Revisiting Access and Aggregation Network Architecture

Optical technologies allow the end-user to take advantage of a very high bitrate access. This in turn modifies traffic patterns to be supported by access and aggregation (metro) networks. The present paper first proposes tentative traffic scenarios to assess future capacity requirements for these networks. It is shown that the current aggregation architecture based on primary and secondary aggregation rings should be reconsidered to limit potential bottlenecks and to take account of both infrastructure costs and potential energy savings. The paper then presents alternative architectures to revise and move the boundaries existing today between access and aggregation networks. A first alternative architecture is fully centralized and performs traffic aggregation in a central location. The second alternative architecture proposes to locate the first aggregation points (called "Next Generation Points of Presence") on the primary aggregation ring and to centralize control functions.