Dual sim dual active subscriber identification module with a single transmit chain and dual or single receive chain

Abstract

A method, an apparatus, and a computer program product are provided. The apparatus may be configured to establish a first call for a first subscription, and accept a second call for a second subscription while maintaining the first call. A single RF transmit chain may be scheduled for uplink transmissions associated with the first call and uplink transmissions associated with the second call. A timesharing schedule for the transmit chain may determine timing for the uplink transmissions associated with the first call is transmitted and when the uplink transmissions associated with the second call is transmitted on the transmit chain. Downlink transmissions associated with the first and second calls may be received using different receive chain. Downlink transmissions associated with the first and second calls may be received using the same receive chain.

What is claimed is: 
     
         1 . A method of managing multiple connections for an access terminal, comprising:
 establishing a first call for a first subscription associated with the access terminal;   accepting a second call for a second subscription associated with the access terminal while maintaining the first call in an active state; and   scheduling a single radio frequency (RF) transmit chain provided in the access terminal for uplink transmissions associated with the first call and uplink transmissions associated with the second call when the access terminal is operating in a first mode.   
     
     
         2 . The method of  claim 1 , further comprising:
 scheduling the single RF transmit chain provided in the access terminal to restrict uplink transmissions to a single call when the access terminal is operating in a second mode; and   falling back to the second mode from the first mode when one or more channel conditions are determined, the channel conditions comprising high network loading, high transmit power or adverse RF coexistence conditions.   
     
     
         3 . The method of  claim 2 , wherein the first mode is a dual SIM dual active (DSDA) mode and the second mode is a dual SIM dual stand-by (DSDS) mode. 
     
     
         4 . The method of  claim 2 , further comprising:
 selecting either the first call or the second call to be dropped when the access terminal falls back to the second mode from the first mode, wherein a call is selected for dropping based on relative priorities associated with the first call and the second call, channel conditions, quality of service requirements of the first call and the second call.   
     
     
         5 . The method of  claim 1 , wherein scheduling the single RF transmit chain comprises:
 establishing a timesharing schedule for the single RF transmit chain, wherein the timesharing schedule determines timing for uplink transmissions associated with the first call and for uplink transmissions associated with the second call on the single RF transmit chain.   
     
     
         6 . The method of  claim 5 , wherein scheduling the single RF transmit chain comprises:
 controlling a switch provided between a modem and the single RF transmit chain in accordance with the timesharing schedule.   
     
     
         7 . The method of  claim 5 , wherein scheduling the single RF transmit chain comprises:
 configuring the timesharing schedule based on at least one of relative priorities associated with the first call and the second call, channel conditions, and quality of service requirements of the first call and the second call.   
     
     
         8 . The method of  claim 1 , wherein the first call is established as a highest priority call and further comprising:
 gating uplink transmissions associated with the second call when an uplink transmission associated with the first call is available.   
     
     
         9 . The method of  claim 8 , wherein the uplink transmissions associated with the second call that are gated include an ACK channel transmission. 
     
     
         10 . The method of  claim 8 , wherein gating uplink transmissions associated with the second call includes:
 fully gating all ACK channel transmissions associated with the second call when network scheduling of the first call requires the ACK channel transmission associated with the second call to be partially gated.   
     
     
         11 . The method of  claim 1 , wherein the first call is established on a Global System for Mobile Communications (GSM) network and the second call is established on a Code Division Multiple Access (CDMA) network. 
     
     
         12 . The method of  claim 1 , wherein the first call is established on a Global System for Mobile Communications (GSM) network and the second call is established on a Universal Mobile Telecommunications System (UMTS) network. 
     
     
         13 . The method of  claim 1 , wherein the first call is established on a GSM network and the second call is established on a long-term evolution (LTE) network configured for time-division duplex LTE (LTE-TDD/TD-LTE) or frequency division duplex LTE (LTE-FDD). 
     
     
         14 . The method of  claim 1 , wherein the first call is established on a GSM network and the second call is established on a Code Division Multiple Access 2000 (cdma2000) Evolution-Data Optimized network. 
     
     
         15 . The method of  claim 1 , wherein the first call is established on a GSM network and the second call is established on a cdma2000 1xRTT network. 
     
     
         16 . The method of  claim 1 , wherein the first call is established on a GSM network and the second call is established on a GSM network. 
     
     
         17 . The method of  claim 1 , wherein the first call is established on a GSM network and the second call is established using time division synchronous code division multiple access (TD-SCDMA). 
     
     
         18 . The method of  claim 1 , wherein the first call is established on a cdma2000 1xRTT network and the second call is established on an LTE-FDD or an LTE-TDD/TD-LTE network. 
     
     
         19 . The method of  claim 1 , wherein accepting the second call comprises:
 boosting a traffic-to-pilot ratio or increasing overhead channel gain.   
     
     
         20 . The method of  claim 1 , further comprising:
 scheduling a single RF receive chain provided in the access terminal to receive downlink transmissions associated with the first call and downlink transmissions associated with the second call.   
     
     
         21 . The method of  claim 20 , wherein scheduling the single RF receive chain comprises:
 establishing a timesharing schedule for the single RF receive chain, wherein the timesharing schedule determines when networks corresponding to the first call and the second call are monitored.   
     
     
         22 . The method of  claim 21 , wherein scheduling the single RF receive chain comprises:
 controlling a switch provided between a modem and the single RF receive chain in accordance with the timesharing schedule.   
     
     
         23 . The method of  claim 21 , wherein scheduling the single RF receive chain comprises:
 configuring the timesharing schedule based on relative priorities associated with the first call and the second call, channel conditions, or quality of service requirements of the first call and the second call.   
     
     
         24 . The method of  claim 20 , further comprising:
 compensating for phase discontinuities in a pilot signal detected on a network corresponding to one of the first call and the second call.   
     
     
         25 . The method of  claim 1 , wherein scheduling the single RF transmit chain or scheduling a single RF receive chain comprises:
 dynamically adapting a frequency at which transmitter power of a number of neighboring transmitters is monitored based on the number of the neighboring sectors.   
     
     
         26 . The method of  claim 1 , wherein scheduling the single RF transmit chain or scheduling a single RF receive chain comprises:
 decreasing a power monitoring duration for a GSM network.   
     
     
         27 . The method of  claim 1 , wherein scheduling the single RF transmit chain or scheduling a single RF receive chain comprises:
 dropping one or more frames of a speech packet in the uplink transmissions based on channel conditions.   
     
     
         28 . The method of  claim 1 , wherein scheduling the single RF transmit chain or scheduling a single RF receive chain comprises:
 skipping a portion of a plurality of frames of a speech packet in downlink transmissions based on channel conditions.   
     
     
         29 . The method of  claim 1 , wherein scheduling the single RF transmit chain or scheduling a single RF receive chain comprises:
 skipping a portion of a plurality of frames of a speech packet in downlink transmissions when the speech packet is decoded using early decoding.   
     
     
         30 . The method of  claim 1 , wherein scheduling the single RF transmit chain or scheduling a single RF receive chain comprises:
 substituting silent frames for at least a portion of a plurality of frames transmitted or received on a GSM network.   
     
     
         31 . The method of  claim 1 , wherein the first call and the second call are GSM calls, and wherein the first call has a higher priority than the second call, and wherein the method further comprises:
 dropping the second call when the first call and the second call are allocated a common time slot for communicating on a GSM network.   
     
     
         32 . An access terminal configured for managing multiple connections, comprising:
 means for establishing a first call for a first subscription associated with the access terminal;   means for accepting a second call for a second subscription associated with the access terminal while maintaining the first call in an active state; and   means for scheduling a single radio frequency (RF) transmit chain provided in the access terminal for uplink transmissions associated with the first call and uplink transmissions associated with the second call when the access terminal is operating in a first mode.   
     
     
         33 . The access terminal of  claim 32 , wherein the means for scheduling is configured to:
 schedule the single RF transmit chain provided in the access terminal to restrict uplink transmissions to a single call when the access terminal is operating in a second mode; and   fall back to the second mode from the first mode when one or more channel conditions are determined, the channel conditions comprising high network loading, high transmit power or adverse RF coexistence conditions.   
     
     
         34 . The access terminal of  claim 33 , wherein the first mode is a dual SIM dual active (DSDA) mode and the second mode is a dual SIM dual stand-by (DSDS) mode. 
     
     
         35 . The access terminal of  claim 33 , the means for scheduling the single RF transmit chain is configured to:
 select either the first call or the second call to be dropped when the access terminal falls back to the second mode from the first mode, wherein a call is selected for dropping based on relative priorities associated with the first call and the second call, channel conditions, quality of service requirements of the first call and the second call.   
     
     
         36 . The access terminal of  claim 32 , wherein the means for scheduling the single RF transmit chain is configured to:
 establishing a timesharing schedule for the single RF transmit chain, wherein the timesharing schedule determines timing for uplink transmissions associated with the first call and for uplink transmissions associated with the second call on the single RF transmit chain.   
     
     
         37 . The access terminal of  claim 36 , wherein the means for scheduling the single RF transmit chain is configured to:
 controlling a switch provided between a modem and the single RF transmit chain in accordance with the timesharing schedule.   
     
     
         38 . The access terminal of  claim 36 , wherein scheduling the single RF transmit chain comprises:
 configuring the timesharing schedule based on at least one of relative priorities associated with the first call and the second call, channel conditions, and quality of service requirements of the first call and the second call.   
     
     
         39 . The access terminal of  claim 32 , wherein the first call is established as a highest priority call and wherein uplink transmissions associated with the second call are gated when an uplink transmission associated with the first call is available. 
     
     
         40 . The access terminal of  claim 39 , wherein the uplink transmissions associated with the second call that are gated include an ACK channel transmission. 
     
     
         41 . The access terminal of  claim 39 , wherein the uplink transmissions that are gated include ACK channel transmissions associated with the second call, and wherein the ACK channel transmissions are fully gated when network scheduling of the first call requires the ACK channel transmission associated with the second call to be partially gated. 
     
     
         42 . The access terminal of  claim 32 , wherein the first call is established on a Global System for Mobile Communications (GSM) network and the second call is established on a Code Division Multiple Access (CDMA) network. 
     
     
         43 . The access terminal of  claim 32 , wherein the first call is established on a Global System for Mobile Communications (GSM) network and the second call is established on a Universal Mobile Telecommunications System (UMTS) network. 
     
     
         44 . The access terminal of  claim 32 , wherein the first call is established on a GSM network and the second call is established on a long-term evolution (LTE) network configured for time-division duplex LTE (LTE-TDD/TD-LTE) or frequency division duplex LTE (LTE-FDD). 
     
     
         45 . The access terminal of  claim 32 , wherein the first call is established on a GSM network and the second call is established on a Code Division Multiple Access 2000 (cdma2000) Evolution-Data Optimized network. 
     
     
         46 . The access terminal of  claim 32 , wherein the first call is established on a GSM network and the second call is established on a cdma2000 1xRTT network. 
     
     
         47 . The access terminal of  claim 32 , wherein the first call is established on a GSM network and the second call is established on a GSM network. 
     
     
         48 . The access terminal of  claim 32 , wherein the first call is established on a GSM network and the second call is established using time division synchronous code division multiple access (TD-SCDMA). 
     
     
         49 . The access terminal of  claim 32 , wherein the first call is established on a cdma2000 1xRTT network and the second call is established on an LTE-FDD or an LTE-TDD/TD-LTE network. 
     
     
         50 . The access terminal of  claim 32 , wherein the means for accepting the second call is configured to:
 boost a traffic-to-pilot ratio or increasing overhead channel gain.   
     
     
         51 . The access terminal of  claim 32 , further comprising:
 means for scheduling a single RF receive chain provided in the access terminal to receive downlink transmissions associated with the first call and downlink transmissions associated with the second call.   
     
     
         52 . The access terminal of  claim 51 , wherein the means for scheduling the single RF receive chain is configured to:
 establish a timesharing schedule for the single RF receive chain, wherein the timesharing schedule determines when networks corresponding to the first call and the second call are monitored.   
     
     
         53 . The access terminal of  claim 52 , wherein the means for scheduling the single RF receive chain is configured to:
 control a switch provided between a modem and the single RF receive chain in accordance with the timesharing schedule.   
     
     
         54 . The access terminal of  claim 52 , wherein the means for scheduling the single RF receive chain is configured to:
 configure the timesharing schedule based on relative priorities associated with the first call and the second call, channel conditions, or quality of service requirements of the first call and the second call.   
     
     
         55 . The access terminal of  claim 51 , further comprising:
 means for compensating for phase discontinuities in a pilot signal detected on a network corresponding to one of the first call and the second call.   
     
     
         56 . The access terminal of  claim 32 , wherein the means for scheduling the single RF transmit chain or means for scheduling a single RF receive chain is configured to:
 dynamically adapt a frequency at which transmitter power of a number of neighboring transmitters is monitored based on the number of the neighboring sectors.   
     
     
         57 . The access terminal of  claim 32 , wherein the means for scheduling the single RF transmit chain or means for scheduling a single RF receive chain is configured to:
 decrease a power monitoring duration for a GSM network.   
     
     
         58 . The access terminal of  claim 32 , wherein the means for scheduling the single RF transmit chain or means for scheduling a single RF receive chain is configured to:
 drop one or more frames of a speech packet in the uplink transmissions based on channel conditions.   
     
     
         59 . The access terminal of  claim 32 , wherein the means for scheduling the single RF transmit chain or means for scheduling a single RF receive chain is configured to:
 skip a portion of a plurality of frames of a speech packet in downlink transmissions based on channel conditions.   
     
     
         60 . The access terminal of  claim 32 , wherein the means for scheduling the single RF transmit chain or the means for scheduling the single RF receive chain is configured to:
 skip a portion of a plurality of frames of a speech packet to be transmitted when the speech packet is decoded using early decoding.   
     
     
         61 . The access terminal of  claim 32 , wherein the means for scheduling the single RF transmit chain or means for scheduling a single RF receive chain is configured to:
 substitute silent frames for at least a portion of a plurality of frames transmitted or received on a GSM network.   
     
     
         62 . The access terminal of  claim 32 , wherein the first call and the second call are GSM calls, and wherein the first call has a higher priority than the second call, and wherein the second call is dropped when the first call and the second call are allocated a common time slot for communicating on a GSM network. 
     
     
         63 . An access terminal configured for wireless communication, comprising:
 a communications interface; and   a processing circuit configured to:
 establish a first call for a first subscription associated with the access terminal; 
 accept a second call for a second subscription associated with the access terminal while maintaining the first call in an active state; and 
 schedule a single radio frequency (RF) transmit chain provided in the access terminal for uplink transmissions associated with the first call and uplink transmissions associated with the second call when the access terminal is operating in a first mode. 
   
     
     
         64 . The access terminal of  claim 63 , wherein the processing circuit is configured to:
 schedule the single RF transmit chain provided in the access terminal to restrict uplink transmissions to a single call when the access terminal is operating in a second mode; and   fall back to the second mode from the first mode when one or more channel conditions are determined, the channel conditions comprising high network loading, high transmit power or adverse RF coexistence conditions.   
     
     
         65 . The access terminal of  claim 64 , wherein the first mode is a dual SIM dual active (DSDA) mode and the second mode is a dual SIM dual stand-by (DSDS) mode. 
     
     
         66 . The access terminal of  claim 64 , wherein the processing circuit is configured to:
 select either the first call or the second call to be dropped when the access terminal falls back to the second mode from the first mode, wherein a call is selected for dropping based on relative priorities associated with the first call and the second call, channel conditions, quality of service requirements of the first call and the second call.   
     
     
         67 . The access terminal of  claim 63 , wherein the processing circuit is configured to:
 establish a timesharing schedule for the single RF transmit chain, wherein the timesharing schedule determines timing for uplink transmissions associated with the first call and for uplink transmissions associated with the second call on the single RF transmit chain.   
     
     
         68 . The access terminal of  claim 63 , wherein the processing circuit is configured to:
 schedule a single RF receive chain provided in the access terminal to receive downlink transmissions associated with the first call and downlink transmissions associated with the second call.   
     
     
         69 . The access terminal of  claim 68 , wherein the processing circuit is configured to:
 establish a timesharing schedule for the single RF receive chain, wherein the timesharing schedule determines when networks corresponding to the first call and the second call are monitored.   
     
     
         70 . The access terminal of  claim 69 , wherein the processing circuit is configured to:
 control a switch provided between a modem and the single RF receive chain in accordance with the timesharing schedule.   
     
     
         71 . A processor-readable storage medium having one or more instructions which, when executed by at least one processing circuit, cause the at least one processing circuit to:
 establish a first call for a first subscription associated with an access terminal;   accept a second call for a second subscription associated with the access terminal while maintaining the first call in an active state; and   schedule a single radio frequency (RF) transmit chain provided in the access terminal for uplink transmissions associated with the first call and uplink transmissions associated with the second call when the access terminal is operating in a first mode.   
     
     
         72 . The processor-readable storage medium of  claim 71 , wherein the instructions cause the at least one processing circuit to:
 schedule the single RF transmit chain provided in the access terminal to restrict uplink transmissions to a single call when the access terminal is operating in a second mode; and   fall back to the second mode from the first mode when one or more channel conditions are determined, the channel conditions comprising high network loading, high transmit power or adverse RF coexistence conditions.   
     
     
         73 . The processor-readable storage medium of  claim 72 , wherein the first mode is a dual SIM dual active (DSDA) mode and the second mode is a dual SIM dual stand-by (DSDS) mode. 
     
     
         74 . The processor-readable storage medium of  claim 72 , wherein the instructions cause the at least one processing circuit to:
 select either the first call or the second call to be dropped when the access terminal falls back to the second mode from the first mode, wherein a call is selected for dropping based on relative priorities associated with the first call and the second call, channel conditions, quality of service requirements of the first call and the second call.   
     
     
         75 . The processor-readable storage medium of  claim 71 , wherein the instructions cause the at least one processing circuit to:
 establish a timesharing schedule for the single RF transmit chain, wherein the timesharing schedule determines timing for uplink transmissions associated with the first call and for uplink transmissions associated with the second call on the single RF transmit chain.   
     
     
         76 . The processor-readable storage medium of  claim 71 , wherein the instructions cause the at least one processing circuit to:
 schedule a single RF receive chain provided in the access terminal to receive downlink transmissions associated with the first call and downlink transmissions associated with the second call.   
     
     
         77 . The processor-readable storage medium of  claim 76 , wherein the instructions cause the at least one processing circuit to:
 establish a timesharing schedule for the single RF receive chain, wherein the timesharing schedule determines when networks corresponding to the first call and the second call are monitored.   
     
     
         78 . The processor-readable storage medium of  claim 77 , wherein the instructions cause the at least one processing circuit to:
 control a switch provided between a modem and the single RF receive chain in accordance with the timesharing schedule.