Kristiaan Johan Hubert Venken

Dynamic bandwidth allocation on SuperPON

Currently, the first FSAN compliant ATM-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. The SuperPON system exploits all possible upgrades of an FSAN APON system. It comprises namely an upgrade on the following parameters: range: 100 km instead of 20 km; split: 2048 instead of 64; and bitrates: 2.4 Gbit/s downstream instead of 622 Mbit/s and 311 Mbit/s upstream instead of 155 Mbit/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. Main challenges specific to the SuperPON are the impact of long range and high number of users on the efficiency of the MAC protocol.

Evaluation of medium access mechanisms in HFC systems with ATM cell transport

An important element in the performance of the Medium Access and Control (MAC) layer of Hybrid Fiber Coax (HFC) systems are the medium access mechanisms employed: e.g. requests via contention mini-slots, piggybacking requests, request poling, etc. Therefore, the starting point in the design of the MAC of ATM cell based HFC systems, is an evaluation of the candidate mechanisms, which is presented in this paper. Furthermore, it is shown that different traffic types need different ideal MAC mechanisms, or different ideal combinations of them. Several proposals will be given for different traffic classes, and while in standardization and early deployment a lot of attention goes to Internet traffic today, this paper will consider in addition also the very different traffic of ATM terminals, which is rate controlled according to the ATM traffic characteristics.