Self-Management for Unified Heterogeneous Radio Access Networks. Symposium on Wireless Communication Systems. Brussels, Belgium August 25, 2015

Transcription

1 Self-Management for Unified Heterogeneous Radio Access Networks Twelfth ISWCS International 2015 Symposium on Wireless Communication Systems Brussels, Belgium August 25, 2015

2 AAS Evolution: SON solutions for Vertical & Virtual Sectorisatrion Konstantinos Trichias (TNO)

3 SEMAFOUR Vision NETWORK OPERATOR General Network- Oriented ObjecGves SERVICE PROVIDER Network Status related to General Network- Oriented ObjecGves UNIFIED SELF-MANAGEMENT SYSTEM Integrated SON Management Decision Support System Monitoring & Diagnosis Policy- Based SON Management OperaGonal SON CoordinaGon MulG- RAT / MulG- layer SON WLAN Mgmt. 2G / 3G SON LTE SON Physical Network Resources Physical Network Resources Physical Network Resources HETEROGENEOUS NETWORK 3 Workshop on Self-Management for Unified Heterogeneous Radio Access Networks, August 25, 2015

4 Motivation Increasing traffic demand in mobile networks New systems & features for higher network capacity & improved performance Active Antenna Systems (AAS) Improved network performance Reduced costs Long-term sustainability Vertical / Virtual Sectorisation (VS / ViS) Increased network capacity Improved UE performance Self-Organizing Networks (SON) Intelligent networks Multi-layer & multi-rat functionality High degree of flexibility High degree of adaptability Spatial traffic variations Temporal traffic variations How to combine VS / ViS with SON to maximize gains and optimize performance? 4 Workshop on Self-Management for Unified Heterogeneous Radio Access Networks, August 25, 2015

5 Vertical Sectorisation (VS) Active Antenna System (AAS) technology : RF components integrated in the antenna UE beam stearing Separate Tx-Rx tilting Separate carrier tilting Vertical Sectorisation (VS): The antenna can support two sectors Original cell is split into an inner and an outer sector The newly formed sectors have distinct cell IDs Total transmit (Tx) power is shared between the sectors Capacity enhancement through network densification 5 Workshop on Self-Management for Unified Heterogeneous Radio Access Networks, August 25, 2015

6 Virtual Sectorisation (ViS) Evolution of VS -> ViS Generate a beam virtual sector- anywhere in the cell Virtual sector is a new cell with distinct cell ID Higher spatial degree of freedom Improved adaptation to current traffic distribution Macro cell and virtual sector need to share resources: Tx power sharing or Spectrum sharing 6 Workshop on Self-Management for Unified Heterogeneous Radio Access Networks, August 25, 2015

7 VS / ViS challenges Conditions for (de)activation of VS / ViS to ensure performance gains as a function of: Traffic distribution Time reactivity Propagation, in terms of Vertical Angular Spread (VAS) Optimal power allocation between sectors for VS and its dynamic adjustment based on: Own cell s traffic conditions Neighboring cells traffic conditions Optimal sector localization for ViS based on traffic distribution Design simple SON algorithms for: VS (de)activation VS Power allocation ViS spectrum sharing (resource allocation) & interference management 7 Workshop on Self-Management for Unified Heterogeneous Radio Access Networks, August 25, 2015

8 Hannover scenario & modeling Advanced AAS model based on Kathrein 3GPP contributions Realistic in/outdoor ray tracing propagation model (including 3D building data) Realistic traffic intensity maps Attribute Value Area size 5x7 km 2 (3x5 km 2 ) N o sites / cells 63 (36) / 84 (51) Frequency band Bandwidth Cell max Tx power Antenna gain Antenna mech. tilt Session file size Scheduling Link adaptation 1800 MHz 20 MHz 40 W (46 dbm) 18 dbi 4 o 16 Mb Fair sharing Modified Shannon curve 8 Workshop on Self-Management for Unified Heterogeneous Radio Access Networks, August 25, 2015

9 Initial VS performance Static deployment VS offers significant gains for average and 10 th percentile user throughput (network wide) Performance varies based on VS deployment parameters (down-tilt, power split) Poor choice of VS parameters can lead to performance degradation VS has a noticeable effect on neighboring cells 9 Workshop on Self-Management for Unified Heterogeneous Radio Access Networks, August 25, 2015

10 Impact of propagation on performance Angular Spread (AS) Per pixel Per cell Cells with larger Angular Spread are generally expected to provide lager gains when vertically sectorised Possible cell selection criterion 10 Workshop on Self-Management for Unified Heterogeneous Radio Access Networks, August 25, 2015

11 VS SON function (De)Activation of VS decision boundary in the inner and outer cell load plane, ρ inner and ρ outer The decision boundary is calibrated using simulation results Estimation of inner & outer load is necessary when VS is OFF Optimized & Simplified SON Calculate / Estimate Load Ratio= N outer τ / N inner τ />α Find optimum (de)activation point based on Load ratio α SON reactivity time τ (sec) Find optimum power split SON algorithm optimum performance α = -> Activate inner sector even for 1 user τ = 0 -> Take (de)activation decisions on a per call arrival / departure basis 11 Workshop on Self-Management for Unified Heterogeneous Radio Access Networks, August 25, 2015

12 VS SON Performance VS offers very large throughput & capacity gains SON algorithm optimizes the deployment of VS and offers an additional significant gain Larger gains observed for heavy traffic conditions SON algorithm mostly beneficial for cell edge users (10 th percentile) Larger gains observed for dense LTE deployments (small ISD between cells) SON VS Gain vs NO VS vs Full VS Average 45% 9.5% 10 th percentile 140% 26% 12 Workshop on Self-Management for Unified Heterogeneous Radio Access Networks, August 25, 2015

13 Static ViS performance & SON development Hot-spot coverage analysis for various virtual cell deployments (multiple electrical tilt and azimuth values) ViS gain increases with optimum localization of virtual cell in order to cover the pockets of heavy traffic Static BW split analysis between macro and virtual cells Static BW split leads to performance degradation in most cases SON development for adaptive BW split Current number of users in macro / virtual cells 13 Workshop on Self-Management for Unified Heterogeneous Radio Access Networks, August 25, 2015

14 ViS SON Performance Serving hot-spot locations with a virtual cell significantly increases the experienced SINR in the cell The dynamic adjustment of the BW split based on current traffic distribution always yields a gain (performance never below the baseline performance) Good localization of the virtual cell leads to maximization of gains SON ViS Gain ref NO ViS Average 44% 10 th percentile 89% 14 Workshop on Self-Management for Unified Heterogeneous Radio Access Networks, August 25, 2015

15 Summary Vertical Sectorisation Significant gains especially under heavy loading conditions SON algorithm maximizes VS gains Increased gains for dense deployments (intense interference conditions) Optimization trade-off: VSed cell performance vs neighboring cell performance Virtual Sectorisation Application without SON functionality leads to degradation of performance Application with SON BW split leads to significant gains Increased gains under heavy loading conditions & for hot-spot coverage Further research SON VS evolution Dynamic tilting of inner sector Application of VS based on Angular Spread measurements SON ViS evolution Auto-targeting of virtual cell towards traffic hot-spots Upgraded BW split algorithm (e.g. taking interference into account) 15 Workshop on Self-Management for Unified Heterogeneous Radio Access Networks, August 25, 2015

16 Don t miss! DEMONSTRATOR on Self-Organized Vertical Sectorisation Presented in Room SN22.2 during the next break! POSTERS on the SEMAFOUR use cases Presented during the next break in Room SN Workshop on Self-Management for Unified Heterogeneous Radio Access Networks, August 25, 2015

17 Thank you for your attention 17 Workshop on Self-Management for Unified Heterogeneous Radio Access Networks, August 25, 2015