Empirical compatibility assessment in Poland LTE causes interference to ARNS Mateusz Berlik Office...

Empirical compatibility assessment in PolandLTE causes interference to ARNS

Mateusz BerlikOffice of Electronic Communications, Poland

Department of Frequency Resources Management

ITU Regional Seminar for Europe and CIS CountriesWarsaw, 7 - 9 May 2012

Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012

Agenda

• Introduction to the LTE vs. ARNS problem• Aims and conditions of the measurements• Radio systems under tests• Measurements action• Summary


Introduction to the LTE vs. ARNS problemWRC-12 AI 1.17 - to consider results of sharing studies between the mobile service and other services in the band 790-862 MHz in Regions 1 and 3, in accordance with Resolution 749 (WRC-07), to ensure the adequate protection of services to which this frequency band is allocated, and take appropriate action.

MOBILE

FIXED BROADCASTING

ARNS


Introduction to the LTE vs. ARNS problem



• Two approaches proposed by CPM-12:– coordination distances: 125 – 515 km

(depending on ARNS system and scenario)– coordination field strength triggers

• aggregate values – eg. 13 dBµV/m @ 10m in 6 MHz RBW for RLS1 radar;

• single values – eg. -24.24 dBµV/m @ 10m for ARNS terrestrial station


Agenda



Aims of the measurements:

• to analyse an impact of the LTE system on the radar system;

• to determine/assess the maximum level of the interfering signal.


What did we have?

• 4 ARSN systems operating in Poland;• agreement of the army on measurements

(with some restrictions);• LTE test terminals (provided by the

operator);• LTE signal generator (provided by Nokia

Siemens Networks Poland);• ARNS’s system operators/service staff.


What did we NOT have?

• detailed knowledge about the ARNS systems;

• documentation of the ARNS systems;• specialists in old ARNS systems;• compatibility criteria(!).


Agenda



Scenario

LTE terminal/signal generator ARNS ground station


Object of the measurements

• RSP-10 MN-1 radar system:– primary (RLS1) / secondary (RLS2) radar;– only RLS1 module currently in use;– radiolocator for traffic controllers;– less than 100 km operational radius;– is going to be replaced by modern systems.


RSP-10 Radar system (RLS1)


Agenda



Military base15-16.02.201130.03.2011

Military airfield17-18.02.2011


Measurement I (Toruń, 15-16.02.2011)

• The radar under maintenance works;• Direct connection to the radar receiver.


RSP-10

(part of RSP10)

G4-76A 75/50

RSP-10

50/75

indicator

oscilloscope

receiver unit

LTE signal generator

Signal

generator

Power adder

(double pulse)

Pulse gen.

2 dB 2 dB

6 dB 0.3 dB 0.4 dB

0.4 dB

0.4 dB 0.3 dB




LTE parameters:

Bandwidth [MHz] 5 5 10 20 5 5

Modulation QPSK 16-QAM 16-QAM 16-QAM 16-QAM 16-QAM

G4-76A generator settings:

„Reflected” signal [dBm] - 92.3 - 92.3 - 92.3 - 92.3 -82.3 -72.3

LTE generator „critical” power:

LTE Power [dBm] - 89.1 - 89.1 - 89.1 - 89.1 -87.1 -87.1

Sensitivity: -92.3 dBm Pol H: E = 24.6 dBμV/mPol V: E = 48.6 dBμV/m


Measurement II (Malbork, 17-18.02.2011)

• Operating radar used by military airfield in Malbork


Measurement II (Malbork, 17-18.02.2011)

• The radar in „receive-only” mode:– very optimistic results

(allowable interference > 50 dBµV/m);• Received interference’s level dramatically

higher when it works in regular „send-and-receive” mode;– there was no ability to repeat the

measurements.


Measurement III (Toruń, 30.03.2011)

• Operating radar (after maintenance works);• Measurements similar to ones performed in

Malbork;• LTE terminals as interfering transmitters.



Measure No. Received power [dBm]

Field strength at receiving

point [dBμV/m]

Distance [m] Frequencies

1 -95,2 35,5 706RSP-10: 835 MHzLTE: 834.75 MHz

2 -96,5 34,2 1 488RSP-10: 835 MHzLTE: 834.75 MHz

3 -96,3 34,4 1 504RSP-10: 835 MHzLTE: 834.75 MHz

4 -80,3 50,4 128RSP-10: 835 MHzLTE: 839.5 MHz

5 -69,7 61,0 128RSP-10: 835 MHzLTE: 840.5 MHz


Agenda



Summary

• Because of the lack of the technical compatibility criteria, it was difficult to use the results as a point in discussion.

• General conclusions:– LTE terminal does really interfere RSP-10 radar;– allowable interference field strength is probably higher

than protection level from the CPM-12 Report.• The results were useful for our administration.

Empirical compatibility assessment in Poland LTE causes interference to ARNS Mateusz Berlik Office...

Documents

Transcript of Empirical compatibility assessment in Poland LTE causes interference to ARNS Mateusz Berlik Office...