We evaluate a modification of irregular repetition slotted ALOHA (IRSA) involving intermediate decoding and early transmission termination by some nodes, upon their decoding success. This is meant to avoid unnecessary transmissions, thereby reducing energy consumption. We expect this to be particularly useful at low loads, where most transmissions can be avoided as they do not often result in a collision and are therefore redundant. To validate this proposal, we observe that most of the literature related to IRSA considers an asymptotic heavily loaded regime; thus, we also present a model of energy consumption and success probability for frames of limited length and low offered loads. Thanks to our analysis, also confirmed by simulation, we are able to show that the proposed technique is able to reduce IRSA energy consumption by minimizing transmissions, while preserving performance gains over standard ALOHA. For example, we are able to get a 33% energy saving at offered loads around 10% without affecting throughput.

翻译：本文评估了一种改进的不规则重复时隙ALOHA（IRSA）方案，该方案引入了中间解码机制，允许部分节点在成功解码后提前终止传输。此举旨在避免不必要的传输，从而降低能耗。我们预期该方案在低负载场景下尤为有效，因为此时大多数传输不会引发碰撞，属于冗余操作，可以被规避。为验证此提案，我们注意到现有IRSA相关文献大多关注渐近高负载状态；因此，我们同时建立了有限帧长与低负载条件下的能耗与成功概率模型。通过理论分析与仿真验证，我们证明所提技术能在维持对标准ALOHA性能优势的同时，通过最小化传输次数有效降低IRSA系统的能耗。例如，在负载率约为10%时，系统可在不影响吞吐量的前提下实现33%的节能效果。