5 research outputs found
Control-Data Separation with Decentralized Edge Control in Fog-Assisted Uplink Communications
Fog-aided network architectures for 5G systems encompass wireless edge nodes,
referred to as remote radio systems (RRSs), as well as remote cloud center
(RCC) processors, which are connected to the RRSs via a fronthaul access
network. RRSs and RCC are operated via Network Functions Virtualization (NFV),
enabling a flexible split of network functionalities that adapts to network
parameters such as fronthaul latency and capacity. This work focuses on uplink
communications and investigates the cloud-edge allocation of two important
network functions, namely the control functionality of rate selection and the
data-plane function of decoding. Three functional splits are considered: (i)
Distributed Radio Access Network (D-RAN), in which both functions are
implemented in a decentralized way at the RRSs, (ii) Cloud RAN (C-RAN), in
which instead both functions are carried out centrally at the RCC, and (iii) a
new functional split, referred to as Fog RAN (F-RAN), with separate
decentralized edge control and centralized cloud data processing. The model
under study consists of a time-varying uplink channel in which the RCC has
global but delayed channel state information (CSI) due to fronthaul latency,
while the RRSs have local but more timely CSI. Using the adaptive sum-rate as
the performance criterion, it is concluded that the F-RAN architecture can
provide significant gains in the presence of user mobility.Comment: 28 pages, 11 figures. This manuscript was presented in part at
arXiv:1606.0913
Non-Orthogonal Multiplexing of Ultra-Reliable and Broadband Services in Fog-Radio Architectures
The fifth generation (5G) of cellular systems is introducing Ultra-Reliable
Low-Latency Communications (URLLC) services alongside more conventional
enhanced Mobile BroadBand (eMBB) traffic. Furthermore, the 5G cellular
architecture is evolving from a base station-centric deployment to a fog-like
set-up that accommodates a flexible functional split between cloud and edge. In
this paper, a novel solution is proposed that enables the non-orthogonal
coexistence of URLLC and eMBB services by processing URLLC traffic at the Edge
Nodes (ENs), while eMBB communications are handled centrally at a cloud
processor as in a Cloud-Radio Access Network (C-RAN) system. This solution
guarantees the low-latency requirements of the URLLC service by means of edge
processing, e.g., for vehicle-to-cellular use cases, as well as the high
spectral efficiency for eMBB traffic via centralized baseband processing. Both
uplink and downlink are analyzed by accounting for the heterogeneous
performance requirements of eMBB and URLLC traffic and by considering practical
aspects such as fading, lack of channel state information for URLLC
transmitters, rate adaptation for eMBB transmitters, finite fronthaul capacity,
and different coexistence strategies, such as puncturing.Comment: Submitted as Journal Pape