A thermal sensor is pushed into a housing bushing so that a pin of the sensor is locked in an opening of the housing bushing. The fill system includes a source of liquid connected to a nozzle for dispensing the liquid into a container. In such a configuration, there is no need to define gate features, so the layout is simplified. By varying the frequency of the two source light waves, the intensity of the combined Raman-scattered light can be modulated to achieve finer resolution. Several embodiments describe the signaling interaction between an access network and subscriber stations belonging to a multicast group to allow the access network to assign a channel conveying the multicast service between the access network and the subscriber stations.