Method and network node for managing a transmission power parameter for a D2D link

1. A method, performed by a first device, for managing a transmission power parameter indicating transmission power for a Device-To-Device (D2D) transmission to be sent on at least one D2D link between the first device and a second device, the method comprising: determining a load based on one or more metrics of at least one D2D communication between at least the first and second devices; and determining the transmission power parameter based on the determined load, wherein the determining the transmission power parameter comprises determining the transmission power parameter based on the load in an at least partly inverse manner while not exceeding a maximum transmit power of the first device.

2. The method of claim 1 , further comprising sending the transmission power parameter to at least the second device.

3. The method of claim 1 , wherein the determining the load is based on at least one of:

a number of physical resource blocks used for the D2D communication;

a number of sub-frames occupied by the D2D communication;

a number of devices involved in the D2D communication;

statistics concerning decoding of D2D physical channels of the D2D communication;

a received power per packet of the D2D communication;

a delay of D2D discovery;

a delay of D2D transmissions in the D2D communication, and

a percentage of neighboring devices, being neighbors to at least one of the first device and the second device, which neighboring devices are capable of successfully receiving one D2D packet within one transmission period.

4. A network node configured to manage a transmission power parameter indicating transmission power for a Device-To-Device (D2D) transmission to be sent on at least one D2D link between a first device and a second device, the network node comprising:

a processing circuit configured to cause the network node to:

determine a load based on one or more metrics of at least one D2D communication between at least the first and second devices;

determine the transmission power parameter based on the load, wherein the network node is configured for determining the transmission power parameter by determining the transmission power parameter based on the load in an at least partly inverse manner while not exceeding a maximum transmit power of the first device; and

sending the determined transmission power parameter to at least the first device.

5. The network node of claim 4 , wherein the processing circuit is configured to cause the network node to determine the load based on at least one of:

a number of physical resource blocks used for the D2D communication;

a number of sub-frames occupied by the D2D communication;

a number of devices involved in the D2D communication;

statistics concerning decoding of D2D physical channels of the D2D communication;

a received power per packet of the D2D communication;

a delay of D2D discovery;

a delay of D2D transmissions in the D2D communication, and

a percentage of neighboring devices, being neighbors to at least one of the first device and the second device, which neighboring devices are capable of successfully receiving one D2D packet within one transmission period.

6. A first device configured for managing a transmission power parameter indicating transmission power for a Device-To-Device (D2D) transmission to be sent on at least one D2D link between the first device and a second device, the first device comprising: a processing circuit configured to cause the first device to: determine a load based on one or more metrics of at least one D2D communication between at least the first and second devices; and determine the transmission power parameter based on the determined load, wherein the processing circuit is configured to cause the first device to determine the transmission power parameter based on the load in an at least partly inverse manner while not exceeding a maximum transmit power of the first device.

7. The first device of claim 6 , wherein the processing circuit is configured to cause the first device to send the transmission power parameter to the second device.

8. The first device of claim 6 , wherein the processing circuit is configured to cause the first device to determine the load based on at least one of:

a number of physical resource blocks used for the D2D communication;

a number of sub-frames occupied by the D2D communication;

a number of devices involved in the D2D communication;

statistics concerning decoding of D2D physical channels of the D2D communication;

a received power per packet of the D2D communication;

a delay of D2D discovery;

a delay of D2D transmissions in the D2D communication, and

a percentage of neighboring devices, being neighbors to at least one of the first device and the second device, which neighboring devices are capable of successfully receiving one D2D packet within one transmission period.

9. A computer program product stored in a non-transitory computer readable medium for managing a transmission power parameter indicating transmission power for a Device-To-Device (D2D) transmission to be sent on at least one D2D link between a first device and a second device, the computer program product comprising software instructions which, when run on a processing circuit of a network node or the first device or, causes the corresponding network node or first device to: determine a load based on one or more metrics of at least one D2D communication between at least the first and second devices; and determine the transmission power parameter based on the determined load, wherein the determining the transmission power parameter comprises determining the transmission power parameter based on the load in an at least partly inverse manner while not exceeding a maximum transmit power of the first device.

10. The computer program product of claim 9 :

wherein the processing circuit is a portion of the network node; and

wherein the software instructions, when run on the processing circuit of the network node, cause the network node send the determined transmission power parameter to the first device.

11. The computer program product of claim 9 :

wherein the processing circuit is a portion of the first device; and

wherein the software instructions, when run on the processing circuit of the first device, cause the first device to send the determined transmission power parameter to the second device.

12. A method, performed by a network node, for managing a transmission power parameter indicating transmission power for a Device-To-Device (D2D) transmission to be sent on at least one D2D link between the first device and a second device, the method comprising:

determining a load based on one or more metrics of the D2D communication between at least the first and second devices; and

determining the transmission power parameter based on the determined load, wherein the determining of the transmission power parameter comprises determining the transmission power parameter based on the load in an at least partly inverse manner while not exceeding a maximum transmit power of the first device; and

sending, to at least one of the first device and the second device, the transmission power parameter.

13. The method of claim 12 , wherein the determining of the load is based on at least one of:

a number of physical resource blocks used for the D2D communication;

a number of sub-frames occupied by the D2D communication;

a number of devices involved in the D2D communication;

statistics concerning decoding of D2D physical channels of the D2D communication;

a received power per packet of the D2D communication;

a delay of D2D discovery;

a delay of D2D transmissions in the D2D communication, and

a percentage of neighboring devices, being neighbors to at least one of the first device and the second device, which neighboring devices are capable of successfully receiving one D2D packet within one transmission period.