Fronthaul evolution: From CPRI to Ethernet

It is proposed that using Ethernet in the fronthaul, between base station baseband unit (BBU) pools and remote radio heads (RRHs), can bring a number of advantages, from use of lower-cost equipment, shared use of infrastructure with fixed access networks, to obtaining statistical multiplexing and optimised performance through probe-based monitoring and software-defined networking. However, a number of challenges exist: ultra-high-bit-rate requirements from the transport of increased bandwidth radio streams for multiple antennas in future mobile networks, and low latency and jitter to meet delay requirements and the demands of joint processing. A new fronthaul functional division is proposed which can alleviate the most demanding bit-rate requirements by transport of baseband signals instead of sampled radio waveforms, and enable statistical multiplexing gains. Delay and synchronisation issues remain to be solved

Ultraprecise Rydberg atomic localization using optical vortices

We propose a robust localization of the highly-excited Rydberg atoms, interacting with doughnut-shaped optical vortices. Compared with the earlier standing-wave (SW)-based localization methods, a vortex beam can provide an ultrahigh-precision two-dimensional localization solely in the zero-intensity center, within a confined excitation region down to the nanometer scale. We show that the presence of the Rydberg-Rydberg interaction permits counter-intuitively much stronger confinement towards a high spatial resolution when it is partially compensated by a suitable detuning. In addition, applying an auxiliary SW modulation to the two-photon detuning allows a three-dimensional confinement of Rydberg atoms. In this case, the vortex field provides a transverse confinement while the SW modulation of the two-photon detuning localizes the Rydberg atoms longitudinally. To develop a new subwavelength localization technique, our results pave one-step closer to reduce excitation volumes to the level of a few nanometers, representing a feasible implementation for the future experimental applications.Comment: oe in pres

Pilvipohjaisen radioliityntäverkon kustannusten mallintaminen

The rapid growth of mobile data traffic is challenging the current way of building and operating the current radio access network. Cloud-based radio access network is researched as a solution to provide the required capacity for rapidly growing traffic demand in more economical manner. Scope of this thesis is to evaluate the costs of different existing and future radio access network architectures depending on the given network and traffic scenario. This is done by creating a cost model based on expert interviews to solve the most economical solution for the given network in terms of total cost of ownership. The results show that the cloud-based radio access network’s cost benefits are dependent on the expected traffic growth. In the low traffic growth scenario, the cost benefits of cloud-based radio access network are questionable, but in the high traffic growth scenario clear cost benefits are achieved.Mobiilidataliikenteen nopea kasvu haastaa nykyisen tavan rakentaa ja hallinnoida tämän hetkisiä radioliityntäverkkoja. Pilvipohjaista radioliityntäverkkoa tutkitaan ratkaisuksi tarjota tarvittavaa verkkokapasiteettia entistä taloudellisemmin. Tämän opinnäytetyön tarkoituksena on arvioida nykyisten ja pilvipohjaisten radioliityntäverkkoarkkitehtuurien kustannuksia riippuen verkon rakenteesta ja liikenteestä. Tämä toteutetaan luomalla kustannusmalli, joka perustuu asiantuntijoiden haastatteluihin. Mallin avulla on mahdollista vertailla annetun verkon eri arkkitehtuurien kokonaiskustannuksia ja selvittää taloudellisin radioliityntäverkkoarkkitehtuuri verkolle. Mallinnuksen tulokset osoittavat, että pilvipohjaisen radioliityntäverkon taloudelliset hyödyt ovat riippuvaisia dataliikenteen kasvusta verkossa. Vähäisellä data-liikenteen kasvulla pilvipohjaisen radioliityntäverkon kustannusedut ovat kyseenalaiset, mutta suurella dataliikenteen kasvulla saadaan selviä säästöjä verrattuna nykyisiin arkkitehtuureihin

A Survey on the Contributions of Software-Defined Networking to Traffic Engineering

Since the appearance of OpenFlow back in 2008, software-defined networking (SDN) has gained momentum. Although there are some discrepancies between the standards developing organizations working with SDN about what SDN is and how it is defined, they all outline traffic engineering (TE) as a key application. One of the most common objectives of TE is the congestion minimization, where techniques such as traffic splitting among multiple paths or advanced reservation systems are used. In such a scenario, this manuscript surveys the role of a comprehensive list of SDN protocols in TE solutions, in order to assess how these protocols can benefit TE. The SDN protocols have been categorized using the SDN architecture proposed by the open networking foundation, which differentiates among data-controller plane interfaces, application-controller plane interfaces, and management interfaces, in order to state how the interface type in which they operate influences TE. In addition, the impact of the SDN protocols on TE has been evaluated by comparing them with the path computation element (PCE)-based architecture. The PCE-based architecture has been selected to measure the impact of SDN on TE because it is the most novel TE architecture until the date, and because it already defines a set of metrics to measure the performance of TE solutions. We conclude that using the three types of interfaces simultaneously will result in more powerful and enhanced TE solutions, since they benefit TE in complementary ways.European Commission through the Horizon 2020 Research and Innovation Programme (GN4) under Grant 691567 Spanish Ministry of Economy and Competitiveness under the Secure Deployment of Services Over SDN and NFV-based Networks Project S&NSEC under Grant TEC2013-47960-C4-3-

Self-optimization of pilot power in enterprise femtocells using multi objective heuristic

Deployment of a large number of femtocells to jointly provide coverage in an enterprise environment raises critical challenges especially in future self-organizing networks which rely on plug-and-play techniques for configuration. This paper proposes a multi-objective heuristic based on a genetic algorithm for a centralized self-optimizing network containing a group of UMTS femtocells. In order to optimize the network coverage in terms of handled load, coverage gaps, and overlaps, the algorithm provides a dynamic update of the downlink pilot powers of the deployed femtocells. The results demonstrate that the algorithm can effectively optimize the coverage based on the current statistics of the global traffic distribution and the levels of interference between neighboring femtocells. The algorithm was also compared with the fixed pilot power scheme. The results show over fifty percent reduction in pilot power pollution and a significant enhancement in network performance. Finally, for a given traffic distribution, the solution quality and the efficiency of the described algorithm were evaluated by comparing the results generated by an exhaustive search with the same pilot power configuration