Wireless communication method and apparatus for processing enhanced uplink scheduling grants
A method for generating a serving grant at a wireless transmit/receive unit is disclosed. An absolute grant channel signal is decoded to obtain an absolute grant from a serving cell. A relative grant channel signal is decoded to obtain a relative grant from a serving radio link set and a relative grant from a non-serving radio link. A first serving grant candidate is generated based on the absolute grant from the serving cell or the relative grant from the serving radio link set. A second serving grant candidate is generated based on the relative grant from the non-serving radio link. The serving grant is generated based on the first serving grant candidate and the second serving grant candidate.
1. A method for generating a serving grant (SG) at a wireless transmit/receive unit (WTRU), comprising:
decoding an absolute grant channel (AGCH) signal to obtain an absolute grant (AG) from a serving cell;
decoding a relative grant channel (RGCH) signal to obtain a relative grant (RG) from a serving radio link set (RLS) and an RG from a non-serving radio link (RL);
generating a first SG candidate based on at least one of: the AG from the serving cell or the RG from the serving RLS;
generating a second SG candidate based on the RG from the non-serving RL; and
generating the SG based on the first SG candidate and the second SG candidate.
2. The method of claim 1 , wherein the RG is one of: an UP command to increase a previous SG by a predetermined step size, a DOWN command to decrease the previous SG by a predetermined step size, or a HOLD command to maintain the previous SG.
3. The method of claim 1 , further comprising:
determining whether the AG is a primary AG or a secondary AG;
on a condition that the AG is a primary AG, determining whether an AG value in the AG is “INACTIVE”; and
on a condition that the AG value is not “INACTIVE”, setting the SG with the AG value.
4. The method of claim 3 , further comprising:
determining whether a transmission time interval (TTI) is 10 ms or 2 ms;
on a condition that the TTI is 10 ms, activating all hybrid automatic repeat request (H-ARQ) processes;
on a condition that the TTI is 2 ms, further determining whether an activation flag in the AG is “SINGLE” or “ALL”;
on a condition that the activation flag is “SINGLE”, activating a particular H-ARQ process; and
on a condition that the activation flag is “ALL”, activating all H-ARQ processes.
5. The method of claim 3 , further comprising:
on a condition that the AG value is “INACTIVE”, further determining whether a transmission time interval (TTI) is 2 ms or 10 ms;
on a condition that the TTI is 2 ms, further determining whether an activation flag in the AG is “SINGLE” or “ALL”; and
on a condition that the activation flag is “SINGLE”, deactivating a particular H-ARQ process.
6. The method of claim 5 , further comprising:
on a condition that the TTI is 10 ms or the activation flag is “ALL”, further determining whether a secondary radio network temporary identity (RNTI) is configured;
on a condition that the secondary RNTI is not configured, deactivating all H-ARQ processes; and
on a condition that the secondary RNTI is configured, activating all H-ARQ processes, and setting a secondary AG mode.
7. The method of claim 6 , further comprising:
on a condition that the secondary RNTI is configured, setting the SG based on a latest received AG value.
8. The method of claim 3 , further comprising:
on a condition that the AG is a secondary AG, determining whether a scheduling mode is a secondary AG mode;
on a condition that the scheduling mode is a secondary AG mode, setting the SG based on the AG value; and
on a condition that the scheduling mode is not a secondary AG mode, saving the AG value.
9. The method of claim 3 , further comprising:
on a condition that the AG value is “INACTIVE”, further determining whether an activation flag is “SINGLE” or “ALL”;
on a condition that the activation flag is “SINGLE”, further determining whether a transmission time interval (TTI) is 10 ms or 2 ms,
on a condition that the TTI is 10 ms, waiting for a next TTI, and
on a condition that the TTI is 2 ms, deactivating a particular hybrid automatic repeat request (H-ARQ) process.
10. The method of claim 9 , further comprising:
on a condition that the activation flag is “ALL”, further determining whether a secondary radio network temporary identity (RNTI) is configured;
on a condition that the secondary RNTI is not configured, further determining whether a TTI is 10 ms or 2 ms;
on a condition that the TTI is 10 ms, waiting for a next TTI;
on a condition that the TTI is 2 ms, deactivating a particular hybrid automatic repeat request (H-ARQ) process; and
on a condition that the secondary RNTI is configured, activating all H-ARQ processes and setting a secondary AG mode.
11. The method of claim 10 , further comprising:
on a condition that the secondary RNTI is configured, setting the SG based on a latest received AG value.
12. The method of claim 3 , wherein the serving cell sends a secondary AG before switching a scheduling mode from a primary AG mode to a secondary AG mode.
13. The method of claim 3 , wherein the serving cell sends a secondary AG before switching a scheduling mode from a primary AG mode to a secondary AG mode on a condition that there is an out-of-date secondary AG.
14. The method of claim 13 , wherein the serving cell determines the existence of the out-of-date secondary AG by implementing a time threshold.
15. The method of claim 14 , wherein the time threshold is static.
16. The method of claim 14 , wherein the time threshold is dynamically adjusted based on a predetermined factor.
17. The method of claim 16 , wherein the predetermined factor includes at least one of: a traffic condition change rate, an interference condition variation rate, or vehicle speed.