Memory consumption analysis for the GOE and PET Unequal Erasure Protection schemes
Unequal Erasure Protection (UEP) is an attractive approach to protect data flows that contain information of different priority levels. The various solutions that have been proposed can be classified into three families. The first one consists of specific, UEP-aware FEC codes, that map the information dependency within the code structure. It enables to design a specific solution, valid for a specific data flow, as in [3]. However, because this is a specific solution, its practical interest is also narrowed. In this work we focus on two additional solution families. One family implements UEP thanks to a dedicated packetization scheme, as it is the case with Priority Encoding Transmission (PET) [2], while the other family uses a dedicated signaling scheme, as is the case with the Generalized Object Encoding (GOE) [6]. These two solutions have the main benefit of being compatible with existing standardized Application Layer FEC (AL-FEC) schemes, which is a major practical benefit. Through a careful modeling of both proposals, we have demonstrated that the protection performance of both approaches are equivalent [7]. However additional key differences become apparent when considering such a practical metric as the peak memory consumption. Thanks to a modeling of the packet storage behavior at the receiver side, and by considering two major parameters, namely the channel loss probability and the permutation type, we show that the GOE scheme (without interleaver) requires a smaller memory storage than PET. This result is reversed if GOE uses a uniform interleaver.