Performing resume request procedure

1. A method of a current base unit, the method comprising:

receiving a resume request from a remote unit in an inactive state;

in response to receiving the resume request, sending a message to a last serving base unit separate from the current base unit; and

in response to receiving a response from the last serving base unit, sending a configuration message to the remote unit to maintain the remote unit in the inactive state.

2. The method of claim 1 , wherein the resume request includes a cause of the resume request.

3. The method of claim 2 , wherein the cause is a periodic radio access network (“RAN”) notification area update.

4. The method of claim 1 , wherein the message includes a resume ID or a user equipment (“UE”) ID.

5. The method of claim 1 , wherein the last serving base unit continues storing a user equipment (“UE”) context of the remote unit.

6. The method of claim 1 , further comprising:

sending an indicator to the last serving base unit; and

in response to receiving an acknowledge response from the last serving base unit, sending the configuration message to the remote unit.

7. The method of claim 6 , wherein a resume ID or a user equipment (“UE”) ID is included in the indicator.

8. The method of claim 1 , wherein the configuration message is sent by a signal radio bearer.

9. The method of claim 1 , further comprising:

sending a Retrieve user equipment (“UE”) Context Request to the last serving base unit; and

in response to receiving a UE context of the remote unit from the last serving base unit, sending the configuration message to the remote unit.

10. The method of claim 9 , wherein the configuration message is sent by a signal radio bearer.

11. The method of claim 9 , wherein an assistant indicator is included in the Retrieve user equipment (“UE”) Context Request to instruct the last serving base unit to continue storing the UE context of the remote unit.

12. A current base unit comprising:

a transceiver that:

receives a resume request from a remote unit in an inactive state;

in response to receiving the resume request, sends a message to a last serving base unit separate from the current base unit; and

in response to receiving a response from the last serving base unit, sends a configuration message to the remote unit to maintain the remote unit in the inactive state.

13. The base unit of claim 12 , wherein the resume request includes a cause of the resume request.

14. The base unit of claim 12 , wherein the transceiver:

sends an indicator to the last serving base unit; and

in response to receiving an acknowledge response from the last serving base unit, sends the configuration message to the remote unit.

15. The base unit of claim 12 , wherein the transceiver:

sends a Retrieve user equipment (“UE”) Context Request to the last serving base unit; and

in response to receiving a UE context of the remote unit from the last serving base unit, sends the configuration message to the remote unit.

16. A remote unit in an inactive state, wherein the remote unit comprises:

a transceiver that:

sends a resume request to a current base unit; and

in response to sending the resume request, receives a configuration message from the current base unit to maintain the remote unit in the inactive state, wherein the current base unit, in response to receiving the resume request, sends a message to a last serving base unit and sends the configuration message in response to receiving a response from the last serving base unit.

17. The remote unit of claim 16 , wherein the resume request includes a cause of the resume request.

18. The remote unit of claim 17 , wherein the cause is a periodic radio access network (“RAN”) notification area update.

19. The remote unit of claim 16 , wherein the transceiver receives the configuration message by a signal radio bearer.

20. The remote unit of claim 16 , wherein the transceiver receives the configuration message by a signal radio bearer.