Currently the wireless networks are replacing the connection cables via radio or infrared waves. Emission/reception terminals are installed to cover zones in relation with a quality of service. Thus users can be connected to the local area network thanks to an adapter that emits and receives on this network. There are technological radio solutions : Bluetooth, WiFi, and optics constituted by an infrared base and modules. Infrared technology has important advantages: Transmitted data security, radio and medical immunity, etc. Nevertheless, the optical systems seem to present a limit because the network management is based on only one wavelength and several users. The solution suggested, scope of this document, is at a crossroads with the telecoms with optical fibre, optics in free space and data processing domains. Indeed, it is a question, of using WDM technology and transmitting these various wavelengths in free space, using optical Multiplexer/Demultiplexer and optical modules, which are compatible in wavelength. Each mission/reception module has a defined and personal wavelength, with a link with the terminal identification (addresses MAC or IP). This approach has full duplex data rate for a minimum of a dozen Mbps per user for a broadcasting, and hundred Mbps for a line of sight system. The application field for the suggested system is potentially included in the following networks types: WirLAN, WirDAN or WirPAN.