R&S®CMWrun - Battery life measurements

T&M solution

With the Internet of Things (IoT) world and its diverse applications that require a battery charge to last at least ten years, battery life testing becomes more important than ever. And for smartphones where more and more apps are running, it is crucial to test the latest features for reducing power consumption. Driven by the new IoT requirements for ultra-low power, in its latest releases (12 and 13) the 3GPP standardization recently defined features such as power save mode (PSM) and enhanced DRX (eDRX) in the diverse IoT UE categories as well as cDRX to reduce power consumption as much as possible.

The performance of these features to reduce power consumption can only be tested and analyzed in a controlled emulated network environment. R&S^®CMWrun offers the right solution for such tests under real, yet controlled conditions based on the well-known R&S^®CMW500. The R&S^®CMWrun CMW-KT051 collects samples from the R&S^®RT-ZVC02A/R&S^®RT-ZVC04A multi-channel power probe with autoranging at a high sample rate and displays the current and voltage or even the calculated instantaneous power (in Watt) over time.

Specific signaling trigger events (e.g. LTE attach, connected, idle signaling state or IMS registration) have been implemented, providing more details (i.e. more samples). These are displayed and time-correlated on the power consumption diagram. The power consumption diagram is also correlated to events at the IP level by using IP traffic analysis (R&S^®CMW-KM051), which indicates which app or IP flow affects the battery lifetime of smartphones or other wireless devices.

The R&S ^® RT-ZVC02A/R&S^®RT-ZVC04A multi-channel power probe with autoranging with R&S^®CMWrun allows you to monitor (in real scenarios) the power (current and voltage) consumed by IoT or M2M devices being powered by their own batteries, an A/C power adapter or even a USB connection. Smartphones use their own batteries and not simply a dummy battery. It is possible to monitor multiple channels and compare the power that parts on a board consume. For instance comparing how much the application processor, the RF power stage, or even individual components contribute to the total consumed power – always under a real signaling scenario. The R&S®CMWrun setup controlling the R&S^®CMW500 and the R&S^®RT‑ZVC02A/R&S^®RT‑ZVC04A multi-channel power probe with autoranging covers all power testing requirements of IoT devices, M2M applications, wireless modules used in the automotive industry, RF components under any signaling or non-signaling scenario for R&D, performance, regression or acceptance testing.

Battery life testing with the R&S®RT‑ZVC02A/ R&S®RT-ZVC04A multi-channel power probe with autoranging

The latest specifications for battery life measurement require not only monitoring of the current over time but also the voltage, including calculation of the instantaneous power at high sampling rates. For such testing requirements, it must be possible to measure the power a device consumes based on a real use case, i.e. powered by a real battery or from the USB interface or even from an AC adapter.

The R&S®RT‑ZVC02A/R&S®RT-ZVC04A multi-channel power probe with autoranging is designed to cover precisely such uses cases, and even offers up to two (with R&S®RT-ZVC02A) or four (with R&S®RT-ZVC04A) voltage and current channels.

Each power measurement group consists of a voltmeter and ammeter with 18-bit A/D resolution and 5 Msample/s sampling rate. The built-in multiplier function, available for each group, ensures synchronous, sample-by-sample multiplication of current and voltage samples at a rate of 5 Msample/s. An internal decimation unit accumulates the consumed power by averaging over 100, 1000 or 10 000 samples. This ensures that even very short power consumption peaks are captured, while reducing the data transfer rate to a level a PC can handle. Based on this data, R&S®CMWrun estimates the battery life and displays all power group measurements such as current, voltage and instantaneous power on the event graph.

The R&S®RT-ZVC02A/R&S®RT-ZVC04A multi-channel power probe’s ammeter is equipped with internal shunts that can be selected for one of the different measurement ranges of interest. The current can also be measured based on an external shunt that is configured and fitted directly to the device under test. In this case, the current is calculated based on the voltage drop across this external reference shunt – the internal ammeter becomes a high impedance voltmeter, effectively avoiding connection cable losses caused by high currents.

An autoranging mode for current measurements using either internal or external shunts is also available. It ensures highest current measurement precision by automatically changing the scale based on the current reading. The autoranging feature allows seamless current, voltage and power measurements up to a data rate of 50 ksample/s.

For the connection to the DUT, various connectivity options, such as 4 mm plugs, pin connectors and solder-in pins, are available to cover all kinds of application scenarios.

Battery life measurements and IP throughput testing are available in the following standard-specific R&S^®CMWrun packages:

• R&S^®CMW-KT053: for WCDMA/HSPA and GSM/(E)GPRS
• R&S^®CMW-KT054: for TD-SCDMA
• R&S^®CMW-KT055: for LTE/LTE-A (FDD/TDD)
• R&S^®CMW-KT057: for WLAN/Bluetooth^®
• R&S^®CMW-KT058: for CDMA2000^®, 1xRTT/1xEV-DO

The following option is mandatory:

• R&S^®CMW-KT051: adds E2E services, FTP/iPerf and controls the R&S^®CMW500 data application unit (DAU) and remotely controls the R&S^®RT‑ZVC02A/R&S^®RT‑ZVC04A multi-channel power probe with autoranging

R&S®CMWrun at a glance

The automation tool for the R&S^®CMW platform

Today the R&S^®CMW is the leading, most popular multistandard platform for UE testing. It is used by network operators, test houses, handset vendors and chipset manufacturers alike. The R&S^®CMWrun automation software meets all requirements for executing remote control test sequences on the R&S^®CMW in R&D, quality assurance, production and service for both current and future wireless equipment.

The software engine is based on the execution of test DLLs (plug-in assemblies). This architecture allows easy and straightforward configuration of test sequences without requiring specific programming knowledge of how to remotely control the instrument. It also provides full flexibility when configuring parameters and limits for the test items provided in the standard-specific R&S^®CMWrun package options.

Intuitive and easy to use

The intuitive graphical user interface makes it simple for users to test wireless devices for compliance with the 3GPP protocols for various technologies.

The applications are diverse. For example, in combined user experience tests, synchronized markers show the IP throughput and current drain at a glance. During analysis, event markers help the user optimize IP throughput and battery life. At the end of the test, an easy-to-read test report containing limits, test results and verdict is generated. The report is available in csv, txt, xml and pdf format.

Key facts

• Multitechnology solution for all standards supported by the R&S^®CMW family
• Ready-to-use solution for superior user experience test scenarios
• Just GUI, no programming, no code compilation
• Test creation, parameterization, execution and analysis in a single tool
• Full test script and DUT automation (R&S^®CMWrun own ADB/Android APP for iPerf/FTP)
• Application for SCPI remote control via LAN, GPIB interface or USB
• Sample test plans included