Determining frequency band suitability for communication

An apparatus for determining a suitability of a frequency band for data communication with a node by way of a communication channel, the apparatus comprising:

• a receiver;
• a transmitter;
• and
• processing circuitry communicatively coupled to the receiver and the transmitter, the processing circuitry being configured to cause the transmitter to transmit to the node, by way of the communication channel, first and second signals each comprising frequencies in the said frequency band, the first signal comprising a calibration signal and the second signal comprising predetermined reference data, and wherein the receiver is configured to receive, by way of the communication channel, an indication from the node of the suitability of the frequency band for data communication with the node;
• wherein the receiver is configured to receive the indication of the said suitability of the frequency band for data communication with the node by being configured to receive from the node, by way of the communication channel, third and fourth signals having frequencies within a respective frequency band, wherein the third signal comprises a calibration signal and the fourth signal contains the said indication of the suitability of the frequency band for data communication with the node by way of the communication channel;
• and
• wherein the processing circuitry is configured to:
• determine a calibration function depending on the third signal;
• process the fourth signal depending on the calibration function;
• and determine the indication of the suitability of the frequency band for data communication with the node depending on the processed fourth signal.

A system for determining a suitability of one or more frequency bands for data communication between a first node and a second node by way of a communication channel, the system comprising:

• a first apparatus of a first node, comprising:
• a first receiver;
• a first transmitter;
• and
• first processing circuitry communicatively coupled to the first receiver and the first transmitter, the first processing circuitry being configured to cause the first transmitter to transmit to the second node, by way of the communication channel, first and second signals each comprising frequencies in the frequency band, the first signal comprising a calibration signal and the second signal comprising predetermined reference data, and wherein the first receiver is configured to receive, by way of the communication channel, an indication from the second node of the suitability of the frequency band for data communication with the second node;
• and
• a second apparatus of the second node, comprising:
• a second receiver configured to receive the first and second signals from the first node by way of the communication channel;
• and
• second processing circuitry communicatively coupled to the second receiver, the second processing circuitry being configured to determine a calibration function depending on the first signal, process the second signal depending on the calibration function, determine the suitability of the frequency band for data communication with the first node by way of the communication channel depending on the processed second signal, and output the indication of the suitability, wherein the second processing circuitry is configured to determine the suitability of the frequency band for data communication with the first node depending on the processed second signal by comparison of the processed second signal to the predetermined reference data.

A method for determining a suitability of a frequency band for data communication with a node by way of a communication channel, the method comprising:

• receiving first and second signals from the node by way of the communication channel, the first and second signals having frequencies within the frequency band;
• determining a calibration function depending on the first signal;
• processing the second signal depending on the calibration function;
• determining a suitability of the frequency band for data communication with the node depending on the processed second signal;
• and
• outputting an indication of the suitability,
• wherein the determining the suitability of the frequency band for data communication with the node comprises comparing the processed second signal to predetermined reference data.

A method for determining a suitability of a frequency band for data communication with a node by way of a communication channel, the method comprising:

• transmitting to the node, by way of the communication channel, first and second signals each comprising frequencies in the said frequency band, the first signal comprising a calibration signal and the second signal comprising predetermined reference data;
• and
• receiving, by way of the communication channel, an indication from the node of the suitability of the frequency band for data communication with the node;
• wherein receiving the indication of the said suitability of the frequency band for data communication with the node comprises receiving from the node, by way of the communication channel, third and fourth signals having frequencies within a respective frequency band, wherein the third signal comprises a calibration signal and the fourth signal contains the said indication of the suitability of the frequency band for data communication with the node by way of the communication channel;
• the method further comprising:
• determining a calibration function depending on the third signal;
• processing the fourth signal depending on the calibration function;
• and determining the indication of the suitability of the frequency band for data communication with the node depending on the processed fourth signal.

An apparatus for determining a suitability of a frequency band for data communication with a node by way of a communication channel, the apparatus comprising:

• a receiver;
• a transmitter;
• and
• processing circuitry communicatively coupled to the receiver and the transmitter, the processing circuitry being configured to cause the transmitter to transmit to the node, by way of the communication channel, first and second signals each comprising frequencies in the frequency band, the first signal comprising a calibration signal and the second signal comprising predetermined reference data, and wherein the receiver is configured to receive, by way of the communication channel, an indication from the node of the suitability of the frequency band for data communication with the node,
• wherein the processing circuitry is configured to:
• determine that no indication of the suitability of the frequency band for data communication have been received from a first node of a plurality of nodes, and in response thereto to cause the transmitter to transmit a FIND command to a second node of the plurality of nodes in respect of the first node.

An apparatus for determining a suitability of a frequency band for data communication with a node by way of a communication channel, the apparatus comprising:

• a receiver;
• a transmitter;
• and
• processing circuitry communicatively coupled to the receiver and the transmitter, the processing circuitry being configured to cause the transmitter to transmit to the node, by way of the communication channel, first and second signals each comprising frequencies in the frequency band, the first signal comprising a calibration signal and the second signal comprising predetermined reference data, and wherein the receiver is configured to receive, by way of the communication channel, an indication from the node of the suitability of the frequency band for data communication with the node,
• wherein the processing circuitry is configured to cause the transmitter to transmit the first and second signals to the node in response to a FIND command relating to the node received by the receiver from a finding node.