The new modulation technologies used by DOCSIS 3.0 and up require very high laser quality even at the return path transmitter of the optical node. This means, the old Fabry-Perot lasers cannot be used further, they must be changed to DFB types with narrower optical bandwidth and lower noise level. The base node can be used further, only the transmitter module should be replaced. If this is not available or is not cost efficient, COMTECH undertakes to develope it. Such a module is the ROT-AN for Antech LLRX200 type.