16,756 research outputs found
Backhaul For Low-Altitude UAVs in Urban Environments
Unmanned Aerial Vehicles (UAVs) acting as access points in cellular networks
require wireless backhauls to the core network. In this paper we employ
stochastic geometry to carry out an analysis of the UAV backhaul performance
that can be achieved with a network of dedicated ground stations. We provide
analytical expressions for the probability of successfully establishing a
backhaul and the expected data rate over the backhaul link, given either an LTE
or a millimeter-wave backhaul. We demonstrate that increasing the density of
the ground station network gives diminishing returns on the performance of the
UAV backhaul, and that for an LTE backhaul the ground stations can benefit from
being colocated with an existing base station network
Integrated mmWave Access and Backhaul in 5G: Bandwidth Partitioning and Downlink Analysis
With the increasing network densification, it has become exceedingly
difficult to provide traditional fiber backhaul access to each cell site, which
is especially true for small cell base stations (SBSs). The increasing maturity
of millimeter wave (mmWave) communication has opened up the possibility of
providing high-speed wireless backhaul to such cell sites. Since mmWave is also
suitable for access links, the third generation partnership project (3GPP) is
envisioning an integrated access and backhaul (IAB) architecture for the fifth
generation (5G) cellular networks in which the same infrastructure and spectral
resources will be used for both access and backhaul. In this paper, we develop
an analytical framework for IAB-enabled cellular network using which we provide
an accurate characterization of its downlink rate coverage probability. Using
this, we study the performance of two backhaul bandwidth (BW) partition
strategies, (i) equal partition: when all SBSs obtain equal share of the
backhaul BW, and (ii) load-based partition: when the backhaul BW share of an
SBS is proportional to its load. Our analysis shows that depending on the
choice of the partition strategy, there exists an optimal split of access and
backhaul BW for which the rate coverage is maximized. Further, there exists a
critical volume of cell-load (total number of users) beyond which the gains
provided by the IAB-enabled network disappear and its performance converges to
that of the traditional macro-only network with no SBSs
Rate Optimal design of a Wireless Backhaul Network using TV White Space
The penetration of wireless broadband services in remote areas has primarily
been limited due to the lack of economic incentives that service providers
encounter in sparsely populated areas. Besides, wireless backhaul links like
satellite and microwave are either expensive or require strict line of sight
communication making them unattractive. TV white space channels with their
desirable radio propagation characteristics can provide an excellent
alternative for engineering backhaul networks in areas that lack abundant
infrastructure. Specifically, TV white space channels can provide "free
wireless backhaul pipes" to transport aggregated traffic from broadband sources
to fiber access points. In this paper, we investigate the feasibility of
multi-hop wireless backhaul in the available white space channels by using
noncontiguous Orthogonal Frequency Division Multiple Access (NC-OFDMA)
transmissions between fixed backhaul towers. Specifically, we consider joint
power control, scheduling and routing strategies to maximize the minimum rate
across broadband towers in the network. Depending on the population density and
traffic demands of the location under consideration, we discuss the suitable
choice of cell size for the backhaul network. Using the example of available TV
white space channels in Wichita, Kansas (a small city located in central USA),
we provide illustrative numerical examples for designing such wireless backhaul
network
Hybrid Radio/Free-Space Optical Design for Next Generation Backhaul Systems
The deluge of date rate in today's networks imposes a cost burden on the
backhaul network design. Developing cost efficient backhaul solutions becomes
an exciting, yet challenging, problem. Traditional technologies for backhaul
networks include either radio-frequency backhauls (RF) or optical fibers (OF).
While RF is a cost-effective solution as compared to OF, it supports lower data
rate requirements. Another promising backhaul solution is the free-space optics
(FSO) as it offers both a high data rate and a relatively low cost. FSO,
however, is sensitive to nature conditions, e.g., rain, fog, line-of-sight.
This paper combines both RF and FSO advantages and proposes a hybrid RF/FSO
backhaul solution. It considers the problem of minimizing the cost of the
backhaul network by choosing either OF or hybrid RF/FSO backhaul links between
the base-stations (BS) so as to satisfy data rate, connectivity, and
reliability constraints. It shows that under a specified realistic assumption
about the cost of OF and hybrid RF/FSO links, the problem is equivalent to a
maximum weight clique problem, which can be solved with moderate complexity.
Simulation results show that the proposed solution shows a close-to-optimal
performance, especially for practical prices of the hybrid RF/FSO links
Joint Access-Backhaul Perspective on Mobility Management in 5G Networks
The ongoing efforts in the research development and standardization of 5G, by
both industry and academia, have resulted in the identification of enablers
(Software Defined Networks, Network Function Virtualization, Distributed
Mobility Management, etc.) and critical areas (Mobility management,
Interference management, Joint access-backhaul mechanisms, etc.) that will help
achieve the 5G objectives. During these efforts, it has also been identified
that the 5G networks due to their high degree of heterogeneity, high QoS demand
and the inevitable density (both in terms of access points and users), will
need to have efficient joint backhaul and access mechanisms as well as enhanced
mobility management mechanisms in order to be effective, efficient and
ubiquitous. Therefore, in this paper we first provide a discussion on the
evolution of the backhaul scenario, and the necessity for joint access and
backhaul optimization. Subsequently, and since mobility management mechanisms
can entail the availability, reliability and heterogeneity of the future
backhaul/fronthaul networks as parameters in determining the most optimal
solution for a given context, a study with regards to the effect of future
backhaul/fronthaul scenarios on the design and implementation of mobility
management solutions in 5G networks has been performed.Comment: IEEE Conference on Standards for Communications & Networking,
September 2017, Helsinki, Finlan
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