PMSE LTE Coexistence

Transcription

1 PMSE LTE Coexistence Results of the JRC measurement session of November 13-15, Serving society Stimulating innovation Supporting legislation

2 LTE-PMSE coexistence measurements When: November 13-15, 2013 Where: JRC Radio Spectrum Laboratory, Ispra, Italy Who: Experts from the PMSE industry, the GSMA, test equipment manufacturers, and the JRC 2

3 Test event objective To evaluate whether the deployment of LTE small cells operating in the 2600 MHz band in combination with inter-band handover can protect PMSE systems operating in the MHz LTE duplex gap. 3

4 PMSE in the LTE FDD Duplex Gap Problem: Interference from LTE Out-Of-Band (OOB) emissions LTE band #20 FDD DL (BS) FDD UL (UE) 10 MHz Duplex Gap PMSE 791 MHz 821 MHz 832 MHz 862 MHz 4

5 UL power [dbm] Measured LTE UE OOB emissions in the Duplex Gap -5,00-10,00-15,00 UE 1 UE 2 UE 3 UE 4-20,00-25,00-30,00-35,00-40,00-45,00-50,00 f [MHz] 6

6 PMSE-LTE coexistence Current scenario PMSE venue Wireless microphone (800 MHz band) LTE Macro BS (800 MHz band) LTE UL FM Audio LTE UE LTE UE LTE UL LTE Macro BS (800 MHz band) LTE UL LTE UE PMSE receiver (800 MHz band) - PMSE operates in the MHz LTE duplex gap. - LTE UEs are registered with remote macro BS operating in the MHz band. - Long distance => High path loss => High UL power => Adjacent channel interference to PMSE. 7

7 Potential solution: LTE Small cells and inter-band handover LTE cell types and their characteristics Cell type Typical cell radius Transmit power range [Typical value) Deployment location Capacity [no. of users) Base Station class Output power limit Macro > 1 km 20 W W [40 W) Outdoor >256 Wide Area BS None Micro 250 m - 1 km 2 W - 20 W (5 W) Outdoor Medium Range BS 38 dbm (6.3 W) Pico Femto < 100 m 100 mw mw Indoor m m 1 W - 5 W Outdoor m - 50 m 10 mw mw Indoor mw - 1 W Outdoor 8-32 Local Area BS Home BS 24 dbm (250 mw) 20 dbm (100 mw) [1 Tx antenna port] 17 dbm (50 mw) [2 Tx antenna ports] 14 dbm (25 mw) [4 Tx antenna ports] < 11 dbm (13 mw) [8 Tx antenna ports] Source: Fujitsu, NSN Source: ETSI TS V For reasons of simplicity small cells will be referred to as picocells in this presentation 8

8 PMSE-LTE coexistence Possible future scenario PMSE venue Wireless microphone (800 MHz band) LTE Macro BS (800 MHz band) FM Audio LTE UE LTE UL LTE UL LTE Pico BS (2600 MHz band) LTE Macro BS (800 MHz band) LTE UE LTE UE PMSE receiver (800 MHz band) LTE UL LTE Pico BS (2600 MHz band) - PMSE operates in the MHz LTE duplex gap. - LTE UE have registered with on-site pico BS operating in the 2600 MHz band. - Frequency separation + low UL power => No interference to PMSE 9

9 Coexistence measurements - Test cases 1. In operation 2. Start-up 10

10 Test case 1 In operation PMSE venue Wireless microphone (800 MHz band) LTE Pico BS (2600 MHz band) d 2 d 3 d 4 d 1 > d 2, d 3, d 4 FM Audio d 4 d 3 d 2 LTE UE LTE UL LTE Macro BS 800 MHz band) LTE UE LTE UL PMSE receiver (800 MHz band) d 1 11

11 In-operation test - Handover LTE UE Tx power received by the LTE pico BS P Thresh3 P Thresh2 P Thresh1 LTE UE UL centre frequency Time 2535 MHz 837 MHz t Delay Time 12

12 Test case 2 Start-up PMSE venue Wireless microphone (800 MHz band) LTE Pico BS (2600 MHz band) d 1 d 2 d 4 d 3 >> d 1, d 2, d 4 FM Audio d 4 d 2 d 1 LTE UE d 3 LTE Macro BS (800 MHz band) PMSE receiver (800 MHz band) 13

13 Interference scenario PMSE system operating at its sensitivity limit Lowest possible RF signal level that produces a 30 db SINAD (analogue receivers) or the nominal SINAD (for digital receivers: 60 db) Signal levels between -91 and -102 dbm, corresponding to a maximum path attenuation of db between wireless microphone and receiver Silent PMSE test signal (3 khz deviation) PMSE squelch disabled LTE UE traffic pattern simulating heavily varying uplink traffic No Transmit Power Control 14

14 What was measured? Amount of LTE UE OOB emissions in the MHz band LTE centre frequency: 837 MHz LTE channel width: 10 MHz ( MHz) Impact of LTE OOB emissions on PMSE audio signal quality (SINAD) Potential interference effects caused by the LTE UE during and after handover Potential interference effects caused by the LTE UE during start-up and BS selection 16

15 Test setup LTE base station emulator R&S CMW500 Dual channel version macro and pico BS in one unit Commercial LTE user equipment (USB modems, smartphones) Specific LTE UE configuration (resource block and Tx power patterns) to simulate UL traffic generated by a large number of UEs using the 10 MHz channel adjacent to the duplex gap (identical to the one used in the IRT Munich measurements) Commercial PMSE equipment (analogue and digital) PMSE test signal generator Test signal: FM Carrier frequencies , 830.1, , , , MHz Deviation 3 khz; modulating frequency 1 khz 17

16 Test setup LTE USB modems / Analogue PMSE Channel 1 LTE Macro BS 800 MHz (LTE band 20) Channel 2 LTE Micro/Pico BS 2600 MHz (LTE band 7) Timing reference LTE BS emulator Ch 1 Ch 2 R&S CMW500 Spectrum analyzer RF combiner Mini-Circuits ZFRSC-123-S+ RF combiner Mini-Circuits ZN2PD2-63-S+ Directional coupler Atlantic A RF combiner Mini-Circuits ZFRSC-123-S+ Uplink (800 MHz) LTE UE LTE spectrum & PMSE audio recorder Tektronix RSA6114A NI PXI LP filter LPF2 DC-1700 MHz Mini-Circuits VLF Programmable Attenuator A1 Agilent Attenuator driver Agilent 11713B FM Signal generator Audio DAC PMSE Receiver RF combiner RF combiner Mini-Circuits Mini-Circuits ZFSC S+ ZN2PD2-63-S+ R&S SMU 200A Focusrite Scarlet 2i2 18

17 In-operation measurements (1) Impact of LTE OOB emissions on analogue PMSE SINAD SINAD [db] Separation [db] Receiver A MHz Receiver A MHz Receiver B MHz Receiver B MHz 20

18 In-operation measurements (1) Impact of LTE OOB emissions on digital PMSE SINAD Receiver D MHz 21

19 Demonstration video OOB Emissions Impact of OOB emissions from LTE UE operating in the MHz band approaching an analogue PMSE receiver operating at MHz. 22

20 LTE UE - PMSE receiver separation [db] Minimum separation between LTE UE and PMSE receiver Measured values for two analogue PMSE receivers and four LTE UE PMSE receiver A PMSE receiver B MHz MHz 24

21 In-operation measurements (2) Handover The LTE UE moves towards the PMSE receiver. SINAD [db] Handover is initiated when the 25 power received from the LTE UE 20 reaches a certain threshold. For the lab measurements the 15 Handover MHz MHz handover was initiated at a 10 predefined separation between 5 LTE UE and PMSE receiver. 0 Separation [db] 25

22 Demonstration video - Handover Handover of an LTE UE approaching an analogue PMSE receiver operating at MHz. 26

23 Interference measurements - Handover Power measured in the MHz band No harmful interference detected 27

24 Interference measurements - Start-up Power measured in the duplex gap ( MHz) during LTE UE startup. Some low-level energy but no harmful interference detected. 28

25 Results (1) In-operation measurements Impact of LTE OOB emissions Close to the LTE band edge, all tested LTE UE generated harmful interference to PMSE systems even at high path attenuations At 830,950 MHz, the SINAD started decreasing at path attenuations between 81 and 97 db => minimum MHz = 97 db At 825,925 MHz, the SINAD started decreasing at path attenuations between 56 and 77 db => minimum separation@ MHz = 77 db 29

26 Results (2) In-operation measurements - Handover When a handover was initiated by the BS it was usually executed within less than 2 seconds. In some cases, however, handover took a long time (more than 20 seconds). The cause of the delay could not be determined. When a handover was executed outside the protection range of the PMSE receiver no interference was observed. No harmful interference resulting from the LTE handover process itself could be observed in the MHz band. In the dual-band PMSE scenario, no harmful interference resulting from the handover process could be observed in the 1800 MHz band. 30

27 Results (3) Startup measurements During multiple test runs the LTE UE always connected to the BS with the stronger signal, in this case the pico BS operating at 2535 MHz. No harmful interference in the MHz band could be observed during the start-up process. 31

28 Conclusions The negative impact of LTE OOB emissions on PMSE signal quality identified in previous measurements (IRT, DKE, BNetzA, Ofcom, others) was confirmed. The utilisation of LTE picocells in combination with inter-band handover can reduce interference from active LTE UE to PMSE if handovers are executed outside the protection radius of the PMSE receivers. The utilisation of LTE picocells operating in the 2600 MHz band can reduce interference from LTE UE that are activated in the vicinity of a PMSE receiver operating in the 800 MHz LTE duplex gap. 32

29 LTE Picocell Deployment Considerations Translating minimum separation values into protection distances Comparison of various LOS and NLOS path loss models 33

30 LTE Picocell Deployment Considerations Link budgets Downlink The maximum output power of an LTE Pico BS is +24 dbm. An LTE UE that is to receive data at a speed of 2 Mbits per second requires a minimum received signal strength of -91 dbm. The resulting maximum permissible path loss between an LTE pico BS and an LTE UE is 115 db. Uplink The maximum output power of an LTE UE is +23 dbm. For transferring data at a speed of 2 Mbits per second the required minimum received signal strength at the LTE pico BS is -95 dbm. The resulting maximum permissible path loss between an LTE UE and an LTE pico BS is 118 db. 34

31 LTE UE PMSE separation distances MHz 2535 MHz MHz 115 db PMSE receiver LTE pico BS 77 db 97 db LTE UE 35

32 Suggestions for further research and analysis Practical implementation Handover management Reliability of LTE UE signal detection Reliability and speed of inter-band handover Intra-band handover between picocells Pico cell capacity Backhaul Consider possible alternative solutions Distributed Antenna Systems (DAS) Local IP Access (LIPA) 36

33 Distributed Antenna Systems (DAS) A DAS Network can be deployed outdoors or within large buildings and partially enclosed structures, and a DAS Network can range from two to hundreds of DAS Nodes. Features small indoor antennas in various building locations. Each DAS Node typically transmits RF signals at much lower power levels than macro base stations. Can be operated by 3rd party operator-independent companies Especially used as multi-operator indoor coverage solution Source: DAS Forum, Nokia Siemens Networks 37

34 Distributed Antenna Systems (DAS) Application examples Source: Nokia Siemens Networks 38

35 Local IP Access (LIPA) Introduced in 3GPP rel. 9 and defined in 3GPP TR Provides seamless interworking between LTE and WiFi. Data traffic can be offloaded to WiFi while time-critical services such as VoIP will be delivered via LTE. 39

36 Thank you Detlef Fuehrer 40

37 Backup slides 41

38 Test case 3 Multi-band PMSE PMSE venue Wireless microphone (800 MHz band) LTE Pico BS (2600 MHz band) Wireless microphone (1800 MHz band) FM Audio FM Audio LTE UE PMSE receiver (1800 MHz band) LTE UL LTE Macro BS 800 MHz band) PMSE receiver (800 MHz band) 42

39 Dual-band PMSE system measurement Parallel operation of two PMSE systems (830 and 1800 MHz), both operating at the respective receivers sensitivity limits. Minimum distance between LTE UE and both PMSE receivers. The audio signal of the 1800 MHz PMSE receiver was monitored while multiple handovers from 837 to 2535 MHz were executed. No interference could be observed. 43

40 Test setup LTE USB modems / Analogue PMSE Channel 1 LTE Macro BS 800 MHz (LTE band 20) Channel 2 LTE Micro/Pico BS 2600 MHz (LTE band 7) Timing reference LTE BS emulator Ch 1 Ch 2 R&S CMW500 Spectrum analyzer RF combiner Mini-Circuits ZFRSC-123-S+ RF combiner Mini-Circuits ZN2PD2-63-S+ Directional coupler Atlantic A RF combiner Mini-Circuits ZFRSC-123-S+ Uplink (800 MHz) LTE UE LTE spectrum & PMSE audio recorder Tektronix RSA6114A NI PXI LP filter LPF2 DC-1700 MHz Mini-Circuits VLF Programmable Attenuator A1 Agilent Attenuator driver Agilent 11713B FM Signal generator Audio DAC PMSE Receiver RF combiner RF combiner Mini-Circuits Mini-Circuits ZFSC S+ ZN2PD2-63-S+ R&S SMU 200A Focusrite Scarlet 2i2 44

41 Test setup LTE smartphones / Analogue PMSE Channel 1 LTE Macro BS 800 MHz (LTE band 20) Channel 2 LTE Micro/Pico BS 2600 MHz (LTE band 7) Timing reference LTE BS emulator Ch 1 Ch 2 R&S CMW500 Spectrum analyzer RF combiner Mini-Circuits ZFRSC-123-S+ RF combiner Mini-Circuits ZN2PD2-63-S+ Directional coupler Atlantic A Uplink (800 MHz) Test fixture LTE UE Tektronix RSA6114A LTE spectrum & PMSE audio recorder NI PXI LP filter LPF2 DC-1700 MHz Mini-Circuits VLF Programmable Attenuator A1 Agilent Attenuator driver Agilent 11713B FM Signal generator Audio DAC PMSE Receiver RF combiner RF combiner Mini-Circuits Mini-Circuits ZFSC S+ ZN2PD2-63-S+ R&S SMU 200A Focusrite Scarlet 2i2 45

42 Test setup LTE USB modems / Digital PMSE 46

43 Test setup Dual-band analogue PMSE Channel 1 LTE Macro BS 800 MHz (LTE band 20) Channel 2 LTE Micro/Pico BS 2600 MHz (LTE band 7) Timing reference LTE BS emulator Ch 1 Ch 2 R&S CMW500 Spectrum analyzer RF combiner Mini-Circuits ZFRSC-123-S+ RF combiner Mini-Circuits ZN2PD2-63-S+ Directional coupler Atlantic A RF combiner Mini-Circuits ZFRSC-123-S+ Uplink (800 MHz) LTE UE Tektronix RSA6114A LTE spectrum & PMSE audio recorder NI PXI Programmable Attenuator A1 Agilent RF combiner Mini-Circuits ZFSC S+ Attenuator driver Agilent 11713B FM Signal generator (800 MHz) Audio DAC PMSE Receiver 1800 MHz RF combiner Mini-Circuits ZN4PD1-63W-S+ RF combiner Mini-Circuits ZN2PD2-63-S+ R&S SMU 200A FM Signal generator (1800 MHz) Focusrite Scarlet 2i2 PMSE Receiver 800 MHz R&S SMBV 100A 47

44 UL power [dbm] LTE UE Uplink Spectrum and OOB emissions Comparison (USB modems) 40,00 30,00 20,00 UE 1 UE 2 UE 3 UE 4 10,00 0,00-10,00-20,00-30,00-40,00-50,00 f [MHz] 48

45 UL power [dbm] LTE UE Uplink Spectrum and OOB emissions Comparison (Smartphones) UE 5 UE 6 0 UE f [MHz] 49

46 LTE UE OOB emissions UE 1 (USB) 50

47 LTE UE OOB emissions UE 2 (USB) 51

48 LTE UE OOB emissions UE 3 (USB) 52

49 LTE UE OOB emissions UE 4 (USB) 53

50 LTE UE OOB emissions UE 5 (Smartphone) 54

51 LTE UE OOB emissions UE 6 (Smartphone) 55

52 LTE UE OOB emissions UE 7 (Smartphone) 56

53 C-Message Filter C-message weighting filter is a bandpass filter used to measure audiofrequency noise on telephone circuits. The C-message filter is typically used for North American telephone circuits. Source: Bell Systems. "Transmission Parameters Affecting Voice-band Transmission Measuring Techniques." Bell System Technical Reference, Pub , May