Method for performing random access procedures and terminal thereof
AssigneeOptis Cellular Technology, LLC
InventorsSeung-June Yi, Sung-Jun Park, Young-Dae Lee, Sung-Duck Chun
Life of this patent
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Abstract
A random access procedure between a mobile terminal and a network is performed based upon the characteristics of a RACH preamble. If the RACH preamble was explicitly signaled by the network, a downlink channel is monitored until a new transmission is indicated according to radio resource allocation information received from the network. If the RACH preamble was not explicitly signaled by the network, a contention resolution timer is started and the downlink channel is monitored until the contention resolution timer expires. Such monitoring of downlink channels in a more efficient manner, results in effective reduction in power consumption.
Claims11
A communications terminal configured to perform a random access procedure with a network, comprising:
- a transmitter to transmit to the network a first type of random access preamble or a second type of random access preamble;
- a receiver to receive a random access response sent from the network in response to transmission of the first type of random access preamble or the second type of random access preamble;
- where the first type of random access preamble is based on a preamble selection by the communications terminal, the second type of random access preamble is not based on a preamble selection by the communications terminal, and the first type of random access preamble is a contention-based preamble for a contention-based random access procedure;
- a contention resolution timer;
- and
- processing circuitry to:
- start operation of the contention resolution timer;
- decode a downlink control channel while the contention resolution timer operates;
- apply a back-off time when an indication of allocation of radio resources for a new transmission is not received by a time when the contention resolution timer expires;
- stop decoding the downlink control channel during the back-off time;
- and
- perform random access again after the back-off time.
A communications terminal configured to perform a random access procedure with a network, comprising:
- a transmitter to transmit a first type of random access preamble or a second type of random access preamble to the network;
- a receiver to receive a random access response sent from the network in response to transmission of the first type of random access preamble or the second type of random access preamble, the random access response including a random access preamble identifier, uplink channel grant information, timing adjustment information, and a temporary cell identifier;
- where the first type of random access preamble is based on a preamble selection by the communications terminal, the second type of random access preamble is not based on a preamble selection by the communications terminal, and the first type of random access preamble is a contention-based random access preamble,
- a contention resolution timer;
- and
- processing circuitry to:
- when the random access response is intended for the communications terminal, control the transmitter to transmit data using uplink channel grant information and including a communications terminal identifier that is different from the temporary cell identifier, and
- start the contention resolution timer after transmission of the data over the uplink.
Dependencies are inferred from the claim text.