Method and access node for supporting UE as well as a UE and corresponding method carried out by the UE in a wireless communication system

1. A method for supporting one or more user equipments (UEs) in a wireless communication system, the method comprising:

transmitting, from an access node, a first reference signal in a beam;

determining, at the access node, whether the access node received at least one indication from a UE about the UE's presence in the coverage area of the beam;

switching from transmitting of the first reference signal to transmitting a second reference signal in the beam from the access node if it is determined that the access node received at least one indication about the UE's presence in the coverage area of the beam; and

deactivating the beam, if it is determined that no indication about the UE's presence in the coverage area is received within a first predetermined time period.

2. The method of claim 1 , further comprising maintaining the beam for a second predetermined time period if a UE's presence is detected by the received indication.

3. The method of claim 1 , further comprising transmitting instructions to the one or more UEs in the coverage area of the beam, wherein the instructions indicate to the one or more UEs:

which reference signals the one or more UEs have to listen to in the beam; and/or

when to indicate to the access node UE's presence in the coverage area of the beam.

4. The method of claim 1 , further comprising activating the beam for reference signal transmission based on:

knowledge of the UE's location;

an indication that another beam with poor reception already exists for the UE; and/or

a request of the UE for activation of the beam.

5. The method of claim 1 , further comprising activating the beam for reference signal transmission sporadically or periodically for a predetermined time period to check for a UE's presence.

6. The method of claim 1 , wherein a message from the UE giving the indication about the UE's presence specifies the UE based on identification information and/or indicates beam quality.

7. A method carried out by a user equipment (UE) in a wireless communication system, the method comprising:

receiving reference signals in a beam from an access node;

determining whether at least two consecutively received reference signals in the beam indicate a switch from a first reference signal to a second reference signal; and

if a switch is determined, adapting a time period after the expiration of which an indication about the UE's presence in the coverage area of the beam is transmitted by the UE.

8. The method of claim 7 , further comprising:

obtaining instructions related to the beam transmitted from the access node; and

transmitting, if the time period expires and to the access node, the indication about the UE's presence in the coverage area of the beam in accordance with the instructions received from the access node.

9. The method of claim 8 , wherein the instructions indicate to the UE:

which reference signals the UE has to listen to in the beam; and/or

how to obtain the time period after the expiration of which the indication to the access node about the UE's presence is transmitted in the coverage area of the beam.

10. The method of claim 8 , wherein the instructions are obtained by:

receiving the instructions in an instruction message from the access node;

receiving the instructions in broadcasted system information;

retrieving the instructions from an internal storage; and/or

deriving the instructions from a received reference signal based on a predefined mapping between the reference signal and a set of instructions.

11. The method of claim 7 , further comprising informing the access node to activate the beam for reference signal transmission by providing:

an indication about the UE's presence in the coverage area of the beam;

an indication that another beam with poor reception already exists for the UE; and/or

an explicit request of the UE to activate the beam.

12. The method of claim 7 , wherein a message from the UE giving the indication about the UE's presence specifies the UE based on identification information and/or indicates beam quality.

13. An access node supporting one or more user equipments (UEs) in a wireless communication system, the access node comprising:

a transmitter configured to transmit a first reference signal in a beam;

processing circuitry configured to:

determine whether the access node received at least one indication from a UE about the UE's presence in the coverage area of the beam;

control a switch from the transmission of the first reference signal to a transmission of a second reference signal in the beam by the transmitter if the access node received at least one indication about the UE's presence in the coverage area of the beam;

deactivate the beam, if it is determined that no indication about the UE's presence in the coverage area is received within a first predetermined time period.

14. A user equipment (UE) of a wireless communication system, the UE comprising:

a receiver configured to receive reference signals in a beam from an access node;

processing circuitry configured to determine whether at least two consecutively received reference signals in the beam indicate a switch from a first reference signal to a second reference signal; and

a UE timer configured to adapt, if a switch is determined, a time period after the expiration of which an indication about the UE's presence in the coverage area of the beam is transmitted.