Method of controlling uplink synchronization state at a user equipment in a mobile communication system
First Claim
Patent Images
1. A method of maintaining time alignment of a user equipment (UE) in a mobile communication system by performing random access procedures, the method comprising:
- transmitting a random access channel (RACH) preamble from the user equipment to a network to perform a random access procedure;
receiving, by the UE, a random access channel (RACH) response from the network, wherein the RACH response comprises a timing command to enter into a synchronization state;
starting, by the UE, a time alignment timer for uplink time alignment when the timing command is received from the network, wherein the time alignment timer is for controlling an uplink synchronization state of the UE; and
receiving, by the UE, a contention resolution message from the network to determine whether the random access procedure is successful or not, wherein the UE considers itself as in an asynchronous state if the UE determines that the random access procedure is not successful based on the contention resolution message,wherein, when the UE has a dedicated random access preamble, the UE performs a random access procedure using the dedicated random access preamble regardless of whether the UE is in the uplink synchronization state or the uplink asynchronous state.
1 Assignment
0 Petitions
Accused Products
Abstract
A method of controlling uplink synchronization state at a user equipment in a mobile communication system is disclosed. The method of controlling an uplink synchronization state at a user equipment in a mobile communication system comprises receiving control information associated with controlling uplink synchronization state of the user equipment from a network, releasing uplink resources allocated from the network if the uplink synchronization state is shifted from a synchronization state to an asynchronous state based on the control information.
206 Citations
12 Claims
-
1. A method of maintaining time alignment of a user equipment (UE) in a mobile communication system by performing random access procedures, the method comprising:
-
transmitting a random access channel (RACH) preamble from the user equipment to a network to perform a random access procedure; receiving, by the UE, a random access channel (RACH) response from the network, wherein the RACH response comprises a timing command to enter into a synchronization state; starting, by the UE, a time alignment timer for uplink time alignment when the timing command is received from the network, wherein the time alignment timer is for controlling an uplink synchronization state of the UE; and receiving, by the UE, a contention resolution message from the network to determine whether the random access procedure is successful or not, wherein the UE considers itself as in an asynchronous state if the UE determines that the random access procedure is not successful based on the contention resolution message, wherein, when the UE has a dedicated random access preamble, the UE performs a random access procedure using the dedicated random access preamble regardless of whether the UE is in the uplink synchronization state or the uplink asynchronous state. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A user equipment (UE) for maintaining time alignment in a mobile communication system by performing random access procedures, the user equipment configured to:
-
transmit a random access channel (RACH) preamble to a network to perform a random access procedure; receive a random access channel (RACH) response from the network, wherein the RACH response comprises a timing command to enter into a synchronization state; start a time alignment timer for uplink time alignment when the timing command is received from the network, wherein the time alignment timer is for controlling an uplink synchronization state of the UE; and receive a contention resolution message from the network to determine whether the random access procedure is successful or not, wherein the UE considers itself as in an asynchronous state if the UE determines that the random access procedure is not successful based on the contention resolution message, wherein, when the UE has a dedicated random access preamble, the UE performs a random access procedure using the dedicated random access preamble regardless of whether the UE is in the uplink synchronization state or the uplink asynchronous state. - View Dependent Claims (8, 9, 10, 11, 12)
-
Specification