LTE Optimization Docs from IEEE

[ptt3i]

Dynamic Neighbor Cell List Management for Handover Optimization in LTE

Abstract:
Self-optimization of the neighbor cell list (NCL) is expected to improve handover performance and reduce the need for site surveys. 3GPP Long Term Evolution (LTE) has introduced automatic neighbor relation (ANR), which enables a base station to manage neighbor cells on the basis of measurements made by mobiles. Because the radio coverage changes during network operations, it is essential to immediately update the NCL to improve handover performance, especially when the number of measured neighbor cells exceeds the upper limit of NCL size. In this paper, we propose a dynamic NCL management scheme to enhance NCL convergence and alleviate missing neighbor problems. The proposed scheme gives higher priority to newly detected neighbor cells over existing cells and ensures fast and accurate NCL updates after radio coverage changes. According to the LTE network simulations, the proposed scheme provides 70% faster recovery of the average radio link failure rate due to the missing neighbors compared with the non-prioritized scheme. It was also confirmed that the duration of missing neighbors is reduced by 39% on average.

© 2010 Alcatel-Lucent.

Link: http://adf.ly/h7gz3
pass:lte-1

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[ptt3i]

Autonomous neighbor relation detection and handover optimization in LTE

Abstract
Handovers require serving cells to have knowledge about the existence of neighboring cells. This information is stored in neighbor relation tables (NRTs), which can be automatically generated during a procedure called automatic neighbor relation (ANR) by leveraging measurements carried out by terminals. We show, using simulations, how fast the NRT converges with respect to the number of terminals and their speeds, as well as how incomplete NRTs influence the handover drop rate. By means of a field trial, we demonstrate that ANR works successfully in a real-life environment. In addition, we investigate solutions for problematic handover scenarios and self-optimization of relevant handover parameters based on decentralized approaches. We show that some handover parameters have more impact on network performance than others. Two promising self-optimization methods are discussed, based on either a cost function or a genetic programming technique which searches for a suitable algorithm that determines the parameters.

© 2010 Alcatel-Lucent.

Link: http://adf.ly/heQJn
pass: lte-2

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[ptt3i]

Self-optimization of LTE networks utilizing Celnet Xplorer

Abstract
In order to meet demanding performance objectives in Long Term Evolution (LTE) networks, it is mandatory to implement highly efficient, autonomic self-optimization and configuration processes. Self-optimization processes have already been studied in second generation (2G) and third generation (3G) networks, typically with the objective of improving radio coverage and channel capacity. The 3rd Generation Partnership Project (3GPP) standard for LTE self-organization of networks (SON) provides guidelines on self-configuration of physical cell ID and neighbor relation function and self-optimization for mobility robustness, load balancing, and inter-cell interference reduction. While these are very important from an optimization perspective of local phenomenon (i.e., the eNodeB's interaction with its neighbors), it is also essential to architect control algorithms to optimize the network as a whole. In this paper, we propose a Celnet Xplorer-based SON architecture that allows detailed analysis of network performance combined with a SON control engine to optimize the LTE network. The network performance data is obtained in two stages. In the first stage, data is acquired through intelligent non-intrusive monitoring of the standard interfaces of the Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) and Evolved Packet Core (EPC), coupled with reports from a software client running in the eNodeBs. In the second stage, powerful data analysis is performed on this data, which is then utilized as input for the SON engine. Use cases involving tracking area optimization, dynamic bearer profile reconfiguration, and tuning of network-wide coverage and capacity parameters are presented.

© 2010 Alcatel-Lucent.

Link: http://adf.ly/hhAl7
pass: lte-3

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[ptt3i]

Self-organizing interference management for LTE

Abstract
In orthogonal frequency division multiple access (OFDMA) systems such as Long Term Evolution (LTE), it is extremely important to reduce interference between neighboring cells, especially for cell edge users, since the only interference in LTE is inter-cell interference due to the orthogonality of the sub-carriers used in the transmissions. This paper describes a few self-organizing and self-optimizing techniques to manage and reduce this inter-cell interference. These self-optimizing network (SON)-based techniques are inter-cell interference coordination (ICIC) and uplink (UL) interference over thermal (IoT) control. Simulation results are presented showing the improvements that can be obtained with the use of such techniques in interference limited operating scenarios

© 2010 Alcatel-Lucent.

Link: http://adf.ly/hmCFn
pass: lte-3

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[ptt3i]

ICIC in DL and UL with network distributed and self-organized resource assignment algorithms in LTE

Abstract
Inter-cell Interference coordination (ICIC) has gained much interest in the 3rd Generation Partnership Project's (3GPP's) Long Term Evolution (LTE) standardization of a new air interface. Due to the new physical layer, interference can now be predicted and avoided on a frequency basis. Such schemes are based on cell wise usage restrictions or resource preferences. After explaining the general degrees of freedom, we present an “inverted” reuse scheme for downlink and uplink and explain its advantages. This is supported by 3GPP-compliant system simulations. The question of assignment of restrictions or preferences naturally leads to a need for self-organization. For that, the concept of semi-static ICIC based on a request-grant mechanism applicable to load balancing is explained. For the static ICIC case with frequency planning, a novel and fully distributed algorithm provides optimized assignment of resource restrictions to the cells in a self-organizing way. It is capable of resolving sub-optimal aspects and comprises methods to detect and prevent possible system instabilities. The algorithms presented lead to an integrated ICIC-self-organizing network (SON) concept that can be realized in a multi-cell network solution

© 2010 Alcatel-Lucent.

Link: http://adf.ly/iNCYI
pass: lte-4

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[ptt3i]

Autonomous spectrum sharing for unstructured cellular networks with femtocells

Abstract
To fulfill the needs for high speed ubiquitous coverage, fourth generation networks give rise to dense deployments of short range cells, such as femtocells. Generally deployed in residential or business areas, they complement the macrocellular service, thanks to guaranteed indoor coverage and improved multimedia experience. However, the addition of user-installed femtocells along with macrocells in a shared spectrum band raises critical management issues for controlling interference. In this paper, we address the problem of spectrum resource selection by the femtocells. The aim is to devise autonomous mechanisms for femtocells to adjust their spectrum resources, without manual configuration, so that they achieve high data rates and generate no interference to traditional macrocells. In this work, we are mainly concerned with the performance of solutions that are compliant with standards like Long Term Evolution (LTE). Detailed performance analysis is provided thanks to a complete simulation platform combining a physical layer ray-tracing tool with an upper layer orthogonal frequency division multiple access (OFDMA) simulator. Our results suggest that user channel quality measurements can be used to set the level of sharing between femtocells and macrocells and that finding the correct level of sharing is important for optimal network performance.

© 2010 Alcatel-Lucent.

Link: http://adf.ly/ifC2q
pass: lte-6


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ptt3i.

[ptt3i]

Self-optimization of LTE networks utilizing Celnet Xplorer

Abstract
In order to meet demanding performance objectives in Long Term Evolution (LTE) networks, it is mandatory to implement highly efficient, autonomic self-optimization and configuration processes. Self-optimization processes have already been studied in second generation (2G) and third generation (3G) networks, typically with the objective of improving radio coverage and channel capacity. The 3rd Generation Partnership Project (3GPP) standard for LTE self-organization of networks (SON) provides guidelines on self-configuration of physical cell ID and neighbor relation function and self-optimization for mobility robustness, load balancing, and inter-cell interference reduction. While these are very important from an optimization perspective of local phenomenon (i.e., the eNodeB's interaction with its neighbors), it is also essential to architect control algorithms to optimize the network as a whole. In this paper, we propose a Celnet Xplorer-based SON architecture that allows detailed analysis of network performance combined with a SON control engine to optimize the LTE network. The network performance data is obtained in two stages. In the first stage, data is acquired through intelligent non-intrusive monitoring of the standard interfaces of the Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) and Evolved Packet Core (EPC), coupled with reports from a software client running in the eNodeBs. In the second stage, powerful data analysis is performed on this data, which is then utilized as input for the SON engine. Use cases involving tracking area optimization, dynamic bearer profile reconfiguration, and tuning of network-wide coverage and capacity parameters are presented. © 2010 Alcatel-Lucent.

Link: http://adf.ly/ikhL5
pass: lte-7

BRs,
ptt3i.