Methods and systems for obtaining a value indicative of resource-related activity in respect of a plurality of devices using a network of metering means arranged to be in communication with one another, the metering means being associated with resource-consuming or resource-providing devices and being arranged to obtain local resource-related activity data therefrom, the method comprising: a first metering means initiating a circulation procedure by sending a token to a downstream metering means, the token comprising an activity field for carrying a value indicative of resource-related activity data; the circulation procedure continuing, until the token has returned to the first metering means, by each downstream metering means in turn receiving the token, updating the activity field in dependence on its own locally-obtained resource-related activity data, and forwarding the token to a further downstream metering means; and once the token has returned to the first metering means, obtaining a value indicative of the combined level of resource-related activity in respect of devices associated with the metering means in said network in dependence on the value carried by the activity field.