Apple Inc.

Si Li

Srinivasan Vasudevan

Giri Prassad Deivasigamani

Tarik Tabet

Sarma V Vangala

Li Su

Zhu Ji

Sreevalsan Vallath

Samy Khay-Ibbat

Swaminathan Balakrishnan

Wanping Zhang

Gaurav Nukala

Tahir Shamim

Yingjie Zhao

Wael S Barakat

Deepak Chitlur Lakshman

A wireless communication system is presented for adaptive uplink (UL) link adaptation (LA). The adaptive UL LA can include multiple outer loops, for which multiple block error rate (BLER) filtering is performed. Each of the multiple BLER filtering can be performed on groups or sub-groups of subframes, in which each group has the same or similar coding characteristics. For example, one group in TD-LTE could be subframes with sounding reference signal (SRS) and another group could be subframes without SRS. Each of the multiple BLER filtering can use the same or different BLER algorithm, BLER target and/or BLER parameters.

Adaptive uplink link adaptation

A wireless voice call may be established between an originating user equipment (UE) and a terminating UE, via a cellular network, using preconditions. The originating UE may transmit an invitation for a packet-switched wireless voice call, beginning a first period of time. The terminating UE may cancel the invitation in response to determining that a first precondition, such as establishment of a dedicated bearer between the originating UE and the cellular network, is not satisfied within the first period of time. The first period of time may be interrupted in response to determining that the first precondition is satisfied, and a second period of time may then begin. The cellular network may cancel the invitation in response to determining that a second precondition, such as establishment of a dedicated bearer between the terminating UE and the cellular network, is not satisfied within the second period of time.

VoLTE quality of service enhancement with preconditions

Improving uplink behavior for a user equipment (UE) having a radio capable of communicating using at least a first radio access technology (RAT) and a second RAT. The UE may be configured to use the radio for both the first RAT and the second RAT. The UE may receive a first uplink grant corresponding to the first RAT. Prior to completing a process corresponding to the first uplink grant for the first RAT, the UE may communicate using the second RAT. After communicating using the second RAT, the UE may transmit an uplink request for the first RAT instead of completing the process corresponding to the first uplink grant.

Uplink behavior for a device using multiple radio access technologies

Apparatus and methods of performing a network cell reselection for a mobile device after a handover attempt fails. Initially, a handover is attempted for the mobile device in a radio resource control (RRC) connected mode from a serving network base station to a target network base station. Next a failure condition associated with the handover attempt is identified by the mobile device. In one scenario, the failure condition is identified in response to the mobile device receiving an RRC connection release message from its serving network base station. In another scenario, the failure condition is identified when the mobile device detects a radio link failure event. Thereafter, the mobile device performs a network scan to identify any available network base stations for the network cell reselection. Subsequently, the mobile device attaches to a preferred network base station of the identified available network base stations to complete the network cell reselection.

Dynamic network cell reselection after a failed handover

Regaining uplink synchronization after timing alignment failure in cellular communications. An out-of-sync condition with a cellular network may be detected. A first type of random access procedure may be initiated in response to detecting the out-of-sync condition. It may be determined whether or not a message transmitted as part of the first type of random access procedure is received by the cellular network. If the message transmitted as part of the first type of RACH is received by the network and no response to the message is received from the cellular network, a second type of RACH may be initiated. The second type of RACH may include a message having an indication that an out-of-sync condition occurred.

Recovery from uplink timing alignment failures in cellular communications

User Equipment (UE) based forced inter radio access technology (iRAT) handover. A connection to a network may be established via a first cell operating according to a first radio access technology (RAT). It may be determined to initiate a handover of the UE from the first cell to a second cell operating according to a second RAT. An indication may be transmitted to the network to initiate a handover of the UE from the first cell to the second cell. An indication may be received from the network to perform handover of the UE from the first cell to the second cell in response to the indication to initiate the handover. Handover of the UE from the first cell to the second cell may be performed in response to the indication to perform the handover. Handover may include releasing the connection to the network via the first cell and establishing a connection to the network via the second cell.

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Santa Clara, CA, United States of America

Si Li