Preamble transmission in a wireless device
View Patent ↗A wireless device receives a control order initiating a random access procedure on a first cell during an ongoing random access procedure on a second cell. The wireless device restarts a first counter and a second counter. The wireless device performs an LBT for transmission of the preamble. The wireless device considers the RA procedure unsuccessfully completed if a first condition based on a first counter is met. The wireless device considers the RA procedure unsuccessfully completed if a condition based on a second counter is met.
1. A method comprising:
receiving, by a wireless device, at least one radio resource control (RRC) message indicating a maximum counter value;
receiving a control order initiating a random access (RA) procedure on a first cell during an ongoing RA procedure on a second cell;
restarting a first preamble transmission counter and a second preamble transmission opportunity counter;
instructing, by a media access control (MAC) layer, a physical layer to transmit a preamble on the first cell; and
when a corresponding RA response is not received:
considering the RA procedure on the first cell unsuccessfully completed if the first preamble transmission counter reaches the maximum counter value regardless of whether the first cell is a licensed or licensed-assisted-access (LAA) cell, the first preamble transmission counter configured to count a number of physical layer transmissions of the preamble,
otherwise considering the RA procedure on the first cell unsuccessfully completed if the second preamble transmission opportunity counter reaches the maximum counter value and the first cell is a LAA cell, the second preamble transmission opportunity counter is employed only if the first cell is a LAA cell, and the second preamble transmission opportunity counter is increased when the physical layer performs listen-before-talk (LBT) for transmission of the preamble.
2. The method of claim 1 , further comprising canceling the ongoing RA procedure.
3. The method of claim 1 , wherein the first cell is the same as the second cell.
4. The method of claim 1 , wherein the first cell is different than the second cell.
5. The method of claim 1 , further comprising setting a preamble power parameter employing the first preamble transmission counter.
6. The method of claim 1 , further comprising, when the first cell is the LAA cell:
performing, by the physical layer, the LBT for transmission of the preamble at a transmission opportunity;
transmitting, by the physical layer, the preamble at the transmission opportunity if the LBT succeeds, otherwise dropping transmission of the preamble at the transmission opportunity; and
receiving, by the MAC layer, a power ramping suspension indication from the physical layer when the transmission of the preamble is dropped due to a failure of the LBT.
7. The method of claim 1 , further comprising considering the RA procedure successfully completed when the wireless device receives the RA response.
8. The method of claim 1 , wherein the second preamble transmission opportunity counter is configured to count a number of transmission opportunities of the preamble.
9. The method of claim 8 , further comprising selecting random access resources for preamble transmission if:
the RA response is not received;
the first condition is not met; and
the second condition is not met.
10. The method of claim 1 , further comprising monitoring a downlink channel for the corresponding RA response within a random access response window, the corresponding RA response comprising a preamble identifier that matches the preamble.
11. The method of claim 1 , further comprising:
increasing the first preamble transmission counter when the preamble is transmitted by the physical layer; and
increasing the second preamble transmission opportunity counter when the physical layer performs the LBT for transmission of the preamble at a transmission opportunity of the preamble.
12. The method of claim 1 , wherein the control order is received over a physical downlink control channel (PDCCH) and comprises a preamble index and a random access mask index.
13. The method of claim 1 , wherein the at least one RRC message further comprises:
configuration parameters of a plurality of cells comprising the first cell and the second cell;
random access resource information elements of a random access channel (RACH) on the first cell and the second cell; and
a random access response window information element.
14. A method comprising:
receiving, by a wireless device, at least one radio resource control (RRC) message comprising a maximum counter value;
receiving a control order initiating a random access (RA) procedure on a first licensed assisted access (LAA) cell during an ongoing RA procedure on a second LAA cell;
restarting a first preamble transmission counter and a second preamble transmission opportunity counter;
instructing, by a media access control (MAC) layer, a physical layer to transmit a preamble as a part of the RA procedure on the first LAA cell;
performing listen-before-talk (LBT) for transmission of the preamble at a transmission opportunity of the preamble;
when a corresponding RA response is not received:
increasing the first preamble transmission counter when the LBT is successful;
increasing the second preamble transmission opportunity counter regardless of success or failure of the LBT;
considering the RA procedure on the first LAA cell unsuccessfully completed if the first preamble transmission counter reaches the maximum transmission counter value; and
otherwise considering the RA procedure on the first LAA cell unsuccessfully completed if the second preamble transmission opportunity counter reaches the maximum counter value.
15. The method of claim 14 , further comprising considering the RA procedure on the first LAA cell successfully completed when the wireless device receives the corresponding RA response.
16. The method of claim 14 , further comprising, when the first cell is the LAA cell:
transmitting, by the physical layer, the preamble at the transmission opportunity if the LBT succeeds, otherwise dropping transmission of the preamble at the transmission opportunity; and
receiving, by the MAC layer, a power ramping suspension indication from the physical layer when the transmission of the preamble is dropped due to a failure of the LBT.
17. The method of claim 14 , wherein the first cell is the same as the second cell.
18. The method of claim 14 , wherein the first cell is different than the second cell.
19. The method of claim 14 , further comprising setting a preamble power parameter employing the first preamble transmission counter.
20. A wireless device comprising:
one or more processors; and
memory storing instructions that, when executed, cause the wireless device to:
receive at least one radio resource control (RRC) message comprising a maximum counter value;
receive a control order initiating a random access (RA) procedure on a first licensed assisted access (LAA) cell during an ongoing RA procedure on a second LAA cell;
restart a first preamble transmission counter and a second preamble transmission opportunity counter;
instruct, by a media access control (MAC) layer, a physical layer to transmit a preamble as a part of the RA procedure on the first LAA cell;
perform listen-before-talk (LBT) for transmission of the preamble at a transmission opportunity of the preamble;
when a corresponding RA response is not received:
increase the first preamble transmission counter when the LBT is successful;
increase the second preamble transmission opportunity counter regardless of success or failure of the LBT;
consider the RA procedure on the first LAA cell unsuccessfully completed if the first preamble transmission counter reaches the maximum transmission counter value; and
otherwise consider the RA procedure on the first LAA cell unsuccessfully completed if the second preamble transmission counter reaches the maximum counter value.