On the Next-generation Optical Access Architecture

Optical access, or Fiber-To-The-Home (FTTH), has long been considered a final solution to the problem of upgrading the current bottlenecked access to the one capable of delivering future broadband, integratedservices. The high cost of large-scale deployment of fiber and optical network systems in the field under traditional point-to-point architecture, however, is a major economic barrier to the optical access. Also, current static optical network architectures cannot meet dynamic user demands based on on-demand service/usage models very well. In this paper, we first discuss a new architectural trend in optical networks ranging from Wide Area Networks (WANs) to Metropolitan Area Networks (MANs) to Access, and investigate the issues these new optical network architectures try to address. Then we introduce “Stanford University aCCESS” (SUCCESS in short), a next-generation hybrid WDM/TDM optical access architecture. In designing the SUCCESS architecture we focus on providing practical migration paths from currentgeneration TDM-Passive Optical Networks (PONs) to future WDM-based optical access networks; through advanced WDM techniques, the SUCCESS architecture provides backward compatibility to the users on existing TDM-PONs while simultaneously providing upgraded, high-bandwidth services to the users on new WDM-PONs. The topology of SUCCESS architecture is based on a collector ring and several distribution stars connecting the Central Office (CO) and users. Semi-passive configuration of the remote nodes together with this hybrid topology enables protection and restoration, making it possible to support both business and residential users on the same access infrastructure.