Network surveying

A method comprising:

• transmitting, via a base station apparatus, a first downlink signal in a first frequency band, the first downlink signal conveying system conveying system information indicating a first PLMN;
• receiving, via the base station apparatus, an area update request from a mobile communication device;
• performing an area update procedure to register the mobile communication device with the first PLMN;
• transmitting, to the mobile communication device via the base station apparatus, one or more messages to cause the mobile communication device to provide measurement data indicative of reception, by the mobile communication device, of one or more downlink signals within one or more frequency bands different to the first frequency band;
• receiving, from the mobile communication device via the base station apparatus, the measurement data;
• and
• assessing, using the received measurement data, availability of one or more PLMNs different from the first PLMN in a region of coverage of the base station apparatus.

One or more non-transitory storage media comprising machine-readable instructions which, when executed by a computer communicatively coupled to a base station apparatus, cause the computer to carry out operations comprising:

• transmitting, via the base station apparatus, a first downlink signal in a first frequency band, the first downlink signal conveying system conveying system information indicating a first PLMN;
• receiving, via the base station apparatus, an area update request from a mobile communication device;
• performing an area update procedure to register the mobile communication device with the first PLMN;
• transmitting, to the mobile communication device via the base station apparatus, one or more messages to cause the mobile communication device to provide measurement data indicative of reception, by the mobile communication device, of one or more downlink signals within one or more frequency bands different to the first frequency band;
• receiving, from the mobile communication device via the base station apparatus, the measurement data;
• and
• assessing, using the received measurement data, availability of one or more PLMNs different from the first PLMN in a region of coverage of the base station apparatus.