A self-calibrating carbon dioxide sensor that includes a carbon dioxide detector and a carbon dioxide gas generator. In one aspect, the presently claimed invention includes a system andor method that is configured for broadcasting a first multicast MAC address by a first host to at least one first client in a predetermined geographic area and broadcasting the first multicast MAC address by a second host to at least one second client in the predetermined geographic area. Next, the silicon oxide film is left between the gate electrodes, and the second silicon nitride film on the laminated film is removed, and the cap insulating film left above the gate electrode is removed, and a metal silicide film is formed on a surface of the gate electrode, and then a third silicon nitride film is left on the gate electrode. Once the ky-kz plane is partitioned and the view orderings are defined, MR data is acquired for the set of views in the inner region and for all of the views in each of the outer regions in an alternating acquisition order where the set of views in the inner region are acquired more frequently than the views in each of the outer regions. Call data are transmitted in the network using timeslot hopping in which the call data of each user of the network are transmitted with a different timeslot hopping sequence. For example, when an STS-48 carries 12 STS-1’s from a first SONETSDH ring and 12 STS-1’s from a second SONETSDH ring, the STS-48 carries: the automatic protection switching channel for the 12 STS-1’s from the first SONETSDH ring ; and the automatic protection switching channel for the 12 STS-1’s from the second SONETSDH ring.