Results of ARNS/LTE compatibility study in Ukraine (carried out in 2011)

1. Results of ARNS/LTE compatibility study in Ukraine (carried out in 2011) Anatolii Tychynskyi Ukrainian State Centre of Radio Frequencies

2. Preliminary study objectives • To get an empirical values of protection criteria for RSBN and Radars from LTE • To check an aggregation interference effect of LTE on RSBN and Radars Ukrainian State Centre of Radio Frequencies

3. Part 1 Obtaining an empirical values of protection criteria for RSBN RSBN protection criteria values applied in Framework Agreement Ukrainian State Centre of Radio Frequencies

4. Revision of the Dsep. value outlined in the Framework Agreement Calculation conditions: • Worst case EIRP summation: EIRP max sum = 55dBm/5 MHz + 9 dB – 2,2 dB = 31,8 dBW/3 MHz; • 46 dBμkV/1MHz = 50,7 dBμkV/3MHz; • for Rec. ITU-R P.1546-4: • 10% of time, 50% of locations, land, h2 =10 m. • hant BS = 30m, heff = 30 m; • site height = 0 m, TCA angle = 0 deg., delta H = 50 m; • f = 800 MHz. Ukrainian State Centre of Radio Frequencies

5. Remarks to the values mentioned in Framework Agreement • The value of separation distance does not comply with protection criteria • An aggregation interference effect is not confirmed in practical cases • Propagation model is not adequate to real conditions • There are no accounted critical cases (EIRP ≥55 dBm, hant ≥30 m, heff - ?) • Due to the complicated RSBN technical requirements it is desirable to measure the protection criterion (allowable interference level) Ukrainian State Centre of Radio Frequencies

6. Typical frequency allocation plan in coordination area • Partial consideration, from part to part of the band allows to develop the special requirements to the value of coordination criterion for each part of the band. • In equal situation the LTE BSs – RSBN impact is the worst mutual influence in case of close RSBN (≤20 km) allocation to the border line. • MSs LTE – RLS impact probably has the critical nature in case of close (≤10 km) location of RLS to the border line. Permissible field strength for RLS is supposedly close to the typical value in this band due to accounting only side lobes reception . In case of impossibility to measure this value the main value need to be verified is aggregate power of LTE MSs. Ukrainian State Centre of Radio Frequencies

7. Input requirements for the RSBN allowable interference level test measurements • Wanted and interfering signals have to be received by RSBN receiver through the equal air line-of-site conditions. • Wanted signal has to be corresponded to the maximum distant airborne signal thus imitating the real signal-to-noise ratio. The modulation of imitated signal should corresponds to the real airborne signal (for instance coordinates data signal). • For the allowed interference estimation the C/(I+N)≥2 criterion has to be used. This criterion is established by technical documentation on RSBN. This criterion is not used independently. It is used together with two other criteria that describe the receiver operation quality and decoding quality. • The test measurements has to be carried out in accordance with Spectrum Monitoring Handbook procedure for field strength measurements. Ukrainian State Centre of Radio Frequencies

8. Ukrainian State Centre of Radio Frequencies

9. Assessment of the test measurements results • The measured value 12, 7 dBμV/m/9 kHz should be transformed to the Agreement calculation method and conditions (see below). • There was not possibility to measure other values and effects due to unavailability of LTE equipment to full operation (there was not stable control from core EPC equipment). Only test regime of LTE base station was available. • Due to close LTE-RSBN distance the measured value was received with critical value of BS TPC (42 dB attenuation). To get the more correct result it is need to have the more remote BS transmitter. In spite of that the obtained value is quite reliable as measured value. Ukrainian State Centre of Radio Frequencies

10. Conversion of measured value to the calculation method 1. Result of measurement (12,7dBμV/m is average value from 9 measurements, which were made during 23 minutes in the point 800 MHz and its neighborhood in the measurement band 9 kHz) is reduced to the 1 MHz measurement band. We obtain correction factor К1: Es. bs = 12,7 + К1 = 33,3 dBμV/m dBuV/m; K1, dB = 10 log (1000/9) = 20,6 dB 2. Adding the losses in the feeder of measurement antenna: Es. bs = 33,3 + 1,3 = 34,6 dBμV/m; 3. Taking into account the cross polarization factor of LTE BS. Results of power measurements of LTE BS by spectrum analyser Advantest U3772-4 using horn antenna under attenuation of BS signal of 25 dB. Horizontal and vertical components approximately equal). Factor may not be taken into account. 4. Conversion of the measurement antenna height 5,5 m to 10 m by using formula 27b in point 9 of Annex 5 of ITU Rec. Р. 1546 [4] (formula for correction of receiving antenna height) gives correction factor -5,5 dB. 5. The final result of measured permissible interference field strength Es. bs = 34,6 + 5,5 = 40,1 dBμV/m. Ukrainian State Centre of Radio Frequencies

11. Proposals to the text of Agreement and to further study • After coordination procedure inside Ukraine the value 40,1 dBμV/m/1MHz.can be used as the single criterion in the text of Agreement. The value of separation distance mentioned in the Agreement does not reflect the real value of distance because of an exclusive data values (heff, hant, EIRP) of some LTE BS frequency assignments arising occasionally in network planning process. • Meanwhile the separation distance (35 km or another value) can be used in coordination procedure simultaneously with the limitation of main values (heff, hant, EIRP) in coordination area. Another case is the impossibility to calculate an aggregate value of field strength created by LTE BS at the border line (for example, after overcoming the permissible field strength). • Due to the essential distinctions in the calculations results with usage of different prorogation models it is need to continue the study process on the matter of proper prorogation models utilization. Ukrainian State Centre of Radio Frequencies

12. Part 2 Amendment to the aggregation method used in study of LTE UE – Radars impact RLS protection criteria values applied in Framework Agreement Herein the worst case EIRPsum =23 dBm + 5 dB = 28 dBm for 1 cell. Ukrainian State Centre of Radio Frequencies

13. Remarks to the aggregated power value 28dBm • An aggregation method of JTG 5-6 does not account the technology features, particularly the limited resource blocks (N = 25) allocated to active terminals • The assumption about the UE maximum power neglecting the power control is in contradiction to the uniform spatial distribution of UE • The Agreement approach does not account the probability of concentration all of the UE’s exceptionally on the cell edges (that is, the probability of all of them operate at a maximum power mode) Ukrainian State Centre of Radio Frequencies

14. Technological factors that define the LTE UEs aggregate power effect • The limitation of frequency and power resources allocated in LTE downlink channel. The number of simultaneously served UEs in the cell (sector) is limited by the number of resource blocks (RB). • The procedure of RB allocation to the cell (sector) is defined by the service quality algorithm (QoS) that is used with allocation of frequency and power resource to UEs. • UEs activity can be defined indirectly by the relation between traffics in downlink and uplink channels and by other way.

15. Z4 Z2 Z3 Z1 The main idea – to account the LTE RB distribution to UE’s in accordance with the QoS algorithm inherent to LTE Radio Resource Strategy. According to model depicted lower, any mobile terminal which is located in close proximity to the BS has in average m times better chance for a certain RB than some cell-edge terminal. Doc. JTG 5-6 Compendium, Annex 5-4 Uniform distribution Trapezoid distribution of RB to UE’s in service aria of RB to UE’s in service aria jjj Cell zones for n=4 Ukrainian State Centre of Radio Frequencies

16. Proposal to the methodology for calculation of interference from LTE Uplink to the RLS The total sell radiated power where KL is the average mobile station activity factor (KL0.08 ); U(x) is the probability density function: PUE(x) is the function of the UE radiated power dependence from the range x. It can be expressed as a product of two other functions: where P(x) is the specific power (the power of one resource block- RB): Ukrainian State Centre of Radio Frequencies

17. Q(x) is the function which describes the expectation value of the number of RB, allocated for any UE’s depending on the range x: Pcell calculation results derived with above approach: • KL= 1 KL = 0,5 KL = 0,08 • For N=25, m=2, Pcell = 24,3 dBm= 21,3 dBm = 13,3 dBm • For N=25, m=1, Pcell = 24,8 dBm= 21,5 dBm = 13,8 dBm • Conclusions and proposals for part 2: 1. The value KLdescribes the modern traffic rate in up-and downlink channels. 2. With accounting of the growing traffic load in uplink channel and data rates in up-and downlink channels the KLcan be forecasted to the value 0,5. 3. The above approach give the reduction of Pcell up to the value 8% from the maximum aggregate power of UE’s in the cell 4.Proposal1:To account this approach in protection criteria calculation after the test measurements for aggregation effect estimation. 5. Proposal 2:To provide the test measurements with similar equipment, for example, CDMA UE. Ukrainian State Centre of Radio Frequencies

18. Questions? Thank you for attention! Anatolii Tychynskyi tychinskij@ucrf.gov.ua +38 (044) 422-85-86 Ukrainian State Centre of Radio Frequencies