Abstract:
A scheduling technique is described for discontinuous transmission and reception. The scheduling technique may be implemented in a mobile communication device with multiple SIMs. The scheduling technique facilitates enhanced communication capability for the mobile communication device. In one implementation, the scheduling technique helps avoid substantial overlap between discontinuous receive cycles of the SIMs, for example by renegotiating a discontinuous transmit/receive offset if too much overlap exists. The renegotiation process may be incorporated into a future industry standard communication protocol (e.g., 3GPP release 11 or later), or may be implemented as an extension to an existing communication protocol.

Description:
PRIORITY CLAIM 
       [0001]    This application is a continuation of U.S. application Ser. No. 13/453,841 filed Apr. 23, 2012, which claims the benefit of priority to the following U.S. provisional patent applications:
   U.S. Patent Application No. 61/569,621, filed Dec. 12, 2011;   U.S. Patent Application No. 61/587,521, filed Jan. 17, 2012; and   U.S. Patent Application No. 61/595,546, filed Feb. 6, 2012.   
 
     
    
     TECHNICAL FIELD 
       [0005]    This disclosure relates to communication devices with multiple Subscriber Identity Modules (SIMs). The disclosure also relates to enhanced discontinuous transmit and receive mode operation when radio frequency resources are shared between SIMs. 
       BACKGROUND 
       [0006]    Rapid advances in electronics and communication technologies, driven by immense customer demand, have resulted in the widespread adoption of mobile communication devices. The extent of the proliferation of such devices is readily apparent in view of some estimates that put the number of wireless subscriber connections in use around the world at nearly 80% of the world&#39;s population. Furthermore, other estimates indicate that (as just three examples) the United States, Italy, and the UK have more mobile phones in use in each country than there are people living in those countries. 
         [0007]    Relatively recently, cellular phone manufactures have introduced phone designs that include multiple SIM cards. Each SIM card facilitates a separate connection to the same network or different networks. As a result, the SIMs provide the owner of the phone with, for example, two different phone numbers handled by the same phone hardware. Accordingly, the multiple SIM approach alleviates to some degree the need to carry different physical phones, and improvements in multiple SIM communication devices will continue to make such devices attractive options for the consumer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The innovation may be better understood with reference to the following drawings and description. In the figures, like reference numerals designate corresponding parts throughout the different views. 
           [0009]      FIG. 1  shows an example of user equipment with multiple SIMs. 
           [0010]      FIG. 2  shows a timing example of DTX scheduling. 
           [0011]      FIG. 3  shows a timing example of DRX scheduling. 
           [0012]      FIG. 4  is an example of a timing diagram that shows the overlap in the SIM1 DRX pattern and the SIM2 DRX pattern. 
           [0013]      FIG. 5  is an example timing diagram that shows the effect of the user equipment negotiating a change the DRX parameters. 
           [0014]      FIG. 6  shows a timing diagram showing the result of the shift in the SIM2 DRX pattern. 
           [0015]      FIG. 7  shows an example timing diagram  700  that continues the example shown in  FIG. 2 . 
           [0016]      FIG. 8  shows a timing diagram in which the user equipment has negotiated with the Node B to shift the SIM2 DTX pattern ahead three subframes. 
           [0017]      FIG. 9  shows discontinuous mode enhancement logic (DMEL). 
           [0018]      FIG. 10  shows an example of a network controller  1000  that supports DTX/DRX negotiation. 
           [0019]      FIG. 11  shows an example of the DTX/DRX parameter negotiation logic (PNL) that may be implemented at the network controller. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    The discussion below makes reference to user equipment. User equipment may take many different forms and have many different functions. As one example, user equipment may be a cellular phone capable of making and receiving wireless phone calls. The user equipment may also be a smartphone that, in addition to making and receiving phone calls, runs general purpose applications. User equipment may be virtually any device that wirelessly connects to a network, including as additional examples a driver assistance module in a vehicle, an emergency transponder, a pager, a satellite television receiver, a networked stereo receiver, a computer system, music player, or virtually any other device. The discussion below addresses how to manage discontinuous mode reception and transmission in user equipment that includes multiple (e.g., two) SIMs. 
         [0021]      FIG. 1  shows an example of user equipment  100  with multiple SIMs, in this example the SIM1  102  and the SIM2  104 . An electrical and physical interface  106  connects SIM1  102  to the rest of the user equipment hardware, for example, to the system bus  110 . Similarly, the electrical and physical interface  108  connects the SIM2 to the system bus  110 . 
         [0022]    The user equipment  100  includes a communication interface  112 , system logic  114 , and a user interface  118 . The system logic  114  may include any combination of hardware, software, firmware, or other logic. The system logic  114  may be implemented, for example, in a system on a chip (SoC), application specific integrated circuit (ASIC), or other circuitry. The system logic  114  is part of the implementation of any desired functionality in the user equipment  100 . In that regard, the system logic  114  may include logic that facilitates, as examples, running applications, accepting user inputs, saving and retrieving application data, establishing, maintaining, and terminating cellular phone calls, wireless network connections, Bluetooth connections, or other connections, and displaying relevant information on the user interface  118 . The user interface  118  may include a graphical user interface, touch sensitive display, voice or facial recognition inputs, buttons, switches, and other user interface elements. 
         [0023]    The communication interface  112  may include one or more transceivers. The transceivers may be wireless transceivers that include modulation/demodulation circuitry, amplifiers, phase locked loops (PLLs), clock generators, analog to digital and digital to analog converters and/or other logic for transmitting and receiving through one or more antennas, or through a physical (e.g., wireline) medium. The transmitted and received signals may adhere to any of a diverse array of formats, protocols, modulations, frequency channels, bit rates, and encodings. As one specific example, the communication interface  112  may support transmission and reception under the Universal Mobile Telecommunications System (UMTS). The techniques described below, however, are applicable to other communications technologies regardless of whether they arise from the 3rd Generation Partnership Project (3GPP), GSM (R) Association, Long Term Evolution (LTE) (TM) efforts, or other partnerships or other standards bodies. 
         [0024]    Existing communication standards define a discontinuous receive mode (DRX) and a discontinuous transmit mode (DTX) for the user equipment  100 . One goal of DRX/DTX is to extend battery life by not constantly receiving or transmitting on, for example, the radio resource control channels during the entire time that the user equipment  100  is assigned the radio resource. Instead, the user equipment  100  may regularly enter power saving states that significantly reduce power consumption of the user equipment  100 . In the power saving states, the radio frequency (RF) modems and other system logic consume significantly less power. 
         [0025]    The DTX/DRX modes are particularly beneficial when the user equipment  100  has relatively low activity on the radio frequency (RF) channel that may result because the user equipment  100  is carrying out functions that only infrequently send or receive data. As a specific example of DTX, the user equipment  100  may enter a power saving mode during the sometimes frequent periods of silence in a voice conversation. DRX is also beneficial when a particular SIM is not in connected mode. Specifically, instead of the disconnected SIM waking up to listen for pages for the entire duration of the entire paging channel, the SIM may only wake and receive its assigned subchannels in the paging channel to determine if the SIM is being paged. In between the assigned subchannels, the user equipment  100  may be able to enter a power saving mode. 
         [0026]    In one implementation, the system logic  114  includes one or more processors  116  and a memory  120 . The memory  120  stores, for example, scheduling instructions  122  that the processor  114  executes. SIM1  102  and SIM2  104  may be on the same or different networks, and may be served by the same or different cells. For example, the Node B  128  may manage a particular cell to which SIM1  102  is connected, while the Node B  129  may manage a different cell to which SIM2  104  is connected. Accordingly, the DTX/DRX modes may be established for each of SIM1 and SIM2 independently. The user equipment  100  may stores a set of DTX/DRX parameters for each of the SIMs in the memory  120  as the SIM1 DRX/DTX parameters  124  and the SIM2 DRX/DTX parameters  126 . The Node Bs  128  and  129  (e.g., UMTS network base stations) can signal the DTX/DRX parameters to the user equipment  100  through Information Elements in a control channel, for example. As mentioned above, the Node B  128  may be part of a network that supports SIM1  102 , while the Node B  129  may be part of the same or different network that supports SIM2  104 . As will be described in more detail below, the system logic  114  will try to reduce inefficient DTX/DRX overlap between SIM1  102  and SIM2  104 . Such inefficiencies sometimes result because the different networks that assign the DTX/DRX parameters typically do not coordinate between themselves when assigning the parameters. 
         [0027]    Examples of the DRX/DTX parameters  124  and  126  include DRX/DTX offset, DRX/DTX cycle information, and other parameters such as those shown in sections 10.3.6.34a “DTX-DRX information” and 10.3.6.34b “DTX-DRX timing information”, in the 3GPP V9.6.0 Radio Resource Control (RRC) Protocol specification, and further explained in section 6C “Discontinuous transmission and reception procedures” in the 3GPP V9.5.0 Physical Layer Procedures (FDD) document. Before turning to the scheduling techniques in detail, a short summary of the DTX/DRX parameters are given next in Table 1 with accompanying explanation. Below, E-DCH is a reference to an Enhanced Dedicated Channel, while TTI is a reference to Transmission Time Interval, a UMTS parameter that specifies duration for encapsulating data from higher layers into frames for transmission on the radio interface, as examples, frames of length 2 ms, 10 ms, 20 ms, 40 ms, or 80 ms. 
       Examples of DTX/DRX Parameters 
       [0028]      
         [0000]    
       
         
               
             
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 exemplary DTX/DRX parameters 
               
             
          
           
               
                 Information Element/Group name 
                 Type and reference 
               
               
                   
               
               
                 DTX Information 
                   
               
               
                 &gt;CHOICE E-DCH TTI length 
               
               
                 &gt;&gt;10 ms 
               
               
                 &gt;&gt;&gt;UE DTX cycle 1 
                 Enumerated (1, 5, 10, 20) subframes 
               
               
                 &gt;&gt;&gt;UE DTX cycle 2 
                 Enumerated (5, 10, 20, 40, 80, 160) 
               
               
                 &gt;&gt;&gt;MAC DTX cycle 
                 Enumerated (5, 10, 20) subframes 
               
               
                 &gt;&gt;2 ms 
               
               
                 &gt;&gt;&gt;UE DTX cycle 1 
                 Enumerated (1, 4, 5, 8, 10, 16, 20) 
               
               
                   
                 subframes 
               
               
                 &gt;&gt;&gt;UE DTX cycle 2 
                 Enumerated (4, 5, 8, 10, 16, 20, 32, 40, 64, 
               
               
                   
                 80, 128, 160) subframes 
               
               
                 &gt;&gt;&gt;MAC DTX cycle 
                 Enumerated (1, 4, 5, 8, 10, 16, 20) 
               
               
                   
                 subframes 
               
               
                 &gt;Inactivity Threshold for UE DTX 
                 Enumerated (1, 4, 8, 16, 32, 64, 128, 256) 
               
               
                 cycle 2 
                 E-DCH TTIs 
               
               
                 &gt;Default SG in DTX Cycle 2 
                 Integer (0 . . . 37, 38) 
               
               
                   
                 Serving Grant value to be used at the 
               
               
                   
                 transition in DTX-Cycle-2. 
               
               
                   
                 (0 . . . 37) indicates E-DCH serving grant index 
               
               
                   
                 as defined in [15]; index 38 means zero 
               
               
                   
                 grant. 
               
               
                 &gt;UE DTX long preamble length 
                 Enumerated (4, 15) slots 
               
               
                 &gt;MAC Inactivity Threshold 
                 Enumerated (1, 2, 4, 8, 16, 32, 64, 128, 256, 
               
               
                   
                 512, Infinity) E-DCH TTIs 
               
               
                 &gt;CQI DTX Timer 
                 Enumerated (0, 1, 2, 4, 8, 16, 32, 64, 128, 
               
               
                   
                 256, 512, Infinity) subframes 
               
               
                 &gt;UE DPCCH burst_1 
                 Enumerated (1, 2, 5) subframes 
               
               
                 &gt;UE DPCCH burst_2 
                 Enumerated (1, 2, 5) subframes 
               
               
                 DRX Information 
               
               
                 &gt;UE DRX cycle 
                 Enumerated (4, 5, 8, 10, 16, 20) subframes 
               
               
                 &gt;Inactivity Threshold for UE DRX 
                 Enumerated (0, 1, 2, 4, 8, 16, 32, 64, 128, 
               
               
                 cycle 
                 256, 512) subframes 
               
               
                 &gt;Inactivity Threshold for UE Grant 
                 Enumerated (0, 1, 2, 4, 8, 16, 32, 64, 128, 
               
               
                 Monitoring 
                 256) E-DCH TTIs 
               
               
                 &gt;UE DRX Grant Monitoring 
                 Boolean 
               
               
                 Uplink DPCCH slot format information 
                 Enumerated (1, 4) 
               
               
                   
                 Slot format # to be used on UL DPCCH. 
               
               
                 Information Element/Group name 
                 Type and reference 
               
               
                 CHOICE timing 
               
               
                 &gt;Continue 
                 (no data) 
               
               
                 &gt;New timing 
               
               
                 &gt;&gt;Enabling Delay 
                 Enumerated (0, 1, 2, 4, 8, 16, 32, 64, 128) 
               
               
                   
                 radio frames 
               
               
                 &gt;&gt;UE DTX DRX Offset 
                 Integer (0 to 159) subframes. Offset of the 
               
               
                   
                 DTX and DRX cycles at the given TTI. 
               
               
                   
               
             
          
         
       
     
         [0029]    Regarding the parameters in Table 1, for discontinuous transmission, e.g., discontinuous uplink (UL) Dedicated Physical Control Channel (DPCCH) transmission: 
         [0030]    CQI_DTX_TIMER: Specifies the number of subframes during which the Channel Quality Indicator (CQI) reports have higher priority than the DTX pattern. This is the initial value of CQI nominal reporting timer. 
         [0031]    UE_DTX_cycle — 1: Specifies the UL DPCCH burst pattern length in subframes. 
         [0032]    UE_DTX_cycle — 2: Specifics the UL DPCCH burst pattern length in subframes. 
         [0033]    Inactivity_Threshold_for_UE_DTX_cycle — 2: Defines a number of consecutive E-DCH TTIs without an E-DCH transmission, after which the user equipment  100  moves from UE_DTX_cycle — 1 to using UE_DTX_cycle — 2. 
         [0034]    UE_DPCCH_burst — 1: Determines the Uplink DPCCH burst length in subframes, when UE_DTX_cycle — 1 is applied. 
         [0035]    UE_DPCCH_burst — 2: Determines the Uplink DPCCH burst length in subframes, when UE_DTX_cycle — 2 is applied. 
         [0036]    UE_DTX_Iong_preamble_length: Determines in slots the length of the preamble associated with the UE_DTX_cycle — 2. 
         [0037]    For both discontinuous UL DPCCH transmission and discontinuous downlink reception: 
         [0038]    UE_DTX_DRX Offset: Determines the UL DPCCH burst pattern and HS-SCCH reception pattern offset in subframes. 
         [0039]    Enabling_Delay: ensures that the uplink DPCCH and downlink F-DPCH are transmitted continuously for Enabling_Delay radio frames after DTX_DRX_STATUS is set to TRUE or ensures that, with DTX_DRX_STATUS set to TRUE, the uplink DPCCH on the secondary uplink frequency is transmitted continuously for Enabling_Delay radio frames after application of secondary uplink frequency activation. 
         [0040]    For discontinuous downlink reception: 
         [0041]    UE_DRX cycle: Determines the HS-SCCH reception pattern length in subframes. 
         [0042]    Inactivity_Threshold_for_UE_DRX_cycle: Defines the number of subframes after an HS-SCCH reception or after the first slot of an HS-PDSCH reception during which the user equipment  100  monitors the HS-SCCHs in the user equipment&#39;s HS-SCCH set with the exceptions of N_acknack_transmit&gt;1 or InterTTI&gt;1. 
         [0043]    UE_DRX_Grant_Monitoring: A Boolean which determines whether the user equipment is required to monitor the E-AGCH transmissions from the serving E-DCH cell and the E-RGCH from cells in the serving E-DCH radio link set when certain conditions are met. 
       Example Discontinous Timing Patterns 
       [0044]      FIG. 2  shows a timing example of DTX scheduling  200  for SIM1  102  and for SIM2  104 . Each SIM may have different DTX and DRX patterns because each SIM may be connected to different networks that supply different timing parameters. For example, the SIM1  102  may receive its parameters from the Node B  128  and SIM2  104  may receive its parameters from the Node B  129 .  FIG. 2  shows a radio frame  202  which in this example is 10 ms long, and an example DTX uplink burst pattern  204  for SIM1  102 . The uplink burst pattern  204  shows that SIM1  102  transmits discontinuously during the radio frame  202 . In particular, in this example, the DTX parameters have established that SIM1 will only transmit during the first subframe in each radio frame  202 . In other subframes, the SIM1  102  does not transmit and the user equipment  100  may enter a low power mode if the radio resource otherwise remains unused. 
         [0045]      FIG. 2  also shows that SIM2  104  has its own DTX timing. In particular, SIM2  104  also has its own radio frame  206 , and the timing need not be the same as the timing for SIM1  102 . SIM2 also has its own uplink burst pattern  208 . The uplink burst pattern  208  may be established by the timing parameters provided by the Node B  129 , for example. Similar patterns exist for the DRX mode of operation, as will be described in more detail below. 
         [0046]    Section 6C, titled Discontinuous transmission and reception procedures, in the 3GPP V9.5.0 Physical Layer Procedures (FDD) document explains the way in which the DRX/DTX parameters establish the DRX and DTX patterns. However, the techniques described in this document are not limited to any particular way of defining the DRX or DTX patterns based on the DRX and DTX parameters. Just as an example to help illustrate the DRX and DTX pattern determination, Table 2 summarizes how the DTX patterns are determined under Section 6C and Table 3 summarizes how the DRX patterns are determined under Section 6C for high speed shared control channels (HS-SCCH). Tables 2 and 3 also highlight one way in which the UE_DTX_DRX_Offset parameter shifts the DTX and DRX patterns by moving the first subframe in the uplink burst or the subframes that are received. 
         [0000]    
       
         
               
             
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                 Summary of DTX pattern determination 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 The Uplink DPCCH burst pattern may define a minimum set of slots (e.g., subframes) in 
               
               
                 which the user equipment transmits (e.g., transmits a UL-DPCCH). The UL DPCCH burst 
               
               
                 pattern may be derived as follows: 
               
               
                 1) With no E-DCH transmission for the last Inactivity_Threshold_for_UE_DTX_cycle_2 E- 
               
               
                 DCH TTIs, and at least this many TTIs have passed since the end of the Enabling_Delay, 
               
               
                 then: 
               
               
                 1a) The transmission length in the Uplink DPCCH burst pattern is: 
               
               
                 UE_DPCCH_burst_2 subframes. 
               
               
                 1b) The gap length following the DPCCH transmission burst in the Uplink DPCCH burst 
               
               
                 pattern is: (UE_DTX_cycle_2 − UE_DPCCH_burst_2) subframes, 
               
               
                 1c) The first subframe in each Uplink DPCCH burst pattern shall be such that 
               
               
                 the CFN and DPCCH subframe number S satisfy: 
               
               
                 ((5*CFN − UE_DTX_DRX_Offset + S) MOD UE_DTX_cycle_2) = 0 
               
               
                 2) Otherwise: 
               
               
                 2a) The transmission length in the Uplink DPCCH burst pattern is: 
               
               
                 UE_DPCCH_burst_1 subframes. 
               
               
                 2b) The gap length following the DPCCH transmission burst in the Uplink DPCCH burst 
               
               
                 pattern is: (UE_DTX_cycle_1 − UE_DPCCH_burst_1) subframes. 
               
               
                 2c) The first subframe in each Uplink DPCCH burst pattern shall be such that 
               
               
                 the CFN and DPCCH subframe number S satisfy: 
               
               
                 ((5*CFN − UE_DTX_DRX_Offset + S) MOD UE_DTX_cycle_1) = 0 
               
               
                   
               
             
          
         
       
     
         [0000]                          TABLE 3               Summary of DRX pattern determination                                The HS-SCCH reception pattern may be derived from discontinuous reception subframe       numbering using the following assumptions, where CFN is a reference to the Connection       Frame Number and HS-PDSCH is a reference to the high speed physical downlink shared       channel:       1) The discontinuous HS-SCCH reception subframe numbering is such that:       a) A HS-SCCH discontinuous reception radio frame is 10 ms long and is indexed using       CFN_DRX.       b) The start of the HS-SCCH discontinuous reception radio frame of CFN_DRX n is       aligned with the start of the HS-SCCH subframe that starts τDRX chips after the start of       the associated downlink F-DPCH of Connection Frame Number (CFN) n.       c) The HS-SCCH subframe S_DRX=0 is aligned with the start of the HS-SCCH       discontinuous reception radio frame. The HS-SCCH subframes are numbered S_DRX=0       to S_DRX=4.       d) The HS-PDSCH discontinuous reception radio frame of CFN_DRX n starts τHS-       PDSCH chips after the start of the HS-SCCH discontinuous reception radio frame of       CFN_DRX n. The HS-PDSCH subframe S_DRX=0 is aligned with the start of the HS-       PDSCH discontinuous reception radio frame. The HS-PDSCH subframes are numbered       S_DRX=0 to S_DRX=4.       e) The HS-DPCCH discontinuous transmission radio frame of CFN_DRX n starts at the       HS-DPCCH subframe boundary closest in time to 1280 chips after the start of the HS-       SCCH discontinuous reception radio frame of CFN_DRX n as received at the UE. The       HS-DPCCH subframe S_DRX=0 is aligned with the start of the HS-DPCCH discontinuous       transmission radio frame. The HS-DPCCH subframes are numbered S_DRX=0 to       S_DRX=4.       2) The HS-SCCH reception pattern is the set of subframes whose HS-SCCH       discontinuous reception radio frame number CFN_DRX and subframe number S_DRX       satisfy:       ((5*CFN_DRX − UE_DTX_DRX_Offset + S_DRX ) MOD UE_DRX cycle) = 0                    
Enhanced Discontinuous Mode Operation p In some implementations of the user equipment  100 , the SIMs share radio frequency resources, including the transmit/receive paths in the communication interface  122 . As a result, both SIMs cannot receive at the same time or transit at the same time. Instead, the user equipment  100  allows the SIMs to share the radio frequency resources in a time division manner.
 
         [0047]    Sharing the radio frequency resources, in combination with DTX/DRX, can lead to situations in which the radio frequency resources are used less efficiently than they might otherwise be used.  FIG. 3  shows timing diagrams  300  for DRX scheduling. The timing diagrams  300  show the SIM1 radio frame  302 , and the five subframe HS-SCCH channel  304  within the radio frame  302 . The DRX parameters received from the Node B  128  have configured the radio access for SIM1  102  to provide a DRX pattern  306  through which the SIM1  102  receives every fourth subframe of the HS-SCCH channel  304 . In other words, UE_DRX_Cycle=4. In this example, SIM1  102  only needs to be active on the radio resources to receive one out of every four HS-SCCH frames. 
         [0048]    Similarly, SIM2  104  operates with a 10 ms radio frame  308 , which is not typically synchronized in time with the SIM1 radio frame  302 . The DRX parameters received from the Node B  129  have also configured the SIM2  104  to receive every fourth subframe of the HS-SCCH channel for the network that SIM2  104  is on. SIM2 thus has the DRX pattern  310 . 
         [0049]      FIG. 4  is a timing diagram  400  that shows the overlap in the SIM1 DRX pattern  306  and the SIM2 DRX pattern  310 . In particular due to the timing similarities in the SIM1 DRX pattern  306  and the SIM2 DRX pattern  310 , each pattern has substantial overlap. One specific example is the timing overlap  402 , which is about 60% overlap between SIM1  102  and SIM2  104 . The timing overlap  402  repeats regularly, each time both SIM1  102  and SIM2  104  are configured to be active and receiving on the radio resource. 
         [0050]    The time sharing of the radio frequency resources support multiple SIM operation in the user equipment  100 . However, this time sharing can cause inefficiencies in responding to wake-up paging signals and in general receiving data while connected. This is particularly true when the multiple SIMs have significant overlap in reception timing, as shown in the examples in  FIGS. 3 and 4 . More specifically, the discontinuous reception parameters have established that both SIMs are supposed to be receiving at the same time (i.e., during the overlap  402 ), but cannot do so because the radio resources are shared and only permit access one SIM at a time. As a result, when there is overlap, one SIM cannot receive pages (e.g., in the HS-SCCH) or data because the other SIM is active instead. 
         [0051]    To enhance the discontinuous modes of operation, the system logic  114  determines the amount of overlap in DRX or DTX cycles between SIM1 and SIM2 (and optionally additional SIMs if present in the user equipment  100 ) and attempts to shift the DRX pattern, DTX pattern, or both to enhance the discontinuous mode of operation. In one implementation, the scheduling instructions  122  determine whether the DRX or DTX patterns meet predetermined efficiency criteria  130 . 
         [0052]    Examples of efficiency criteria include: whether there is DRX or DTX overlap, whether overlap is less than a threshold percentage (e.g., 10%) of overlap, whether fewer than ‘n’ subframes overlap in any amount out of every ‘r’ subframes, or whether at least some number of subframe, chip, timing or other gap exists between DRX or DTX accesses for different SIMs. When the efficiency criteria  130  is not met, for example when the amount of overlap exceeds an overlap threshold, the system logic  114  may then attempt to shift the DRX pattern, DTX pattern, or both (when they may be shifted independently under a given communication standard), to satisfy the efficiency criteria  130  for the discontinuous mode of operation. 
         [0053]    Shifting the DRX/DTX patterns may include negotiating various parameters with the network controllers (e.g., the Node B  128  and Node B  129 ) for any of the SIMs in the user equipment  100 . For example, the scheduling instructions  122  may negotiate the UE_DTX_DRX Offset parameter with the Node B  128  to reach the enhancement goal of reducing DRX overlap between SIM1  102  and SIM2  104  to less than a predetermined percentage. The negotiation may include, as one example, the scheduling instructions  122  communicating a desired UE_DTX_DRX Offset for SIM1  102  or for SIM2  104  to the Node B  128 , and receiving acknowledgement from the Node B  128  that the UE_DTX_DRX Offset is accepted and may be used going forward. The negotiation may additionally or alternatively include, as another example, the scheduling instructions  122  forcing a connection (e.g., a phone call or data connection) currently handled by SIM1  102  or SIM2  104  to drop, even though there are no particular quality or performance issues with the connection itself. As a result, when the Node B  128  re-establishes the call, the Node B  128  may specify a different UE_DTX_DRX Offset parameter that results in more efficient discontinuous mode operation. The user equipment  100  may force the connection to drop as often as desired in order to obtain a more suitable UE _DTX_DRX Offset parameter. 
         [0054]    A third way to negotiate the DRX/DTX operation involves the network messages that carry discontinuous mode parameters or that otherwise specify discontinuous mode configuration. In particular, the scheduling instructions  122  may analyze the discontinuous mode parameters to determine whether the resulting DRX/DTX patterns meet the efficiency criteria  130 . If the DRX/DTX patterns do not meet the efficiency criteria  130 , then the scheduling instructions  122  may send (e.g, through a RRC layer message) a status message to the Node B  128  that indicates Configuration Failure. In other words, the user equipment  100  may inform the Node B  128  that the user equipment  100  cannot set the discontinuous mode parameters provided by the Node B  128 . The status message may also include a Failure Cause, for example, that the suggested discontinuous mode parameters would result in inefficient operation. The Node B  128  may respond to such a message by providing different discontinuous operational mode parameters, asking the user equipment  100  to send suggested discontinuous mode parameters to the Node B  128 , or in other ways. One benefit of the Configuration Failed status message approach is that is does not force a call to drop. 
         [0055]    In other implementations, the scheduling instructions  122  may negotiate other DTX/DRX parameters individually or in combination in an effort to enhance discontinuous mode operation and reach the enhancement goal. As examples, the scheduling instructions  122  may attempt to negotiate the UE DTX cycle 1, UE DTX cycle 2, UE DPCCH burst — 1, or UE DPCCH burst — 2 parameters for SIM1  102  or SIM2  104  individually or in combination (along with UE_DTX_DRX Offset). 
         [0056]      FIG. 5  is an example timing diagram  500  that shows the effect of the user equipment  100  negotiating a change the DRX parameters. In this example, the scheduling instructions  122  have caused the user equipment  100  to communicate with the Node B  129  responsible for SIM2&#39;s network. The scheduling instructions have issued, for example, a parameter change request message to the Node B  129 , requesting that UE_DTX_DRX_Offset for SIM2  104  be set to a value of 1. This causes the shift by one slot in the SIM2 DRX reception to obtain the new SIM2 DRX reception pattern  502 . 
         [0057]      FIG. 6  shows a timing diagram  600  showing the result of the shift in the SIM2 DRX pattern. Instead of DRX overlap, there is now a DRX gap  602 . The DRX gap  602  may, for example, provide sufficient time for the user equipment  100  to switch radio access between SIM1  102  and SIM2  104  so that both SIMs can receive using the shared radio resources. As a result, both SIM1  102  and SIM2  104  have enhanced ability to receive pages, data, and other communications. Note that the DRX patters may be shifted by more than one slot, any may be reconfigured in many different ways. For example, if the DRX gap  602  does not provide sufficient time to allow the radio resource to switch to SIM2, then the user equipment  100  may instead try to negotiate a DRX offset that increases the DRX gap  602  to any degree needed to allow SIM2 to access the radio resource (and to satisfy the efficiency criteria  130 ). 
         [0058]    Similar inefficiencies may arise if the DTX patterns for SIM1  102  and SIM2  104  overlap, and the system logic  114  may similarly request or negotiate changes to the DRX/DTX parameters to reach any desired efficiency criteria because of DTX pattern overlap.  FIG. 7  shows an example timing diagram  700  that continues the example shown in  FIG. 2 . In particular,  FIG. 7  shows the DTX overlap  702  between the SIM1 DTX pattern  204  and the SIM2 DTX pattern  208 . The entirety, 100%, of the SIM1 DTX pattern  204  overlaps with the SIM2 DTX pattern  208 . Conversely, about 33% of the SIM2 DTX pattern  208  conflicts with the SIM1 DTX pattern  204 . In this scenario, SIM1  102  cannot transmit at all, if SIM2  104  has the radio access, and SIM2  104  cannot use its full DTX allocation if the user equipment  100  will allow SIM1  102  to access the radio resource with SIM2  104 . 
         [0059]      FIG. 8  shows a timing diagram  800  in which the user equipment  100  has negotiated with the Node B  129  to shift the SIM2 DTX pattern ahead three subframes, e.g., UE_DTX_DRX_Offset=3. The SIM2 DTX burst previously had the pattern  802 , but has been shifted to pattern  804 . As a result, the DTX overlap  702  has been eliminated, and each SIM may transmit uninterrupted by the other. 
         [0060]      FIG. 9  shows discontinuous mode enhancement logic (DMEL)  900 . The system logic  114 , scheduling instructions  122 , or other parts of the user equipment  100  may implement the enhancement logic  900 . The DMEL  900  obtains the DTX/DRX parameters for SIM1 ( 902 ) and for SIM2 ( 904 ). The DMEL  900  may then determine the DTX pattern, DRX pattern, or both for SIM1  102  and SIM2  104  ( 906 ). Given the DRX/DTX patterns, the DMEL  900  determines whether the DRX/DTX patterns meet the efficiency goal defined in the user equipment  100  ( 908 ). For example, the DMEL  900  may determine whether there is any overlap in the DRX patterns or in the DTX patterns. 
         [0061]    If the DMEL  900  determines for any reason to shift the DTX/DRX patterns ( 910 ), then the DMEL  900  determines which DTX/DRX parameters to negotiate ( 912 ). There may be many such parameters operating together, as described above for example, that determine the DTX/DRX patterns. As one example, the DMEL  900  may determine a new value for UE_DTX_DRX_Offset that avoids overlap in the DRX pattern, the DTX pattern, or both. 
         [0062]    The DMEL  900  communicates a negotiation message to the supervising network controller (e.g., to the Node B  128  or  129 ) that specifies the desired DTX/DRX parameters. The DMEL  900  receives a response from the network ( 916 ). If the negotiation was successful then the DMEL  900  may set and implement the new DTX/DRX parameters ( 918 ). Or, if no further attempts are desired, then the process may end. Otherwise, the DMEL may try again, try different parameters, or different network controllers ( 920 ). For example, rather than shifting the DRX pattern for SIM2 through negotiation with the Node B  129 , the DMEL  900  may instead try to shift the DRX pattern for SIM1 through negotiation with the Node B  128 . Furthermore, the DMEL  900  may receive (e.g., in the response from the network) suggestions for parameter values or combinations of parameter values that the network can implement. The DMEL  900  may choose among the suggested parameters values and respond to the network controller with its selection. 
         [0063]      FIG. 10  shows an example of a network controller  1000  (e.g., the Node B  128 ) that supports DTX/DRX negotiation. The network controller  1000  includes a communication interface  1002 , processors  1004 , and a memory  1006 . The hardware and software in the network controller  1000  may be implemented as a UMTS Node B, GSM base station, or other type of network controller. 
         [0064]    The network controller  1000  is extended to include logic for handing DTX/DRX negotiation with user equipment. For example, the network controller  1000  may include DTX/DRX parameter negotiation logic  1010 . The network controller  1000  may also operate with respect to a particular set of communication standard rulesets  1016 , which may be extended to include DTX/DRX parameter negotiation. For example, in addition to communicating the UE_DTX_DRX_Offset to the user equipment, the network controller  1000  may also receive negotiation messages  1012  from user equipment, determine whether the requested DRX/DTX parameters in the negotiation messages  1012  are permissible in view of the rulesets  1016 , and prepare and respond to the user equipment with negotiation response messages  1014 . 
         [0065]      FIG. 11  shows an example of the DTX/DRX parameter negotiation logic (PNL)  1010  that may be implemented at the network controller  1000 . The PRL  1010  receives a negotiation message from the user equipment that contains suggested DRX/DTX parameters, such as a suggested new value for UE_DTX_DRX_Offset for a particular user equipment SIM ( 1102 ). The PNL  1010  obtains the suggested parameters from the message ( 1104 ). The PNL  1010  determines whether the suggested parameters are acceptable ( 1106 ). For example, the PNL  1010  may determine whether the suggested parameters meet the criteria set forth in the communication standard ruleset  1016 , and will be acceptable for (e.g., not cause interference with) ongoing communications with other user equipment served by the network controller  1000 . 
         [0066]    If the suggested parameters are acceptable, then the PNL  1010  may set and implement the suggested parameters for the user equipment SIM ( 1108 ). The PNL  1010  prepares a negotiation response message indicating that the parameters were acceptable ( 1110 ) and sends the negotiation response message back to the user equipment that originated the negotiation message ( 1112 ). 
         [0067]    If the suggested parameters are not acceptable, then the PNL  1010  may determine if there are DRX/DTX parameter alternatives that it can support for the user equipment and the SIM ( 1113 ). If so, the PNL  1010  may prepare the response message and specify the alternate DRX/DTX parameters ( 1114 ). If there no alternate options, then the PNL  1010  may prepare a response message indicating that the suggest parameters are not acceptable and that there are no alternatives available ( 1116 ). 
         [0068]    The techniques described above are not limited to any particular communication standard, DRX/DTX parameters, control or communication channels, frame structures, or slot structures. Instead, the techniques described above are applicable to any shift of DTX/DRX patterns to achieve any desired efficiency goal in a communication system. 
         [0069]    The methods, devices, techniques, and logic described above may be implemented in many different ways in many different combinations of hardware, software or firmware or both hardware and software. For example, all or parts of the system may include circuitry in a controller, a microprocessor, or an application specific integrated circuit (ASIC), or may be implemented with discrete logic or components, or a combination of other types of analog or digital circuitry, combined on a single integrated circuit or distributed among multiple integrated circuits. All or part of the logic described above may be implemented as instructions for execution by a processor, controller, or other processing device and may be stored in a tangible or non-transitory machine-readable or computer-readable medium such as flash memory, random access memory (RAM) or read only memory (ROM), erasable programmable read only memory (EPROM) or other machine-readable medium such as a compact disc read only memory (CDROM), or magnetic or optical disk. Thus, a product, such as a computer program product, may include a storage medium and computer readable instructions stored on the medium, which when executed in an endpoint, computer system, or other device, cause the device to perform operations according to any of the description above. 
         [0070]    The processing capability of the system may be distributed among multiple system components, such as among multiple processors and memories, optionally including multiple distributed processing systems. Parameters, databases, and other data structures may be separately stored and managed, may be incorporated into a single memory or database, may be logically and physically organized in many different ways, and may implemented in many ways, including data structures such as linked lists, hash tables, or implicit storage mechanisms. Programs may be parts (e.g., subroutines) of a single program, separate programs, distributed across several memories and processors, or implemented in many different ways, such as in a library, such as a shared library (e.g., a dynamic link library (DLL)). The DLL, for example, may store code that performs any of the system processing described above. While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents.