327 research outputs found
Performance Comparison of Dual Connectivity and Hard Handover for LTE-5G Tight Integration
Communications at frequencies above 10 GHz (the mmWave band) are expected to
play a major role for the next generation of cellular networks (5G), because of
the potential multi-gigabit, ultra-low latency performance of this technology.
mmWave frequencies however suffer from very high isotropic pathloss, which may
result in cells with a much smaller coverage area than current LTE macrocells.
High directionality techniques will be used to improve signal quality and
extend coverage area, along with a high density deployment of mmWave base
stations (BS). However, when propagation conditions are hard and it is
difficult to provide high quality coverage with mmWave BS, it is necessary to
rely on previous generation LTE base stations, which make use of lower
frequencies (900 MHz - 3.5 GHz), which are less sensitive to blockage and
experience lower pathloss. In order to provide ultra-reliable services to
mobile users there is a need for network architectures that tightly and
seamlessly integrate the LTE and mmWave Radio Access Technologies. In this
paper we will present two possible alternatives for this integration and show
how simulation tools can be used to assess and compare their performance.Comment: This paper was accepted for presentation at the ninth EAI SIMUtools
2016 conference, August 22 - 23, 2016, Prague, Czech Republi
Performance Comparison of Dual Connectivity and Hard Handover for LTE-5G Tight Integration in mmWave Cellular Networks
MmWave communications are expected to play a major role in the Fifth
generation of mobile networks. They offer a potential multi-gigabit throughput
and an ultra-low radio latency, but at the same time suffer from high isotropic
pathloss, and a coverage area much smaller than the one of LTE macrocells. In
order to address these issues, highly directional beamforming and a very
high-density deployment of mmWave base stations were proposed. This Thesis aims
to improve the reliability and performance of the 5G network by studying its
tight and seamless integration with the current LTE cellular network. In
particular, the LTE base stations can provide a coverage layer for 5G mobile
terminals, because they operate on microWave frequencies, which are less
sensitive to blockage and have a lower pathloss. This document is a copy of the
Master's Thesis carried out by Mr. Michele Polese under the supervision of Dr.
Marco Mezzavilla and Prof. Michele Zorzi. It will propose an LTE-5G tight
integration architecture, based on mobile terminals' dual connectivity to LTE
and 5G radio access networks, and will evaluate which are the new network
procedures that will be needed to support it. Moreover, this new architecture
will be implemented in the ns-3 simulator, and a thorough simulation campaign
will be conducted in order to evaluate its performance, with respect to the
baseline of handover between LTE and 5G.Comment: Master's Thesis carried out by Mr. Michele Polese under the
supervision of Dr. Marco Mezzavilla and Prof. Michele Zorz
Temporal and spatial combining for 5G mmWave small cells
This chapter proposes the combination of temporal processing through Rake combining based on direct sequence-spread spectrum (DS-SS), and multiple antenna beamforming or antenna spatial diversity as a possible physical layer access technique for fifth generation (5G) small cell base stations (SBS) operating in the millimetre wave (mmWave) frequencies. Unlike earlier works in the literature aimed at previous generation wireless, the use of the beamforming is presented as operating in the radio frequency (RF) domain, rather than the baseband domain, to minimise power expenditure as a more suitable method for 5G small cells. Some potential limitations associated with massive multiple input-multiple output (MIMO) for small cells are discussed relating to the likely limitation on available antennas and resultant beamwidth. Rather than relying, solely, on expensive and potentially power hungry massive MIMO (which in the case of a SBS for indoor use will be limited by a physically small form factor) the use of a limited number of antennas, complimented with Rake combining, or antenna diversity is given consideration for short distance indoor communications for both the SBS) and user equipment (UE). The proposal’s aim is twofold: to solve eroded path loss due to the effective antenna aperture reduction and to satisfy sensitivity to blockages and multipath dispersion in indoor, small coverage area base stations. Two candidate architectures are proposed. With higher data rates, more rigorous analysis of circuit power and its effect on energy efficiency (EE) is provided. A detailed investigation is provided into the likely design and signal processing requirements. Finally, the proposed architectures are compared to current fourth generation long term evolution (LTE) MIMO technologies for their anticipated power consumption and EE
Waveform Design for 5G and Beyond
5G is envisioned to improve major key performance indicators (KPIs), such as
peak data rate, spectral efficiency, power consumption, complexity, connection
density, latency, and mobility. This chapter aims to provide a complete picture
of the ongoing 5G waveform discussions and overviews the major candidates. It
provides a brief description of the waveform and reveals the 5G use cases and
waveform design requirements. The chapter presents the main features of cyclic
prefix-orthogonal frequency-division multiplexing (CP-OFDM) that is deployed in
4G LTE systems. CP-OFDM is the baseline of the 5G waveform discussions since
the performance of a new waveform is usually compared with it. The chapter
examines the essential characteristics of the major waveform candidates along
with the related advantages and disadvantages. It summarizes and compares the
key features of different waveforms.Comment: 22 pages, 21 figures, 2 tables; accepted version (The URL for the
final version:
https://onlinelibrary.wiley.com/doi/abs/10.1002/9781119333142.ch2
Fast-RAT Scheduling in a 5G Multi-RAT Scenario
The authors exploit a Fast RAT switch solution to improve QoS
metrics of the system by means of efficient RAT
scheduling. Analyses presented here show
a better understanding concerning which system
measurements are most efficient in a mutliple-RAT
scenario. More specifically, they present an analysis
concerning the metrics that should be used as
RAT scheduling criteria and how frequent these
switching evaluations should be done
Multi-Connectivity Management and Orchestration Architecture Integrated With 5g Multi Radio Access Technology Network
The significant growth in the number of devices and the tremendous boost in
network/user traffic types and volume as well as the efficiency constraints of 4G
innovations have encouraged industry efforts and also financial investments towards
defining, developing, and releasing systems for the fifth generation. The 5G of mobile
broadband wireless networks with multiple Radio Access Technologies (Multi-RATs)
have actually been designed to satisfy the system and service requirements of the
existing as well as the coming applications. The multi-RAT access network is
considered the key enabling technology to satisfy these requirements based on low
latency, high throughput. To utilize all available network resources efficiently, research
activities have been proposed on multi-connectivity to connect, split, steer, switch, and
orchestrate across multiple RATs. Recently, multi-connectivity management and
orchestration architecture standardization has just started; therefore, further study and
research is needed. This project proposed a multi-connectivity management and
orchestration architecture integrated with 5G, Long-Term Evolution (LTE), and
Wireless LANs (WLAN) technologies. The simulations experiments conducted to
measure the Quality of Experience (QoE) by provisioning network resources
efficiently, which are: data rate, latency, bit error rate. The results show that the 5G
requirements have been achieved with latency and throughput around 1ms and 200
Mbps, respectively
Reliable Video Streaming over mmWave with Multi Connectivity and Network Coding
The next generation of multimedia applications will require the
telecommunication networks to support a higher bitrate than today, in order to
deliver virtual reality and ultra-high quality video content to the users. Most
of the video content will be accessed from mobile devices, prompting the
provision of very high data rates by next generation (5G) cellular networks. A
possible enabler in this regard is communication at mmWave frequencies, given
the vast amount of available spectrum that can be allocated to mobile users;
however, the harsh propagation environment at such high frequencies makes it
hard to provide a reliable service. This paper presents a reliable video
streaming architecture for mmWave networks, based on multi connectivity and
network coding, and evaluates its performance using a novel combination of the
ns-3 mmWave module, real video traces and the network coding library Kodo. The
results show that it is indeed possible to reliably stream video over cellular
mmWave links, while the combination of multi connectivity and network coding
can support high video quality with low latency.Comment: To be presented at the 2018 IEEE International Conference on
Computing, Networking and Communications (ICNC), March 2018, Maui, Hawaii,
USA (invited paper). 6 pages, 4 figure
- …