Abstract:
A method of and device for predicting the power consumption of a battery-powered mobile terminal ( 15 ) used for carrying out a sequence of user activities. Each user activity involves an interaction with the terminal and each user activity causes one or more terminal activities involving power consumption of the terminal. The method comprises the steps of: determining ( 4 ), for each user activity, which terminal activities it causes, carrying out ( 6 ) a series of user activities ( 2   a   , . . . , 2   m ), the terminal activities (Ia . . . In) of the series involving at least all terminal activities of the sequence, measuring ( 6 ) the power consumption of the terminal while carrying out the series of user activities, deriving ( 10 ) the power consumption of each terminal activity from the measured power consumption of the terminal, adding ( 12 ), for each of the user activities of the sequence, the stored power consumption of the respective terminal activities caused by the particular user activity to obtain the power consumption of the respective user activity, and adding ( 14 ) the respective power consumption of the user activities of the sequence to obtain the power consumption of the sequence.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to a system for the prediction of the power consumption of a mobile terminal, in particular a battery-powered mobile terminal. The invention also relates to a method for the prediction of the power consumption of a mobile terminal. 
       BACKGROUND OF THE INVENTION 
       [0002]    The battery life (that is, the time span during which a battery can be used before the battery charge is depleted) of a battery-powered mobile terminal is a very important factor in the user experience of such a terminal. A shorter than expected battery life can be very unsatisfactory and can harm the user&#39;s satisfaction, in spite of any appealing features of the terminal such as colour screen, camera and browsing services. Examples of battery-powered mobile terminals are a mobile phone, a barcode scanner, a remote control unit and a personal digital assistant (PDA). 
         [0003]    The battery life of a battery-powered terminal is dependent on the way a user uses the battery-powered terminal (which user activities are carried out, for how long). A different (battery-powered) terminal usage will cause different time durations before a terminal shuts down due to low battery. As a consequence battery-powered terminals will differ in their relative battery performance for typical groups of users. In order to relate power off time to a typical group of users, usage profiles can be used. 
         [0004]    In order for a battery-powered operator/terminal vendor to provide the end user with a terminal that has a satisfactory battery life, exhaustive measuring and testing of the battery-powered terminal is necessary. This includes the ‘classic’ (standardized) testing of talk-time and standby-time (these values are often used by terminal vendors/operators when selling their battery-powered terminals). During such tests the terminal is used according to a usage profile until the battery charge is depleted, whereby the usage profile comprises a plurality of user activities, like performing a voice call, to be performed by a user. 
         [0005]    Nowadays these tests are not satisfactory because of the extended functionality of battery-powered terminals. Users can perform a large number of other user activities on their battery-powered terminal, such as browsing, running java applications, camera use, etc. It is a problem that there is no standardized method of measuring the power consumption of these activities. This makes it difficult to benchmark the battery life of battery-powered terminals, in particular to benchmark per usage profile, where each usage profile comprises a number of user activities. 
         [0006]    The Prior Art fails to provide a satisfactory solution. U.S. Pat. No. 6,957,091 discloses a portable multi-band communication device containing a power amplifier, a battery and a controller which controls the output power level of the communication device. The controller monitors the digital output signal and in response determines the consumption of electrical energy from the battery. A control value of the output power amplifier is used for power consumption estimation. Clearly, U.S. Pat. No. 6,957,091 fails to take the power consumption effects of various distinct user activities into account. 
         [0007]    United States Patent Application US 2004/098222 discloses a method of determining usage time for a plurality of modes of a mobile device. Storage locations are provided for storing current usage values, each storage location being associated with a particular mode of the terminal. Thus various modes may be taken into account, but the individual power consumption of different user activities, and the causes of those differences, are not addressed, thus necessarily causing inaccurate estimates when the power consumption due to various user activities has to be predicted. 
       SUMMARY OF THE INVENTION 
       [0008]    It is an object of the invention to provide a method and device for predicting the power consumption of a battery-powered terminal related to user activities, using a non-exhaustive test. 
         [0009]    This object is achieved according to the present invention by a method of predicting the power consumption of a battery-powered mobile terminal used for carrying out a sequence of user activities, wherein each user activity involves an interaction with the terminal and wherein each user activity causes one or more terminal activities involving power consumption of the terminal, the method comprising the steps of:
       determining, for each user activity, which terminal activities it causes,   carrying out a series of user activities, the terminal activities of the series involving at least all terminal activities of the sequence,   measuring the power consumption of the terminal while carrying out the series of user activities,   deriving the power consumption of each terminal activity from the measured power consumption of the terminal,   adding, for each of the user activities of the sequence, the power consumption of the respective terminal activities caused by the particular user activity to obtain the power consumption of the respective user activity, and   adding the respective power consumption of the user activities of the sequence to obtain the power consumption of the sequence.       
 
         [0016]    By determining the terminal activities that the terminal performs during a certain user activity, it is possible to predict very accurately the power consumed during the user activity. Determining which terminal activities are associated with a certain user activity may be carried out by observation and subsequent (manual or computerised) recording, but are preferably carried out electronically, for instance by analysing signals produced in the terminal. 
         [0017]    The series of user activities may be identical to the sequence of user activities. However, the present invention offers the further advantage that the series may not identical to the sequence. That is, the sequence of user activities of which the power consumption is to be predicted does not have to be tested as such, as long as the power consumption of all terminal activities associated with (the user activities of) the sequence is known. The present invention therefore offers a very accurate method of predicting the power consumption of a sequence of user activities without having to test the sequence itself. When carrying out the series of user activities, the terminal activities of the series should normally involve at least all terminal activities of the sequence. Alternatively, the various user activities and/or terminal activities may be carried out at different points in time, while storing the results, thus making it unnecessary to carry out (part or all of) a series of user activities when the power consumption of a new sequence of user activities is to be predicted. 
         [0018]    The step of deriving the power consumption of each terminal activity may comprise the sub-step of storing the power consumption of each terminal activity. Similarly, the step of determining, for each user activity, which terminal activities it causes may involve storing its results. It will be understood that in all steps of the inventive method, intermediary and/or final results may be stored when necessary. 
         [0019]    In an advantageous embodiment, the series of user activities may be defined by a test template, such as a test profile, which may correspond to a usage profile. Accordingly, a usage profile may be tested using the method of the present invention. 
         [0020]    The step of measuring the power consumption of the terminal may comprise measuring the current consumption of the terminal, preferably also measuring a power source voltage from a power source connected to the terminal. 
         [0021]    In an embodiment of the present invention, calculating at least one terminal activity power consumption measure from at least one user activity power consumption measure comprises solving a set of linear equations with user activity power consumption measures and terminal activity consumption measures. By simple linear algebra the terminal activity power consumption can be established. 
         [0022]    A further embodiment of the present invention, wherein measuring the power consumption of the mobile terminal comprises measuring the current consumption of the mobile terminal, provides a simplification of the method in that no power source voltage has to be taken into account while establishing the power consumption. 
         [0023]    A still further embodiment of the present invention, wherein the measuring the power consumption of the mobile terminal further comprises measuring a power source voltage from a power source connected to the terminal, has the advantage that the power consumption of the terminal can be established more accurately, since, when the power source voltage drops, the current consumption increases. Various batteries used as power source may have different characteristics regarding the voltage behaviour while being depleted. Using the power consumption based upon power source voltage and current provides a better measure for comparison between various types of power sources, i.e. batteries. 
         [0024]    A yet further embodiment of the present invention additionally comprises the step of displaying the terminal power consumption measure on a display. This embodiment has the advantage that the result can be made available in a user friendly way. 
         [0025]    The present invention additionally provides a software program product for carrying out at least some of the method steps of the present invention. The software program product may comprise a plurality of instructions allowing a processor to carry out method steps. The software program product may, for example, be stored on a carrier, such as a CD or DVD, or on a (remote) server. 
         [0026]    The present invention also provides a system for the prediction of the power consumption of a battery-powered mobile terminal used for carrying out a sequence of user activities, wherein each user activity involves an interaction with the terminal and wherein each user activity causes one or more terminal activities involving power consumption of the terminal, the system comprising:
       a power source,   terminal connection means for connecting the power source to the terminal, the terminal connection means comprising a current measuring device,   a data acquisition interface connected to the current measuring device for inputting a terminal current measure,   a terminal power consumption evaluation processor connected to the data acquisition interface,   wherein the processor is arranged for measuring the power consumption of the mobile terminal during a series of user activities, the terminal activities of the series involving at least all terminal activities of the sequence, and   wherein the processor is further arranged for performing the steps of:   deriving the power consumption of each terminal activity from the measured power consumption of the terminal activity,   adding, for each of the user activities of the sequence, the power consumption of the respective terminal activities caused by the particular user activity to obtain the power consumption of the respective user activity, and   adding the respective power consumption of the user activities of the sequence to obtain the power consumption of the sequence.       
 
         [0036]    An advantageous embodiment, wherein the data acquisition interface has means for inputting a power source voltage, has the advantage that the power consumption of the terminal can be established more accurately, since the current consumption increases when the power source voltage drops. Different batteries used as power source may have different characteristics regarding the voltage behaviour while being depleted. Using the power consumption based upon both power source voltage and current provides a better measure for comparison between various types of power sources, i.e. batteries. 
         [0037]    A further embodiment, wherein the system further comprises a display and wherein the processor is arranged for displaying the terminal power consumption measure on the display, has the advantage that the result can be made readily accessible to a user. 
         [0038]    Measuring all relevant terminal activities only once will give insight in a wide range of user profiles (that can be adjusted when necessary) and give insight in what area the terminal vendor should improve to achieve better results. Benchmarking can be performed per user activity or terminal activity which gives useful arguments in discussions with terminal vendors. Furthermore it provides useful information for marketeers because the effect of terminals (and terminal improvements) can be mapped on user profiles. This may give insight in the best terminal for each market segment. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0039]      FIG. 1  schematically shows the interdependence of terminal activities, user activities and usage profiles. 
           [0040]      FIG. 2  schematically shows a diagram of an embodiment of a method according to the present invention. 
           [0041]      FIG. 3  schematically shows a diagram of an embodiment of a system according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0042]    In this description, embodiments of the invention are disclosed in relation with a mobile phone as a mobile terminal. It will be clear to a person skilled in the art that the use of a mobile phone is just an example and that the invention is applicable to, and may be used with, any type of (battery-powered) mobile terminal, such as PDAs (Personal Digital Assistants), laptop and notebook computers, and cameras. 
         [0043]    In order to relate mobile terminal usage to battery life, typical usage profiles  3   a , . . . ,  3   l  can be formulated. These usage profiles  3   a , . . . ,  3   l , which each comprise one or more user activities, are assumed to represent typical mobile terminal usage by a certain type of user. For this reason, the usage profiles are also referred to as user profiles. 
         [0044]    Usage of a mobile terminal can be divided into several user activities  2   a , . . . ,  2   m . A user activity  2   a , . . . ,  2   m  is a single activity a user may perform on a mobile terminal during a certain period of time. Examples of user activities can be, browsing, writing a message, performing a voice call, playing a streaming video. Many other user activities can be envisaged by a person skilled in the art. The power consumption of these user activities vary, e.g. a voice call consumes another amount of current (per second) than executing a java application. Because the power consumption determines the battery life, the battery life is heavily affected by the type and duration of the activities the user performs. 
         [0045]    Thus, a usage profile describes an array of user activities, preferably including relative user activity duration, typical for a specific user. Relative user activity durations are used, defined as a percentage of the total time a terminal is used. The interdependence of terminal activities, user activities and usage profiles is shown in  FIG. 1 . A usage profile comprises a plurality of user activities, which in turn comprise at least one terminal activity. A terminal activity therefore is an activity of the terminal caused by a user activity. Accordingly, a number of terminal activities are typically associated with each user activity, although some user activities may only involve a single terminal activity. 
       Example Usage Profile 1: 
       [0046]    4% of time: browsing 
         [0047]    4% of time: executing java application 
         [0048]    70% of time: stand-by 
         [0049]    10% of time: voice call 
         [0050]    2% of time: camera usage 
         [0051]    10% of time: sending text (SMS and/or MMS) messages 
         [0052]    A usage profile can be tested according to a known method by actually performing the user activities in a described usage profile. This method is also known as a stress test, because the battery is completely exhausted for every usage profile  3   a  . . .  3   l  tested. The steps in this known method can be:
       1: Describing a series of usage profiles in terms of user activities.   2: Fully charging the battery of mobile terminal.   3: Performing a usage profile according to step 1 repeatedly until power off of the mobile terminal due to an empty battery.   4: Repeating steps 2 and 3 for each usage pattern.       
 
         [0057]    An example of performing steps 1, 2 and 3 is: 
         [0058]    15 minutes browsing 
         [0059]    10 minutes java application 
         [0060]    60 minutes stand-by 
         [0061]    15 minutes voice call 
         [0062]    60 minutes stand-by 
         [0063]    10 minutes camera usage 
         [0064]    2 minutes creating MMS 
         [0065]    10 seconds sending MMS 
         [0066]    60 minutes stand-by 
         [0067]    . . . and repeating until the battery is depleted. 
         [0068]    This Prior Art method is a very time-consuming and labour-intensive, and therefore expensive method. Furthermore, this known method cannot identify the most power consuming user activity in a usage profile. No predictions can be made for other usage profiles and no suggestions to terminal vendors can be distilled, while benchmarking is not useful. The better the battery, the longer each measurement step will take. The more usage profiles are defined, the longer the complete measurement will take. 
         [0069]    In the method according to the present invention the stress tests are replaced by power consumption measurements per user activity. 
         [0070]    A user activity  2   a , . . . ,  2   m  can be subdivided into at least one predefined terminal activity  1   a  . . .  1   n . A terminal activity is a single activity a terminal performs when it is in use. Examples of terminal activities can be: receiving data packets, searching a mobile network, backlighting a display, running a java program. Many other terminal activities can be readily recognised by a person skilled in the art. Each terminal activity  1   a  . . .  1   n  may have its start and stop moment in time anywhere during the user activity. Terminal activities  1   a  . . .  1   n  may occur simultaneously or consecutively. 
         [0071]    The power consumption of these terminal activities  1   a  . . .  1   n  has to be determined in order to compare terminals. It is not possible to calculate all terminal activities  1   a  . . .  1   n  directly, because a user activity  2   a , . . . ,  2   m  usually comprises a plurality of terminal activities  1   a  . . .  1   n , e.g. browsing comprises lighting backlight+sending data+receiving data. The power consumption of terminal activities can be derived from the user activities. 
         [0072]    To determine the cause of a bad battery performance of a terminal, the terminal activities  1   a  . . .  1   n  can be compared with those of other terminals. E.g. very high power consumption during browsing of a first terminal could be caused by the fact that the backlight power consumption is twice as high as the backlight power consumption of a second terminal. 
         [0073]    The power consumption measure of a user activity  2   a , . . . ,  2   m  can be an array of several terminal  1   a  . . .  1   n  activities power consumption measures, including relative activity duration (expressed as percentages of the total power consumption of that terminal activity). Example: the user activity ‘browsing’ may comprise the mobile terminal activities 100% ‘backlight’+2% ‘sending data’+23% ‘receiving data’. This assumes that during browsing users are actively sending and receiving data 25% of their time, where reading/watching content is done for 75% of their time. Backlight will be on for 100% of the browsing time. 
         [0074]    To summarize, usage profiles  3   a  . . .  3   l  can be built from user activities  2   a  . . .  2   m  which in turn can be built from terminal activities  1   a  . . .  1   n , as visualized by  FIG. 1 . 
         [0075]    The proposed method according to the invention makes it possible to measure current consumption related to a terminal activity  1   a  . . .  1   n . By means of the formulas below the power off time for each profile can be predicted. 
         [0000]    
       
         
           
             
               
                 
                   
                     
                       
                         E 
                         
                           User 
                            
                           
                               
                           
                            
                           Activity 
                         
                       
                        
                       
                         ( 
                         m 
                         ) 
                       
                     
                     = 
                     
                       
                         ∑ 
                         n 
                       
                        
                       
                           
                       
                        
                       
                         { 
                         
                           
                             
                               E 
                               
                                 Terminal 
                                  
                                 
                                     
                                 
                                  
                                 Activity 
                               
                             
                              
                             
                               ( 
                               n 
                               ) 
                             
                           
                           * 
                           
                             
                               T 
                               
                                 Terminal 
                                  
                                 
                                     
                                 
                                  
                                 Activity 
                               
                             
                              
                             
                               ( 
                               n 
                               ) 
                             
                           
                         
                         } 
                       
                     
                   
                   , 
                 
               
               
                 
                   [ 
                   1 
                   ] 
                 
               
             
           
         
       
     
         [0000]    wherein E User Activity  (m) is the power consumption in Wh of the m th  user activity  2   a  . . .  2   m , E Terminal Activity  (n) the power consumption of the n th  terminal activity and T Terminal Activity  (n) the relative duration of the n th  terminal activity with respect to the m th  user activity. 
         [0000]    
       
         
           
             
               
                 
                   
                     
                       
                         E 
                         
                           Usage 
                            
                           
                               
                           
                            
                           Profile 
                         
                       
                        
                       
                         ( 
                         1 
                         ) 
                       
                     
                     = 
                     
                       
                         ∑ 
                         m 
                       
                        
                       
                           
                       
                        
                       
                         { 
                         
                           
                             
                               E 
                               
                                 User 
                                  
                                 
                                     
                                 
                                  
                                 activity 
                               
                             
                              
                             
                               ( 
                               m 
                               ) 
                             
                           
                           * 
                           
                             
                               T 
                               
                                 User 
                                  
                                 
                                     
                                 
                                  
                                 Activity 
                               
                             
                              
                             
                               ( 
                               m 
                               ) 
                             
                           
                         
                         } 
                       
                     
                   
                   , 
                 
               
               
                 
                   [ 
                   2 
                   ] 
                 
               
             
           
         
       
     
         [0000]    wherein E Usage Profile  (l) is the power consumption in Wh of the l th  usage profile  3   a  . . .  3   l , E User Activity  (m) the power consumption of the m th  user activity in the usage profile  3   a  . . .  3   l  and T User1 Activity  (m) the relative duration of the m th  user activity with respect to the usage profile  3   a  . . .  3   l . 
         [0000]    
       
         
           
             
               
                 
                   
                     
                       T 
                       off 
                     
                     = 
                     
                       
                         Battery 
                          
                         
                             
                         
                          
                         capacity 
                         * 
                         Aging 
                          
                         
                             
                         
                          
                         factor 
                       
                       
                         E 
                         
                           Usage 
                            
                           
                               
                           
                            
                           Profile 
                         
                       
                     
                   
                   , 
                 
               
               
                 
                   [ 
                   3 
                   ] 
                 
               
             
           
         
       
     
         [0000]    wherein T off  is the power-off time, that is the time a mobile terminal can be used according to a usage profile, and wherein the aging factor is due to battery recharging cycles. 
         [0076]    From the measured power consumption per terminal activity  1   a  . . .  1   n  also the power consumption of a specific User activity  2   a , . . . ,  2   m  during one battery cycle can be determined: 
         [0000]      Power consumption User Activity during one battery charge cycle [ Wh ]=Battery life [ h ]* Power consumption User Activity [ Wh ]*Relative duration User Activity 
         [0077]    An example of applying the method according to an embodiment of the invention is shown in  FIG. 2  and described below. 
         [0078]    The measurements are preferably automated as far as possible. A test engineer who uses the method according to an embodiment of the invention has to start with supplying information about some characteristics of the measurement and the terminal involved. 
       Measurement Characteristics: 
       [0079]    In each test, the measurement characteristics may differ. In order to be able to look for specific environment influences on the tests, the measurement characteristics and the terminal characteristics should be recorded in step 4 of  FIG. 2 . 
         [0080]    The measurement characteristics can be, for example (see Table 1): 
         [0000]    
       
         
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
             
             
               
                   
                 Test number 
               
               
                   
                 Date 
               
               
                   
                 Comments before measurement 
               
               
                   
                 Comments after measurement 
               
               
                   
                 Test engineer 
               
               
                   
                 Test location 
               
               
                   
                 GSM coverage (RF level) 
               
               
                   
                 Power Control Level 
               
               
                   
                 IMEI 
               
               
                   
                   
               
             
          
         
       
     
       Terminal Characteristics: 
       [0081]    For the correct calculation of power consumption and its comparison to the power consumption of other terminals (and reference values) the terminal characteristics should be recorded: 
         [0000]    
       
         
               
             
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                 (terminal characteristics): 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Terminal Type 
               
               
                 Hardware version 
               
               
                 Software version 
               
               
                 Battery type (Li-ion, Li-p) 
               
               
                 Battery capacity (mAh) 
               
               
                 Battery age (new, used, old) 
               
               
                 First and second display 
               
               
                 Display type (TFT, LCD) 
               
               
                 Display size (mm * mm) 
               
               
                 Display size (pixels * pixels) 
               
               
                 Display power management characteristics (15 sec less bright; 30 sec off) 
               
               
                 Keylight (yes/no) 
               
               
                 Keylight characteristics 
               
               
                 Terminal with/without flip 
               
               
                 Camera 
               
               
                 Java 
               
               
                   
               
             
          
         
       
     
         [0082]    In addition, the relationships between user activities and terminal activities may be recorded in step 4, if they are already known. Alternatively, these relationship may be established during the actual test phase. 
       Measurements: 
       [0083]    After the measurement characteristics and terminal characteristics have been entered in step 4 ( FIG. 2 ), power consumption tests are performed in step  6 , preferably on the basis of a test template  5 . The test template  5  comprises the user activities to be performed by the test engineer. In step  6  the test engineer performs the user activities as prescribed by the test template  5 . The terminal power consumption during the user activities is measured and recorded, and optionally integrated (that is, summed). The terminal power consumption can be established by measuring the terminal current and optionally the voltage of the power source ( 17  in  FIG. 3 ) during the terminal activities performed by the test engineer. The user activity power consumptions thus established can be stored in step  7  in a data structure  8  matching the test template  5  for performing calculations off line. 
         [0000]    
       
         
               
             
               
             
           
               
                 TABLE 3 
               
               
                   
               
               
                 (exemplary measurements): 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 A. Power consumption voice call, flip open, backlight off, 
               
               
                 B. Backlight Power consumption 1, (2 nd  display off, key light off), 
               
               
                 C. Backlight Power consumption 2, (2 nd  display on, key light off), 
               
               
                 D. Backlight Power consumption 3, (2 nd  display off, key light on), 
               
               
                 E. Backlight Power consumption 4, (2 nd  display on, key light on), 
               
               
                 F. Browsing, split by the test engineer into: 
               
               
                    a. Receiving data 
               
               
                    b. Sending data 
               
               
                 G. Power consumption in coverage, (no user activities, flip closed), 
               
               
                 H. Power consumption non-coverage, (no user activities, flip closed, this 
               
               
                   measurement has to be performed for a long time to be able to also 
               
               
                   determine the search pattern, coming from good coverage/starting 
               
               
                   from non-coverage), split into: 
               
               
                    a. Search activity 
               
               
                    b. Sleep activity 
               
               
                 I. Power consumption offline Java application, 
               
               
                 J. Power consumption camera search function, (default settings; write 
               
               
                   down default settings, like: is 2 nd  display on), 
               
               
                 K. Power consumption playing video from phone memory 
               
               
                 L. Power consumption playing video via streaming 
               
               
                   
               
             
          
         
       
     
       Terminal Activities: 
       [0084]    The terminal activities power consumptions that must be calculated in step  10  may be: 
         [0000]    
       
         
               
             
               
               
             
           
               
                 TABLE 4 
               
               
                   
               
               
                 (terminal activities 1a . . . 1n): 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                  1. Voice call 
               
               
                   
                  2. Receiving data 
               
               
                   
                  3. Sending data 
               
               
                   
                  4. Backlight main display 
               
               
                   
                  5. Backlight other display 
               
               
                   
                  6. Keylight 
               
               
                   
                  7. Run Java application 
               
               
                   
                  8. Camera search function 
               
               
                   
                  9. Video displaying 
               
               
                   
                 10. Sleep in coverage 
               
               
                   
                 11. Sleep in non coverage 
               
               
                   
                 12. Search activity 
               
               
                   
                   
               
             
          
         
       
     
         [0085]    As stated above, a user activity  2   a , . . . ,  2   m  (like browsing and messaging) comprises one or more terminal activities  1   a  . . .  1   n . The power consumptions of these terminal activities la . . .  1   n  have to be determined in order to compare terminals. It is not possible to calculate all terminal activities directly (e.g. because browsing consists of backlight+sending data+receiving data). From the user activity power consumption measurements the terminal activities power consumptions can be calculated in step  10  using a template  9  as described, by way of example, below: 
       A=‘1’ 
     B=‘4’ 
     C=‘4’+‘5’ 
     D=‘4’+‘6’ 
     E=‘4’+‘5’+‘6’ 
     Fa=‘2’+‘4’+‘5’+‘6’ 
     Fb=‘3’+‘4’+‘5’+‘6’ 
     G=‘10’ 
     Ha=‘12’ 
     Hb=‘11’ 
     I=‘7’+‘4’+‘5’+‘6’ 
     J=‘8’+‘4’+‘5’+‘6’ 
     K=‘9’+‘4’+‘5’+‘6’ 
     L=‘9’+‘2’+‘4’+‘5’+‘6’ 
       [0086]    The numbers between apostrophes refer to the terminal activity power consumption corresponding with the terminal activities in Table 4. 
         [0087]    Hence: 
       ‘1’=A 
     ‘4’=B 
     ‘5’=B+C 
     ‘6’=B+D 
       [0088]    . . . etc. 
         [0089]    On the basis of the calculated terminal activity power consumptions, user activity power consumption values can be calculated in step  12  according to a user activity calculation template  11 . This template  11  may contain the relationships between the user activities and the associated terminal activities. In step  12  user activity power consumption values can be calculated for user activities which may not have been tested, but of which the associated terminal activities are known. 
       Customer Report: 
       [0090]    The results of the automated measurement suite that can be reported in step  14  to a customer can be as listed as in Table 5 (below), for example, wherein each item is a linear combination of user activity power consumptions according to a usage profile  3   a  . . .  3   l . A template  13  may be used for compiling the report. 
         [0000]    
       
         
               
             
               
               
             
           
               
                 TABLE 5 
               
               
                   
               
               
                 (report): 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Talk time terminal 
               
               
                   
                 Standby time 
               
               
                   
                   In coverage 
               
               
                   
                   Non-coverage 
               
               
                   
                 Search pattern 
               
               
                   
                   Starting in non-coverage 
               
               
                   
                   Coming from good coverage 
               
               
                   
                 Power consumption Voice call 
               
               
                   
                 Power consumption Backlight main display 
               
               
                   
                 Power consumption Backlight other display 
               
               
                   
                 Power consumption Keylight 
               
               
                   
                 Power consumption Browsing 
               
               
                   
                 Power consumption Stand-by 
               
               
                   
                   In coverage 
               
               
                   
                   Non-coverage 
               
               
                   
                 Power consumption Java application 
               
               
                   
                 Power consumption Camera usage 
               
               
                   
                 Power consumption Video playing from terminal memory 
               
               
                   
                 Power consumption Video streaming 
               
               
                   
                   
               
             
          
         
       
     
         [0091]    From these results the impact of several usage profiles  3   a  . . .  3   l  on the overall power consumption measure of the terminal can be calculated. These results can further be compared to usage profiles of other terminals. 
         [0092]    The method according to the invention as described above can be implemented in a system for the prediction of the power consumption of a terminal  15  according to an embodiment of the invention. A block diagram of an embodiment of this system is shown in  FIG. 3 . 
         [0093]    This system for the prediction of the power consumption of a terminal  15  comprises an electrical power source  17 . This can be for example a power supply connected to the mains, a battery or a rechargeable battery fit for supplying the terminal with electric energy. Preferably the battery is removed from the terminal, placed in a holder and connected to the terminal using terminal connection means  16   a  . . .  16   d . The voltage may vary per terminal  15  and terminal type under test, but usually for a mobile phone the voltage is around 3.6 V. The power source  17  may further comprise a plurality of power sources depending on the terminal under test. A terminal power source  17  may have a plurality of connections as shown in  FIG. 3  by example of three connections  16   a  . . .  16   d , depending on the terminal  15  under test. According to the invention, the power consumption from the terminals having the largest voltage is established. 
         [0094]    The power source  17  has terminal connection means  16   a  . . .  16   d . This can be a cable fit for connecting the terminal  15  to the power source  17 , using a connector, but the connection means  16   a  . . .  16   d  may also comprise a terminal mount or holder in which a terminal  15  may be inserted for connecting to the power source  17 . 
         [0095]    The terminal connection means  16   a  . . .  16   d  comprises a current measuring device  18  for measuring the terminal current  20 . The currents to be measured are typically in the range of 5 to 3000 mA where the terminal  15  under test is a mobile phone, but the system is not limited to this range; any current range and even AC current may apply. 
         [0096]    The current measuring device  18  may comprise a current to voltage converter, well known to a person skilled in the art. The current measuring device  18  is connected to a data acquisition interface  21  for digitising the terminal current resulting in a momentary terminal current value. The current measuring device  18  can be an AD-converter having a plurality of inputs fit for digitizing a signal. The AD-converter may further be equipped with leads and inputs  19   a ,  19   b  for a power source  17  voltage measurement, or if the power source  17  is a battery, the battery voltage. The AD-converter can digitise the power source  17  voltage resulting in a momentary power source voltage value. 
         [0097]    The data acquisition interface  21  may be an integral part of or connected to a terminal power consumption evaluation processor  22  for forwarding and processing of the terminal current value and the momentary power source voltage value. From here on the terminal power consumption evaluation processor  22  is referred to as the processor  22 . The processor  22  may be a personal computer, for example a laptop computer or a dedicated, embedded, computer. 
         [0098]    A momentary terminal power consumption value can be established by multiplying the momentary power source voltage value with the momentary terminal current value by the processor  22 . Alternatively, if the power source  17  voltage is not measured, the momentary power consumption is determined by the momentary terminal current alone. 
         [0099]    The momentary power consumption is integrated during a user activity  2   a , . . . ,  2   m  power consumption measurement to obtain a user activity power consumption measure. 
         [0100]    During or following the test of step  6  in the process described above, the user activity power consumptions are stored  7  in a data structure  8  by the processor  22 . 
         [0101]    A user activity power consumption measure is treated as the sum of its terminal power consumptions measures. After a set of user activity power consumption measures have been established, the processor  22  is arranged to calculate the terminal activity power consumption measure, by linearly combining the user activity power consumption measures, i.e. by solving a set of linear equations. The results can be stored by the processor in data structures representing the terminal activities power consumption measures. 
         [0102]    The processor can be further equipped with a data structure representing a usage profile  3   a  . . .  3   l . The usage profile  3   a  . . .  3   l  comprises representations of user activities  2   a  . . .  2   m  that are performed during a certain time. This time may be represented in time units, or by a percentage of a time related to the usage profile. 
         [0103]    By combining the terminal activity power consumption measures the impact of several usage profiles on the overall power consumption measure of the terminal can be calculated. The power consumption measure can further be compared to the same usage profile of other terminals. 
         [0104]    The present invention may alternatively be defined as method for the prediction of the power consumption of a mobile terminal, which method may comprise the steps of:
       performing at least one user activity on the mobile terminal,   measuring the power consumption of the mobile terminal during the at least one user activity, wherein the at least one user activity comprises at least one terminal activity,   establishing a user activity power consumption measure by integrating the power consumption of the mobile terminal during the at least one user activity,   calculating at least one terminal activity power consumption measure from the at least one user activity power consumption measure,   calculating a user activity power consumption measure from the at least one terminal activity power consumption measure, and   calculating a terminal power consumption measure from the at least one user activity power consumption measure, using a usage profile comprising at least one user activity.       
 
         [0111]    By measuring the terminal current drawn from the power source, the power consumption can be established. The power consumption is measured during a limited number of user activities according to a usage profile. From the measured power consumption during the actually performed user activities, that is the power consumption of the terminal activities, it is possible to calculate the power consumption of further user activities that have not actually been performed, but of which is previously established which terminal activities contribute to such further user activities. Thus the power consumption of various usage profiles having different user activities or having the same user activities, but in a different mix in time, may be calculated based upon the terminal activity power consumptions, whereby such usage profiles do not actually have to be performed. 
         [0112]    It will be understood by those skilled in the art that many modifications and amendments are possible without departing from the scope of the invention as defined by the appended claims.