A device comprising: a sensor means for deriving, on basis of one or more sensor signals that are descriptive of respective physical characteristics pertaining to a user, at least one measurement signal that is descriptive of a characteristic pertaining to the user; a communication means for wireless communication over a wireless link ; and a control means for causing the device to perform at least the following: obtain, from said sensor means , first measurement data that comprises one or more values indicated by the at least one measurement signal and transferring the first measurement data to a server device over a first wireless link ; receive, from the server device , device information that comprises at least a device identifier and access information for another device that is capable of providing second measurement data that is descriptive of one or more characteristics pertaining to the same user; in response to receiving said device information, detect presence of said another device and establish a second wireless link with said another device using said device information received from the server device ; and receive the second measurement data from said another device via the second wireless link and transferring the second measurement data to the server device via the first wireless link . a sensor means for deriving, on basis of one or more sensor signals that are descriptive of respective physical characteristics pertaining to a user, at least one measurement signal that is descriptive of a characteristic pertaining to the user; a communication means for wireless communication over a wireless link ; and a control means for causing the device to perform at least the following: obtain, from said sensor means , first measurement data that comprises one or more values indicated by the at least one measurement signal and transferring the first measurement data to a server device over a first wireless link ; receive, from the server device , device information that comprises at least a device identifier and access information for another device that is capable of providing second measurement data that is descriptive of one or more characteristics pertaining to the same user; in response to receiving said device information, detect presence of said another device and establish a second wireless link with said another device using said device information received from the server device ; and receive the second measurement data from said another device via the second wireless link and transferring the second measurement data to the server device via the first wireless link . obtain, from said sensor means , first measurement data that comprises one or more values indicated by the at least one measurement signal and transferring the first measurement data to a server device over a first wireless link ; receive, from the server device , device information that comprises at least a device identifier and access information for another device that is capable of providing second measurement data that is descriptive of one or more characteristics pertaining to the same user; in response to receiving said device information, detect presence of said another device and establish a second wireless link with said another device using said device information received from the server device ; and receive the second measurement data from said another device via the second wireless link and transferring the second measurement data to the server device via the first wireless link . <EOS>