1,418 research outputs found
A survey of self organisation in future cellular networks
This article surveys the literature over the period of the last decade on the emerging field of self organisation as applied to wireless cellular communication networks. Self organisation has been extensively studied and applied in adhoc networks, wireless sensor networks and autonomic computer networks; however in the context of wireless cellular networks, this is the first attempt to put in perspective the various efforts in form of a tutorial/survey. We provide a comprehensive survey of the existing literature, projects and standards in self organising cellular networks. Additionally, we also aim to present a clear understanding of this active research area, identifying a clear taxonomy and guidelines for design of self organising mechanisms. We compare strength and weakness of existing solutions and highlight the key research areas for further development. This paper serves as a guide and a starting point for anyone willing to delve into research on self organisation in wireless cellular communication networks
Separation Framework: An Enabler for Cooperative and D2D Communication for Future 5G Networks
Soaring capacity and coverage demands dictate that future cellular networks
need to soon migrate towards ultra-dense networks. However, network
densification comes with a host of challenges that include compromised energy
efficiency, complex interference management, cumbersome mobility management,
burdensome signaling overheads and higher backhaul costs. Interestingly, most
of the problems, that beleaguer network densification, stem from legacy
networks' one common feature i.e., tight coupling between the control and data
planes regardless of their degree of heterogeneity and cell density.
Consequently, in wake of 5G, control and data planes separation architecture
(SARC) has recently been conceived as a promising paradigm that has potential
to address most of aforementioned challenges. In this article, we review
various proposals that have been presented in literature so far to enable SARC.
More specifically, we analyze how and to what degree various SARC proposals
address the four main challenges in network densification namely: energy
efficiency, system level capacity maximization, interference management and
mobility management. We then focus on two salient features of future cellular
networks that have not yet been adapted in legacy networks at wide scale and
thus remain a hallmark of 5G, i.e., coordinated multipoint (CoMP), and
device-to-device (D2D) communications. After providing necessary background on
CoMP and D2D, we analyze how SARC can particularly act as a major enabler for
CoMP and D2D in context of 5G. This article thus serves as both a tutorial as
well as an up to date survey on SARC, CoMP and D2D. Most importantly, the
article provides an extensive outlook of challenges and opportunities that lie
at the crossroads of these three mutually entangled emerging technologies.Comment: 28 pages, 11 figures, IEEE Communications Surveys & Tutorials 201
Practical design of optimal wireless metropolitan area networks: model and algorithms for OFDMA networks
A thesis submitted to the University of Bedfordshire, in partial fulfilment of the requirements for the degree of Ph.D.This thesis contributes to the study of the planning and optimisation of wireless metropolitan area networks, in particular to the access network design of OFDMAbased systems, where different parameters like base station position, antenna tilt and azimuth need to be configured during the early stages of the network life. A practical
view for the solution of this problem is presented by means of the development of a
novel design framework and the use of multicriteria optimisation. A further consideration of relaying and cooperative communications in the context of the design
of this kind of networks is done, an area little researched.
With the emergence of new technologies and services, it is very important to accurately identify the factors that affect the design of the wireless access network and define how to take them into account to achieve optimally performing and cost-efficient networks. The new features and flexibility of OFDMA networks seem particularly suited to the provision of different broadband services to metropolitan areas. However, until now, most existing efforts have been focused on the basic access capability networks. This thesis presents a way to deal with the trade-offs generated during the
OFDMA access network design, and presents a service-oriented optimization framework that offers a new perspective for this process with consideration of the technical and economic factors.
The introduction of relay stations in wireless metropolitan area networks will bring numerous advantages such as coverage extension and capacity enhancement due to the
deployment of new cells and the reduction of distance between transmitter and receiver.
However, the network designers will also face new challenges with the use of relay
stations, since they involve a new source of interference and a complicated air interface;
and this need to be carefully evaluated during the network design process.
Contrary to the well known procedure of cellular network design over regular or
hexagonal scenarios, the wireless network planning and optimization process aims to
deal with the non-uniform characteristics of realistic scenarios, where the existence of
hotspots, different channel characteristics for the users, or different service requirements will determine the final design of the wireless network. This thesis is structured in three main blocks covering important gaps in the existing literature in planning (efficient simulation) and optimisation. The formulation and ideas proposed in the former case can still be evaluated over regular scenarios, for the sake of simplicity, while the study of latter case needs to be done over specific scenarios that will be described when
appropriate. Nevertheless, comments and conclusions are extrapolated to more general
cases throughout this work.
After an introduction and a description of the related work, this thesis first focuses
on the study of models and algorithms for classical point-to-multipoint networks on
Chapter 3, where the optimisation framework is proposed. Based on the framework, this
work:
- Identifies the technology-specific physical factors that affect most importantly
the network system level simulation, planning and optimization process.
- It demonstrates how to simplify the problem and translate it into a formal optimization routine with consideration of economic factors.
- It provides the network provider, a detailed and clear description of different
scenarios during the design process so that the most suitable solution can be found. Existing works on this area do not provide such a comprehensive framework.
In Chapter 4:
- The impact of the relay configuration on the network planning process is analysed.
- A new simple and flexible scheme to integrate multihop communications in the
Mobile WiMAX frame structure is proposed and evaluated.
- Efficient capacity calculations that allow intensive system level simulations in a multihop environment are introduced.
In Chapter 5:
- An analysis of the optimisation procedure with the addition of relay stations and the derived higher complexity of the process is done.
- A frequency plan procedure not found in the existing literature is proposed, which combines it with the use of the necessary frame fragmentation of in-band relay communications and cooperative procedures.
- A novel joint two-step process for network planning and optimisation is proposed.
Finally, conclusions and open issues are exposed
- …