9416101 Albanese This encoding technique was motivated by a trial offering a low cost "Best Effort" ATM/Cell Relay Service. The service is being used to explore applications for ATM services with unpredictable (no-guarantees) Quality Of Service (QOS). An initial contribution was submitted to the Enterprise Network Roundtable (ENR) user group of the ATM Forum describing the feasibility of a video multicast application over Unspecified Bit Rate (UBR) services. Our contribution proposes to implement a new, optional and selective multilevel Forward Error Correction (FEC) method in the application layer based on information priority levels versus having a fixed FEC implementation in the lower layers. Preliminary research has consisted in software simulation and initial implementations of PET systems using deterministic algorithms like polynomial and linear independent equations over finite fields. These algorithms are quadratic in complexity and the message-size/packet-size ratio limits its application to recovering IP packet losses only. Proposed work includes: 1) exploring firmware implementations and the use of probabilistic algorithms to achieve faster software implementations required to recover IP packets and ATM cell losses in real-time MPEG-2 and JPEG video streams, where delay is a key issue for interactive applications; 2) exploring mechanisms based on user priorities for network routers to discard/filter large amounts of packets that could cause congestion in low performance networks and receivers during video multicast transmission by high performance workstations, 3) realizing performance analysis based on benchmark studies consisting of tests and measurements done in heterogeneous wide area network (MBone/Internet/ATM) scenarios; and 4) in collaboration with researchers at UC Berkeley and local industries, investigating integrating PET systems into specific applications such as MPEG-2. ***
