Microwave link transmission control with transmission of low rate dummy data
The present disclosure relates to methods and arrangements for controlling point-to-point microwave transmission on a microwave link between a first and a second microwave network node, wherein the microwave link is configured for payload data transmission at a payload data rate. The method comprises obtaining information indicative of a current data rate capability of the microwave link and comparing the current data rate capability to the configured payload data rate. When the current data rate capability is below the configured payload data rate, transmission on the microwave link is adapted to comprise transmission of dummy data on the microwave link between the first and second microwave network node.
1. A method, performed in a microwave link controller, for controlling point-to point microwave transmission on a microwave link between a first microwave network node and a second microwave network node, wherein the microwave link is configured for transmission of payload data at a configured payload data rate, the method comprising:
obtaining information indicative of a current data rate capability of the microwave link;
comparing the current data rate capability of the microwave link to the configured payload data rate of the microwave link; and
responsive to the current data rate capability of the microwave link being below the configured payload data rate of the microwave link, adapting transmission on the microwave link to transmit dummy data on the microwave link between the first microwave network node and the second microwave network node.
2. The method of claim 1 , wherein adapting transmission on the microwave link comprises transmitting, on the microwave link, the dummy data in lieu of the payload data responsive to the current data rate capability being below the configured payload data rate.
3. The method of claim 2 , further including
rerouting the payload data from the microwave link between the first microwave network node and the second microwave network node to a microwave link from the first microwave network node to a third microwave network node responsive to the current data rate capability being below the configured payload data rate.
4. The method of claim 1 , wherein transmission of payload data on the microwave link is disabled responsive to the current data rate capability being below the configured payload data rate.
5. The method of claim 1 , wherein the configured payload data rate is a fixed payload data rate and wherein the dummy data is transmitted at a data rate below the fixed payload data rate responsive to the current data rate capability being below the configured payload data rate.
6. The method of claim 5 , wherein the microwave link is arranged for adaptive coding, adaptive modulation, or adaptive coding and modulation, ACM, or adaptive coding, modulation and baud rate, ACM(B), and wherein the dummy data is transmitted at a pre-configured lowest transmission rate or at a transmission rate below the fixed payload data rate responsive to the current data rate capability being below the configured payload data rate.
7. The method of claim 6 , wherein adapting transmission on the microwave link comprises selecting a lower modulation order responsive to the current data rate capability being below the configured payload data rate, and selecting a higher modulation order when the current data rate capability is at or above the configured payload data rate.
8. The method of claim 6 , wherein adapting transmission on the microwave link comprises selecting a modulation order and/or a coding with a lower spectral efficiency in terms of bits/sec/Hz responsive to the current data rate capability being below the configured payload data rate, and selecting a higher spectral efficiency in terms of bits/sec/Hz when the current data rate capability is at or above the configured payload data rate.
9. The method of claim 1 , further comprising repeating obtaining the information indicative of the current data rate capability of the microwave link, comparing the current data rate capability to the configured payload data rate; and transmitting payload data on the microwave link responsive to the current data rate capability is on or above the configured payload data rate.
10. The method of claim 1 , wherein the current data rate capability being below the configured payload data rate is indicative of a bandwidth reduction of the microwave link.
11. The method of claim 1 , wherein the current data rate capability being below the configured payload data rate is indicative of a signal to noise ratio, SNR, reduction of the microwave link.
12. The method of claim 1 , wherein the current data rate capability being below the configured payload data rate is indicative of an increase in interference of the microwave link.
13. The method of claim 1 , where adapting transmission on the microwave link further comprises transmitting control plane data on the microwave link.
14. The method of claim 13 , wherein the control plane data is transmitted at a default lowest order modulation of binary phase shift keying, BPSK, or 4 or 16 quadrature amplitude modulation, QAM.
15. The method of claim 1 , wherein the microwave link is a high capacity backhaul link and the first microwave network node and the second microwave network node are small radio base stations, RBSs, of a wireless communication network.
16. The method of claim 15 , wherein the first microwave network node and the second microwave network node are pico eNBs of a 3GPP LTE network.
17. The method of claim 1 , wherein the microwave link controller is further arranged to control transmission on at least a further microwave link between nodes of a microwave network.
18. A microwave link controller configured to control point-to-point microwave transmission on a microwave link configured for transmission of payload data at a configured payload data rate between a first microwave network node and a second microwave network node, the microwave link controller comprising:
processing circuitry configured to:
obtain information indicative of a current data rate capability of the microwave link;
compare the current data rate capability of the microwave link to the configured payload data rate of the microwave link; and
responsive to the current data rate capability of the microwave link being below the configured payload data rate of the microwave link, adapt transmission on the microwave link to transmit dummy data on the microwave link between the first microwave network node and the second microwave network node.
19. The microwave link controller of claim 18 , wherein the processing circuitry comprises a processor and a memory containing instructions executable by said processor.
20. A microwave link controller comprising:
an I/O interface configured to receive a data signal on a microwave link;
a digital signal processor configured to obtain information indicative of a current data rate capability of the microwave link by processing the data signal;
a comparator configured to receive the current data rate capability of the microwave link from the digital signal processor and to compare the current data rate capability of the microwave link to a configured payload data rate of the microwave link;
a demultiplexer configured to separate payload data and control data received from the digital signal processor; and
a multiplexer configured to multiplex dummy data with payload data on the microwave link responsive to the current data rate capability of the microwave link being below the configured payload data rate of the microwave link.