Method and apparatus for power conservation for a mobile device in
Contents
1. Soa quem t III PPP PII tn YA A t X wA AAA E S E he FIGURE I May 10 2012 Sheet 3 of 9 US 2012 0115552 A1 Patent Application Publication E DIA 9 9 9 vya 980 1706 970 070 5919 0 N Ul 9900 dn sayem IN 900911 15910 0 XH N 1340 09159091911 4 00 8706 COE Patent Application Publication May 10 2012 Sheet 4 of 9 US 2012 0115552 A1 B deeem FIGURE 4 Patent Application Publication May 10 2012 Sheet 5 of 9 US 2012 0115552 A1 ME all setup delay io the highest call setup delay Determine call setup delay according to current battery voltage kweli E i i Else Follow normal DEX cycle Dueterm ne wake up insatunt cali setup d elay i e THRESHOLD VOLTAGE FIGURE S Patent Application Publication May 10 2012 Sheet 6 of 9 US 2012 0115552 A1 FIGURE Ya Patent Application Publication May 10 2012 Sheet 7 of 9 US 2012 0115552 AI im 83 P i H ES zycie fh BIEN the pracdofined 3 if cunentband s DRX velt is LOW Hires sid Heu fas bove ah pesieduel Signal e fewer ps 1 PECH on belts innat ope than ote he quant i i H H i H H H H H H H H H H H H H H H H H i H H H H H H H H H i i H H H H H H H H H H H H H H H H H H H H H H H2. H H H H H H H H H H H H H H H H H H H H H H H i Patent Application Publication May 10 2012 Sheet 8 of 9 US 2012 0115552 A1 FIGURE 7 Patent Application Publication May 10 2012 Sheet 9 of 9 US 2012 0115552 AI FHGURES US 2012 0115552 Al METHOD AND APPARATUS FOR POWER CONSERVATION FOR A MOBILE DEVICE IN IDLE MODE RELATED APPLICATIONS 0001 This application claims priority to India Application No 2293 CHE 2010 filed on Aug 10 2010 and is incorpo rated herein by reference in its entirety TECHNICAL FIELD 0002 The present application relates generally to an appa ratus and a method for power conservation for a mobile device in idle mode BACKGROUND 0003 When a user equipment UE is put in idle mode where there is not an active radio resource control RRC connection the UE may continue going through discontinu ous reception DRX cycles In each DRX cycle the UE sleeps for certain amount oftime determined by an associated access network such as a Universal Terrestrial Radio Access Network UTRAN and then wakes up to see if there is any incoming call by checking the paging indicator channel PICH at a predetermined paging occasion The DRX cycle goes on continuously when UE is camped on to a cell It consumes energy that each time the UE wakes up and per forms tasks such as monitoring for active calls even the chance for receiving a call during certain time period of a d
3. cycle at the user equipment upon an occurrence of a triggering event and waking up from the power saving mode and checking for an active call after an occurrence of a second triggering event 2 The method according to claim 1 wherein determining the sleep cycle further comprises determining the number of discontinuous reception cycles based on qualities of consecu tively received paging indicator channel signals and a degree of mobility of the user equipment 3 The method according to claim 1 wherein checking for the active call comprises one of checking a paging indicator channel for a positive paging indicator and checking a ran dom access memory buffer for a stored positive paging indi cator 4 The method according to claim 1 wherein the triggering event comprises at least one of an arrival of a time of a day a manual activation of the power saving mode by a user via a user interface and the current available battery power level falling below a predetermined threshold wherein the arrival of the time of the day comprises the arrival of a night time when a likelihood of receiving a call is low 5 The method according to claim 1 wherein the second triggering event comprises at least one of an expiration ofthe sleep cycle and a manual deactivation of the power saving mode by a user via a user interface 6 The method according to claim 1 wherein entering the power saving mode further comprises waking up M times during the sle
4. and a second option to deactivate the power saving mode manually 17 The apparatus according to claim 10 wherein the trig gering event comprises at least one of an arrival of a time ofa day a manual activation of the power saving mode by a user via a user interface and the current available battery power level falling below a predetermined threshold wherein the arrival of the time of the day comprise the arrival of a night time when a likelihood of receiving a call is low and wherein the second triggering event comprises at least one of an expi ration of the sleep cycle and a manual deactivation of the power saving mode by the user via the user interface 18 A computer program product comprising a computer readable medium bearing computer program code embodied therein for use with a computer the computer program code comprising code for determining a sleep cycle comprising a number of discontinuous reception cycles at a user equipment based at least on one ofa current available battery power level a call setup delay interval and a quality of a received paging indicator channel signal code for entering a power saving mode during the deter mined sleep cycle at the user equipment upon an occur rence of a triggering event and US 2012 0115552 Al code for waking up from the power saving mode and checking for an active call after an occurrence of a sec ond triggering event 19 The computer program product according to claim
5. during the determined sleep cycle at the user equipment UE upon an occurrence of a triggering event and wake up May 10 2012 from the power saving mode and checking for an active call after an occurrence of a second triggering event BRIEF DESCRIPTION OF DRAWINGS 0007 For a more complete understanding of example embodiments of the present invention reference is now made to the following descriptions taken in connection with the accompanying drawings in which 0008 FIG 1 illustrates an example wireless system 100 that supports power saving mode operation in accordance with an example embodiment of the invention 0009 FIG 2 illustrates an example method for power saving operation in accordance with an example embodiment of the invention and 0010 FIG 3 illustrates an example sleep mode in accor dance with an example embodiment of the invention 0011 FIG 4 illustrates an example apparatus for support ing power saving operation in accordance with an example embodiment of the invention 0012 FIG 5 illustrates an example algorithm for deter mining call setup delay in accordance with an example embodiment of the invention 0013 FIG Sa illustrates an example operation of the algo rithm for determining call setup delay in accordance with an example embodiment of the invention 0014 FIG 6 illustrates an example algorithm determining call setup delay in accordance with an example embodiment of the invention
6. medium that may be any media or means that can contain or store the instructions for use by or in connection with an instruction execution system appara tus or device such as a computer 0056 If desired the different functions discussed herein may be performed in a different order and or concurrently with each other Furthermore if desired one or more of the above described functions may be optional or may be com bined 0057 Although various aspects ofthe invention are set out in the independent claims other aspects of the invention comprise other combinations of features from the described embodiments and or the dependent claims with the features US 2012 0115552 Al of the independent claims and not solely the combinations explicitly set out in the claims 0058 Itis also noted herein that while the above describes example embodiments of the invention these descriptions should not be viewed in a limiting sense Rather there are several variations and modifications which may be made without departing from the scope of the present invention as defined in the appended claims We claim 1 A method comprising determining a sleep cycle comprising a number of discon tinuous reception cycles at a user equipment based at least on one of a current available battery power level a call setup delay interval and a quality of a received paging indicator channel signal entering a power saving mode during the determined sleep
7. 0015 FIG 7 illustrates an example user interface to sup port user manual activation and deactivation of power saving mode in accordance with an example embodiment of the invention and 0016 FIG 8 illustrates an example wireless apparatus in accordance with an example embodiment of the invention DETAILED DESCRIPTION 0017 Disclosed herein are a method and an apparatus for further saving battery power when the UE is in an idle mode The UE takes into account the parameter such as time of the day and the number of times the paging is repeated before waking up from deep sleep to monitor the paging indicator channel for an arrival of an incoming call 0018 An example embodiment of the present invention and its potential advantages are best understood by referring to FIGS 1 through 8 of the drawings like numerals being used for like and corresponding parts of the various drawings 0019 FIG 1 illustrates an example wireless system 100 that supports power saving mode operation in accordance with an example embodiment of the invention The wireless system 100 includes a base station 110 such as a LTE Node B nodeB and two associated UEs 102 and 104 The UEs 102 and 104 may contain a power saving module as illustrated in FIG 4 and FIG 8 and described hereinafter and may be configured to execute a method as illustrated in FIG 2 and described hereinafter The power saving module of each UEs may operate independently without any input fr
8. 18 wherein the triggering event comprises at least one of an arrival of a time of a day a manual activation of the power saving mode by a user via a user interface and the current available battery power level falling below a predetermined May 10 2012 threshold wherein the arrival of the time of the day comprise the arrival of a night time when a likelihood of receiving a call is low 20 The computer program product according to claim 18 wherein the second triggering event comprises at least one of an expiration of the sleep cycle and a manual deactivation of the power saving mode by a user via a user interface x
9. E 102 and the UE 104 of FIG 1 or by the apparatus 800 of FIG 8 The method 200 is for illustration only and the steps of the method 200 may be combined divided or executed in a different order than illustrated with out departing from the scope of the invention of this example embodiment 0036 FIG 3 illustrates example power saving mode 300 for a UE in accordance with an example embodiment of the invention The example power saving mode 300 may include asleep cycle 302 and the sleep cycle 302 may include N DRX cycles numbered 304a through 304 An associated base station may repeat a paging indicator once a DRX cycle and the UE in the power saving mode 300 may wake up once each sleep cycle or N DRX cycles to check forthe paging indicator foran active call The length of each DRX cycle is determined by the base station and is known to each UE via a standard protocol The length of the sleep cycle or N DRX cycles is determined by the method as described above in the descrip tion of FIG 2 0037 FIG 4 illustrates an example apparatus 400 for sup porting power saving mode operation in accordance with an example embodiment of the invention The example appara tus 400 may include a radio signal measurement unit 402 a paging indicator PI RAM buffer 404 a PICH signal quality measurement unit 406 and a control processor 408 0038 In one example embodiment the radio signal mea surement unit 402 is configured to received downlink sig
10. US 20120115552A1 09 United States a2 Patent Application Publication co Pub No US 2012 0115552 Al Bhattacharya 43 Pub Date May 10 2012 54 METHOD AND APPARATUS FOR POWER Publication Classification CONSERVATION FOR A MOBILE DEVICE IN 51 Int Cl IDLE MODE H04W 52 02 2009 01 H04W 88 02 2009 01 75 Inventor Kaushik Bhattacharya Bangalore H04B 1 38 2006 01 IN 52 MUS CL eda cete nae eene det 455 574 57 ABSTRACT 73 Assignee NOKIA CORPORATION Espoo In accordance with an example embodiment of the present FI invention a method comprises determining a sleep cycle comprising a number of discontinuous reception DRX 21 Appl No 13 207 098 cycles at a user equipment UE based at least on one of a current available power level a call setup delay interval and E a quality of a received paging indicator channel PICH sig 22 Filed Aug 10 2011 nal entering a power saving mode during the determined sleep cycle at the user equipment UE upon an occurrence of 30 Foreign Application Priority Data a triggering event and waking up from the power saving mode and checking for an active call after an occurrence of a Aug 10 2010 IN w 2293 CHE 2010 second triggering event 00 r3 Patent Application Publication May 10 2012 Sheet 1 of 9 US 2012 0115552 A1 FIGURE i Patent Application Publication May 10 2012 Sheet 2 of 9 US 2012 0115552 A1 HR
11. ay such as hours from mid night to early morning is very low SUMMARY 0004 Various aspects of the invention are set out in the claims 0005 In accordance with an example embodiment of the present invention a method comprises determining a sleep cycle comprising a number of discontinuous reception DRX cycles at a user equipment UE based at least on one of a current available power level a call setup delay interval and a quality of a received paging indicator channel PICH signal entering a power saving mode during the determined sleep cycle at the user equipment UE upon an occurrence of a triggering event and waking up from the power saving mode and checking for an active call after an occurrence of a second triggering event 0006 In accordance with an example embodiment of the present invention an apparatus comprises a signal measure ment unit configured to wake up and collect a paging indica tor channel PICH signal and a paging indicator random access memory RAM buffer configured to store a PICH signal sample with a quality higher than a predefined thresh old The apparatus also comprises a control processor con figured to determine a sleep cycle comprising a number of discontinuous reception DRX cycles at a user equipment UE based at least on one ofa current available battery power level a call setup delay interval and a quality of a received paging indicator channel PICH signal enter a power saving mode
12. ay manually interrupt the sleep cycle and wake up the UE 102 via a user interface menu option In another example embodiment the base station 110 may uniformly define a sleep cycle for all UEs within a cell or an access network and send the sleep cycle to the UEs via broadcast or point to point messages The base station 110 may decide the sleep cycle based on the current and past system wide traffic conditions the number of UEs in the cell and other factors Each UE such as the UE 102 or the UE 104 within the cell may take the default sleep cycle sent from the base station 110 or override it with its own sleep cycle 0022 FIG 2 illustrates an example method 200 for power saving operations at a UE such as the UE 102 and the UE 104 of FIG 1 The method 200 may include deciding a length of a sleep cycle at block 202 entering a power saving mode upon occurrence ofa triggering event at block 204 and wak ing up from the sleep mode upon occurrence of another trig gering event at block 206 The method 200 may also include checking for positive paging indicator at block 208 and set ting up a call if a positive paging indicator is detected The method 200 may also include collecting PICH signal samples at block 222 obtaining quality measurements of PICH signal samples at block 224 and updating a stored paging indicator in a random access memory RAM buffer at block 226 0023 Inone example embodiment deciding the length of the sleep cycle at b
13. cle via a system information block SIB message In this case a UE may either adopt the cell wide length of the sleep cycle or override the default sleep cycle with its own In the former case the consideration of power level measured quality of PICH signal and call setup delay may be skipped 0027 In one example embodiment entering the power saving mode at block 204 may include entering the power saving mode upon occurrence of a triggering event The trig gering event may include an arrival of a time of a day such as night time when the chance of receiving a callis very low The triggering events may also include a low battery level of the UE and a manual activation of power saving mode by a user via a user interface such as the one shown in FIG 7 In one example embodiment entering the power saving mode at block 204 may include entering one of different levels of power saving mode For example in a deep power saving mode all processing modules may be turned off to conserve more power In a medium level of power saving mode all processing modules except for some essential units such as a PICH signal unit may be shut down 0028 In one example embodiment waking up from the power saving mode at block 206 may include waking up from the power saving mode upon occurrence of another triggering event The triggering event may be one ofan expiration ofthe sleep cycle with a predefined number of DRX cycles and a manual interruption of the pow
14. cordance with an example embodiment of the invention The example user interface 700 may include a menu 702 for operation modes and a submenu 710 for power saving operation mode The menu 702 may include a menu item power_saving 704 among other menu items such as Silent General Office and Offline The sub menu 710 for the power saving menu items may include an activate_power_ saving option 712 and a deactivate_power_saving option 714 The activate_power_saving option 712 and the deactivate_ power_saving option 714 may allow a user to manually acti vate or deactivate the power saving mode independent of a predefined triggering event such as arrival of night time The example user interface 700 may be part of the UE 102 and the UE 104 of FIG 1 US 2012 0115552 Al 0047 FIG 8 illustrates an example wireless apparatus in accordance with an example embodiment of the invention In FIG 8 the wireless apparatus 800 may include a processor 815 a memory 814 coupled to the processor 815 and a suitable transceiver 813 having a transmitter TX and a receiver RX coupled to the processor 815 coupled to an antenna unit 818 The memory 814 may store programs such as a power saving module 812 The wireless apparatus 800 may be at least part of a UE or an LTE compatible mobile station 0048 The processor 815 or some other form of generic central processing unit CPU or special purpose processor such as digital signal processor DSP may ope
15. e period reaches the end of a call setup delay period the signal samples stored in the sample RAM buffer are flushed because the stored signal samples may become stale 0039 In one example embodiment if there is a positive call indicator on the PICH channel the paging indicator is received by the radio signal measurement unit 402 and stored in the paging indicator RAM buffer 404 The control proces sor 408 is configured to detect a triggering event such as an expiration of a sleep cycle and wake up and check for the active call in the in paging indicator RAM buffer 404 when a triggering event is detected If there is an active paging indi cator the control process 408 is configured to process the active call in coordination with other modules of the UE 0040 In one embodiment the control processor 408 or the PICH signal quality measurement unit 406 may be configured to maintain a counter to keep track of the number of times the PICH quality value goes above a defined threshold and reset the counter to zero when the control processor 408 wakes up to end the current sleep cycle If the UE receives PICH signal with quality lesser than a threshold value in any of the DRX cycles of the sleep cycle the control processor 408 may be interrupted in the DRX cycle to facilitate the reselection to get a good quality channel On the other hand when the PICH signal quality in the previous DRX cycle was high and the PICH signal quality in the immed
16. echnical effect of one or more of the example embodiments disclosed herein is that the power sav ing is achieved with little effect on the call setup delay and thus little effect on the user s perception of delay in receiving acall as well A third technical effect is an increased reliabil ity in receiving paging indicator because only high quality PICH signal samples are kept and used 0055 Embodiments of the present invention may be implemented in software hardware application logic or a combination of software hardware and application logic The software application logic and or hardware may reside on user equipment such as a handset a computer and other mobile device If desired part of the software application logic and or hardware may reside on user equipment and part of the software application logic and or hardware may reside on a network element such as a base station In an example embodiment the application logic software or an instruction set is maintained on any one of various conventional com puter readable media In the context of this document a computer readable medium may be any media or means that can contain store communicate propagate or transport the instructions for use by or in connection with an instruction execution system apparatus or device such as a computer with one example of a computer described and depicted in FIG 8 A computer readable medium may comprise a com puter readable storage
17. ep cycle wherein the sleep cycle comprises N discontinuous reception cycles and 1 lt M lt N 7 The method according to claim 1 further comprising receiving a value for the discontinuous reception cycles contained in a system information block message from an associated base station 8 The method according to claim 1 wherein the sleep cycle is bound by smaller one of the call setup delay interval and a number of times the paging indicator is repeated 9 The method according to claim 1 further comprising collecting paging indicator channel signal samples and obtaining a signal quality measurement of the collected paging indicator channel signal samples 10 An apparatus comprising at least one processor and at least one memory including computer program code for one or more programs the at least one memory and the computer program code configured to with the at least one processor cause the apparatus to perform at least the following May 10 2012 determine a sleep cycle comprising a number of discon tinuous reception cycles at a user equipment based at least on one of a current available battery power level a call setup delay interval and a quality of a received paging indicator channel signal enter a power saving mode during the determined sleep cycle at the user equipment upon an occurrence of a triggering event and wake up from the power saving mode and checking for an active call after an occurrence o
18. er saving mode The number of DRX cycles within a sleep cycle may be set according to the factors described above at block 202 or may be set manu ally by the user according to a need to overwrite the prede termined DRX cycles In addition a user may also interrupt the sleep cycle on a need basis For example in middle of a night a user may have the UE enter the active mode in anticipation of a conference call from a different time zone 0029 In one example embodiment checking for positive paging indicator at block 208 may include checking the PICH channel to see if any active call indicator arrives at that US 2012 0115552 Al moment In another embodiment checking for positive pag ing indicator at block 208 may also include checking a RAM buffer that may store the latest positive paging indicator Multiple positive paging indicators may be sent from a base station in an attempt to establish a call and only the latest indicator with a quality higher than a threshold may be stored in the RAM buffer If checking for the positive call indicator at block 208 yields a positive result processing active call at block 210 may include proceeding to establishing a connec tion for the call and processing the call to its completion The processing active call at block 210 may also include entering the sleep mode once the active call is processed to completion if there is not any new triggering event that has occurred during the call processing to i
19. f a second triggering event 11 The apparatus according to claim 10 further compris ing a signal measurement unit configured to wake up and col lect a paging indicator channel signal and a paging indicator random access memory buffer config ured to store a paging indicator channel signal sample with a quality higher than a predefined threshold 12 The apparatus according to claim 11 wherein the signal measurement unit is configured to wake up at each discon tinuous reception cycle to collect the paging indicator chan nel signal sample without waking up other components of the apparatus 13 The apparatus according to claim 12 further compris ing a signal quality measurement unit configured to obtain a quality measurement of the collected paging indicator chan nel signal samples 14 The apparatus according to claim 13 wherein the qual ity measurement of the collected paging indicator channel signal is based on an estimation of a path loss obtained from a received signal code power measure a common pilot chan nel transmission power and an estimation of a downlink inter ference 15 The apparatus according to claim 10 wherein the appa ratus is further configured to cause a reselection process ini tiated when one or more low quality paging indicator channel signals are received 16 The apparatus according to claim 10 further compris ing auser interface comprising an option to activate the power saving mode manually
20. he threshold and the store high quality signal obtained at the DRX cycle X is overwritten and the control processor remains uninterrupted In a similar fashion during the subsequent DRX cycles 526 528 and 530 the received PICH signal with a quality higher than a threshold is retrained in the buffer at the end of each DRX cycles The control processor may check only the paging indicator channel for the current DRX cycle Since the quality of the received signals remained high during the call setup delay the UE wakes up at the end of the DRX cycle X 4 to process any positive call indicator if one is available 0044 FIG 6 illustrates an example algorithm 600 for determining a call setup delay in accordance with an example embodiment of the invention The example algorithm itself is self explanatory and may be one of different ways to deter mine a call set up delay based on the quality of the received PI indicator for the current and previous DRX cycles 0045 In one example embodiment the algorithm 500 and the algorithm 600 may be implemented by the example appa ratus 400 The algorithms are for illustration only and the steps of each of the algorithms may be combined divided or executed in a different order than illustrated without depart ing from the scope of the invention of this example embodi ment 0046 FIG 7 illustrates an example user interface 700 to support user manual activation and deactivation of power saving mode in ac
21. hreshold value the call setup delay may be set according to actual available power level If the current time is outside the power May 10 2012 saving time interval a normal DRX cycle is followed and the UE may wake up at each DRX cycle to check for an active call indicator The call setup delay may be used to determine the number of DRX cycles between two consecutive UE wake ups 0042 The algorithm 500 is for illustration only and it may be extended to accommodate other situation without depart ing from this invention For example if there is a need the algorithm may be extended to time intervals of the day other than the power saving interval during night time The current available battery level is taken into account because operation and saving requirements of the UE may change depending on the battery voltage level The step of determining the param eter call setup delay from battery voltage may be performed via a table lookup method 0043 FIG 5a shows an example operation 500a of the algorithm 500 for setting call setup delay In the example operation 500a the call setup delay duration includes 4 DRX cycles At the beginning ofthe first DRX cycle X labeled 522 because the quality of the received signal is higher than a threshold the stored signal in the RAM buffer is overwritten and the control processor is not interrupted At the beginning ofthe DRX cycle X 1 labeled 524 the received signal quality is higher than t
22. i May 10 2012 ated network to set up call to avoid any chance of missing the call due to poor PICH quality If the paging indicator is tested negative it may not be ascertained whether the paging indi cator is actually negative or an erroneous indicator due to the poor quality of PICH signals Thus in one example embodi ment when the PICH signal quality goes below a predefined threshold and the paging indicator is positive a cell reselec tion may be initiated to obtain a better quality PICH signal In another example embodiment if the PICH signal quality is low and the paging indicator is negative the reselection may be initiated regardless In another embodiment the decision of reselection may depend on an accumulative count of times when the low quality PICH signals are received over a num ber of times the paging indicator is repeated 0034 In one example embodiment updating the RAM paging indicator at block 226 may include updating the posi tive call indicator buffer according to the quality of the received call indicator If the quality of the collected call indicator is better than a threshold value and the buffer is empty the collected call indicator is stored Otherwise the stored call indicator in the RAM buffer is retained The updated paging indicator stored in the RAM buffer may be used for checking for positive call indicator at block 208 0035 In one example embodiment the method 200 may be implemented at the U
23. iately subsequent DRX cycle is also high the control processor 408 is not interrupted from the power saving mode In one embodiment the two variables may be maintained at the UE such as a current signal quality and a previous signal quality to keep track of the current and previous DRX cycle signal quality These two variables may be set to a binary value such as high or low to simplify the counter operation As described above the cen tral processor 408 may be configured to check only one PICH frame with minimal power consumption if the signal is of a quality higher than a threshold while in the power saving mode In one example embodiment the control processor 408 is a layer 1 protocol processor 0041 FIG 5 illustrates an example algorithm 500 for determining call setup delay in accordance with an example embodiment of the invention In one example embodiment according to the example algorithm 500 the call set up delay may be set to a maximum call setup delay possible if the current time is within the designated power saving interval and if there is no manual deactivation of the power saving mode The maximum call setup delay may be determined based on a maximum delay tolerance level that the user may have In case that the current battery level is below a prede termined threshold value the call setup delay may be set to the maximum call setup delay to conserve the power Other wise if the current battery power level is above the t
24. ice The transceiver 813 may provide frequency shift ing converting received RF signals to baseband and convert ing baseband transmit signals to RF for example In some descriptions a radio transceiver or RF transceiver may be understood to include other signal processing functionality such as modulation demodulation coding decoding inter leaving deinterleaving spreading despreading inverse fast fourier transforming IFFT fast fourier transforming FFT cyclic prefix appending removal and other signal processing functions In some embodiments the transceiver 813 por tions of the antenna unit 818 and an analog baseband pro cessing unit may be combined in one or more processing units and or application specific integrated circuits ASICs Parts of the transceiver may be implemented in a field program mable gate array FPGA or reprogrammable software de fined radio 0051 In an example embodiment the antenna unit 818 may be provided to convert between wireless signals and electrical signals enabling the wireless apparatus 800 to send and receive information from a cellular network or some other available wireless communications network or from a peer wireless device In an embodiment the antenna unit 818 may include multiple antennas to support beam forming and or multiple input multiple output MIMO operations As is known to those skilled in the art MIMO operations may provide spatial diversity and multiple parallel channe
25. ll is to be mini mized If there is a need the length of the sleep may be set in such a way that the UE wakes up at every DRX cycle as in busy mode of operation ofthe UE during day time 0025 Inone example embodiment deciding the length of the sleep cycle at block 202 may also include taking into consideration the past history of sample signals For example if the UE received a string of high quality PICH signals for a minimum duration continuously in the past the number of DRX cycles in the sleep cycle may be set higher for a deep sleep to further save battery power In addition the mobility ofthe UE may also be considered During off peak night time UE likely remains stationary if the UE continues getting good signal for a minimum number of DRX cycles and if total number of DRX cycles in the sleep cycle is less than a limit in terms of time duration the quality of the downlink signal may likely not change much in next DRX cycle So if these conditions are satisfied and paging indicator is repeated a minimum number of times such as three times the UE may enter a deep sleep mode and switch off everything to further conserve power 0026 In one example embodiment a base station such as the nodeB 110 of FIG 1 may decide a sleep cycle for power saving operation and decide the number of DRX cycles on an access network wide or cell wide basis The base station may send to all UEs in the access network or the cell a length ofthe sleep cy
26. lock 202 may include deciding on a num ber DRX cycles included within the sleep cycle based on factors such as a current battery power level a measured quality of received PICH signals and a call setup delay In one example embodiment if the current available battery power level is high the power saving strategy may be less aggres sive On the other hand if the available power level is lower than a threshold point a more aggressive power saving strat egy may be adopted to enter the power saving mode sooner and the sleep cycles may be longer than would otherwise In one example embodiment the measured quality of PICH signals may also be taken into consideration for deciding the length ofthe sleep cycle For example ifthe measured quality of the PICH signal is poor the power saving strategy may be less aggressive and sleep cycle shorter so that the UE may wake up more frequently to check PICH to avoid missing an active call due to a poor quality of signal transmissions 0024 Inone example embodiment deciding the length of the sleep cycle at block 202 may include taking into consid eration the call setup delay For example if the desired call setup delay is shorter than normal the power saving strategy may be less aggressive and sleep cycle may be shorter in order May 10 2012 to accommodate a shorter call setup delay The call setup delay may set an upper bound on the DRX cycles if the perceived delay by the user in receiving a ca
27. ls which May 10 2012 can be used to overcome difficult channel conditions and or increase channel throughput The antenna unit 818 may include antenna tuning and or impedance matching compo nents RF power amplifiers and or low noise amplifiers 0052 As shown in FIG 8 the wireless apparatus 800 may further include a measurement unit 816 which measures the signal strength level that is received from another wireless device and compare the measurements with a configured threshold The measurement unit may be utilized by the wire less apparatus 800 in conjunction with various exemplary embodiments of the invention as described herein 0053 In general the various exemplary embodiments of the wireless apparatus 800 may include but are not limited to part of a UE or a wireless device such as a portable computer having wireless communication capabilities Internet appli ances permitting wireless Internet access and browsing as well as portable units or terminals that incorporate combina tions of such functions In one embodiment the wireless apparatus 800 may be implemented in the UE 102 and the UE 104 of FIG 1 0054 Without in any way limiting the scope interpreta tion or application of the claims appearing below a technical effect of one or more of the example embodiments disclosed herein is that UE may save considerable amount of power during a time period of day when it is least likely to receive any call Another t
28. mples Obtaining quality measurements ofthe collected PICH signal samples at block 224 may also include aggregating multiple radio signals of the collected samples over previous DRX periods and averaging them out to obtain a collective quality measurement The obtained quality measurements of the PICH signals may be fed into the step of deciding the length of sleep cycle at block 202 for deciding the length of the sleep cycle More details on obtaining quality of PICH signals may be found in FIG 6 and described hereafter 0032 Inone example embodiment if PICH signal quality is high and a paging indicator is tested negative it may mean thatthe paging indicator has not been transmitted in that DRX cycle and a positive paging indicator had not been transmitted in the previous N 1 DRX cycle If the UE misses a paging indicator the paging indicator would be repeated N times by the base station Hence if the paging indicator is tested nega tive at a particular DRX cycle when the PICH quality is high the paging indicator information is believed to be reliable If the positive paging indicator has been transmitted in the past N 1 DRX cycles the paging indicator should be positive at the current DRX cycle 0033 In one example embodiment if the PICH quality is below a predefined threshold the paging indicator informa tion may not be as reliable as otherwise If the paging indictor is tested positive in this case the UE may contact the assoc
29. nals and a default PICH signal transmission power level wake up at each DRX cycle collect PICH signal samples on the PICH channel and pass the collected signal samples to the PICH signal quality measurement unit 406 The PICH signal quality measurement unit 406 may be configured to estimate PICH signal power level based on the received signal code power RSCP ofthe common pilot channel CPICH and a default PICH transmission power which may be configured by the network side and passed to the radio signal measurement unit 402 from a higher network layer The PICH signal quality measurement unit 406 may be further configured to estimate a downlink signal quality If the signal quality 1s higher than a predefined threshold the PICH signal quality measurement US 2012 0115552 Al unit 406 may be configured to store the signal into a PICH signal sample buffer maintained within the PICH signal qual ity measurement unit 406 if the buffer is empty The signal sample data in the PICH signal quality unit 406 may not be processed or decoded immediately Actual processing task may include applying a different channelization code such as an Orthogonal Variable Spreading Factor OVSF code witha correlation algorithm to extract PICH data from a signal channel In the subsequent DRX cycles if the quality of the received PICH signal is higher than a predefined threshold value the stored PICH signal sample may be maintained Also when one complete sleep cycl
30. nterrupt the power saving mode 0030 In one example embodiment collecting PICH sig nal samples at block 222 may include waking up at each of DRX cycles and performing a quick PICH signal sample collection The sample collection may be performed by a small portion of the UE with minimal power consumption in part because the task of collecting radio signal sample is simple with little complication of additional tasks Sample collection may be performed independently from waking up from the power saving mode to check for the positive call indicator partially because collecting radio signal sample such a PICH single is relatively simple and short Collecting the PICH signal samples at block 222 may also include put ting the collected samples into a RAM storage for subsequent processing Depending on time of the day either one or mul tiple collected PICH signal samples may be put in the RAM storage During the day time multiple PICH signal samples may be stored to increase the reliability During the night time a single PICH signal sample may be sufficient 0031 In one example embodiment obtaining quality measurements on PICH signal at block 224 may include taking measurement as the PICH signal is collected without first storing the PICH signals In an alternative embodiment obtaining quality measurements on PICH signals at block 224 may include taking collected radio signal samples from the RAM storage and take measurements of the signal sa
31. om any other network nodes or in collaboration with the base station 110 0020 In one example embodiment the UEs 102 and 104 enter a sleep mode as a triggering event occurs The triggering event may be an arrival of a predefined time period when the chance of receiving a call is low the time period such as 11 o clock in the night The UE 102 and UE 104 may have separate independent triggering events For example the UE US 2012 0115552 Al 102 may enter the sleep mode at 11 pm and the UE 104 may enter the sleep mode at 11 30 pm The UEs 102 and 104 may wake up from the sleep mode after a predefined sleep cycle check for active call indicator at a call indicator buffer or on a paging indicator channel and process the active call if there is one The sleep cycle may include a predefined number of DRX cycles and the number of the DRX cycles may depend on a number of factors such as a quality of the paging indi cator channel a current power level a desired call setup delay and the like The UE 102 may have a sleep cycle that is different from that of the UE 104 because the factors affect ing the number of DRX cycles in a sleep cycle may be differ ent If the UE 102 or the UE 104 detects an active call it proceeds to processing the active call and the UE may go back into the power saving mode after the call if there is not any other triggering event to interrupt the sleep cycle 0021 In one example embodiment the owner of UE 102 m
32. rate to control the various components of the wireless apparatus 800 in accordance with embedded software or firmware stored in memory 814 or stored in memory contained within the pro cessor 815 itself In addition to the embedded software or firmware the processor 815 may execute other applications or application modules stored in the memory 814 or made available via wireless network communications The applica tion software may comprise a compiled set of machine read able instructions that configures the processor 815 to provide the desired functionality or the application software may be high level software instructions to be processed by an inter preter or compiler to indirectly configure the processor 815 0049 In an example embodiment the power saving mod ule 812 may be configured to decide a number of sleep DRX cycles within a sleep cycle based at least on one of a current available battery power level a call setup delay interval and a quality of the paging indicator channel The power saving module 812 may be configured to enter a power saving mode upon an occurrence of a triggering event comprising an arrival of a time of a day such as night time when likelihood of receiving a call is low and wake up from a sleep mode and checking for an active call after an expiration of the number of sleep DRX cycles 0050 In one example embodiment the transceiver 813 is for bidirectional wireless communications with another wire less dev
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