Software Defined Radio Analysers for LMR Testing Lex Grubner Managing Director RF Test Solutions Ltd May 2010

Worldwide LMR Unit Numbers 16.1 M Digital Radios in Use 40% of total 24.7 M Analog Radios in Use 60% of total

Target Application for LMR Test Sets Manufacturing Test Bench Repair Repair PCB to component level “I” Level Test Repair to PCB or major part level “O” Level Test Confirm if Radio has fault Research & Development Green = Likely all you need Amber = May only be part what you need Red = Not likely to meet your need

Usage model for LMR Test Sets Bench Repair Fault tracing & component level repair on a circuit board 10% of job volume Average repair time 1- 2 hours 28% of test set time usage “I” Level Test Minor repair - replace board/part to get radio back in service 30% of job volume Average repair time 0.5 – 1 hours 44% of test set time usage “O” Level Test Quick go/no-go check of radio 60% of job volume Average repair time 0.25 hours 28% of test set time usage

LMR Test Set Situation in NZ Personally responsible for selling over 200 units for analogue radio test. Estimated analogue radio test sets in NZ. 85% over 10 years old. 20% over 20 years old. Estimated 30 SDR (digital capable) test sets.

What is Changing Analog to digital modulation. More Information same narrow bandwidth. More open standard deployments (P25, TETRA, DMR etc). Less proprietary standard deployments (SmartNet, EDACS etc). Radios operate in integrated network.

What is needed today in a LMR Test Set RF performance needs to be even better. Must support digital modulation. Must emulate network enough for radio to operate. SDR architecture to provide the modulation flexibility & protocol analysis power. A whole new set of measurement techniques.

Architecture of an Analogue Test Set

Internals of an Analogue Test Set

Architecture of a SDR Test Set

Internals of a SDR Test Set

Primary Advantages of a SDR Test Set Smaller and Lighter. More reliable (fewer components). Lower Power Consumption. Protocols and feature upgrades managed by user. Connectivity and Networking. Greater configuration flexibility (not limited by hardware paths). Cost.

Smaller and Lighter

Adding Protocols & Features To This!

Cost In 1990 a HP8920A base system = NZ$30,000. Inflation adjusted over 20 years = NZ$48,000 today. A R8000 base system today = NZ$26,000. A 1990 loaded HP8920A = NZ$40-45,000. Inflation adjusted = NZ$64–72,000 today. 3GHz R8000 Every HW option + DMR & P25 = NZ$48,500.

Challenges Testing Digital Radios Computer, networking and software skills as important as RF skills (problem may not be the radio). Learning & understanding SDR architectures, and Digital Modulation. Manufacturer Specific RSS (Radio Service Software) needed to put radio in test modes.

Terminology is Changing RF Carrier Power Deviation (FM) Mod Depth (AM) SINAD S/N Distortion Can make CW Measurements Simple Single Tone Audio Assessment Envelope Power (NXDN FDMA) Slot Power (DMR TDMA) BER FSK Error (DMR) Modulation Fidelity (P25/NXDN) Eye Diagrams Constellation Displays Modulation ALWAYS exists Each Digital Standard has unique test patterns. NAC (P25) Colour Code (DMR). Voice loopback.

Example DMR Test Screen

Example P25 Test Screen

Example Voice Record/Playback Screen

What to Look for in a SDR Test Set Good RF performance. Sufficient coverage of analogue/legacy signaling formats (CTCSS, POCSAG, DTMF, CDCSS etc). Support of digital formats of interest (DMR, P25, NXDN, LTR etc). Large display to view set up and results at same time. Adequate sensitivity for off air measurements. Fast, low noise Spectrum Analyser + TG with RL/DTF. Easily transportable & low power consumption.

Questions? Thank you (and please visit our stand!).