7.5 WDM PON

At the time of writing, there was an emerging consensus in the industry that after the various versions of 10G PON, and maybe in competition with 10G PON, the next generation would be WDM PON. There are at least as many definitions of WDM PON as there are contributors to the standards forums. This section explores a few of the issues and options but does not attempt to predict the winners.

A certain amount of WDM PON is already deployed in venues such as Korea. Generally speaking, however, current technology is too costly to compete with G-PON or EPON. Vendors of WDM PON systems argue their merits in specialized applications, such as symmetric high-capacity (high-revenue) business services, or carrying specialized protocols such as CPRI, or wavelength unbundling.