A WDM dynamic bandwidth allocation algorithm for EPONS

The increase in user numbers and bandwidth demands triggered by some new killer applications has always posed difficulties for network operators in supporting these unforeseen bandwidth demands during the design and planning period of networks. The solution of upgrading the capacity by installing new fibre is not considered as economically viable at this time, as the local access network is always the most cost sensitive section in the entire telecommunications architecture. This is because the overall cost is only shared among a limited number of end-users. However, the application of WDM techniques to existing Passive Optical Networks (PONs) multiplies the capacity of the original fibre structure and is viewed as one of the approaches the upgrading the capacity of access network.
In this paper, a new WDM PON system is proposed where multiple wavelength channels are established for communication in both upstream and downstream directions. The medium access control applied is based on an adaptive polling mechanism, and can be used as an upgrade solution for EPON systems recently proposed and trialled.