Scheduling systems and methods for wireless networks

1. A method comprising, by a base station in a wireless network:

configuring uplink semi-persistent scheduling (SPS) for a user equipment;

receiving from a user equipment a request to reconfigure the already-active uplink SPS,

wherein the already-active uplink SPS grants the user equipment a resource block allocation (RBA) and a modulation and coding scheme (MCS) for periodic uplink transmissions,

wherein the already-active uplink SPS comprises a time-interval parameter, the time-interval parameter specifying a time interval between the periodic uplink transmissions,

wherein the request comprises information related to a proposed adjustment of the time-interval parameter; and

sending a reconfigured already-active uplink SPS to the user equipment, the reconfigured already-active uplink SPS comprising a modified time-interval parameter based, at least in part, on the information.

2. The method of claim 1 , comprising notifying the user device of the reconfigured already-active uplink SPS.

3. The method of claim 1 , comprising receiving from the user device an uplink transmission pursuant to the reconfigured already-active uplink SPS.

4. The method of claim 1 , wherein the reconfigured already-active uplink SPS comprises a starting-subframe identifier.

5. The method of claim 1 , comprising sending updated scheduling information to the user equipment, the updated scheduling information comprising the modified time-interval parameter.

6. The method of claim 1 , comprising receiving an uplink-grant request from the user equipment prior to receiving the request to reconfigure.

7. The method of claim 6 , wherein the uplink-grant request is a scheduling request.

8. The method of claim 6 , wherein the uplink-grant request is specified using one or more reserved bits of a header of an uplink packet.

9. The method of claim 1 , wherein the request to reconfigure is specified in at least one of the following portions of a media access control (MAC) protocol data unit (PDU):

a reserved bit of a header of the MAC PDU;

a control-element field of a payload of the MAC PDU; and

a padding field of the payload.

10. The method of claim 1 , wherein the request to reconfigure is specified in a control-element field of a media access control (MAC) payload, the control-element field identified by a logical channel ID (LCID) value assigned from a set of reserved LCID values.

11. The method of claim 1 , wherein the information related to the proposed adjustment comprises a proposed value of the time-interval parameter.

12. The method of claim 1 , wherein the information related to the proposed adjustment comprises an index to an array of time-interval-parameter values stored in memory on the base station.

13. The method of claim 1 , wherein the time-interval parameter comprises two possible values, the two possible values comprising a current value and an alternative value, and

wherein the information related to the proposed adjustment comprises a toggle indicator.

14. The method of claim 13 , wherein one of the two possible values corresponds to a talk spurt and another of the two possible values corresponds to a silence interval.

15. The method of claim 1 , wherein the information related to the proposed adjustment identifies a proposed starting subframe.