Some important timers and counters used in the establishment process of 5G:
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T300: This is a timer that is used to control the transmission of the initial UE (User Equipment) message from the mobile device to the network. The T300 timer starts when the UE sends the initial message, and if a response is not received within the specified time, the UE assumes that the transmission has failed and retransmits the message.
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T301: This timer is used to control the retransmission of the initial UE message. If the network fails to respond within the T300 timer, the UE will retransmit the message with an increased value of T301.
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T310: This timer is used to control the release of the RRC (Radio Resource Control) connection when no data is being exchanged. If no data is exchanged between the mobile device and the network, the T310 timer starts, and if it expires, the RRC connection is released.
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T311: This timer is used to control the re-establishment of the RRC connection after it has been released. If the mobile device wishes to establish a new RRC connection after the T310 timer has expired, it will send a request to the network, and the network will respond within the T311 timer. If the network fails to respond within this timer, the mobile device will initiate a new establishment process.
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T341: This timer is used to control the release of the data radio bearer. If no data is being exchanged on a data radio bearer, the T341 timer starts, and if it expires, the data radio bearer is released.
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T343: This timer is used to control the re-establishment of a data radio bearer after it has been released. If the mobile device wishes to establish a new data radio bearer after the T341 timer has expired, it will send a request to the network, and the network will respond within the T343 timer. If the network fails to respond within this timer, the mobile device will initiate a new establishment process.
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