Browsing by Author "Rodrigues, A."
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- An enhanced proposal in neighbor list planning for LTE SON radio access networksPublication . Duarte, D.; Martins, A.; Vieira, Pedro; Rodrigues, A.; Silva, N.Nowadays, a coexistence of 2nd Generation (2G), 3rd Generation (3G) and 4th Generation (4G) networks is being witnessed. Due to this situation, it became evident the need for Self-Organizing Networks (SON), which aims to automate most of the associated radio planning and optimization tasks. Within SON, this paper presents the latest work around an algorithm that optimizes the Neighbor Cell List (NCL) for Long Term Evolution (LTE) evolved NodeBs (eNBs). The algorithm is based on intra-site distance, its antenna orientation (azimuth/elevation), radiation pattern and overlap areas between cells. The research initial steps were already published (Duarte, D.; Vieira, P.; Rodrigues, A.; Martins, A.; Oliveira, N.; Varela, L., “Neighbour List Optimization for Real LTE Radio Networks,” Wireless and Mobile, 2014 IEEE Asia Pacific Conference on, pp.183,187, 28-30 Aug. 2014).
- Antenna tilt optimization using a novel QoE model based on 3G radio measurementsPublication . Pedras, V.; Sousa, M.; Vieira, Pedro; Queluz, M. P.; Rodrigues, A.This paper presents a novel Quality of Experience model (QoE), for 3G voice calls; it estimates a user perceived quality, in a Mean Opinion Score (MOS) scale, by evaluating several Radio Frequency (RF) channel metrics. Real Drive Test (DT) data with MOS measurements have been used as reference data, in order to produce a new MOS prediction model, using machine learning techniques. The new developed model enables the application of QoE as a possible network optimization criteria. Furthermore, it is showcased a generic framework to optimize antenna physical parameters. Using this framework, an algorithm was implemented which empowers the network MOS estimation by using the developed QoE model. A Root Mean Square Error (RMSE) of 9% was achieved, on the MOS prediction, using the developed model. Concerning the MOS antenna physical parameters optimization, it resulted in an average network performance gain of 5% comparatively to a interference control generic approach.
- Automated joint access and backhaul planning for 5G millimeter-wave small cell networksPublication . Marques, Beatriz; Sousa, Marco; Vieira, Pedro; Queluz, Maria Paula; Rodrigues, A.Mobile backhauling, small cells and millimeter waves (mmWaves) are key important technologies to support the next-generation cellular networks. The 5th generation (5G) radio networks introduce several different elements from the previous generations and hence, network planning became even more complex. In this work, the focus is on creating a radio network planning algorithm towards 5G mmWave small cell architectures. The algorithm is divided between the radio access network and the backhaul network. The former aims to find optimal locations for small cells to guarantee coverage requirements, while the latter creates backhaul links between the small cells according to a specific topology, and chooses which of them should be gateways. The results give some insights on base station (BS) and gateway density, and demonstrate that the topology most likely to meet Quality of Service (QoS) requirements, while minimizing the number of gateways, is the mesh network. However, tree and star topologies are also useful in certain scenarios. The work also includes a comparison between the 28 GHz and 60 GHz frequency bands, which are two common candidates for mmWave backhauling.
- Automatic backhaul planning for 5G Open RAN Networks based on MNO DataPublication . Marques, Beatriz; Parracho, Diogo; Sousa, Marco; Vieira, Pedro; Queluz, M. Paula; Rodrigues, A.The Quality of Service (QoS) requirements for the 5th Generation (5G) services are ambitious and broad, particularly for the latency targets. To cover those, a flexible and cost-efficient Radio Access Network (RAN) is essential as proposed by the Open-RAN (O-RAN) concept. In addition, the deployment of O-RAN 5G networks can be expedited by considering network access, aggregation, and core locations of legacy technologies, where physical requisites as power supply, fiber optic links, and others are already met. With this in mind, this paper extends previous simulation work that proposed a radio network planning algorithm for 5G Millimeter Wave (mmWave) small cells to O-RAN-based networks. The backhaul planning algorithm considers both the 5G/O-RAN QoS constraints, a real 4th Generation (4G) network topology, and the respective Key Performance Indicators (KPIs) from a Mobile Network Operator (MNO) as the foundation to plan an O-RAN compliant backhaul network. Our findings identified that the latency of current networks is greatly determined by the network load. In the utmost case, comparing the network baseline and busy hour KPIs, the baseline planned O-RAN network requires 7%of the equivalent busy hour network nodes. This approach has the potential to help MNOs to outline an enlightened strategy, minimizing Capital Expenditure (CAPEX) and augmenting QoS towards upgrading legacy networks to O-RAN 5G networks.
- Crossed sector automatic detection in 4G Radio Access NetworksPublication . Martins, A.; Vieira, Pedro; Franco, C.; Rodrigues, A.; Silva, N.The Long Term Evolution (LTE) is the latest step in the advancing series of mobile telecommunications systems, it is called the fourth Generation (4G). In order to boost performance and deal with the increasing complexity within the operating 3G/4G networks, the Self-Organizing Networks (SON) concept was introduced.
- Detecting and reducing interference in 3G and beyond wireless access networksPublication . Gomes, A.; Sousa, M.; Vieira, Pedro; Rodrigues, A.As wireless access networks evolve, addressing the growing subscribers demand, their complexity has been increasing too. To manage it, Mobile Network Operator (MNO)s rely more often on automatic methods, such as network planning, optimization and maintenance. In this regard, this study focuses on the development of a intra-Radio Access Technology (RAT) coverage optimization and interference reduction algorithm, applying Self-Organizing Networks (SON) concepts. A Genetic Algorithm (GA) was used to optimize multiple antenna tilt parameters, based on Drive Test (DT) measurements and network configuration. This study was applied to the 3rd Generation (3G) technology, nonetheless, it can be adapted to other RAT. It was tested, with both single and multiple cells optimization, resulting in a Radio Frequency (RF) condition improvement. In an urban scenario, the simultaneous optimization of several cells, resulted in a 50th percentile Received Signal Code Power (RSCP) and Energy per Chip on Spectral Noise Density (Ec/No) distributions improvement of 7 dB and 3 dB, respectively. Moreover, the joint optimization of the Electrical Downtilt (EDT) and Mechanical Downtilt (MDT) proved insignificant advantages over just the EDT optimization.
- Developing a new simulation and visualization platform for researching aspects of mobile network performancePublication . Amaro, C.; Saraiva, T.; Duarte, D.; Vieira, Pedro; Queluz, Maria Paula; Rodrigues, A.Nowadays, mobile networks represent one of the most innovative and challenging technological and research-oriented fields of work. The growth on user subscriptions and the advances introduced by Artificial Intelligence (AI) and Internet of Things (IoT), greatly enhanced the complexity and potential of communication networks. The increase on variety of devices and exchanged mobile data traffic resulted in demanding requirements for the network providers. As networks tend to scale and data to increase, some problems start to arise. Traffic congestion, packet loss and high latency being some examples. Therefore, it is important to introduce powerful tools and methods to tackle these challenges. On this perspective, several studies have highlighted AI systems, mainly Machine Learning (ML) algorithms, as the most promising methods, in the context of wireless networks, by improving the overall performance and efficiency. This work proposes to integrate several network optimization algorithms, already developed, in a common and unified visualization platform. These algorithms were developed in C# and Python and some of them use supervised and unsupervised ML techniques. The proposed solution includes multi-threading processes to deal with concurrent simulations, a proxy to communicate between platforms and a dynamic visual interface.
- Energy savings in 3G using dynamic spectrum access and base station sleep modesPublication . Cunha, T.; Rodrigues, A.; Vieira, Pedro; Martins, A.; Silva, N.; Varela, L.The energy consumption and energy efficiency of mobile telecommunication networks are crucial factors for the sustainability of this industry. This paper targets the reduction of the energy consumption at a Base Station (BS) level through the adoption of sleep modes during the off-peak periods of the day and relying in the existence of co-located and overlaid frequency bands to provide the coverage and capacity backup for the switched-off cells. It relies on the Dynamic Spectrum Allocation (DSA) method to opportunely relocate users during the low-load periods while maintaining the service quality of service (QoS). For the input data, real traffic statistics were used. Using this strategy and the proposed algorithm it was possible to achieve savings of about 43% per-site. The results were furthered to the study of a Portuguese mobile operator case and it was concluded that savings of more than 1.25 million euros were easily achieved.
- Evaluating 5G coverage in 3D scenarios under configurable antenna beam patternsPublication . Jesus, Francisco; Sousa, Marco; Freitas, Filipe; Vieira, Pedro; Rodrigues, A.; Queluz, Maria PaulaActive Antenna Systems (AASs) play a key role in the performance of 5 th Generation (5G) networks as they enable the use of Massive Multiple-Input Multiple-Output (mMIMO) and directional beamforming. Besides, AASs can be configured with distinct broadcast beams configurations. In this work, the coverage provided by the broadcast beam configurations of a real AAS is evaluated. A 3-Dimensional (3D) configurable synthetic scenario was proposed to evaluate the resulting 5G coverage from all the possible antenna beam configurations. This analysis revealed that beam configurations with several horizontal beams and one vertical are recommended for urban macro deployments. Moreover, it was demonstrated that the percentage of covered area in a real scenario is approximated by an equivalent synthetic scenario with a Pearson correlation of 0.98. The synthetic scenario has the advantage of not requiring 3D building databases. Finally, an interference analysis in multi-site real scenarios was conducted, where it was verified that some antenna configurations introduce excessive interference for the level of coverage provided.
- A hybrid neighbor optimization algorithm for SON based on network topology, Handover counters and RF measurementsPublication . Duarte, D.; Martins, A.; Vieira, Pedro; Rodrigues, A.With the increasing complexity of current wireless networks, it became evident the need for Self-Organizing Networks (SON), which aims to automate most of the associated radio planning and optimization tasks. Within SON, this paper aims to optimize the Neighbor Cell List (NCL) for radio network cells. An algorithm composed by three decision criteria was developed: geographic localization and orientation, according network topology, Radio Frequency (RF) measurements collected by drive-tests or traces and Performance Management (PM) counters from Handover (HO) statistics. The first decision, proposes a new NCL taking into account the Base Station (BS) location and interference tiers, based on the quadrant method. The last two decision criteria consider signal strength and interference level measurements and HO statistics in a time period, respectively. They also define a priority to each cell and added, kept or removed neighbor relation, based on user defined constraints. The algorithms were developed and implemented over new radio network optimization professional tool. Several case studies were produced using real data from a mobile operator.