Content for TR 26.942 Word version: 19.0.0
7.9 Solution #8: UE application energy consumption measurement based on MTD technique
7.9.1 Key Issue mapping
7.9.2 Functional description
7.9.3 Procedures
7.9.4 Summary
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7.9 Solution #8: UE application energy consumption measurement based on MTD technique p. 60
7.9.1 Key Issue mapping p. 60
This Candidate Solution addresses Key Issue #2.
7.9.2 Functional description p. 60
7.9.2.1 Introduction p. 60
Month-till-Date or Month-to-Date (MTD) is a practical and popular method for performance tracking and analysis since it can be applied to a wide range of metrics and performance indicators. It gives information about how a particular statistic has fared this month in comparison to past months or predetermined goals. It is a widely used concept across different domains for tracking, reporting, and evaluating various metrics and performance indicators within the current month up to the present date [84].
With MTD, a metric's performance is evaluated from the beginning of the current month to the present, taking into account key performance indicators (KPIs). It is usually computed daily and gives an instantaneous picture of performance for the entire month so far.
The monthly total MTD is determined by adding the metrics' values from the first of the month to the present. For instance, adding up the daily battery consumption for a particular application from the first of the month to the current date would yield the total MTD energy consumption of the application.
7.9.2.2 Calculation of MTD p. 61
7.9.2.2.1 High-level description p. 61
At a very high level, calculating an MTD metric involves determining the period from the beginning of the current month up to the present date. It is calculated as follows:
- Identify the current date: Determine today's date, the end point of the MTD calculation.
- Identify the start of the month: Find the first day of the current month. For example, if today is July 15th, the start of the month would be July 1st.
- Count the number of days: Calculate the number of days from the start of the month up to the current date, including today.
7.9.2.2.2 UE battery consumption calculation p. 61
The energy consumed by a UE application can be expressed as an MTD metric. The percentage of total battery consumed by the application in a particular session is calculated using the following formula:
In the example depicted graphically in Figure 7.9.2.2.2-1 below, the total battery consumed is 0.051% of the total battery capacity of a Google Pixel 6 Pro smartphone with total battery capacity of 5003 mAh. The points on the graph show the cumulative battery consumption by the app till a particular time since the start of the session. In this example, the application has consumed a total of 1.03 mAh battery during the first 34.49 seconds of the session. The axes represent the following:
- X-axis: Depicts the time (in seconds) elapsed since the start of the session. 0 on the X-axis represents the start of the energy profiling session.
- Y-axis: Depicts the cumulative battery energy consumed by the application (in mAh) up to a particular point in time since the start of the energy profiling session. The Y-axis starts with 0 mAh.
Figure 7.9.2.2.2-1: Example of energy consumed by an application running on a smartphone
(⇒ copy of original 3GPP image)
(⇒ copy of original 3GPP image)
The actual MTD battery consumption is determined by subtracting the battery end percentage from the battery start percentage, and multiplying it by the percentage of consumption of the application (expressed as a decimal). From this, the mean average percentage consumed per hour can then be derived by dividing the actual consumption by 24.
To determine actual MTD battery consumption, the following formula can be used:
True Consumption (of app 1) = (Battery Start % − Battery End %) × (MTD Consumption % / 10)
To calculate the percentage of battery used per hour:
Battery Usage Per Hour (of app 1) = True Consumption / 24
Based on the data provided in the Figure 7.9.2.2.2-2 above, the calculation for MTD battery consumption is as follows:
- Device battery consumption since last charge = 93% − 78% = 15%
- MTD battery usage = 76% / 10 = 7.6
- True battery consumption = 15% × 7.6 = 114%
- Battery Usage by MTD per hour = 114% / 24 hours = 4.75% per hour
7.9.3 Procedures p. 62
The procedures for reporting this metric from the UE to an external entity are described in Solution #4 in clause 7.5.
7.9.4 Summary p. 62
This Candidate Solution proposes a new metric that allows UE application energy consumption to be measured. It has the following limitations:
- The solution evaluates the battery consumption of individual applications executing on a UE, while other energy consuming aspects such as radio transmissions (4G, 5G, Wi-Fi), etc. may have additional impact on the total battery consumption of the UE.
- The solution is UE implementation-specific, i.e. the same feature may result in different evaluations of battery consumption of the same application running on different UEs.
- The solution may result in different evaluations of battery consumption of the same UE depending upon the test conditions that may vary over time (e.g. environmental changes and radio conditions, etc.).
