21,999 research outputs found
Congestion Control for Machine-Type Communications in LTE-A Networks
Collecting data from a tremendous amount of Internet-of-Things (IoT) devices for next generation networks is a big challenge. A large number of devices may lead to severe congestion in Radio Access Network (RAN) and Core Network (CN). 3GPP has specified several mechanisms to handle the congestion caused by massive amounts of devices. However, detailed settings and strategies of them are not defined in the standards and are left for operators. In this paper, we propose two congestion control algorithms which efficiently reduce the congestion. Simulation results demonstrate that the proposed algorithms can achieve 20~40% improvement regarding accept ratio, overload degree and waiting time compared with those in LTE-A
SymbioCity: Smart Cities for Smarter Networks
The "Smart City" (SC) concept revolves around the idea of embodying
cutting-edge ICT solutions in the very fabric of future cities, in order to
offer new and better services to citizens while lowering the city management
costs, both in monetary, social, and environmental terms. In this framework,
communication technologies are perceived as subservient to the SC services,
providing the means to collect and process the data needed to make the services
function. In this paper, we propose a new vision in which technology and SC
services are designed to take advantage of each other in a symbiotic manner.
According to this new paradigm, which we call "SymbioCity", SC services can
indeed be exploited to improve the performance of the same communication
systems that provide them with data. Suggestive examples of this symbiotic
ecosystem are discussed in the paper. The dissertation is then substantiated in
a proof-of-concept case study, where we show how the traffic monitoring service
provided by the London Smart City initiative can be used to predict the density
of users in a certain zone and optimize the cellular service in that area.Comment: 14 pages, submitted for publication to ETT Transactions on Emerging
Telecommunications Technologie
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
A QUIC Implementation for ns-3
Quick UDP Internet Connections (QUIC) is a recently proposed transport
protocol, currently being standardized by the Internet Engineering Task Force
(IETF). It aims at overcoming some of the shortcomings of TCP, while
maintaining the logic related to flow and congestion control, retransmissions
and acknowledgments. It supports multiplexing of multiple application layer
streams in the same connection, a more refined selective acknowledgment scheme,
and low-latency connection establishment. It also integrates cryptographic
functionalities in the protocol design. Moreover, QUIC is deployed at the
application layer, and encapsulates its packets in UDP datagrams. Given the
widespread interest in the new QUIC features, we believe that it is important
to provide to the networking community an implementation in a controllable and
isolated environment, i.e., a network simulator such as ns-3, in which it is
possible to test QUIC's performance and understand design choices and possible
limitations. Therefore, in this paper we present a native implementation of
QUIC for ns-3, describing the features we implemented, the main assumptions and
differences with respect to the QUIC Internet Drafts, and a set of examples.Comment: 8 pages, 4 figures. Please cite it as A. De Biasio, F. Chiariotti, M.
Polese, A. Zanella, M. Zorzi, "A QUIC Implementation for ns-3", Proceedings
of the Workshop on ns-3 (WNS3 '19), Firenze, Italy, 201
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