An optical equaliser, for use in an optical communications system, comprises a plurality of concatenated, fixed modulation depth, periodic filters. The method includes introducing a first stream of gas into a first stream manifold and directing the first stream from the first stream manifold into a mixing chamber via a plurality of first stream passages flow coupled to the mixing chamber. The request can include a requested pickup location data point. Upon receipt of a content provider ID from the electronic device, in which the application program is executed, the communication terminal authenticates the content provider ID to determine whether the device is authorized to receive the content. A central conductor is disposed in the inner dielectric. This low-power local-area network enables sensors on an asset to transmit sensor data to a mobile terminal affixed on the asset.