Dynamic bandwidth allocation on SuperPON

Currently, the first FSAN compliant ARM-based Passive Optical Networks (APON) are installed in the field. A possible evolution scenario for these types of access networks could be the so-called SuperPON system [I]. The SuperPON system exploits all possible upgrades of an FSAN APON system. It comprises namely an upgrade on the following parameters 1 range: 100km instead of 20km 2 split. 2048 instead of 64 3 bitrates, 2.4Gbit/s downstream instead of 622Mbit/s and 311Mbit/s upstream instead of 155Mbit/s Due to these significant changes in system parameters, it becomes of the utmost importance to implement a dynamic Medium Access Control (MAC) protocol on the SuperPON, since the upstream bit rate is rather limited for such a large number of connected Optical Network Units (ONU). Main challenges specific to the SuperPON are the impact of long range and high number of users on the efficiency of the MAC protocol. Concerning the evaluation of the proposed MAC protocol, we focus on the support of TCP over the ATM Guaranteed Frame Rate (GFR) service. GFR has been proposed in the ATM Forum as an enhancement to the conventional best-effort UBR service category. It provides a MCR guarantee to VCs at the frame level along with an opportunity to fairly use any additional bandwidth left over from higher priority connections. GFR is likely to be used by current internetworking applications. It will be shown that the SuperPON MAC protocol developed in the framework of the ACTS project PELICAN yields very good performance for a wide range of traffic conditions when applied to GFR VCs carrying TCP/IP traffic. The MAC algorithm, being implemented on SuperPON, combined with intelligent buffer management on the ONUs, yields an efficient use of the upstream bandwidth available on SuperPON, while providing bandwidth guarantees ana fairness to individual connections.