| 摘要 |
<p>Efficient transmission and fairness guarantees for upstream traffic in ATM-PONs are achieved using a partial back pressure (PBP) technique for traffic generated from user network interface (UNI) cards, e.g. Ethernet UNI cards or other network interface cards for non-constant bit rate sources. The PBP technique utilizes a feedback flow control mechanism between priority queues and UNI cards in a customer-side interface device, e.g. an Optical Network Termination unit, to achieve improved transmission efficiency and fairness guarantees of incoming traffic. The peak upstream rate of the UNI cards is dynamically controlled based on feedback information from the interface device where a queue status monitor observes the traffic level in the priority queue. Upon reaching a designated threshold level in the priority queue, the status monitor triggers activation of rate controllers in the upstream output of the UNI cards. The rate controllers reduce the peak output of the UNI cards to a controlled peak rate. Once the queue level is reduced beyond a second threshold level, the status monitor deactivates the rate controllers. <IMAGE></p> |
