210 research outputs found
On the Reliability of LTE Random Access: Performance Bounds for Machine-to-Machine Burst Resolution Time
Random Access Channel (RACH) has been identified as one of the major
bottlenecks for accommodating massive number of machine-to-machine (M2M) users
in LTE networks, especially for the case of burst arrival of connection
requests. As a consequence, the burst resolution problem has sparked a large
number of works in the area, analyzing and optimizing the average performance
of RACH. However, the understanding of what are the probabilistic performance
limits of RACH is still missing. To address this limitation, in the paper, we
investigate the reliability of RACH with access class barring (ACB). We model
RACH as a queuing system, and apply stochastic network calculus to derive
probabilistic performance bounds for burst resolution time, i.e., the worst
case time it takes to connect a burst of M2M devices to the base station. We
illustrate the accuracy of the proposed methodology and its potential
applications in performance assessment and system dimensioning.Comment: Presented at IEEE International Conference on Communications (ICC),
201
Priority-based initial access for URLLC traffic in massive IoT networks: Schemes and performance analysis
At a density of one million devices per square kilometer, the10’s of billions of devices, objects, and machines
that form a massive Internet of things (mIoT) require ubiquitous connectivity. Among a massive number of
IoT devices, a portion of them require ultra-reliable low latency communication (URLLC) provided via fifth
generation (5G) networks, bringing many new challenges due to the stringent service requirements. Albeit a surge
of research efforts on URLLC and mIoT, access mechanisms which include both URLLC and massive machine
type communications (mMTC) have not yet been investigated in-depth. In this paper, we propose three novel
schemes to facilitate priority-based initial access for mIoT/mMTC devices that require URLLC services while also
considering the requirements of other mIoT/mMTC devices. Based on a long term evolution-advanced (LTEA) or 5G new radio frame structure, the proposed schemes enable device grouping based on device vicinity
or/and their URLLC requirements and allocate dedicated preambles for grouped devices supported by flexible
slot allocation for random access. These schemes are able not only to increase the reliability and minimize the
delay of URLLC devices but also to improve the performance of all involved mIoT devices. Furthermore, we
evaluate the performance of the proposed schemes through mathematical analysis as well as simulations and
compare the results with the performance of both the legacy LTE-A based initial access scheme and a grant-free
transmission scheme.acceptedVersio
Performance Analysis for Bandwidth Allocation in IEEE 802.16 Broadband Wireless Networks using BMAP Queueing
This paper presents a performance analysis for the bandwidth allocation in
IEEE 802.16 broadband wireless access (BWA) networks considering the
packet-level quality-of-service (QoS) constraints. Adaptive Modulation and
Coding (AMC) rate based on IEEE 802.16 standard is used to adjust the
transmission rate adaptively in each frame time according to channel quality in
order to obtain multiuser diversity gain. To model the arrival process and the
traffic source we use the Batch Markov Arrival Process (BMAP), which enables
more realistic and more accurate traffic modelling. We determine analytically
different performance parameters, such as average queue length, packet dropping
probability, queue throughput and average packet delay. Finally, the analytical
results are validated numerically.Comment: 16 page
Wireless Network-Level Partial Relay Cooperation: A Stable Throughput Analysis
In this work, we study the benefit of partial relay cooperation. We consider
a two-node system consisting of one source and one relay node transmitting
information to a common destination. The source and the relay have external
traffic and in addition, the relay is equipped with a flow controller to
regulate the incoming traffic from the source node. The cooperation is
performed at the network level. A collision channel with erasures is
considered. We provide an exact characterization of the stability region of the
system and we also prove that the system with partial cooperation is always
better or at least equal to the system without the flow controller.Comment: Submitted for journal publication. arXiv admin note: text overlap
with arXiv:1502.0113
Exploiting the Capture Effect to Enhance RACH Performance in Cellular-Based M2M Communications
Cellular-based machine-to-machine (M2M) communication is expected to facilitate services for the Internet of Things (IoT). However, because cellular networks are designed for human users, they have some limitations. Random access channel (RACH) congestion caused by massive access from M2M devices is one of the biggest factors hindering cellular-based M2M services because the RACH congestion causes random access (RA) throughput degradation and connection failures to the devices. In this paper, we show the possibility exploiting the capture effects, which have been known to have a positive impact on the wireless network system, on RA procedure for improving the RA performance of M2M devices. For this purpose, we analyze an RA procedure using a capture model. Through this analysis, we examine the effects of capture on RA performance and propose an Msg3 power-ramping (Msg3 PR) scheme to increase the capture probability (thereby increasing the RA success probability) even when severe RACH congestion problem occurs. The proposed analysis models are validated using simulations. The results show that the proposed scheme, with proper parameters, further improves the RA throughput and reduces the connection failure probability, by slightly increasing the energy consumption. Finally, we demonstrate the effects of coexistence with other RA-related schemes through simulation results
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