ElectroniCast Corp. of San Mateo, Calif., predicts that the market for components for dense wavelength division multiplexing, including components for add-drop multiplexers, will reach $34.6 billion by 2009. The firm believes more than half of that market will remain in North America. In a separate study, Allied Business Intelligence of Oyster Bay, N.Y., predicts that metropolitan communications networks will push the add-drop multiplexer market. Allied Business Intelligence estimates a 53 percent compound average annual growth rate for the devices, from $338 million last year to more than $4 billion in 2006. The company sees the most future growth in remotely reconfigurable add-drops, which metropolitan network providers will need to easily reconfigure systems as they gain and lose customers, or as customers' needs change.