Gratuitous PUSCH grants during LTE RRC connection and NAS attach procedures
One embodiment is directed to sending a request message from the base station to the UE on a downlink channel and making, by the base station, a gratuitous grant, to the UE, of resources on the uplink channel for the UE to transmit a response message on the uplink channel. The response message is responsive to the request message. The gratuitous grant is made without waiting for a request from the UE for a grant of resources on the uplink channel for the UE to transmit the response message on the uplink channel. The base station receives the response message transmitted by the UE on the uplink channel in response to the gratuitous grant. Other embodiments are disclosed.
1. A method performed by a base station in connection with communicating with user equipment (UE) for a cell, the method comprising:
sending a request message from the base station to the UE on a downlink channel;
making, by the base station, a gratuitous grant, to the UE, of resources on an uplink channel for the UE to transmit a response message on the uplink channel, wherein the response message is responsive to the request message and wherein the gratuitous grant is made without waiting for a request from the UE for a grant of resources on the uplink channel for the UE to transmit the response message on the uplink channel; and
receiving, by the base station, the response message transmitted by the UE on the uplink channel in response to the gratuitous grant; and
wherein the gratuitous grant is made after an amount of time sufficient for the UE to be ready to send the response message has elapsed without the base station having received a scheduling request from the UE; and
wherein the request message and the response message comprise signaling messages for the cell.
2. The method of claim 1 , wherein the request message comprises a downlink Long-Term Evolution (LTE) message that comprises a request to which the UE is expected to send an uplink LTE message that includes a response to the request.
3. The method of claim 1 , wherein the request message comprises a set of request packets;
wherein making, by the base station, the gratuitous grant, to the UE, of the resources on the uplink channel for the UE to transmit the response message on the uplink channel comprises:
determining when the base station is provided with feedback indicating that each request packet was successfully received by the UE;
when the base station is provided with feedback indicating that each request packet was successfully received by the UE, determining if a queue for the UE is empty; and
when the queue for the UE is empty, starting a timer; and
wherein the gratuitous grant is made after the timer has expired without the base station having received the scheduling request from the UE.
4. The method of claim 3 , wherein the timer is initialized with an amount of time sufficient for the UE to be ready to send the response message.
5. The method of claim 3 , wherein each request packet comprises a set of code words;
wherein determining when the base station is provided with feedback indicating that each request packet was successfully received by the UE comprises:
determining when the base station is provided with feedback indicating that all of the code words of each request packet was successfully received by the UE.
6. The method of claim 5 , wherein the base station is provided with hybrid automatic repeat request (HARQ) feedback indicating whether each code word of each request packet was successfully received by the UE.
7. The method of claim 3 , wherein the base station is provided with hybrid automatic repeat request (HARQ) feedback indicating whether each request packet was successfully received by the UE.
8. The method of claim 3 , wherein the request message is retransmitted if a retransmission timer expires without the response message having been received by the base station.
9. The method of claim 1 , wherein making, by the base station, the gratuitous grant, to the UE, of the resources on the uplink channel for the UE to transmit the response message on the uplink channel comprises: sending a LTE DCI0 message to the UE.
10. The method of claim 1 , wherein making, by the base station, the gratuitous grant, to the UE, of the resources on the uplink channel for the UE to transmit the response message on the uplink channel comprises:
scheduling resources for at least one of the following so as to take into account any measurement gap state or discontinuous reception state of the UE:
transmitting the gratuitous grant to the UE; and
transmitting the response message from the UE to the base station on the uplink channel.
11. The method of claim 1 , where the request message comprises a last message in a series of back to back request messages sent to the UE.
12. The method of claim 1 , wherein the request message comprises a request message transmitted on at least one of a Long Term Evolution (LTE) Signal Radio Bearer (SRB) and an LTE Downlink Common Control Channel (DL-CCCH).
13. A base station configured to wirelessly communicate with user equipment (UE) for a cell, the base station comprising:
a radio configured to wirelessly communicate with an item of user equipment (UE);
at least one processor configured to cause the base station to do the following:
send a request message from the base station to the UE on a downlink channel;
make, by the base station, a gratuitous grant, to the UE, of resources on an uplink channel for the UE to transmit a response message on the uplink channel, wherein the response message is responsive to the request message and wherein the gratuitous grant is made without waiting for a request from the UE for a grant of resources on the uplink channel for the UE to transmit the response message on the uplink channel; and
receive, by the base station, the response message transmitted by the UE on the uplink channel in response to the gratuitous grant; and
wherein the gratuitous grant is made after an amount of time sufficient for the UE to be ready to send the response message has elapsed without the base station having received a scheduling request from the UE; and
wherein the request message and the response message comprise signaling messages for the cell.
14. The base station of claim 13 , wherein the request message comprises a downlink Long-Term Evolution (LTE) message that comprises a request to which the UE is expected to send an uplink LTE message that includes a response to the request.
15. The base station of claim 13 , wherein the request message comprises a set of request packets;
wherein the at least one processor is configured to cause the base station to make, by the base station, the gratuitous grant, to the UE, of the resources on the uplink channel for the UE to transmit the response message on the uplink channel by causing the base station to do the following:
determine when the base station is provided with feedback indicating that each request packet was successfully received by the UE;
when the base station is provided with feedback indicating that each request packet was successfully received by the UE, determine if a queue for the UE is empty; and
when the queue for the UE is empty, start a timer; and
wherein the gratuitous grant is made after the timer has expired without the base station having received the scheduling request from the UE.
16. The base station of claim 15 , wherein the timer is initialized with an amount of time sufficient for the UE to be ready to send the response message.
17. The base station of claim 15 , wherein each request packet comprises a set of code words;
wherein at least one processor is configured to determine when the base station is provided with feedback indicating that each request packet was successfully received by the UE by causing the base station to do the following:
determine when the base station is provided with feedback indicating that all of the code words of each request packet was successfully received by the UE.
18. The base station of claim 17 , wherein the base station is provided with hybrid automatic repeat request (HARQ) feedback indicating whether each code word of each request packet was successfully received by the UE.
19. The base station of claim 15 , wherein the base station is provided with hybrid automatic repeat request (HARQ) feedback indicating whether each request packet was successfully received by the UE.
20. The base station of claim 15 , wherein the request message is retransmitted if a retransmission timer expires without the response message having been received by the base station.
21. The base station of claim 13 , wherein making, by the base station, the gratuitous grant, to the UE, of the resources on the uplink channel for the UE to transmit the response message on the uplink channel comprises: sending a LTE DCI0 message to the UE.
22. The base station of claim 13 , wherein at least one processor is configured to cause the base station to make, by the base station, the gratuitous grant, to the UE, of the resources on the uplink channel for the UE to transmit the response message on the uplink channel by causing the base station to do the following:
schedule resources for at least one of the following so as to take into account any measurement gap state or discontinuous reception state of the UE:
transmitting the gratuitous grant to the UE;
transmitting the response message from the UE to the base station on the uplink channel.
23. The base station of claim 13 , where the request message comprises a last message in a series of back to back request messages sent to the UE.
24. The base station of claim 13 , wherein the request message comprises a request message transmitted on at least one of a Long Term Evolution (LTE) Signal Radio Bearer (SRB) and an LTE Downlink Common Control Channel (DL-CCCH).
25. The method of claim 1 , wherein the gratuitous grant is made after the base station is provided with feedback indicating that the entire request message was successfully received by the UE.
26. The base station of claim 13 , wherein the gratuitous grant is made after the base station is provided with feedback indicating that the entire request message was successfully received by the UE.