1,513 research outputs found
Ubiquitous Cell-Free Massive MIMO Communications
Since the first cellular networks were trialled in the 1970s, we have
witnessed an incredible wireless revolution. From 1G to 4G, the massive traffic
growth has been managed by a combination of wider bandwidths, refined radio
interfaces, and network densification, namely increasing the number of antennas
per site. Due its cost-efficiency, the latter has contributed the most. Massive
MIMO (multiple-input multiple-output) is a key 5G technology that uses massive
antenna arrays to provide a very high beamforming gain and spatially
multiplexing of users, and hence, increases the spectral and energy efficiency.
It constitutes a centralized solution to densify a network, and its performance
is limited by the inter-cell interference inherent in its cell-centric design.
Conversely, ubiquitous cell-free Massive MIMO refers to a distributed Massive
MIMO system implementing coherent user-centric transmission to overcome the
inter-cell interference limitation in cellular networks and provide additional
macro-diversity. These features, combined with the system scalability inherent
in the Massive MIMO design, distinguishes ubiquitous cell-free Massive MIMO
from prior coordinated distributed wireless systems. In this article, we
investigate the enormous potential of this promising technology while
addressing practical deployment issues to deal with the increased
back/front-hauling overhead deriving from the signal co-processing.Comment: Published in EURASIP Journal on Wireless Communications and
Networking on August 5, 201
Access and metro network convergence for flexible end-to-end network design
This paper reports on the architectural, protocol, physical layer, and integrated testbed demonstrations carried out by the DISCUS FP7 consortium in the area of access - metro network convergence. Our architecture modeling results show the vast potential for cost and power savings that node consolidation can bring. The architecture, however, also recognizes the limits of long-reach transmission for low-latency 5G services and proposes ways to address such shortcomings in future projects. The testbed results, which have been conducted end-to-end, across access - metro and core, and have targeted all the layers of the network from the application down to the physical layer, show the practical feasibility of the concepts proposed in the project
Optical and RF Metrology for 5G
Specification standards will soon be available for 5G mobile RF
communications. What optical and electrical metrology is needed or available to
support the development of the supporting optical communication systems? Device
measurement, digital oscilloscope impairments and improving system resolution
are discussed.Comment: 2017 IEEE Photonics Society Summer Topical Meeting Series (SUM
Fronthaul evolution: From CPRI to Ethernet
It is proposed that using Ethernet in the fronthaul, between base station baseband unit (BBU) pools and remote radio heads (RRHs), can bring a number of advantages, from use of lower-cost equipment, shared use of infrastructure with fixed access networks, to obtaining statistical multiplexing and optimised performance through probe-based monitoring and software-defined networking. However, a number of challenges exist: ultra-high-bit-rate requirements from the transport of increased bandwidth radio streams for multiple antennas in future mobile networks, and low latency and jitter to meet delay requirements and the demands of joint processing. A new fronthaul functional division is proposed which can alleviate the most demanding bit-rate requirements by transport of baseband signals instead of sampled radio waveforms, and enable statistical multiplexing gains. Delay and synchronisation issues remain to be solved
RAN Functional Split Options for Integrated Terrestrial and Non-Terrestrial 6G Networks
Leveraging non-terrestrial platforms in 6G networks holds immense
significance as it opens up opportunities to expand network coverage, enhance
connectivity, and support a wide range of innovative applications, including
global-scale Internet of Things and ultra-high-definition content delivery. To
accomplish the seamless integration between terrestrial and non-terrestrial
networks, substantial changes in radio access network (RAN) architecture are
required. These changes involve the development of new RAN solutions that can
efficiently manage the diverse characteristics of both terrestrial and
non-terrestrial components, ensuring smooth handovers, resource allocation, and
quality of service across the integrated network ecosystem. Additionally, the
establishment of robust interconnection and communication protocols between
terrestrial and non-terrestrial elements will be pivotal to utilize the full
potential of 6G technology. Additionally, innovative approaches have been
introduced to split the functionalities within the RAN into centralized and
distributed domains. These novel paradigms are designed to enhance RAN's
flexibility while simultaneously lowering the costs associated with
infrastructure deployment, all while ensuring that the quality of service for
end-users remains unaffected. In this work, we provide an extensive examination
of various Non-Terrestrial Networks (NTN) architectures and the necessary
adaptations required on the existing 5G RAN architecture to align with the
distinct attributes of NTN. Of particular significance, we emphasize the
crucial RAN functional split choices essential for the seamless integration of
terrestrial and non-terrestrial components within advanced 6G networks
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