Channel Capacity Maximization using NQHN Approach at Heterogeneous Network

In present scenario, the high speed data transmission services has pushed limits for wireless communication network capacity, at same time multimedia transmission in real-time needs provision of QoS, therefore the network capacity and small cell coverage has comes with lots of challenges. Improving the channel capacity and coverage area within the available bandwidth is necessary to provide better QoS to users, and improved channel capacity for the FCUs and MCUs in network. In this paper, we are proposing an NQHN approach that incorporate with efficient power allocation, improving the channel capacity by optimized traffic scheduling process in a small cell HetNets scenario. This work efficiently handle the interference with maintaining the user QoS and the implemented power controller uses HeNB power as per the real time based approach for macro-cell and femto-cell. Moreover, we consider the real traffic scenario to check the performance of our proposed approach with respect to existing algorith

Heterogeneous network optimization using robust power-and-resource based algorithm

In order to meet the increasing mobile data-traffic, spatial densification of network with several low-power nodes, the high-power macro BS and HetNet are the major key enabling solution. However, the HetNet is unplanned in nature, causes irregularities and interferences that without any user association rules. The appropriate deployment of the femto-cell in HetNet can provide effective traffic offloading, where the alleviate mobbing in the macro-cells can decrease the power consumption therefore it optimizes the user experience. Moreover, the protection is also important for the macro and femto cell users in a network through maintaining the min-max level of interferences. In this paper, we proposed RPRA that comprises two robust approach such as robust power-controller and the robust channel-allocation approach, which can improve the spectral efficiency and user experiences at lower network coverage areas via eliminating the week coverage zones. Also provide high user rate connection by effective interference in an efficient spectrum, lowering in transmission power and cost-effectiveness via less time delay. To show the effectiveness of our proposed model we have compared with several existing techniques and we got significant improvement in throughput, also reduction in time delay and transmission power

Resource element-level dimensioning of long term evolution networks

Long Term Evolution (LTE) of Universal Mobile Telecommunications System (UMTS) is the latest cellular technology coined by the third Generation Partnership Project (3GPP) and is currently being deployed worldwide.a crucial step towards the successful deployment scenarios of LTE networks is through the use of accurate budgetary and coverage dimensioning formulas of LTE’s physical air-interface channels and signals to guarantee favourable cell footprint and other capacity targets. In this paper, the total physical downlink resources along with their associated powers are derived and computed. Their corresponding overheads are also presented.The provided formulas serve in various network dimensioning campaigns of the LTE systems

Behind the NAT – A Measurement Based Evaluation of Cellular Service Quality

Abstract—Mobile applications such as VoIP, (live) gaming, or video streaming have diverse QoS requirements ranging from low delay to high throughput. The optimization of the network quality experienced by end-users requires detailed knowledge of the expected network performance. Also, the achieved service quality is affected by a number of factors, including network operator and available technologies. However, most studies focusing on measuring the cellular network do not consider the performance implications of network configuration and management. To this end, this paper reports about an extensive data set of cellular network measurements, focused on analyzing root causes of mobile network performance variability. Measurements conducted over four weeks in a 4G cellular network in Germany show that management and configuration decisions have a substantial impact on the performance. Specifically, it is observed that the association of mobile devices to a Point of Presence (PoP) within the operator’s network can influence the end-to-end RTT by a large extent. Given the collected data a model predicting the PoP assignment and its resulting RTT leveraging Markov Chain and machine learning approaches is developed. RTT increases of 58% to 73% compared to the optimum performance are observed in more than 57% of the measurements

LTE PHY Performance Analysis under 3GPP Standards Parameters

Long Term Evolution (LTE) has been introduced by 3GPP (3rd Generation Partnership Project) and is poised to dominate the 4th generation (4G) of mobile telecommunication networks. In this article, we present an in-depth analysis of the LTE physical layer’s characteristics and its performance. Our work is unique in providing a detailed performance study based on Release 8 of the 3GPP standard. Several works have discussed the LTE performance; however, most have been restricted to limited scenarios. Our work shows a more comprehensive investigation of the maximum data throughput under different conditions and scenarios. Our performance study includes TDD and FDD operational modes for uplink and downlink transmissions in different antenna diversity schemes, data modulation, and code rates. Our results show that LTE (3GPP-Release 8) supports downlink throughputs of up to 300Mbps and for the uplink a throughput of up to 75 Mbps

Esquemas de cooperação entre estações base para o LTE no sentido descendente

The explosive growth in wireless traffic and in the number of connected devices as smart phones or computers, are causing a dramatic increase in the levels of interference, which significantly degrades the capacity gains promised by the point-to-point multi input, multi output (MIMO) based techniques. Therefore, it is becoming increasingly clear that major new improvements in spectral efficiency of wireless networks will have to entail addressing intercell interference. So, there is a need for a new cellular architecture that can take these factors under consideration. It is in this context that LTE-Advanced arises. One of the most promising LTE-Advanced technology is Coordinated Multipoint (CoMP), which allows base stations to cooperate among them, in order to mitigate or eliminate the intercell interference and, by doing so, increase the system’s capacity. This thesis intends to study this concept, implementing some schemes that fall under the CoMP concept. In this thesis we consider a distributed precoded multicell approach, where the precoders are computed locally at each BS to mitigate the intercell interference. Two precoder are considered: distributed zero forcing (DZF) and distributed virtual signal-to-interference noise ratio (DVSINR) recently proposed. Then the system is further optimized by computing a power allocation algorithm over the subcarriers that minimizes the average bit error rate (BER). The considered algorithms are also evaluated under imperfect channel state information. A quantized version of the CSI associated to the different links between the BS and the UT is feedback from the UT to the BS. This information is then employed by the different BSs to perform the precoding design. A new DVSINR precoder explicitly designed under imperfect CSI is proposed. The proposed schemes were implemented considering the LTE specifications, and the results show that the considered precoders are efficiently to remove the interference even under imperfect CSI.O crescimento exponencial no tráfego de comunicações sem-fios e no número de dispositivos utilizados (smart phones, computadores portáteis, etc.) está a causar um aumento significativo nos níveis de interferência, que prejudicam significativamente os ganhos de capacidade assegurados pelas tecnologias baseadas em ligações ponto-a-ponto MIMO. Deste modo, torna-se cada vez mais necessário que os grandes aperfeiçoamentos na eficiência espectral de sistemas de comunicações sem-fios tenham em consideração a interferência entre células. De forma a tomar em consideração estes aspectos, uma nova arquitectura celular terá de ser desenvolvida. É assim, neste contexto, que surge o LTE-Advanced. Uma das tecnologias mais promissoras do LTE-Advanced é a Coordenação Multi-Ponto (CoMP), que permite que as estações base cooperem de modo a mitigar a interferência entre células e, deste modo, aumentar a capacidade do sistema. Esta dissertação pretende estudar este conceito, implementando para isso algumas técnicas que se enquadram no conceito do CoMP. Nesta dissertação iremos considerar a implementação de um sistema de pré-codificação em múltiplas células, em que os pré-codificadores são calculados em cada BS, de modo a mitigar a interferência entre células. São considerados dois pré-codificadores: Distributed Zero Forcing (DZF) e Distributed Virtual Signal-to-Interferance Noise Ratio (DVSINR), recentemente proposto. De seguida o sistema é optimizado com a introdução de algoritmos de alocação de potência entre as sub-portadoras com o objectivo de minimizar a taxa média de erros (BER). Os algoritmos considerados são também avaliados em situações em que a informação do estado do canal é imperfeita. Uma versão quantizada da CSI associada a cada uma das diferentes ligações entre as BS e os UT é assim enviada do UT para a BS. Esta informação é então utilizada para calcular os diferentes pré-codificadores em cada BS. Uma nova versão do pré-codificador DVSINR é proposta de modo a lidar com CSI imperfeito. Os esquemas propostos foram implementados considerandos especificações do LTE, e os resultados obtidos demonstram que os pré-codificadores removem de uma forma eficiente a interferência, mesmo em situações em que a CSI é imperfeita

Increased energy efficiency in LTE networks through reduced early handover

“A thesis submitted to the University of Bedfordshire, in partial fulfilment of the requirements for the degree of Doctor of Philosophy”.Long Term Evolution (LTE) is enormously adopted by several mobile operators and has been introduced as a solution to fulfil ever-growing Users (UEs) data requirements in cellular networks. Enlarged data demands engage resource blocks over prolong time interval thus results into more dynamic power consumption at downlink in Basestation. Therefore, realisation of UEs requests come at the cost of increased power consumption which directly affects operator operational expenditures. Moreover, it also contributes in increased CO2 emissions thus leading towards Global Warming. According to research, Global Information and Communication Technology (ICT) systems consume approximately 1200 to 1800 Terawatts per hour of electricity annually. Importantly mobile communication industry is accountable for more than one third of this power consumption in ICT due to increased data requirements, number of UEs and coverage area. Applying these values to global warming, telecommunication is responsible for 0.3 to 0.4 percent of worldwide CO2 emissions. Moreover, user data volume is expected to increase by a factor of 10 every five years which results in 16 to 20 percent increase in associated energy consumption which directly effects our environment by enlarged global warming. This research work focuses on the importance of energy saving in LTE and initially propose bandwidth expansion based energy saving scheme which combines two resource blocks together to form single super RB, thereby resulting in reduced Physical Downlink Control Channel Overhead (PDCCH). Thus, decreased PDCCH overhead helps in reduced dynamic power consumption up to 28 percent. Subsequently, novel reduced early handover (REHO) based idea is proposed and combined with bandwidth expansion to form enhanced energy ii saving scheme. System level simulations are performed to investigate the performance of REHO scheme; it was found that reduced early handover provided around 35% improved energy saving while compared to LTE standard in 3rd Generation Partnership Project (3GPP) based scenario. Since there is a direct relationship between energy consumption, CO2 emissions and vendors operational expenditure (OPEX); due to reduced power consumption and increased energy efficiency, REHO subsequently proven to be a step towards greener communication with lesser CO2 footprint and reduced operational expenditure values. The main idea of REHO lies in the fact that it initiate handovers earlier and turn off freed resource blocks as compare to LTE standard. Therefore, the time difference (Transmission Time Intervals) between REHO based early handover and LTE standard handover is a key component for energy saving achieved, which is estimated through axiom of Euclidean geometry. Moreover, overall system efficiency is investigated through the analysis of numerous performance related parameters in REHO and LTE standard. This led to a key finding being made to guide the vendors about the choice of energy saving in relation to radio link failure and other important parameters

Contribution to the Design and Operation of Advanced Mobile Communlcations Systems

El objetivo de esta tesis es estudiar la capacidad de los sistemas LTE (LongTerm Evolution) y Mobile WiMAX (Mobi/e Worldwide fnteroperab;/ity far Microwave Access), definida ésta como "el número máximo de usuarios simultáneos, con diferentes perfiles de servicios, que puede soportar cada nodo de acceso, para cada configuración del sistema". Para poder calcular ésta y la tasa binaria (throughput) se requiere primero calcular dinámicamente !a cantidad de recursos demandados y disponibles, que, a su vez, dependen de cómo se forma la correspondiente MAU (Mínimum Allocation Unit), tanto en LTE como en WiMAX. Ambas tecnologías, propuestas como respuesta a la iniciativa IMT (lnternational Mobile Telecommunications)-Advanced, tienen en común que el cómputo de estos MAUs es complejo debido a que parte de los recursos (overhead) tiene que utilizarse para labores necesarias de señalización, control o sincronización. Aunque el conjunto de tecnologías 3G (Third Generation) basadas en WCDMA (Wide-bond Code Division Mu/tiple Access) y HSPA (High-Speed Packet Access) constituyen en la actualidad el fundamento de las redes móviles de banda ancha más empleadas, LTE es, sin embargo, la tecnología móvil con el crecimiento más rápido de toda la historia. LTE es capaz de proporcionar velocidades de datos muy elevadas con una latencia extremadamente reducida, especialmente en el enlace descendente, DL (downlink), a expensas de incrementar su complejidad. Éstas son algunas de las características que convierten a LTE en una tecnología de banda ancha móvil con enormes posibilidades, no solo para usuarios domésticos sino también para aplicaciones novedosas en comunicaciones M2M (machine-to-machine), servicios de salud tipo mHea/th, los nuevos servicios asociados a las ciudades inteligentes (smart grids). Hay varias razones que explican este rápido despliegue de las redes LTE. Por un lado, el mercado de dispositivos móviles está creciente a tasas muy elevadas(::: 80%), constituyendo ya los teléfonos inteligentes (smartphones) el 75% de los dispositivos de usuario. Por otro lado, la técnica OFDMA (Orthogonal Frequency Division Mu/tiple Access) en el enlace descendente permite que LTE sea capaz de soportar tasas de datos más elevadas que las de HSPA. Hay incluso nuevos comportamientos de usuarios, sobre todo del segmento de población más joven, que están modificando sus preferencias a la hora de ver TV, desplazándose progresivamente desde el televisor convencional al streaming en sus smartphones. La combinación de todos estos factores está espoleando una demanda fuertemente creciente de servicios novedosos y muy intensivos en Mbps (HDTV, vídeo bajo demanda (VoG), gaming, etc.): el tráfico de datos ha crecido un ::: 65% entre los primeros cuatrimestres de 2015 y 2016. Además de la utilización de OFDM, LTE y Mobile-WiMAX tiene otros aspectos en común, como la posible integración de técnicas AMC (Adaptive Modulation and Cading) y MIMO (Multip/elnput ond Multip/e-Output) para poder proveer conexiones más fiables y rápidas. Sin embargo, y a pesar de estas similitudes, LTE y Mobile-WiMAX constituyen soluciones tecnológicas muy complejas que exhiben numerosas diferencias. En particular, un elemento crucial que aumenta la dificultan inherente a ambas se encuentra se encuentra en su flexibilidad en el sentido de que se dejan abiertos muchos aspectos de configuración para que cada empresa pueda diseñar la opción que considere más adecuada. El rendimiento de estas redes depende pues de la forma en la que se soluciona el problema de optimización entre la adecuación de los recursos disponibles en cada configuración a los recursos consumidos por !os usuarios. En esta Tesis se realiza diferentes trabajos de investigación tendentes a: 1. Modelar de forma exacta la velocidad de datos (throughput) disponible para los usuarios. Esto requiere calcular en paralelo los recursos disponibles -una vez descontado el overhead -y los recursos demandados. 2. Calcular, utilizando la heurística anterior, !a capacidad (o número máximo de usuarios simultáneos, con diferentes perfiles de servicios, que puede soportar cada nodo de acceso, para cada configuración del sistema). La validez de los modelos obtenidos se ha probado de forma exitosa en una gran variedad de configuraciones posibles en ambas tecnologías, publicando !os resultados en varias revistas y congresos internacionales