Flexible joint scheduling DBA to promote the fair coexistence in 1G and 10G EPONs

The Next Generation Access Networks (NGAN) are the new step forward to deliver broadband services and to facilitate the integration of different technologies. The real challenge faced by 10GEPON new standard IEEE 803.3av is to upgrade the channel capacity for both upstream and downstream channels gracefully, while maintaining the logical layer intact ensuring the coexistence with legacy 1 Gb/s (IEEE 802.3ah). The Dynamic Bandwidth Allocation (DBA) for the upstream shared channel is a key issue. We propose in this paper a distributed DBA-Distributed Dynamic Scheduling for EPON, (DDSPON)-that allows the coexistence among both standards in such mixed architecture. In particular, we remark that, by using the enhanced DDSPON, the new standardized optical network units (ONUs) will take full advantage of the enhanced rate at 10 Gb/s while the legacy 1 Gb/s ONUs keep a good performance, and thus allowing a fair coexistence of both groups of ONUs-legacy and 10 Gb/s-, and even though the individual performance is maximized, no matter the group being evaluated. We compare DDSPON with another well-known scheduling algorithm and we show that it performs better specially when the traffic is bursty. Furthermore, the proposed algorithm is scalable, simple to re-configure, and cost-effective, which facilitates a smoother transition from 1G to 10G EPON.