1. A computer-implemented method for updating shipment information of one or more items being shipped, the method comprising the steps of: detecting, by a first sensor device, a second sensor device entering within a proximity of the first sensor device and responsively storing association information to indicate an association between the first sensor device and the second sensor device, wherein: the first sensor device is configured to sense conditions of a first item being shipped, and the second sensor device is configured to sense conditions of a second item being shipped; receiving, at the first sensor device, sensor information collected by the second sensor device, wherein the sensor information indicates at least one condition of the second item; transmitting to a tracking center, by the first sensor device, the sensor information and the association information; receiving from the tracking center, at the first sensor device, updated shipment information based on at least the sensor information, wherein the updated shipment information comprises routing information for the second item; receiving from the tracking center, at the first sensor device, an updated configuration parameter based on at least the sensor information, wherein the updated configuration parameter reflects a modification to operation of the second sensor device; transmitting to the second sensor device, by the first sensor device, the updated shipment information and the updated configuration parameter; detecting, by the first sensor device, that the second sensor device is no longer within the proximity of the first sensor device and responsively updating the association information to remove the association between the first sensor device and the second sensor device; and transmitting to the tracking center, by the first sensor device, the updated association information.