6 research outputs found
Integration of Carrier Aggregation and Dual Connectivity for the ns-3 mmWave Module
Thanks to the wide availability of bandwidth, the millimeter wave (mmWave)
frequencies will provide very high data rates to mobile users in next
generation 5G cellular networks. However, mmWave links suffer from high
isotropic pathloss and blockage from common materials, and are subject to an
intermittent channel quality. Therefore, protocols and solutions at different
layers in the cellular network and the TCP/IP protocol stack have been proposed
and studied. A valuable tool for the end-to-end performance analysis of mmWave
cellular networks is the ns-3 mmWave module, which already models in detail the
channel, Physical (PHY) and Medium Access Control (MAC) layers, and extends the
Long Term Evolution (LTE) stack for the higher layers. In this paper we present
an implementation for the ns-3 mmWave module of multi connectivity techniques
for 3GPP New Radio (NR) at mmWave frequencies, namely Carrier Aggregation (CA)
and Dual Connectivity (DC), and discuss how they can be integrated to increase
the functionalities offered by the ns-3 mmWave module.Comment: 9 pages, 7 figures, submitted to the Workshop on ns-3 (WNS3) 201
System-Level Analysis of Blockage Dynamics in Millimeter-Wave Communications
The new generation of wireless technology, termed as the fifth generation (5G), introduces a large amount of novel features. An operation in the millimeter-wave (mmWave) spectrum becomes one of those features unlocking a wide bandwidth. The latter allows for a notable increase in the peak data rate by up to tens of gigabits per second and decreases latency to as low as few milliseconds. These improvements provide an opportunity to support high-rate and low-latency applications, such as augmented and virtual reality, eHealth, and many others.
Though mmWave communications have great potential, they suffer from severe attenuation caused by signal blockage. In addition to large-scale blockers (i.e., buildings), small-scale blockers such as human bodies bring new challenges to the operation over mmWave bands. Large attenuation losses, as well as the unpredictable mobility of human body blockers, can significantly decrease a service quality when communicating over a mmWave link. Thereby, there is a need to properly model the blockage process, evaluate its impact on mmWave network performance, and estimate performance gains brought by different blockage mitigation techniques.
The thesis proposes a mathematical methodology to characterize and evaluate the effect of blockage dynamics in mmWave networks. With the help of stochastic geometry and probability theory, it delivers mathematical models of static and dynamic small-scale blockage, as well as static large-scale blockage. It then introduces system-level performance evaluation frameworks accounting for the main features of mmWave communications, such as blockage and multipath propagation. The mathematical frameworks can also evaluate the impact of several blockage mitigation techniques in realistic deployment scenarios
Multiconnectivity for Mobility Robustness in Standalone 5G Ultra Dense Networks with Intrafrequency Cloud Radio Access
Capacity and ultra-reliable communication are some of the requirements for 5th generation (5G) networks. One of the candidate technologies to satisfy capacity requirement is standalone Ultra Dense Network (UDN). However, UDNs are characterized by fast change of received signal strength that creates mobility challenges in terms of increased handovers and connection failures. In this paper, a low layer multiconnectivity scheme is presented for standalone UDN aiming at ultra-reliable communication that is free of interruptions from handover procedures and connection failures. Furthermore, the problem in managing of the set of serving cells, that are involved in multiconnectivity for each user, is formulated. By using numerical method, feasible scheme for management of the set of serving cells is derived. Performance of the proposed multiconnectivity scheme is evaluated and compared against single connectivity. It is shown that the proposed multiconnectivity scheme outperforms single connectivity considerably in terms of connection failures and cell-edge throughput