5,322 research outputs found
Querying Zero-streaming Cameras
Low-cost cameras grow rapidly, producing colossal videos that enable powerful
analytics but also stress network and compute resources. An unexploited
opportunity is that most of the videos remain "cold" without ever being
queried. For resource efficiency, we advocate for these cameras to be
zero-streaming: they capture videos directly to their cheap local storage and
only communicate with the cloud when analytics is requested.
To this end, we present a system that spans the cloud and cameras. Our key
ideas are twofold. When capturing video frames, a camera learns accurate
knowledge on a sparse sample of frames, rather than learning inaccurate
knowledge on all frames; in executing one query, a camera processes frames in
multiple passes with multiple operators trained and picked by the cloud during
the query, rather than one pass processing with operator(s) decided ahead of
the query. On diverse queries over 15 videos and with typical wireless network
bandwidth and low-cost camera hardware, our system prototype runs at more than
100x video realtime. It outperforms competitive alternative designs by at least
4x and up to two orders of magnitude.Comment: Mengwei Xu and Tiantu Xu are co-primary authors. Xuanzhe Liu is the
corresponding autho
Situation-Aware Integration and Transmission of Safety Information for Smart Railway Vehicles
Recent trend of railway train development can be characterized in several
aspects : high speed, infortainment, intelligence in driving, and so on. In
particular, trend of high speed in driving is prominent and competition for
high speed amongst several techno-savvy countries is becoming severe. To
achieve high speed, engines or motors are distributed over multiple vehicles of
train to provide increased motive power, while a single engine or motor has
been mostly used for conventional trains. Increased speed and more complicated
powertrain system naturally incur much higher chance of massive accidents. From
this perspective, importance of proactive safety control before accident takes
place cannot be over-emphasized. To implement proactive safety control requires
situation-aware integration and transmission of safety information obtained
from IoT sensors. Types of critical IoT sensors depend on situational
conditions. Thus, integration and transmission of safety information should be
performed with IoT sensors providing the safety information proper for faced
situation. This brief paper is to devise a methodology how to operate IoT
sensor network enabling proactive safety control for railway vehicles and to
propose a queue management based medium access control scheme.Comment: 15 page
Predictive Green Wireless Access: Exploiting Mobility and Application Information
The ever increasing mobile data traffic and dense deployment of wireless
networks have made energy efficient radio access imperative. As networks are
designed to satisfy peak user demands, radio access energy can be reduced in a
number of ways at times of lower demand. This includes putting base stations
(BSs) to intermittent short sleep modes during low load, as well as adaptively
powering down select BSs completely where demand is low for prolonged time
periods. In order to fully exploit such energy conserving mechanisms, networks
should be aware of the user temporal and spatial traffic demands. To this end,
this article investigates the potential of utilizing predictions of user
location and application information as a means to energy saving. We discuss
the development of a predictive green wireless access (PreGWA) framework and
identify its key functional entities and their interaction. To demonstrate the
potential energy savings we then provide a case study on stored video streaming
and illustrate how exploiting predictions can minimize BS resource consumption
within a single cell, and across a network of cells. Finally, to emphasize the
practical potential of PreGWA, we present a distributed heuristic that reduces
resource consumption significantly without requiring considerable information
or signaling overhead
Energy-efficient Traffic Bypassing in LTE HetNets with Mobile Relays
One of the core technologies being standardized by 3GPP for LTE-A is the
introduction of Relay Nodes (RNs). RNs are intended for ensuring coverage at
cell edges as well as for the provision of enhanced capacity at hot spot areas.
An extension to this concept is the Mobile Relay (MR). MRs can be mounted on
vehicles and the original idea is to serve users inside high speed trains thus
counter fighting the inherent severe fading and vehicle penetration loss. In
this work we present a framework for exploiting Mobile Relay (MRs) even at low
speeds in urban environments for bypassing traffic from nearby users, either
within or outside the vehicles. In particular we show that apart from increased
capacity and good quality coverage this approach achieves important energy
savings for the mobile terminals.Comment: 6 pages, 6 figure
Toward Green Media Delivery: Location-Aware Opportunities and Approaches
Mobile media has undoubtedly become the predominant source of traffic in
wireless networks. The result is not only congestion and poor
Quality-of-Experience, but also an unprecedented energy drain at both the
network and user devices. In order to sustain this continued growth, novel
disruptive paradigms of media delivery are urgently needed. We envision that
two key contemporary advancements can be leveraged to develop greener media
delivery platforms: 1) the proliferation of navigation hardware and software in
mobile devices has created an era of location-awareness, where both the current
and future user locations can be predicted; and 2) the rise of context-aware
network architectures and self-organizing functionalities is enabling context
signaling and in-network adaptation. With these developments in mind, this
article investigates the opportunities of exploiting location-awareness to
enable green end-to-end media delivery. In particular, we discuss and propose
approaches for location-based adaptive video quality planning, in-network
caching, content prefetching, and long-term radio resource management. To
provide insights on the energy savings, we then present a cross-layer framework
that jointly optimizes resource allocation and multi-user video quality using
location predictions. Finally, we highlight some of the future research
directions for location-aware media delivery in the conclusion
Design Considerations for a 5G Network Architecture
The data rates of up to 10 GB/s will characterize 5G networks
telecommunications standards that are envisioned to replace the current 4G/IMT
standards. The number of network-connected devices is expected to be 7 trillion
by the end of this year and the traffic is expected to rise by an order of
magnitude in the next 8 years. It is expected that elements of 5G will be
rolled out by early 2020s to meet business and consumer demands as well as
requirements of the Internet of Things. China's Ministry of Industry and
Information Technology announced in September 2016 that the government-led 5G
Phase-1 tests of key wireless technologies for future 5G networks were
completed with satisfactory results. This paper presents an overview of the
challenges facing 5G before it can be implemented to meet expected requirements
of capacity, data rates, reduced latency, connectivity to massive number of
devices, reduced cost and energy, and appropriate quality of experience.Comment: 16 pages, 10 figure
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
Energy-Efficient Adaptive Video Transmission: Exploiting Rate Predictions in Wireless Networks
The unprecedented growth of mobile video traffic is adding significant
pressure to the energy drain at both the network and the end user. Energy
efficient video transmission techniques are thus imperative to cope with the
challenge of satisfying user demand at sustainable costs. In this paper, we
investigate how predicted user rates can be exploited for energy efficient
video streaming with the popular HTTP-based Adaptive Streaming (AS) protocols
(e.g. DASH). To this end, we develop an energy-efficient Predictive Green
Streaming (PGS) optimization framework that leverages predictions of wireless
data rates to achieve the following objectives 1) minimize the required
transmission airtime without causing streaming interruptions, 2) minimize total
downlink Base Station (BS) power consumption for cases where BSs can be
switched off in deep sleep, and 3) enable a trade-off between AS quality and
energy consumption. Our framework is first formulated as a Mixed Integer Linear
Program (MILP) where decisions on multi-user rate allocation, video segment
quality, and BS transmit power are jointly optimized. Then, to provide an
online solution, we present a polynomial-time heuristic algorithm that
decouples the PGS problem into multiple stages. We provide a performance
analysis of the proposed methods by simulations, and numerical results
demonstrate that the PGS framework yields significant energy savings.Comment: 14 pages, 14 figures, accepted for publication in IEEE Transactions
on Vehicular Technolog
A Survey on High-Speed Railway Communications: A Radio Resource Management Perspective
High-speed railway (HSR) communications will become a key feature supported
by intelligent transportation communication systems. The increasing demand for
HSR communications leads to significant attention on the study of radio
resource management (RRM), which enables efficient resource utilization and
improved system performance. RRM design is a challenging problem due to
heterogenous quality of service (QoS) requirements and dynamic characteristics
of HSR wireless communications. The objective of this paper is to provide an
overview on the key issues that arise in the RRM design for HSR wireless
communications. A detailed description of HSR communication systems is first
presented, followed by an introduction on HSR channel models and
characteristics, which are vital to the cross-layer RRM design. Then we provide
a literature survey on state-of-the-art RRM schemes for HSR wireless
communications, with an in-depth discussion on various RRM aspects including
admission control, mobility management, power control and resource allocation.
Finally, this paper outlines the current challenges and open issues in the area
of RRM design for HSR wireless communications.Comment: 40 pages, 10 figures. Submitted to Computer Communication
Artificial Intelligence-Defined 5G Radio Access Networks
Massive multiple-input multiple-output antenna systems, millimeter wave
communications, and ultra-dense networks have been widely perceived as the
three key enablers that facilitate the development and deployment of 5G
systems. This article discusses the intelligent agent in 5G base station which
combines sensing, learning, understanding and optimizing to facilitate these
enablers. We present a flexible, rapidly deployable, and cross-layer artificial
intelligence (AI)-based framework to enable the imminent and future demands on
5G and beyond infrastructure. We present example AI-enabled 5G use cases that
accommodate important 5G-specific capabilities and discuss the value of AI for
enabling beyond 5G network evolution
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