Testbed Setup

The smartphone used for the measurements is a Nokia N95 which is running Symbian OS  v9.2 as operating system.


When making the measurements, we used scripts to control the phone. This allowed us to measure the consumption without interacting directly with the phone, avoiding to press keys and to have the backlight of the display turned on, which could lead to unprecise results.


We used Python for S60 as programming language to develop the scripts for  testing. We observe that there is no significant penalty in terms of energy and performance by using the Python environment compared to standard Symbian/C++ for the energy levels we deal.

 

The choice of the aforementioned commercial device is due to several reasons. First of all it is equipped with several air interfaces, such as Bluetooth, WLAN, UMTS and secondly it is able to run the in-built energy profiler developed by Nokia.

 

The Nokia Energy Profiler is an application running on the mobile device that allows to make measurements without any additional hardware. It provides the values for power, current, temperature, signal strength and  CPU usage.

 

To further check the correctness of the data measured by the energy profiler on the phone, the complete setup includes the AGILENT 66319D used as multimeter as shown in the  Figure below. It is connected to a PC which is running the Agilent 14565B device characterization software, a tool designed for evaluation of portable battery powered device current profiles.

 

 

Setup for the measurements. The Nokia N95 connected to the AGILENT 66319D equipment.

We have compared results obtained with the energy profiler with the ones obtained with the Agilent 66319D.  The Figure below shows that the two plots  match almost perfectly with each other proving that data given by the Nokia Energy Profiler reliable.

Comparison of data obtained with the energy profiler and the Agilent 66319D while measuring the connection of the phone to a WLAN access point.

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Last update:26-05-2009