User equipment and method for reducing delay in a radio access network

1. User Equipment (UE) comprising processing circuitry to:

determine a delay value indicating a time for an enhanced Node B (eNB) to delay scheduling an uplink grant; and

generate a delayed buffer status report (D-BSR) medium-access control (MAC) control element for transmission to the eNB with a last-scheduled uplink grant, the D-BSR MAC control element to include at least an indicator of the delay value and an indicator of a predicted buffer size,

wherein the D-BSR MAC control element is a request for a delayed grant of uplink bandwidth,

wherein the processing circuitry further configures the D-BSR MAC control element to further include a logical channel identifier (LCID) index to indicate a control element for the delayed buffer status report, and

wherein the UE is configured to receive a delayed grant for uplink bandwidth in response to transmission of the D-BSR MAC control element, the grant being received from the eNB no sooner than the delay value and including a bandwidth allocation sufficient to handle the predicted buffer size.

2. The UE of claim 1 , wherein the predicted buffer size indicates an amount of uplink grant the UE anticipates it will need at a near-future time indicated by the delay value, and

wherein the UE is configured to refrain from requesting the uplink grant in response to receipt of a new uplink packet from an application layer when expecting the delayed grant.

3. The UE of claim 1 , wherein the LIE is to generate the D-BSR MAC control element for transmission to the eNB with the last-scheduled uplink grant when a current buffer size is zero and when the UE anticipates that it will have uplink packets based on the predicted buffer size.

4. The UE of claim 3 , wherein the UE is to refrain from generating the D-BSR MAC control element for transmission to the eNB with the last-scheduled grant when the current buffer size is zero and when the UE does not anticipate that it will have packets based on the predicted buffer size.

5. The UE of claim 3 wherein the UE is to generate a non-delayed BSR control element for transmission to the eNB with the last-scheduled uplink grant when the current buffer size is not zero, the non-delayed BSR control element indicating at least the current buffer size,

wherein the non-delayed BSR control element includes a LCID index to indicate one of a truncated BSR, a short BSR and a long BSR.

6. User Equipment (UE) comprising processing circuitry to:

determine a delay value indicating a time for an enhanced Node B (eNB) to delay scheduling an uplink grant:

generate a delayed buffer status report (D-BSR) medium-access control (MAC) control element for transmission to the eNB with a last-scheduled uplink grant, the D-BSR MAC control element to include at least an indicator of the delay value and an indicator of a predicted buffer size; and

determine the delay value and the predicted buffer size based at least in part on uplink traffic information for one or more applications running on the UE,

wherein the D-BSR MAC control element is a request for a delayed grant of uplink bandwidth, and

wherein the uplink traffic information includes one or more of a packet or bit generation rate, a packet arrival interval (PAI) and packet size (PS) information for the one or more applications.

7. User Equipment (UE) comprising processing circuitry to:

determine a delay value indicating a time for an enhanced Node B (eNB) to delay scheduling an uplink grant; and

generate a delayed buffer status report (D-BSR) medium-access control (MAC) control element for transmission to the eNB with a last-scheduled uplink grant, the D-BSR MAC control element to include at least an indicator of the delay value and an indicator of a predicted buffer size,

wherein the D-BSR MAC control element is a request for a delayed grant of uplink bandwidth,

wherein the D-BSR MAC control element is requesting a delayed grant of uplink bandwidth for data flows, and

wherein the UE is configured to operate within a wireless access network in which the data flows are mapped to bearers using quality-of-service (QoS) class identifiers (QCIs).

8. User Equipment (UE) comprising processing circuitry to:

determine a delay value indicating a time for an enhanced Node B (eNB) to delay scheduling an uplink grant; and

generate a delayed buffer status report (D-BSR) medium-access control (MAC) control element for transmission to the eNB with a last-scheduled uplink grant, the D-BSR MAC control element to include at least an indicator of the delay value and an indicator of a predicted buffer size,

wherein the D-BSR MAC control element is a request for a delayed grant of uplink bandwidth,

wherein the UE is configured to receive a downlink congestion and buffer report (DCBR) from the eNB indicating whether or not congestion exists for downlink traffic, indicating average packet delay (APD), and indicating a downlink buffer size, and

wherein in response to receipt of the DCBR that indicates that congestion exists, the UE is to report information from the DCBR to one or more applications for one or more of traffic rate reduction, congestion mitigation and delay reduction.

9. The UE of claim 8 wherein the DCBR is received as part of a DCBR MAC control element, the DCBR including a congestion indicator (CI), an average packet delay (APD) indicator, and a downlink buffer size (DBS) indicator, the CI indicating whether or not congestion exists for downlink traffic, and

wherein the DCBR MAC control element includes a logical channel identifier (LCID) index to indicate a DCBR.

10. A method for reducing delay in a radio-access network, the method comprising:

determining a delay value indicating a time for an enhanced Node B (eNB) to delay scheduling an uplink grant;

generating a delayed buffer status report (D-BSR) medium-access control (MAC) control element for transmission to the eNB with a last-scheduled uplink grant, the D-BSR MAC control element to include at least an indicator of the delay value and an indicator of a predicted buffer size; and

receiving a delayed grant for uplink bandwidth in response to transmission of the D-BSR MAC control element, the delayed grant being received from the eNB no sooner than the delay value,

wherein the delayed grant includes a bandwidth allocation sufficient to handle the predicted buffer size.

11. The method of claim 10 further comprising:

determining the predicted buffer size; and

configuring the D-BSR MAC control element to include a logical channel identifier (LCID) index to indicate a control element for a delayed buffer status report.

12. A method for reducing delay in a radio-access network, the method comprising:

determining a delay value indicating a time for an enhanced Node B (eNB) to delay scheduling an uplink grant;

generating a delayed buffer status report (D-BSR) medium-access control (MAC) control element for transmission to the eNB with a last-scheduled uplink grant, the D-BSR MAC control element to include at least an indicator of the delay value and an indicator of a predicted buffer size;and

receiving delayed grant for uplink bandwidth in response to transmission of the D-BSR MAC control element the delayed grant being received from the eNB no sooner than the delay value,

wherein the predicted buffer size indicates an amount of uplink grant the UE anticipates it will need at a near-future time indicated by the delay value, and

wherein the method includes refraining from requesting an uplink grant in response to receipt of a new uplink packet from an application layer when expecting a delayed grant.

13. A method for reducing delay in a radio-access network, the method comprising:

determining a delay value indicating a time for an enhanced Node B (eNB) to delay scheduling an uplink grant;

generating a delayed buffer status report (D-BSR) medium-access control (MAC) control element for transmission to the eNB with a last-scheduled uplink grant, the D-BSR MAC control element to include at least an indicator of the delay value and an indicator of a predicted buffer size; and

receiving a delayed grant for uplink bandwidth in response to transmission of the D-BSR MAC control element, the delayed grant being received from the eNB no sooner than the delay value,

wherein the UE is to generate the D-BSR MAC control element for transmission to the eNB with the last-scheduled uplink grant when a current buffer size is zero and when the UE anticipates that it will have uplink packets based on the predicted buffer size.

14. An enhanced Node B (eNB) comprising processing circuitry configured to:

receive an radio-resource control (RRC) message to activate downlink congestion and buffer reporting from user equipment (UE), the message indicating a quality-of-service (QoS) class identifier (QCI) of a bearer where the downlink congestion and buffer reporting is to be activated;

monitor downlink traffic of the indicated QCI to determine whether congestion exists; and

send a downlink congestion and buffer report (DCBR) to the UE along with a medium-access control (MAC) protocol data unit (PDU) (MAC PDU), the DCBR indicating whether or not congestion exists for downlink traffic of the identified QCI, indicating average packet delay, and indicating a downlink buffer size,

wherein in response to receipt of a DCBR that indicates that congestion exists, the UE is to report information from the DCBR to one or more applications for one or more of traffic rate reduction, congestion mitigation and delay reduction,

wherein the QCI indicates a default bearer, and

wherein the eNB is further configured to:

continue to send a DCBR to the UE with MAC PDUs when the downlink buffer size increases for downlink traffic with the indicated QCI;

send MAC PDUs without a DCBR while the downlink buffer size does not increase for downlink traffic with the indicated QCI; and

when downlink congestion is no longer detected, send a DCBR to the UE with a MAC PDU indicating that congestion no longer exists and including a current average packet delay and a downlink buffer size.

15. The eNB of claim 14 wherein the DCBR is included as part of a DCBR MAC control element that includes a congestion indicator, an average packet delay indicator, and a downlink buffer size (DBS) indicator, the congestion indicator indicating whether or not congestion exists for downlink traffic, and

wherein the DCBR MAC control element includes a logical channel identifier (LCID) index to indicate downlink congestion and buffer reporting.