Active Antennas Solutions 1st European Trial of AAU3902 Roman Łapszow, PhD roman.lapszow@orange.com Active Antennas Solutions 1st European Trial of AAU3902 24th -26th September, Kraków

FOCUS ON (e)NodeB SOLUTIONS Agenda Currently available Active Antenna Systems features Horizontal beamforming as a way to enhance capacity Vertical beamforming AAU3902 field implementation Future possible direction for innovations Impact on Green aspects FOCUS ON (e)NodeB SOLUTIONS

Active Antenna Systems (AAS) TODAY VERTICAL Sectorization VIRTUAL Sectorization Sector split for inner and outer cell High dependency on traffic distribution One cell Only PDSCH channels split to inner & outer beam User specific tilt - UST Horizontal Sectorization 4-virtual port antenna Beams are generated by combinations of standard UE PMI Reports (8 beams) UE: 4x2 CL MIMO Multicolumn (wide antenna) is needed Alternative for multisector 4-way Diversity – 4RxDiv Secondary AAS Features Uplink, Downlink, Frequency, RAT differentiated tilting Failure recovery PDSCH – Physical Downlink Shared Channel PMI – Precoding Matrix Indicator Gain in uplink only Virtual receive patterns created either for V and H plane (dual column) Active Antenna Systems

Horizontal Sectorisation

HORIZONTAL Sectorisation Principles Selective transmission in optimized directions brings potential to increase performance efficiency Phenomena of AZIMUTH DIRECTION and AZIMUTH SPREAD of received signal observed in testbed located in urban environment with 10 measuring points on street level and BS on rooftop (examples for UE1 and UE7 below) source: analysis part of the AAS Innovation Project with Ericsson also more information available on http://www.ericsson.com/thecompany/our_publications: Directional Channel Characteristics in Elevation and Azimuth at an Urban Macrocell Base Station

network re-configuration HORIZONTAL Sectorisation Limits A SIMPLE CELL SPLIT IS NOT ENOUGH dB dB network re-configuration is needed (azimuth rotating by 15o) SINR for 6 sectors cluster BASED on 3-sector plan SINR for 6 sectors after re-planning azimuth spread in multipath environment limits the minimum horizontal HPBW side lobe increase with increasing range of beam angle adjustment limits the range of adaptation source: analysis part of the AAS Innovation Project with Huawei

Vertical Sectorisation

VERTICAL Sectorisation (VS) Principles Splitting cell in two: INNER & OUTER spatial separation allows spectrum reuse and increase macro layer capacity WHAT IS NEEDED TO SUPPORT VS: Active antenna with beamforming in baseband DOUBLE the cell number* => RF plan reconfiguration needed Control upper side lobe suppression for inner cell beam NON-UNIFORM TRAFFIC DISTRIBUTION *) not the case of virtual sectorisation

VERTICAL Sectorisation Evaluation + INNER CELL THROUGHPUT GAIN + SECTOR CAPACITY GAIN ONLY if UE’s are located close to the site center + Antenna swap with the same azimuth direction + RF plan changes limited to tilt adjustment +/- Transmitted power reduction to keep total power the same as legacy configuration => potential cell edge coverage degradation - Limited flexibility of site configuration or reconfiguration

VS Trial Scenario 80049 80384 80223 Urban city and Rural Scenario 3 sites, 7 sectors OPL/TMPL Ran-Sharing Scenario 3 carriers in each sector Total power configuration before split 20W; after split 2x10W Pilot Power Configuration 10% VS active on 3 sectors, one sector per site

Site Configuration Before AAU Installation BBU AAU ANT K 742 234 T-Mobile RRU Orange RRU Active Port Passive Port Orange RU Before AAU Installation After Existing Antenna SWAP to AAU3902 RX Div diplexer 1 box saved, but 2 other diplexer needed

Coverage Change – due to antenna pattern change VS - OFF VS - ON 80384 outercell 80049 innercell 80049 80049 outercell 80384 innercell 80384 80223 innercell 80223 outercell 80223 coverage change observed on VS cell borders

VS Trial RESULTS – UL capacity The same sector 3 carriers Increase Traffic within same load Load saving in same Traffic requirement For uplink, VS can bring an average gain about 51%

VS Trial RESULTS – DL capacity AAU_Baseline VS_inner VS_outer Cell Average Throughput(kbps) 80049O2 2250.951063 2532.906732 2221.05459 80223O1 2532.29539 2385.25665 2208.070722 80384O3 2311.716234 1666.025382 2433.032532 number of Active HSDPA Users Assumed 5 0.333147191 4.666852809 0.801915328 4.198084672 1.79105415 3.20894585 Average User Throughput(kbps) 450.1902127 7602.965886 475.9212861 506.4590781 2974.449505 525.9709832 462.3432469 930.1926365 758.2030504 Gain for User Throughput Baseline 1589% 5.72% 487% 3.85% 101% 63.99% Significant throughput gains for inner cell are observed but only available for limited users located in inner cell. For downlink, VS brought an average thp gain for outer cell about 24%.

possible negative gains VS Trial RESULTS – analysis Interference Increase/Capacity Gain Decrease Inner User Number Ratio Increase/Capacity Gain Increase Inner User Number Ratio 30% Scenario Small ISD Complex Multi-path Environment Obstruction Large ISD Open Area No Obstruction 80049O1 97% Ratio 50% 80223O1 83% 80384O3 68% 80049O1 5.72% 80223O1 3.85% ) 80384O3 63.99% Ratio 6% Ratio 16% Ratio 35% Max Gain (theoretically calculated) Capacity Gain will decrease if the environment is more complex If the inner user number ratio increase, the gain may achieve the max value. DOWNLINK ! possible negative gains *) for benchmark collected after tests *) for benchmark collected after tests *) for benchmark collected after tests

Future Innovations

Principles of VVS+HB Virtual Vertical Sectorisation + Horizontal Beamforming Antenna parameters: HPBW H: 66,7° HPBW V: 11,9° range of vertical adjustment: od 0°do 15° beam switching: ± 26,6° (53,2°) Innovation sub-beam 1 sub-beam 3 sub-beam 2 sub-beam 4 Number of ports are assigned according to 3GPP TS 36.211 standard No. 19880/14

Results for VVS+HB DL (VVS) UL (VVS) Reference cell throughput per sector in typical 3-sector passive antenna configuration Estimated cell throughput per sector based on simulations (full buffer) for VVS-type only UL (VVS) DL (VVS) Average cell throughput gain estimations are in range 40 to 70% (both UL and DL) Antenna does not require site construction changes Reduced number of antennas in comparison to multisector configuration

“Green” Energy Savings

AAS Impact on Power Consumption Observations and thesis after trial in Orange Poland with AAU3902 AAS VS feature allows reduction of the maximum emitted power in a single cell from 20W to 10W. Due to improved radio condition for inner cell users the total power emission should be reduced due to power control mechanism (not measured). Reduced interference being consequence of outer cell power reduction should allow reduction of required emitted power in DL that with VS feature is limited to 10W. Higher throughput capacity in UL allows limit time of the transmission by UE and reduce battery consumption (not measured in the trial).

Summary & Conclusions AAS VS features provides gains: UE throughput, capacity gains and they are relevant to traffic distribution and sensitive to the implementation scenario. Self Optimizing Network related features need to be implemented as integral part of E2E VS solution to allow dynamic activation of the feature (to avoid negative gains). First AAS trials proves ability for decrease energy consumption by limiting radiated power in individually created beams.

Thank you

Gain Definitions UL_1: UL_2: DL: