Channel selection in wireless communications

A method comprising:

• receiving, by a first network node from a second network node through a radio path, a first message comprising a pilot sequence;
• processing the received first message and determining, by the first network node as a result of processing the pilot sequence, whether the first message has travelled the radio path as a surface wave along a ground surface or as a reflection from an ionosphere;
• if it is determined that the first message has travelled the radio path as the surface wave, selecting by the first network node a first set of communication parameters for communication with the second network node;
• if it is determined that the first message has travelled the radio path as the reflection from the ionosphere, selecting by the first network node a second set of communication parameters for communication with the second network node, wherein the second set of communication parameters is at least partly different from the first set of communication parameters;
• and
• causing transmission of a second message from the first network node to the second network node by using the selected first or second set of communication parameters.

An apparatus comprising:

• a processing device;
• and
• a storage device to store instructions that, when executed by the processing device, cause the processing device to perform operations comprising:
• receiving, in a first network node from a second network node through a radio path, a first message comprising a pilot sequence;
• processing the received first message and determining, as a result of processing the pilot sequence, whether the first message has travelled the radio path as a surface wave along a ground surface or as a reflection from an ionosphere;
• if it is determined that the first message has travelled the radio path as the surface wave, selecting a first set of communication parameters for communication with the second network node;
• if it is determined that the first message has travelled the radio path as the reflection from the ionosphere, selecting a second set of communication parameters for communication with the second network node, wherein the second set of communication parameters is at least partly different from the first set of communication parameters;
• and
• causing the first network node to transmit a second message to the second network node by using the selected first or second set of communication parameters.

A computer program product embodied on a distribution medium readable by a computer and comprising program instructions that, when executed by an apparatus, perform operations comprising:

• receiving, in a first network node from a second network node through a radio path, a first message comprising a pilot sequence;
• processing the received first message and determining, as a result of processing the pilot sequence, whether the first message has travelled the radio path as a surface wave along a ground surface or as a reflection from an ionosphere;
• if it is determined that the first message has travelled the radio path as the surface wave, selecting a first set of communication parameters for communication with the second network node;
• if it is determined that the first message has travelled the radio path as the reflection from the ionosphere, selecting a second set of communication parameters for communication with the second network node, wherein the second set of communication parameters is at least partly different from the first set of communication parameters;
• and
• causing the first network node to transmit a second message to the second network node by using the selected first or second set of communication parameters.