certain embodiments of the method according to the present invention are explained in the following , with references to fig1 , and 3 . in the flow charts of fig1 and 2 , phase 1 is performed until it is determined that the mobile communication equipment is in a power - off state . this may be realized in practice , for example , as follows . a signal is received from the control logic of a power supply unit . a change in the state of the signal indicates that a power - off state has been entered , whereupon implementation of the method begins . it is characteristic of the method that only a first part of the mobile communication equipment , which essentially consists of timing means , is kept continuously in operation , as indicated by reference number 2 . as shown by phase 3 , the timing means create a timing signal , whose timing period t is formed from a first time interval ti and a second time interval t 2 , in the manner shown by the first part of the timing diagram ( a ) of fig3 . the time interval ti is advantageously noticeably shorter than the time interval t 2 . the flow charts of fig1 and 2 differ from each other only in phase 4 . in the method according to the present invention , shown in fig1 a second part of the mobile communication equipment begins to operate and analyze the signals being monitored during the first time interval t 1 . in the primary embodiment of the method , shown in fig2 which differs from the embodiment of fig1 only in phase 4 , samples of the monitored signals are taken and multiplexed , after which they are analyzed . this happens entirely during the first time interval . the monitored signals may be , for example , a battery voltage signal , a charger detection signal , a signal indicating the state of a power button , and an alarm signal received from a real time clock . it is characteristic of the method that operation of the second part of the mobile communication equipment is disabled except during the first time intervals t 1 . in other words operation is disabled during the time intervals t 2 , as indicated by reference number 5 . if the power - off state is still active , only the first part of the mobile communication equipment , which essentially consists of timing means , is kept in continuous operation , and so on . the timing diagram ( b ) of fig3 illustrates the current consumption i q in the power supply unit of the mobile communication equipment when the method according to the present invention is applied . during the time interval t 2 , the only active circuits in the power supply unit are those needed to create timing signals , such as a clock divider , whose current consumption may be 30 μa , as shown in the timing diagram . during the time interval t 1 , the means for sampling , multiplexing and signal analysis are active , in addition to at least part of the control logic of the power supply unit , and current consumption may be 300 μa , for example , as shown in the timing diagram ( b ). operation can be realized using a function similar to a logic or function , so that a power - on state is entered if an impulse is received from one or more signals . this is detected when the samples are analyzed during the first time interval , and if a impulse is detected , a change is made to continuous monitoring of the signals received in phase 10 , by ending creation of timing signals for sampling , as shown in the timing diagram ( a ) of fig3 . the current consumption i q correspondingly remains at a higher level as shown by the timing diagram ( b ), and at moment t x the state changes from a power - off state to a power - on state as shown by the timing diagram ( c ). fig4 presents a block diagram of a possible embodiment of an arrangement according to the present invention . the parts of a power supply unit of mobile communication equipment that are essential in an arrangement according to the present invention are diagrammatically shown . part 20 of the power supply unit receives a battery voltage signal vbat , a charger detection signal vchar , a power button state signal pwr_btn and an alarm signal of a real time clock alarm . any one of these signals may give an impulse , whereupon the device enters a power - on state . vbat and vchar are analog direct voltage signals , whose level is monitored , and pwr_btn and alarm are digital signals , whose state is monitored . pwr_btn gives an impulse when the power switch button of the device is pressed , and alarm is a signal that gives an impulse to drive the device into a power - on state at a certain preset time . the nominal value of vbat may be 3 v , for example , and the level of charger detection signal vchar may be 0 . 5 v , for example . signals pwr_btn and alarm may be at zero except in an excited state , when they change to the voltage level of the battery voltage , such as 3 v . analysis of all the above - mentioned signals can be returned to signal - level analysis , which can be advantageously realized by normalizing the signals so that they can all be compared to the same threshold voltage . in this example case , the threshold voltage can be 0 . 5 v , and normalization is realized using suitable voltage dividers 21 , 22 ; 23 , 24 ; 25 , 26 ; and 27 , 28 at the outputs of signals vbat , vchar , pwr_btn and alarm . the part 20 of the power supply unit described here includes , first of all , block 29 , which receives normalized signals at its inputs a , b , c and d , and performs sampling and multiplexing . the multiplexed samples are consecutively conducted to a comparator 32 , which compares them to a reference voltage vref obtained from a power supply 31 . the output of the comparator is connected to the control logic 18 of the power supply unit for analysis . if during the analysis it is determined that one of the signals has given an impulse requiring a change into the power - on state , the control logic performs the necessary actions and outputs the necessary controls . part 20 also includes a clock / decoder block 30 , which creates timing signals for sampling . block 30 receives a control signal power_on_status from the control logic , the state of which signal indicates whether or not the power - off state is active . if the control signal indicates that the power - off state is active , timing signals are created in the clock / decoder block 30 according to the beginning of the timing diagram ( a ) of fig3 and correspondingly , signal enable_dig is produced , which activates logic unit 18 during the time interval t 1 to detect the state of the output of comparator 32 of block 20 . signal enable_dig disables operation of the logic unit during the time interval t 2 . the clock / decoder 30 also produces another clock frequency that times sampling . sampling of four signals can be controlled using two bits , which are conducted from block 30 to input a / b / c / d of block 29 . as it was stated earlier , the timing signals needed for periodic sampling are easily obtained , because in any case the power supply unit of mobile communication equipment contains an oscillator , and suitable timing signals are obtained from its frequency by means of clock dividers . suitable timing of sampling could be implemented as follows . once a second , during a 100 millisecond first time interval t 1 , consecutive samples of said four signals are first taken , and the samples are then multiplexed and analyzed during the same time interval . during this 100 millisecond interval , all the necessary circuit parts are enabled , after which they are disabled for the next 900 milliseconds . if one of the signals monitored during the power - off state gives an impulse and a change is made to a power - on state , it is no longer necessary to analyze signals pwr_btn and alarm . depending on the monitoring need , decoding of the multiplexing can be modified , for example , so that the vbat signal is continuously monitored and the status of the charger is monitored once a second , meaning that a sample of signal vchar is taken and analyzed . it is advantageous to realize the arrangement according to the present invention by integrating as much of it as possible in an asic circuit of a power supply unit , which is a typical solution in mobile communication equipment . the present invention may vary within the scope of the enclosed claims .