A communication system comprising: a downhole measurement tool (15; 19) configured to be located within a drill string component, the downhole measurement tool being configured to collect data relating to one or more downhole parameters when the downhole measurement tool and drill string component are located within a borehole; and a device, located at a surface of the borehole, configured for communication with the downhole measurement tool when the downhole measurement tool and drill string component are located at the surface of the borehole; characterised in that: the downhole measurement tool (15, 19) comprises in it a transceiver and an antenna; and the device comprises: a processor module comprising a set of commands and configured to issue a command from the set to the downhole measurement tool and receive a corresponding reply from the downhole measurement tool, the set of commands comprising at least one of a command to switch the downhole measurement tool between a sleep mode and an active mode and a command to download data from the downhole measurement tool; a transceiver module coupled to the processor module; and an antenna coupled to the transceiver module, the antenna and transceiver module being configured to transmit commands and replies between the processor module and the downhole measurement tool, via the transceiver and the antenna in the downhole measurement tool, when the device is located externally of and in close proximity to the downhole measurement tool and drill string component at the surface of the borehole. a downhole measurement tool (15; 19) configured to be located within a drill string component, the downhole measurement tool being configured to collect data relating to one or more downhole parameters when the downhole measurement tool and drill string component are located within a borehole; and a device, located at a surface of the borehole, configured for communication with the downhole measurement tool when the downhole measurement tool and drill string component are located at the surface of the borehole; characterised in that: the downhole measurement tool (15, 19) comprises in it a transceiver and an antenna; and the device comprises: a processor module comprising a set of commands and configured to issue a command from the set to the downhole measurement tool and receive a corresponding reply from the downhole measurement tool, the set of commands comprising at least one of a command to switch the downhole measurement tool between a sleep mode and an active mode and a command to download data from the downhole measurement tool; a transceiver module coupled to the processor module; and an antenna coupled to the transceiver module, the antenna and transceiver module being configured to transmit commands and replies between the processor module and the downhole measurement tool, via the transceiver and the antenna in the downhole measurement tool, when the device is located externally of and in close proximity to the downhole measurement tool and drill string component at the surface of the borehole. the downhole measurement tool (15, 19) comprises in it a transceiver and an antenna; and the device comprises: a processor module comprising a set of commands and configured to issue a command from the set to the downhole measurement tool and receive a corresponding reply from the downhole measurement tool, the set of commands comprising at least one of a command to switch the downhole measurement tool between a sleep mode and an active mode and a command to download data from the downhole measurement tool; a transceiver module coupled to the processor module; and an antenna coupled to the transceiver module, the antenna and transceiver module being configured to transmit commands and replies between the processor module and the downhole measurement tool, via the transceiver and the antenna in the downhole measurement tool, when the device is located externally of and in close proximity to the downhole measurement tool and drill string component at the surface of the borehole. a processor module comprising a set of commands and configured to issue a command from the set to the downhole measurement tool and receive a corresponding reply from the downhole measurement tool, the set of commands comprising at least one of a command to switch the downhole measurement tool between a sleep mode and an active mode and a command to download data from the downhole measurement tool; a transceiver module coupled to the processor module; and an antenna coupled to the transceiver module, the antenna and transceiver module being configured to transmit commands and replies between the processor module and the downhole measurement tool, via the transceiver and the antenna in the downhole measurement tool, when the device is located externally of and in close proximity to the downhole measurement tool and drill string component at the surface of the borehole.