4,623 research outputs found
An efficient data transmission policy in an integrated voice-data ds-cdma network
CDMA schemes appear to be promising access techniques for coping with the requirements of third-generation mobile systems, mainly because of their flexibility. This paper proposes an adaptive S-ALOHA DS-CDMA access scheme as a method for integrating non-real time (i.e. Internet applications) and real-time (i.e. voice) services, by exploiting the potentials of CDMA under time-varying conditions. The adaptive component terminals autonomously change their transmission rate according to the total (voice+data) channel occupancy, so that the minimum possible data delay is almost always achieved.Peer ReviewedPostprint (published version
Analysis of Multi-Cell Downlink Cooperation with a Constrained Spatial Model
Multi-cell cooperation (MCC) mitigates intercell interference and improves
throughput at the cell edge. This paper considers a cooperative downlink,
whereby cell-edge mobiles are served by multiple cooperative base stations. The
cooperating base stations transmit identical signals over paths with
non-identical path losses, and the receiving mobile performs diversity
combining. The analysis in this paper is driven by a new expression for the
conditional outage probability when signals arriving over different paths are
combined in the presence of noise and interference, where the conditioning is
with respect to the network topology and shadowing. The channel model accounts
for path loss, shadowing, and Nakagami fading, and the Nakagami fading
parameters do not need to be identical for all paths. To study performance over
a wide class of network topologies, a random spatial model is adopted, and
performance is found by statistically characterizing the rates provided on the
downlinks. To model realistic networks, the model requires a minimum separation
among base stations. Having adopted a realistic model and an accurate analysis,
the paper proceeds to determine performance under several resource-allocation
policies and provides insight regarding how the cell edge should be defined.Comment: 6 pages, 3 figures, IEEE Global Telecommun. Conf. (GLOBECOM), 2013,
to appear. arXiv admin note: text overlap with arXiv:1210.366
Mobility-aware QoS assurance in software-defined radio access networks: an analytical study
Software-defined networking (SDN) has gained a tremendous attention in the recent years, both in academia and industry. This revolutionary networking paradigm is an attempt to bring the advances in computer science and software engineering into the information and communications technology (ICT) domain. The aim of these efforts is to pave the way for completely programmable networks and control-data plane separation. Recent studies on feasibility and applicability of SDN concepts in cellular networks show very promising results and this trend will most likely continue in near future. In this work, we study the benefits of SDN on the radio resource management (RRM) of future-generation cellular networks. Our considered cellular network architecture is in line with the recently proposed Long-Term Evolution (LTE) Release 12 concepts, such as user/control plane split, heterogeneous networks (HetNets) environment, and network densification through deployment of small cells. In particular, the aim of our RRM scheme is to enable the macro base station (BS) to efficiently allocate radio resources for small cell BSs in order to assure quality-of-service (QoS) of moving users/vehicles during handovers. We develop an approximate, but very time- and space-efficient algorithm for radio resource allocation within a HetNet. Experiments on commodity hardware show algorithm running times in the order of a few seconds, thus making it suitable even in cases of fast moving users/vehicles. We also confirm a good accuracy of our proposed algorithm by means of computer simulations
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
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