14,266 research outputs found
A Survey on Device-to-Device Communication in Cellular Networks
Device-to-Device (D2D) communication was initially proposed in cellular
networks as a new paradigm to enhance network performance. The emergence of new
applications such as content distribution and location-aware advertisement
introduced new use-cases for D2D communications in cellular networks. The
initial studies showed that D2D communication has advantages such as increased
spectral efficiency and reduced communication delay. However, this
communication mode introduces complications in terms of interference control
overhead and protocols that are still open research problems. The feasibility
of D2D communications in LTE-A is being studied by academia, industry, and the
standardization bodies. To date, there are more than 100 papers available on
D2D communications in cellular networks and, there is no survey on this field.
In this article, we provide a taxonomy based on the D2D communicating spectrum
and review the available literature extensively under the proposed taxonomy.
Moreover, we provide new insights to the over-explored and under-explored areas
which lead us to identify open research problems of D2D communication in
cellular networks.Comment: 18 pages; 8 figures; Accepted for publication in IEEE Communications
Surveys and Tutorial
Wireless Network Design for Control Systems: A Survey
Wireless networked control systems (WNCS) are composed of spatially
distributed sensors, actuators, and con- trollers communicating through
wireless networks instead of conventional point-to-point wired connections. Due
to their main benefits in the reduction of deployment and maintenance costs,
large flexibility and possible enhancement of safety, WNCS are becoming a
fundamental infrastructure technology for critical control systems in
automotive electrical systems, avionics control systems, building management
systems, and industrial automation systems. The main challenge in WNCS is to
jointly design the communication and control systems considering their tight
interaction to improve the control performance and the network lifetime. In
this survey, we make an exhaustive review of the literature on wireless network
design and optimization for WNCS. First, we discuss what we call the critical
interactive variables including sampling period, message delay, message
dropout, and network energy consumption. The mutual effects of these
communication and control variables motivate their joint tuning. We discuss the
effect of controllable wireless network parameters at all layers of the
communication protocols on the probability distribution of these interactive
variables. We also review the current wireless network standardization for WNCS
and their corresponding methodology for adapting the network parameters.
Moreover, we discuss the analysis and design of control systems taking into
account the effect of the interactive variables on the control system
performance. Finally, we present the state-of-the-art wireless network design
and optimization for WNCS, while highlighting the tradeoff between the
achievable performance and complexity of various approaches. We conclude the
survey by highlighting major research issues and identifying future research
directions.Comment: 37 pages, 17 figures, 4 table
DynaChanAl: Dynamic Channel Allocation with Minimal End-to-end Delay for Wireless Sensor Networks
With recent advances in wireless communication, networking, and low power
sensor technology, wireless sensor network (WSN) systems have begun to take
significant roles in various applications ranging from environmental sensing to
mobile healthcare sensing. While some WSN applications only require a lim- ited
amount of bandwidth, new emerging applications operate with a notice- ably
large amount of data transfers. One way to deal with such applications is to
maximize the available capacity by utilizing the use of multiple wireless
channels. This work proposes DynaChannAl, a distributed dynamic wireless
channel algorithm with the goal of effectively distributing nodes on multiple
wireless channels in WSN systems. Specifically, DynaChannAl targets applica-
tions where mobile nodes connect to a pre-existing wireless backbone and takes
the expected end-to-end queuing delay as its core metric. We use the link qual-
ity indicator (LQI) values provided by IEEE 802.15.4 radios white-list
potential links with good link quality and evaluate such links with the
aggregated packet transmission latency at each hop. Our approach is useful for
applications that require minimal end-to-end delay (i.e., healthcare
applications). DynaChannAl is a light weight and highly adoptable scheme that
can be easily incorporated with various pre-developed components and
pre-deployed applications. We eval- uate DynaChannAl in on a 45 node WSN
testbed. As the first study to consider end-to-end latency as the core metric
for channel allocation in WSN systems, the experimental results indicate that
DynaChannAl successfully distributes multi- ple (mobile) source nodes on
different wireless channels and enables the nodes to select wireless channel
and links that can minimize the end-to-end latency
Applications of Deep Reinforcement Learning in Communications and Networking: A Survey
This paper presents a comprehensive literature review on applications of deep
reinforcement learning in communications and networking. Modern networks, e.g.,
Internet of Things (IoT) and Unmanned Aerial Vehicle (UAV) networks, become
more decentralized and autonomous. In such networks, network entities need to
make decisions locally to maximize the network performance under uncertainty of
network environment. Reinforcement learning has been efficiently used to enable
the network entities to obtain the optimal policy including, e.g., decisions or
actions, given their states when the state and action spaces are small.
However, in complex and large-scale networks, the state and action spaces are
usually large, and the reinforcement learning may not be able to find the
optimal policy in reasonable time. Therefore, deep reinforcement learning, a
combination of reinforcement learning with deep learning, has been developed to
overcome the shortcomings. In this survey, we first give a tutorial of deep
reinforcement learning from fundamental concepts to advanced models. Then, we
review deep reinforcement learning approaches proposed to address emerging
issues in communications and networking. The issues include dynamic network
access, data rate control, wireless caching, data offloading, network security,
and connectivity preservation which are all important to next generation
networks such as 5G and beyond. Furthermore, we present applications of deep
reinforcement learning for traffic routing, resource sharing, and data
collection. Finally, we highlight important challenges, open issues, and future
research directions of applying deep reinforcement learning.Comment: 37 pages, 13 figures, 6 tables, 174 reference paper
Joint Rate Control and Power Allocation for Non-Orthogonal Multiple Access Systems
This paper investigates the optimal resource allocation of a downlink
non-orthogonal multiple access (NOMA) system consisting of one base station and
multiple users. Unlike existing short-term NOMA designs that focused on the
resource allocation for only the current transmission timeslot, we aim to
maximize a long-term network utility by jointly optimizing the data rate
control at the network layer and the power allocation among multiple users at
the physical layer, subject to practical constraints on both the short-term and
long-term power consumptions. To solve this problem, we leverage the
recently-developed Lyapunov optimization framework to convert the original
long-term optimization problem into a series of online rate control and power
allocation problems in each timeslot. The power allocation problem, however, is
shown to be non-convex in nature and thus cannot be solved with a standard
method. However, we explore two structures of the optimal solution and develop
a dynamic programming based power allocation algorithm, which can derive a
globally optimal solution, with a polynomial computational complexity.
Extensive simulation results are provided to evaluate the performance of the
proposed joint rate control and power allocation framework for NOMA systems,
which demonstrate that the proposed NOMA design can significantly outperform
multiple benchmark schemes, including orthogonal multiple access (OMA) schemes
with optimal power allocation and NOMA schemes with non-optimal power
allocation, in terms of average throughput and data delay.Comment: Accepted to appear in IEEE Journal on Selected Areas in
Communications (JSAC
A Survey on Low Latency Towards 5G: RAN, Core Network and Caching Solutions
The fifth generation (5G) wireless network technology is to be standardized
by 2020, where main goals are to improve capacity, reliability, and energy
efficiency, while reducing latency and massively increasing connection density.
An integral part of 5G is the capability to transmit touch perception type
real-time communication empowered by applicable robotics and haptics equipment
at the network edge. In this regard, we need drastic changes in network
architecture including core and radio access network (RAN) for achieving
end-to-end latency on the order of 1 ms. In this paper, we present a detailed
survey on the emerging technologies to achieve low latency communications
considering three different solution domains: RAN, core network, and caching.
We also present a general overview of 5G cellular networks composed of software
defined network (SDN), network function virtualization (NFV), caching, and
mobile edge computing (MEC) capable of meeting latency and other 5G
requirements.Comment: Accepted in IEEE Communications Surveys and Tutorial
Aerial-Terrestrial Communications: Terrestrial Cooperation and Energy-Efficient Transmissions to Aerial-Base Stations
Hybrid aerial-terrestrial communication networks based on Low Altitude
Platforms (LAPs) are expected to optimally meet the urgent communication needs
of emergency relief and recovery operations for tackling large scale natural
disasters. The energy-efficient operation of such networks is important given
the fact that the entire network infrastructure, including the battery operated
ground terminals, exhibits requirements to operate under power-constrained
situations. In this paper, we discuss the design and evaluation of an adaptive
cooperative scheme intended to extend the survivability of the battery operated
aerial-terrestrial communication links. We propose and evaluate a real-time
adaptive cooperative transmission strategy for dynamic selection between direct
and cooperative links based on the channel conditions for improved energy
efficiency. We show that the cooperation between mobile terrestrial terminals
on the ground could improve the energy efficiency in the uplink depending on
the temporal behavior of the terrestrial and the aerial uplink channels. The
corresponding delay in having cooperative (relay-based) communications with
relay selection is also addressed. The simulation analysis corroborates that
the adaptive transmission technique improves the overall energy efficiency of
the network whilst maintaining low latency enabling real time applications.Comment: To Appear In IEEE Transactions On Aerospace And Electronic Systems,
201
Distortion-Aware Concurrent Multipath Transfer for Mobile Video Streaming in Heterogeneous Wireless Networks
The massive proliferation of wireless infrastructures with complementary
characteristics prompts the bandwidth aggregation for Concurrent Multipath
Transfer (CMT) over heterogeneous access networks. Stream Control Transmission
Protocol (SCTP) is the standard transport-layer solution to enable CMT in
multihomed communication environments. However, delivering high-quality
streaming video with the existing CMT solutions still remains problematic due
to the stringent QoS (Quality of Service) requirements and path asymmetry in
heterogeneous wireless networks. In this paper, we advance the state of the art
by introducing video distortion into the decision process of multipath data
transfer. The proposed Distortion-Aware Concurrent Multipath Transfer (CMT-DA)
solution includes three phases: 1) per-path status estimation and congestion
control; 2) quality-optimal video flow rate allocation; 3) delay and loss
controlled data retransmission. The term `flow rate allocation' indicates
dynamically picking appropriate access networks and assigning the transmission
rates. We analytically formulate the data distribution over multiple
communication paths to minimize the end-to-end video distortion and derive the
solution based on the utility maximization theory. The performance of the
proposed CMT-DA is evaluated through extensive semi-physical emulations in
Exata involving H.264 video streaming. Experimental results show that CMT-DA
outperforms the reference schemes in terms of video PSNR (Peak Signal-to-Noise
Ratio), goodput, and inter-packet delay.Comment: This paper has already accepted for publication in IEEE Transactions
on Mobile Computing on Jun, 23rd, 201
Reliable Wireless Multi-Hop Networks with Decentralized Slot Management: An Analysis of IEEE 802.15.4 DSME
Wireless communication is a key element in the realization of the Industrial
Internet of Things for flexible and cost-efficient monitoring and control of
industrial processes. Wireless mesh networks using IEEE 802.15.4 have a high
potential for executing monitoring and control tasks with low energy
consumption and low costs for deployment and maintenance. However, conventional
medium access techniques based on carrier sensing cannot provide the required
reliability for industrial applications. Therefore, the standard was extended
with techniques for time-slotted medium access on multiple channels. In this
paper, we present openDSME, a comprehensive implementation of the Deterministic
and Synchronous Multi-channel Extension (DSME) and propose a method for
traffic-aware and decentralized slot scheduling to enable scalable wireless
industrial networks. The performance of DSME and our implementation is
demonstrated in the OMNeT++ simulator and on a physically deployed wireless
network in the FIT/IoT-LAB. It is shown that in the given scenarios, twice as
much traffic can be delivered reliably by using DSME instead of CSMA/CA and
that the energy consumption can be reduced significantly. The paper is
completed by presenting important trade-offs for parameter selection and by
uncovering open issues of the current specification that call for further
effort in research and standardization.Comment: 27 pages, 18 figure
Leveraging One-hop Information in Massive MIMO Full-Duplex Wireless Systems
We consider a single-cell massive MIMO full-duplex wireless communication
system, where the base-station (BS) is equipped with a large number of
antennas. We consider the setup where the single-antenna mobile users operate
in half- duplex, while each antenna at the BS is capable of full-duplex
transmissions, i.e., it can transmit and receive simultaneously using the same
frequency spectrum. The fundamental challenge in this system is intra-cell
inter-node interference, generated by the transmissions of uplink users to the
receptions at the downlink users. The key operational challenge is estimating
and aggregating inter-mobile channel estimates, which can potentially overwhelm
any gains from full-duplex operation.
In this work, we propose a scalable and distributed scheme to optimally
manage the inter-node interference by utilizing a "one- hop information
architecture". In this architecture, the BS only needs to know the
signal-to-interference-plus-noise ratio (SINR) from the downlink users. Each
uplink user needs its own SINR, along with a weighted signal-plus-noise metric
from its one-hop neighboring downlink users, which are the downlink users that
it interferes with. The proposed one-hop information architecture does not
require any network devices to comprehensively gather the vast inter-node
interference channel knowledge, and hence significantly reduces the overhead.
Based on the one-hop information architecture, we design a distributed power
control algorithm and implement such architecture using overheard feedback
information. We show that, in typical asymptotic regimes with many users and
antennas, the proposed distributed power control scheme improves the overall
network utility and reduces the transmission power of the uplink users.Comment: Submitted to IEEE/ACM Transactions on Networkin
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