229,068 research outputs found
Feasibility Study of Enabling V2X Communications by LTE-Uu Radio Interface
Compared with the legacy wireless networks, the next generation of wireless
network targets at different services with divergent QoS requirements, ranging
from bandwidth consuming video service to moderate and low date rate machine
type services, and supporting as well as strict latency requirements. One
emerging new service is to exploit wireless network to improve the efficiency
of vehicular traffic and public safety. However, the stringent packet
end-to-end (E2E) latency and ultra-low transmission failure rates pose
challenging requirements on the legacy networks. In other words, the next
generation wireless network needs to support ultra-reliable low latency
communications (URLLC) involving new key performance indicators (KPIs) rather
than the conventional metric, such as cell throughput in the legacy systems. In
this paper, a feasibility study on applying today's LTE network infrastructure
and LTE-Uu air interface to provide the URLLC type of services is performed,
where the communication takes place between two traffic participants (e.g.,
vehicle-to-vehicle and vehicle-to-pedestrian). To carry out this study, an
evaluation methodology of the cellular vehicle-to-anything (V2X) communication
is proposed, where packet E2E latency and successful transmission rate are
considered as the key performance indicators (KPIs). Then, we describe the
simulation assumptions for the evaluation. Based on them, simulation results
are depicted that demonstrate the performance of the LTE network in fulfilling
new URLLC requirements. Moreover, sensitivity analysis is also conducted
regarding how to further improve system performance, in order to enable new
emerging URLLC services.Comment: Accepted by IEEE/CIC ICCC 201
A Novel Framework for Online Amnesic Trajectory Compression in Resource-constrained Environments
State-of-the-art trajectory compression methods usually involve high
space-time complexity or yield unsatisfactory compression rates, leading to
rapid exhaustion of memory, computation, storage and energy resources. Their
ability is commonly limited when operating in a resource-constrained
environment especially when the data volume (even when compressed) far exceeds
the storage limit. Hence we propose a novel online framework for error-bounded
trajectory compression and ageing called the Amnesic Bounded Quadrant System
(ABQS), whose core is the Bounded Quadrant System (BQS) algorithm family that
includes a normal version (BQS), Fast version (FBQS), and a Progressive version
(PBQS). ABQS intelligently manages a given storage and compresses the
trajectories with different error tolerances subject to their ages. In the
experiments, we conduct comprehensive evaluations for the BQS algorithm family
and the ABQS framework. Using empirical GPS traces from flying foxes and cars,
and synthetic data from simulation, we demonstrate the effectiveness of the
standalone BQS algorithms in significantly reducing the time and space
complexity of trajectory compression, while greatly improving the compression
rates of the state-of-the-art algorithms (up to 45%). We also show that the
operational time of the target resource-constrained hardware platform can be
prolonged by up to 41%. We then verify that with ABQS, given data volumes that
are far greater than storage space, ABQS is able to achieve 15 to 400 times
smaller errors than the baselines. We also show that the algorithm is robust to
extreme trajectory shapes.Comment: arXiv admin note: substantial text overlap with arXiv:1412.032
- …