Recovery from Uplink Timing Alignment Failures in Cellular Communications
First Claim
1. A wireless user equipment (UE) device configured to wirelessly communicate with a cellular network, comprising:
- a radio, comprising one or more antennas for performing wireless communication;
a processing element operatively coupled to the radio;
wherein the processing element and the radio are configured to;
detect an out-of-sync condition with the cellular network;
initiate a first type of random access procedure (RACH) in response to detecting the out-of-sync condition;
determine whether or not a message transmitted as part of the first type of RACH is received by the cellular network;
initiate a second type of RACH 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.
1 Assignment
0 Petitions
Accused Products
Abstract
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.
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Citations
25 Claims
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1. A wireless user equipment (UE) device configured to wirelessly communicate with a cellular network, comprising:
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a radio, comprising one or more antennas for performing wireless communication; a processing element operatively coupled to the radio; wherein the processing element and the radio are configured to; detect an out-of-sync condition with the cellular network; initiate a first type of random access procedure (RACH) in response to detecting the out-of-sync condition; determine whether or not a message transmitted as part of the first type of RACH is received by the cellular network; initiate a second type of RACH 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A non-transitory computer readable memory medium comprising program instructions for a wireless user equipment (UE) device to wirelessly communicate with a cellular network, wherein the program instructions are executable to:
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detect an out-of-sync condition with the cellular network with respect to an uplink communication channel; initiate a first random access procedure (RACH) of a first type in response to detecting the out-of-sync condition and based on having uplink data to transmit; determine whether or not a message transmitted as part of the first RACH of the first type is received by the cellular network; perform a second RACH of the first type if the message transmitted as part of the first RACH of the first type is not received by the cellular network; initiate a RACH of a second type if the message transmitted as part of the first RACH of the first type is received by the network and no response to the message transmitted as part of the first RACH of the first type is received from the cellular network; regain synchronization with the cellular network with respect to the uplink communication channel based on the first RACH of the first type, the second RACH of the first type, or the RACH of the second type, wherein regaining synchronization enables use of the uplink communication channel; transmit the uplink data using the uplink communication channel. - View Dependent Claims (12, 13, 14)
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15. A method for operating a wireless user equipment (UE) device configured for cellular wireless communication, the method comprising:
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performing uplink communications with a cellular network using an uplink channel shared by a plurality of cellular devices, wherein performing the uplink communications comprises utilizing a timing advance parameter to synchronize reception of the uplink communications by the cellular network with reception of uplink communications by the cellular network from other cellular devices of the plurality of cellular devices; detecting that the timing advance parameter has expired, wherein expiration of the timing advance parameter causes an out-of-sync condition between the UE and the cellular network; initiating a first type of random access procedure (RACH) based on the out-of-sync condition, wherein the first type of RACH utilizes first device identification information to identify the UE to the cellular network; determining that the cellular network has flushed the first device identification information; initiating a second type of RACH based on determining that the cellular network has flushed the first device identification information, wherein the second type of RACH utilizes second device identification information to identify the UE to the cellular network. - View Dependent Claims (16, 17, 18, 19)
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20. A method for operating a wireless user equipment (UE) device, the method comprising:
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receiving a timing advance parameter from a cellular network, wherein the timing advance parameter facilitates uplink synchronization between the UE and the cellular network; initiating a timer based on receiving the timing advance parameter, wherein the timer is reset upon receiving updates to the timing advance parameter, wherein the UE loses uplink synchronization if the timer expires; determining that the timer has expired; initiating a connected-mode random access procedure (RACH) in response to determining that the timer has expired, determining that the connected-mode RACH has failed in a manner not caused by failure to receive RACH messages from the UE to the network; initiating an idle-mode RACH in response to determining that the connected-mode RACH has failed in a manner not caused by failure to receive RACH messages from the UE to the network. - View Dependent Claims (21, 22, 23)
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24. A wireless user equipment (UE) device configured to wirelessly communicate with a cellular network, comprising:
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a radio, comprising one or more antennas for performing wireless communication; a processing element operatively coupled to the radio; wherein the processing element and the radio are configured to; establish a cellular wireless link with a cellular network via a base station, initiate an RRC_idle random access procedure (RACH), wherein the RRC_idle RACH utilizes a system architecture evolution temporary mobile subscriber identity (S-TMSI) to identify the UE to the cellular network, wherein the RRC_idle RACH establishes an RRC_connected state with the cellular network, wherein establishing the RRC_connected state comprises receiving a timing advance (TA) parameter from the cellular network for synchronizing uplink data communications and a cell radio network temporary identifier (C-RNTI) for identifying the UE to the cellular network while in the RRC_connected state; initiate a timer based on receiving the TA parameter, wherein the timer is reset upon receiving updates to the timing advance parameter, wherein the UE loses uplink synchronization if the timer expires; perform uplink data communications while in the RRC_connected state using the TA parameter; determine that the timer has expired; initiate an RRC_connected RACH in response to determining that the timer has expired, wherein the RRC_connected RACH utilizes the C-RNTI to identify the UE to the cellular network; determine that the cellular network has released the C-RNTI; initiate an RRC_idle RACH in response to determining that the cellular network has released the C-RNTI, wherein the RRC_idle RACH utilizes the S-TMSI to identify the UE to the cellular network. - View Dependent Claims (25)
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Specification