station density and
threshold distance. By assuming the distribution of base stations as a Poisson
point process, we derive the probability of finding a specific content within a
threshold distance and the optimal small cell base station density that
achieves a given target cache hit probability. Furthermore, simulation results
are performed to validate the analytical model.Comment: accepted for publication, IEEE ISWCS 201
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
A Survey on Caching in Distributed Small Cell Networks
The exponential growth of mobile devices such as smartphones and tablets, coupled with proliferation of online social networks has considerably increased the traffic in cellular networks. In contrast to classical cellular traffic that was only based on voice and audio communications, the recent technologies have resulted in bandwidth-intensive services such as video streaming, and video conferencing increases the traffic among users. This traffic surge affects the capacity of existing wireless networks which makes it difficult to ensure the high quality-of-service (QoS) required by the cellular services. In order to handle with the limited capacity of existing cellular networks and keep up with the strict QoS requirements, in terms of data rate and delay tolerable application-specific delays, a new generation of wireless networks has emerged. To achieve the requirements of this new generation and provide efficient infrastructure support for this data deluge, several research challenges must be addressed and solved. In this paper a survey on literature about small cell networks in distributed environment is presented which focus on caching aspect to improve the performance. The related work for caching in distributed small cell networks is also presented
Mean-Field Games for Distributed Caching in Ultra-Dense Small Cell Networks
In this paper, the problem of distributed caching in dense wireless small
cell networks (SCNs) is studied using mean field games (MFGs). In the
considered SCN, small base stations (SBSs) are equipped with data storage units
and cooperate to serve users' requests either from files cached in the storage
or directly from the capacity-limited backhaul. The aim of the SBSs is to
define a caching policy that reduces the load on the capacity-limited backhaul
links. This cache control problem is formulated as a stochastic differential
game (SDG). In this game, each SBS takes into consideration the storage state
of the other SBSs to decide on the fraction of content it should cache. To
solve this problem, the formulated SDG is reduced to an MFG by considering an
ultra-dense network of SBSs in which the existence and uniqueness of the
mean-field equilibrium is shown to be guaranteed. Simulation results show that
this framework allows an efficient use of the available storage space at the
SBSs while properly tracking the files' popularity. The results also show that,
compared to a baseline model in which SBSs are not aware of the instantaneous
system state, the proposed framework increases the number of served files from
the SBSs by more than 69%.Comment: Accepted for publication at American Control Conference 201
On the Benefits of Edge Caching for MIMO Interference Alignment
In this contribution, we jointly investigate the benefits of caching and
interference alignment (IA) in multiple-input multiple-output (MIMO)
interference channel under limited backhaul capacity. In particular, total
average transmission rate is derived as a function of various system parameters
such as backhaul link capacity, cache size, number of active
transmitter-receiver pairs as well as the quantization bits for channel state
information (CSI). Given the fact that base stations are equipped both with
caching and IA capabilities and have knowledge of content popularity profile,
we then characterize an operational regime where the caching is beneficial.
Subsequently, we find the optimal number of transmitter-receiver pairs that
maximizes the total average transmission rate. When the popularity profile of
requested contents falls into the operational regime, it turns out that caching
substantially improves the throughput as it mitigates the backhaul usage and
allows IA methods to take benefit of such limited backhaul.Comment: 20 pages, 5 figures. A shorter version is to be presented at 16th
IEEE International Workshop on Signal Processing Advances in Wireless
Communications (SPAWC'2015), Stockholm, Swede
Cross-Layer Optimization of Fast Video Delivery in Cache-Enabled Relaying Networks
This paper investigates the cross-layer optimization of fast video delivery
and caching for minimization of the overall video delivery time in a two-hop
relaying network. The half-duplex relay nodes are equipped with both a cache
and a buffer which facilitate joint scheduling of fetching and delivery to
exploit the channel diversity for improving the overall delivery performance.
The fast delivery control is formulated as a two-stage functional non-convex
optimization problem. By exploiting the underlying convex and quasi-convex
structures, the problem can be solved exactly and efficiently by the developed
algorithm. Simulation results show that significant caching and buffering gains
can be achieved with the proposed framework, which translates into a reduction
of the overall video delivery time. Besides, a trade-off between caching and
buffering gains is unveiled.Comment: 7 pages, 4 figures; accepted for presentation at IEEE Globecom, San
Diego, CA, Dec. 201