Method and apparatus for determining whether to transmit network slice selection assistance information

1. A method in a network entity comprising:

transmitting to a user equipment via an access stratum signaling an indication as to whether network slice selection assistance information is required as part of radio connection establishment or resumption signaling;

receiving the network slice selection assistance information; and

determining whether to accept or to reject a radio resource control connection establishment or resumption based on the received network slice selection assistance information.

2. The method in accordance with claim 1 , wherein a transmission of the network slice selection assistance information is selectively activated and deactivated in the user equipment responsive to the indication from the network entity as to whether the network slice selection assistance information is identified as being required as part of the radio connection establishment or resumption signaling.

3. The method in accordance with claim 2 , wherein when the network slice selection assistance information is identified in the indication as being required, the transmission of the network slice selection assistance information is activated in the user equipment; and when the network slice selection assistance information is identified in the indication as not being required, the transmission of the network slice selection assistance information is deactivated in the user equipment.

4. The method in accordance with claim 1 , wherein an access stratum layer of the user equipment is informed by a non-access stratum layer about the network slice selection assistance information during an initiation of service request procedure when the user equipment is in a connection management idle state.

5. The method in accordance with claim 1 , wherein the radio resource control connection establishment or resumption is accepted, when the network slice selection assistance information, that has been identified as being required, is included as part of the radio connection establishment or resumption signaling.

6. The method in accordance with claim 1 , wherein the radio resource control connection establishment or resumption is rejected, when the network slice selection assistance information, that has been identified as being required, is not included as part of the radio connection establishment or resumption signaling.

7. The method according to claim 1 , wherein the indication transmitted by the network entity to the user equipment includes system information from a cell of a network.

8. The method according to claim 7 , wherein the system information from the cell of the network is broadcasted system information, which is transmitted while the cell of the network is operating as a serving cell.

9. The method according to claim 1 , wherein the indication transmitted by the network entity includes radio resource control signaling transmitted by the network entity.

10. The method according to claim 9 , wherein the indication transmitted by the network entity included as part of the radio resource control signaling transmitted by the network entity is included as part of a radio resource control connection setup message.

11. The method according to claim 1 , wherein the received network slice selection assistance information is included as part of a radio resource control connection complete message.

12. The method according to claim 1 , wherein an access stratum layer in the user equipment is configured to inform a non-access stratum layer as to whether the network slice selection assistance information is required or not.

13. The method according to claim 1 , wherein the indication includes a parameter, which is always present, that has an associated value that selectively identifies between an indication that the network slice selection assistance information for all allowed slices needs to be included in the radio connection establishment or resumption signaling, an indication that the network slice selection assistance information is included in the radio connection establishment or resumption signaling for at least the slices for which a packet data unit connection is to be activated, and an indication that the network slice selection assistance information does not need to be included.

14. The method according to claim 1 , wherein the indication includes a parameter, which is optionally present, where when present an associated value of the parameter can distinguish between an indication that the network slice selection assistance information for all allowed slices needs to be included in the radio connection establishment or resumption signaling, and an indication that the network slice selection assistance information is included in the radio connection establishment or resumption signaling for at least the slices for which a packet data unit connection is to be activated, and where when absent serves as an indication that the network slice selection assistance information does not need to be included.

15. The method according to claim 1 , wherein when the radio resource control connection establishment or resumption signaling is part of an attempt to resume a connection from an inactive state, the determination as to whether the network slice selection assistance information is required is based upon system information from a cell that is to currently operating as a serving cell.

16. A network entity for communicating with one or more user equipment in a communication network, the network entity comprising:

a controller; and

a transceiver that transmits to a user equipment via an access stratum signaling an indication as to whether network slice selection assistance information is required as part of radio connection establishment or resumption signaling;

wherein the network slice selection assistance information is received via the transceiver; and

wherein the controller determines whether to accept or to reject a radio resource control connection establishment or resumption based on the received network slice selection assistance information.

17. The network entity in accordance with claim 16 , wherein a transmission of the network slice selection assistance information is selectively activated and deactivated in the user equipment responsive to the indication from the network entity as to whether the network slice selection assistance information is identified as being required as part of the radio connection establishment or resumption signaling.

18. The network entity in accordance with claim 17 , wherein when the network slice selection assistance information is identified in the indication as being required, the transmission of the network slice selection assistance information is activated in the user equipment; and when the network slice selection assistance information is identified in the indication as not being required, the transmission of the network slice selection assistance information is deactivated in the user equipment.

19. The network entity in accordance with claim 16 , wherein the radio resource control connection establishment or resumption is accepted, when the network slice selection assistance information, that has been identified as being required, is included as part of the radio connection establishment or resumption signaling.

20. The network entity in accordance with claim 16 , wherein the radio resource control connection establishment or resumption is rejected, when the network slice selection assistance information, that has been identified as being required, is not included as part of the radio connection establishment or resumption signaling.