Method and apparatus for handling uplink bearer split configuration in multi-connectivity system

1. A method for handling an uplink (UL) bearer split configuration in a multi-connectivity system, the method comprising:

identifying, by a mobile terminal, first UL data of a packet data convergence protocol (PDCP) layer;

transmitting, by the mobile terminal, first data of the first UL data to a primary radio link control (RLC) entity for a first time period, and transmitting second data of the first UL data to a secondary RLC entity for a second time period;

identifying, by the mobile terminal, at least one first network parameter of a first UL path associated with the primary RLC entity for the first time period, and identifying at least one second network parameter of a second UL path associated with the secondary RLC entity for the second time period;

irrespective of reception of an UL grant for second UL data of the PDCP layer, determining, by the mobile terminal, a split factor for splitting the second UL data between the primary RLC entity and the secondary RLC entity based on the at least one first network parameter and the at least one second network parameter; and

transmitting, by the mobile terminal, the second UL data to the primary RLC entity and the secondary RLC entity for a third time period based on the split factor.

2. The method of claim 1 , wherein the first time period comprises a same or a different time period as the second time period, and

wherein the third time period comprises a sum of the first time period and the second time period.

3. The method of claim 1 , wherein the at least one first network parameter comprises at least one of a spectrum efficiency (SE) of the first UL path, a block error rate (BER) of the first UL path, buffer occupancy (BO) statistics related to the first UL path, an amount of data arrival related to the first UL path, a latency related to the first UL path, a PDCP protocol data unit (PDU) data type on the first UL path, a number of uplink grants allocated for the first UL path, a scheduling rate related to the first UL path, and a subcarrier spacing (SCS) related to the first UL path, and

wherein the at least one second network parameter comprises at least one of an SE of the second UL path, a BER of the second UL path, BO statistics related to the second UL path, an amount of data arrival related to the second UL path, a latency related to the second UL path, a PDCP PDU data type on the second UL path, a number of uplink grants allocated for the second UL path, a scheduling rate related to the first UL path, and an SCS related to the second UL path.

4. The method of claim 1 , wherein the at least one network parameter of the first UL path and the at least one network parameter of the second UL path are provided by at least one of a physical (PHY) layer and a medium access control (MAC) layer to the PDCP layer.

5. The method of claim 4 , further comprising calculating, by the at least one of the PHY layer and the MAC layer, a spectral efficiency for each of the first UL path and the second UL path, and

sharing, by the at least one of the PHY layer and the MAC layer, the spectral efficiency for each of the first UL path and the second UL path with the PDCP layer.

6. The method of claim 1 , wherein the first UL data is greater than or equal to a UL data split threshold, and the second data is remaining data except the first data transmitted during the first time period from the first UL data.

7. The method of claim 1 , further comprising determining the split factor based on a lookup table for determining a split ratio between the primary RLC entity and the secondary RLC entity.

8. A mobile terminal for handling an uplink (UL) bearer split configuration, comprising:

a transceiver;

at least one processor; and

a memory communicatively coupled to the at least one processor, wherein the memory is configured to store processor-executable instructions, which, when executed, cause the at least one processor to:

identify first UL data of a packet data convergence protocol (PDCP) layer;

control the transceiver to transmit first data of the first UL data to a primary radio link control (RLC) entity for a first time period, and to transmit second data of the first UL data to a secondary RLC entity for a second time period;

identify at least one first network parameter of a first UL path associated with the primary RLC entity for the first time period, and identify at least one second network parameter of a second UL path associated with the secondary RLC entity for the second time period;

irrespective of reception of an UL grant for second UL data of the PDCP layer, determine a split factor for splitting the second UL data between the primary RLC entity and the secondary RLC entity based on the at least one first network parameter and the at least one second network parameter; and

control the transceiver to transmit the second UL data to the primary RLC entity and the secondary RLC entity for a third time period based on the split factor.

9. The mobile terminal of claim 8 , wherein the first time period comprises a same or a different time period as the second time period, and

wherein the third time period comprises a sum of the first time period and the second time period.

10. The mobile terminal of claim 8 , wherein the at least one first network parameter comprises at least one of a spectrum efficiency (SE) of the first UL path, a block error rate (BER) of the first UL path, buffer occupancy (BO) statistics related to the first UL path, an amount of data arrival related to the first UL path, a latency related to the first UL path, a PDCP protocol data unit (PDU) data type on the first UL path, a number of uplink grants allocated for the first UL path, a scheduling rate related to the first UL path, and a subcarrier spacing (SCS) related to the first UL path, and

wherein the at least one second network parameter comprises at least one of an SE of the second UL path, a BER of the second UL path, BO statistics related to the second UL path, an amount of data arrival related to the second UL path, a latency related to the second UL path, a PDCP PDU data type on the second UL path, a number of uplink grants allocated for the second UL path, a scheduling rate related to the first UL path, and an SCS related to the second UL path.

11. The mobile terminal of claim 8 , wherein the at least one network parameter of the first UL path and the at least one network parameter of the second UL path are provided by at least one of a physical (PHY) layer and a medium access control (MAC) layer to the PDCP layer.

12. The mobile terminal of claim 8 , wherein the memory is further configured to store processor-executable instructions, which, when executed, cause the at least one processor to calculate, by the at least one of the PHY layer and the MAC layer, a spectral efficiency for each of the first UL path and the second UL path, and

wherein share, by the at least one of the PHY layer and the MAC layer, the spectral efficiency for each of the first UL path and the second UL path with the PDCP layer.

13. The mobile terminal of claim 8 , wherein the first UL data is greater than or equal to a UL data split threshold, and the second data is remaining data except the first data transmitted during the first time period from the first UL data.

14. The mobile terminal of claim 8 , wherein the memory is further configured to store processor-executable instructions, which, when executed, cause the at least one processor to determine the split factor based on a lookup table for determining a split ratio between the primary RLC entity and the secondary RLC entity.

15. A non-transitory computer readable medium comprising instructions stored thereon which, when processed by at least one processor, cause a mobile terminal to perform a method comprising:

identifying first uplink (UL) data of a packet data convergence protocol (PDCP) layer;

transmitting first data of the first UL data to a primary radio link control (RLC) entity for a first time period, and transmitting second data of the first UL data to a secondary RLC entity for a second time period;

identifying at least one first network parameter of a first UL path associated with the primary RLC entity for the first time period, and identifying at least one second network parameter of a second UL path associated with the secondary RLC entity for the second time period;

irrespective of reception of an UL grant for second UL data of the PDCP layer, determining a split factor for splitting the second UL data between the primary RLC entity and the secondary RLC entity based on the at least one first network parameter and the at least one second network parameter; and

transmitting the second UL data to the primary RLC entity and the secondary RLC entity for a third time period based on the split factor.

16. The medium of claim 15 , wherein the first time period comprises a same or a different time period as the second time period, and

wherein the third time period comprises a sum of the first time period and the second time period.

17. The medium of claim 15 , wherein the first UL data is greater than or equal to a UL data split threshold, and the second data is remaining data except the first data transmitted during the first time period from the first UL data.

18. The medium of claim 15 , wherein the at least one first network parameter comprises at least one of a spectrum efficiency (SE) of the first UL path, a block error rate (BER) of the first UL path, buffer occupancy (BO) statistics related to the first UL path, an amount of data arrival related to the first UL path, a latency related to the first UL path, a PDCP protocol data unit (PDU) data type on the first UL path, a number of uplink grants allocated for the first UL path, a scheduling rate related to the first UL path, and a subcarrier spacing (SCS) related to the first UL path, and

wherein the at least one second network parameter comprises at least one of an SE of the second UL path, a BER of the second UL path, BO statistics related to the second UL path, an amount of data arrival related to the second UL path, a latency related to the second UL path, a PDCP PDU data type on the second UL path, a number of uplink grants allocated for the second UL path, a scheduling rate related to the first UL path, and an SCS related to the second UL path.