2,836 research outputs found
Flat Cellular (UMTS) Networks
Traditionally, cellular systems have been built in a hierarchical manner: many specialized cellular access network elements that collectively form a hierarchical cellular system. When 2G and later 3G systems were designed there was a good reason to make system hierarchical: from a cost-perspective it was better to concentrate traffic and to share the cost of processing equipment over a large set of users while keeping the base stations relatively cheap. However, we believe the economic reasons for designing cellular systems in a hierarchical manner have disappeared: in fact, hierarchical architectures hinder future efficient deployments. In this paper, we argue for completely flat cellular wireless systems, which need just one type of specialized network element to provide radio access network (RAN) functionality, supplemented by standard IP-based network elements to form a cellular network. While the reason for building a cellular system in a hierarchical fashion has disappeared, there are other good reasons to make the system architecture flat: (1) as wireless transmission techniques evolve into hybrid ARQ systems, there is less need for a hierarchical cellular system to support spatial diversity; (2) we foresee that future cellular networks are part of the Internet, while hierarchical systems typically use interfaces between network elements that are specific to cellular standards or proprietary. At best such systems use IP as a transport medium, not as a core component; (3) a flat cellular system can be self scaling while a hierarchical system has inherent scaling issues; (4) moving all access technologies to the edge of the network enables ease of converging access technologies into a common packet core; and (5) using an IP common core makes the cellular network part of the Internet
Cooperative Multi-Cell Networks: Impact of Limited-Capacity Backhaul and Inter-Users Links
Cooperative technology is expected to have a great impact on the performance
of cellular or, more generally, infrastructure networks. Both multicell
processing (cooperation among base stations) and relaying (cooperation at the
user level) are currently being investigated. In this presentation, recent
results regarding the performance of multicell processing and user cooperation
under the assumption of limited-capacity interbase station and inter-user
links, respectively, are reviewed. The survey focuses on related results
derived for non-fading uplink and downlink channels of simple cellular system
models. The analytical treatment, facilitated by these simple setups, enhances
the insight into the limitations imposed by limited-capacity constraints on the
gains achievable by cooperative techniques
Deep Q-Learning for Self-Organizing Networks Fault Management and Radio Performance Improvement
We propose an algorithm to automate fault management in an outdoor cellular
network using deep reinforcement learning (RL) against wireless impairments.
This algorithm enables the cellular network cluster to self-heal by allowing RL
to learn how to improve the downlink signal to interference plus noise ratio
through exploration and exploitation of various alarm corrective actions. The
main contributions of this paper are to 1) introduce a deep RL-based fault
handling algorithm which self-organizing networks can implement in a polynomial
runtime and 2) show that this fault management method can improve the radio
link performance in a realistic network setup. Simulation results show that our
proposed algorithm learns an action sequence to clear alarms and improve the
performance in the cellular cluster better than existing algorithms, even
against the randomness of the network fault occurrences and user movements.Comment: (c) 2018 IEEE. Personal use of this material is permitted. Permission
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Performance Evaluation of Multiterminal Backhaul Compression for Cloud Radio Access Networks
In cloud radio access networks (C-RANs), the baseband processing of the
available macro- or pico/femto-base stations (BSs) is migrated to control
units, each of which manages a subset of BS antennas. The centralized
information processing at the control units enables effective interference
management. The main roadblock to the implementation of C-RANs hinges on the
effective integration of the radio units, i.e., the BSs, with the backhaul
network. This work first reviews in a unified way recent results on the
application of advanced multiterminal, as opposed to standard point-to-point,
backhaul compression techniques. The gains provided by multiterminal backhaul
compression are then confirmed via extensive simulations based on standard
cellular models. As an example, it is observed that multiterminal compression
strategies provide performance gains of more than 60% for both the uplink and
the downlink in terms of the cell-edge throughput.Comment: A shorter version of the paper has been submitted to CISS 201
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