Abstract: Aspects relate to random access channel procedures. In some examples, if a user equipment (UE) has not successfully received a random access channel (RACH) downlink message prior to the end of a random access window for a first RACH attempt, the UE may elect to proceed with a second RACH attempt. For example, the UE may determine whether there are any remaining downlink symbols available during the random access window to receive the RACH downlink message. If not, the UE may retransmit a physical RACH (PRACH) preamble.

Abstract: A UE may obtain an indication of a first subset of PRACH resources in a set of PRACH resources, the first subset of PRACH resources having a set of channel metrics that is greater than or equal to a first threshold value, select a first PRACH resource from the first subset of PRACH resources based on a first set of channel metrics of the first PRACH resource or a first RO associated with the first PRACH resource, and transmit a RACH message to a network node in the first RO. The UE may evaluate the multiple qualifying SSBs/CSI-RSs and select one SSB/CSI-RS among the qualifying SSBs/CSI-RSs based on a scheduling opportunity of the associated ROs and a power usage on the UE side.

Abstract: A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus may be a UE which uses a first antenna and a second antenna for communication with a first RAT. The apparatus determines that the second antenna is to be used for a procedure associated with a second RAT at a first time. The apparatus reduces a UE RI from an initial value to a reduced value for the communication with the first RAT at the first time based on the determination.

Abstract: Some embodiments include a method for processing wireless wide area network paging messages. The method may include receiving, in a fixed device over a wireless local area network (WLAN) interface, a request to monitor wireless wide area network (WWAN) paging messages for a mobile device. The method may include receiving, by the fixed device via a WWAN interface, a WWAN paging message of the WWAN paging messages. The method may also include forwarding, by the fixed device via the WLAN interface, the paging message to the mobile device.

Abstract: Methods, devices, and systems embodiments enable a multi-antenna mobile device to mitigate radio frequency (RF) radiation exposure to users. A processor may determine a distance between the multi-antenna mobile device and the select portion of the user and switch from using a first antenna that is closer to the select portion of the user to using a second antenna when the multi-antenna mobile device is close to the user. The signal strength of the first antenna may be compared to the signal strength of a second antenna of the multi-antenna mobile device, and the second antenna may be used instead of the first antenna when the signal strength of the first antenna is within a predetermined threshold of the signal strength of the second antenna. If acceptable signal quality is not obtained with the second antenna, the multi-antenna mobile device may switch back to the first antenna.

Abstract: Methods and apparatus for of tracking network system timing are provided. In one aspect, a method for wireless communication comprises determining a probability of passing an accessibility test for accessing a network. The method further includes comparing the determined probability to a threshold. The method further includes selectively performing a backoff procedure for a period of time based on the comparison.

Abstract: Methods, devices, and systems embodiments enable a multi-antenna mobile device to mitigate radio frequency (RF) radiation exposure to users. A processor may determine a distance between the multi-antenna mobile device and the select portion of the user and switch from using a first antenna that is closer to the select portion of the user to using a second antenna when the multi-antenna mobile device is close to the user. The signal strength of the first antenna may be compared to the signal strength of a second antenna of the multi-antenna mobile device, and the second antenna may be used instead of the first antenna when the signal strength of the first antenna is within a predetermined threshold of the signal strength of the second antenna. If acceptable signal quality is not obtained with the second antenna, the multi-antenna mobile device may switch back to the first antenna.

Abstract: Embodiment methods and devices enable use of a shared radio resource on a multi-SIM wireless communication device to maintain session information on a service associated with one SIM during unused time slots of an active communication session associated with another SIM. During the session, a processor may calculate radio idle time periods in the active communication session, determine whether any of the radio idle time periods will exceed a predetermined threshold duration, and retune the shared radio resource to receive search samples on a frequency of the non-active network during radio idle time periods that exceed the predetermined threshold duration. Search samples may be stored for processing between radio idle time periods in order to maintain session information on a service associated with one SIM and provide service information to applications executing on the device during the active communication session.

Abstract: An opportunistic receive diversity scheme for VAMOS and similar deployments is disclosed. Receive diversity may be conditionally enabled when a VAMOS call is assigned to one of the SIMs of a mobile device. For example, receive diversity may be enabled when VAMOS data does not overlap with a time slot that is used by another subscription of the mobile device for receiving page messages. Also, receive diversity for a VAMOS call may be limited to situations where the VAMOS channel conditions are poor. Receive diversity may be enabled in cases where multiple subscriptions are assigned the same VAMOS channel, where VAMOS channel conditions have deteriorated, or where one of the subscriptions is not on a VAMOS channel. Also, receive diversity may be dynamically enabled for multiple subscriptions in cases where the subscriptions are assigned to different VAMOS channels.

Abstract: Embodiment methods and devices enable use of a shared radio resource on a multi-SIM wireless communication device to maintain session information on a service associated with one SIM during unused time slots of an active communication session associated with another SIM. During the session, a processor may calculate radio idle time periods in the active communication session, determine whether any of the radio idle time periods will exceed a predetermined threshold duration, and retune the shared radio resource to receive search samples on a frequency of the non-active network during radio idle time periods that exceed the predetermined threshold duration. Search samples may be stored for processing between radio idle time periods in order to maintain session information on a service associated with one SIM and provide service information to applications executing on the device during the active communication session.

Abstract: An opportunistic receive diversity scheme for VAMOS and similar deployments is disclosed. Receive diversity may be conditionally enabled when a VAMOS call is assigned to one of the SIMs of a mobile device. For example, receive diversity may be enabled when VAMOS data does not overlap with a time slot that is used by another subscription of the mobile device for receiving page messages. Also, receive diversity for a VAMOS call may be limited to situations where the VAMOS channel conditions are poor. Receive diversity may be enabled in cases where multiple subscriptions are assigned the same VAMOS channel, where VAMOS channel conditions have deteriorated, or where one of the subscriptions is not on a VAMOS channel. Also, receive diversity may be dynamically enabled for multiple subscriptions in cases where the subscriptions are assigned to different VAMOS channels.

Abstract: A method and apparatus configured to perform fast acquisition in multi-subscription multi-active devices are described. The apparatus may establish a first traffic call associated with a first subscription using a first radio frequency chain and a second traffic call associated with a second subscription using a second radio frequency chain. A subscription corresponding to a third subscription may enter an out-of-service mode when the first and second traffic calls are established. A first network may be acquired for the first subscription using the first RF chain after the first traffic call is terminated. The third subscription may be transitioned from out-of-service mode to idle mode using acquisition information inherited from the subscription corresponding to the first SIM after the first network is acquired. The third subscription and the first network may be associated with a same radio access technology and a same network operator.

Abstract: A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus may receive a signal at least at a first antenna and a second antenna, determine a first strength of the signal received at the first antenna and a second strength of the signal received at the second antenna, and alert a user when a difference between the first and second strengths exceeds a threshold. The difference between the first and second strengths may be caused by an obstruction of the first antenna or the second antenna. For example, the obstruction may be a hand or head of the user of the UE. The UE may also start a timer when the difference exceeds the threshold. The UE may also determine a sensitivity difference between the first and second antennas and adjust the difference between the first and second strengths based on the sensitivity difference.

Abstract: A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus may be a UE which uses a first antenna and a second antenna for communication with a first RAT. The apparatus determines that the second antenna is to be used for a procedure associated with a second RAT at a first time. The apparatus reduces a UE RI from an initial value to a reduced value for the communication with the first RAT at the first time based on the determination.

Abstract: A method and apparatus configured to perform fast acquisition in multi-subscription multi-active devices are described. The apparatus may establish a first traffic call associated with a first subscription using a first radio frequency chain and a second traffic call associated with a second subscription using a second radio frequency chain. A subscription corresponding to a third subscription may enter an out-of-service mode when the first and second traffic calls are established. A first network may be acquired for the first subscription using the first RF chain after the first traffic call is terminated. The third subscription may be transitioned from out-of-service mode to idle mode using acquisition information inherited from the subscription corresponding to the first SIM after the first network is acquired. The third subscription and the first network may be associated with a same radio access technology and a same network operator.