Procedures for multiple active bandwidth parts

1. An apparatus comprising:

a transceiver that communicates with a serving cell; and

a processor coupled to the transceiver, the processor configured to cause the apparatus to:

receive a configuration for a plurality of bandwidth parts (“BWPs”) for the serving cell, wherein multiple BWPs are simultaneously active;

communicate with a serving cell using the multiple active BWPs, wherein communicating using multiple active BWPs comprises concurrently receiving and/or transmitting data on each of the multiple active BWPs;

receive a configuration for multiple configured grants for the serving cell, wherein each of the multiple active BWPs is configured with one of the multiple configured grants;

configure a separate Hybrid Automatic Repeat Request (“HARQ”) entity for each active BWP of the serving cell, each HARQ entity maintaining a set of parallel HARQ processes;

receive a first indication to change a set of active BWPs;

receive a second indication from a base unit of which configured grants are to be used in response to the change to the set of active BWPs, wherein the second indication comprises a bitmap, each bit of the bitmap indicating whether a configured grant is to be activated or deactivated, wherein the first indication to change a set of active BWPs and the second indication of which configured grants are to be used are included in the same message; and

selectively activate a configured grant in response to the change to the set of active BWPs, wherein activating the configured grant in response to the change to the set of active BWPs comprises activating a configured grant for a previously deactivated BWP.

2. The apparatus of claim 1 , wherein the first and second indications are received in a medium access control (“MAC”) control element (“CE”).

3. The apparatus of claim 1 , wherein the change to the set of active BWPs comprises one of: activating, deactivating, or switching an active BWP of the serving cell.

4. The apparatus of claim 1 , wherein a number of active BWPs is greater than a number of activated configured grants.

5. The apparatus of claim 1 , wherein the apparatus supports a plurality of services, each service associated with a different active BWP.

6. The apparatus of claim 1 , wherein the multiple active BWPs are selected from a set of configured BWPs of the serving cell, wherein the processor is further configured to cause the apparatus to:

map one or more logical channels to each of the multiple configured BWPs; and

prioritize data from the logical channels for transmission on an uplink BWP.

7. The apparatus of claim 1 , wherein the processor is further configured to cause the apparatus to:

receive an indication to transition to an inactive state; and

deactivate all active BWPs of the serving cell except a single BWP, the single BWP being an initial BWP or a default BWP.

8. The apparatus of claim 1 , wherein the processor is further configured to cause the apparatus to:

check a pathloss trigger condition in response to the change to the set of active BWPs; and

report power headroom information for each active BWPs.

9. The apparatus of claim 8 , wherein, to check the pathloss trigger condition in response to the change to the set of active BWPs, the processor is further configured to cause the apparatus to check a pathloss trigger condition for subset of the active BWPs.

10. The apparatus of claim 8 , wherein the change to the set of active BWPs comprises switching a first BWP for second BWP, wherein, to check the pathloss trigger condition in response to the change to the set of active BWPs, the processor is further configured to cause the apparatus to:

take a first pathloss measurement on the first BWP;

take a second pathloss measurement on the second BWP;

calculate a pathloss difference using the first pathloss measurement to the second pathloss measurement; and

trigger a power headroom report if the path loss difference is more than a threshold amount.

11. The apparatus of claim 1 , wherein the serving cell is a reference serving cell, wherein the processor is further configured to cause the apparatus to:

receive a pathloss reference linking parameter that links an active downlink BWP to an active uplink BWP, and

estimate a pathloss value for the active uplink BWP using the linked active downlink BWP.

12. The apparatus of claim 11 , wherein the linked active downlink BWP is an initially active downlink BWP within the reference serving cell or a default downlink BWP within the reference serving cell.

13. The apparatus of claim 1 , wherein the change to the set of active BWPs comprises switching a first BWP for a second BWP, wherein the processor is configured to cause the apparatus to continue HARQ protocol operation across the first and second BWPs.

14. The apparatus of claim 1 , wherein different ones of the active BWPs are associated with different timing advance groups.

15. The apparatus of claim 14 , wherein the processor is further configured to cause the apparatus to maintain multiple timing advance loops for the serving cell, each timing advance loop associated with a different one of the timing advance groups.

16. A method comprising:

receiving a configuration for a plurality of bandwidth parts (“BWPs”) for the serving cell, wherein multiple BWPs are simultaneously active;

communicating with a serving cell using multiple active BWP for the serving cell, wherein communicating using multiple active BWPs comprises concurrently receiving and/or transmitting data on each of the multiple active BWPs;

receiving a configuration for with multiple configured grants for the serving cell, wherein each of the multiple active BWPs is configured with one of the multiple configured grants;

configuring a separate Hybrid Automatic Repeat Request (“HARQ”) entity for each active BWP of the serving cell, each HARQ entity maintaining a set of parallel HARQ processes;

receiving a first indication to change a set of active BWPs;

receiving a second indication from a base unit of which configured grants are to be used in response to the change to the set of active BWPs, wherein the second indication comprises a bitmap, each bit of the bitmap indicating whether a configured grant is to be activated or deactivated, wherein the first indication to change a set of active BWPs and the second indication of which configured grants are to be used are included in the same message; and

selectively activating a configured grant in response to the change to the set of active BWPs, wherein activating the configured grant in response to the change to the set of active BWPs comprises activating a configured grant for a previously deactivated BWP.