Recently, the paradigm of massive ultra-reliable low-latency IoT communications (URLLC-IoT) has gained growing interest. Reliable delay-critical uplink transmission in IoT is a challenging task since low-complex devices typically do not support multiple antennas or demanding signal processing tasks. However, in many IoT services the data volumes are small and deployments may include massive number of devices. We consider on a clustered uplink transmission with two cooperation approaches: First, we focus on scenario where location-based channel knowledge map (CKM) is applied to enable cooperation. Second, we consider a scenario where scarce channel side-information is applied in transmission. In both scenarios we also model and analyse the impact of erroneous information. In the performance evaluation we apply the recently introduced data-oriented approach that has gathered significant attention in the context of short-packet transmissions. Specifically, it introduces a transient performance metric for small data transmissions, where the amount of data and available bandwidth play crucial roles. Results show that cooperation between clustered IoT devices may provide notable benefits in terms of increased range. It is noticed that the performance is heavily depending on the strength of the static channel component in the CKM based cooperation. The channel side-information based cooperation is robust against changes in the radio environment but sensitive to possible errors in the channel side-information. Even with large IoT device clusters, side-information errors may set a limit for the use of services assuming high-reliability and low-latency. Analytic results are verified against simulations, showing only minor differences at low probability levels.

翻译：近年来，大规模超可靠低延迟物联网通信范式日益受到关注。物联网中可靠的延迟关键型上行传输是一项具有挑战性的任务，因为低复杂度设备通常不支持多天线或复杂的信号处理任务。然而，在许多物联网服务中，数据量较小且部署可能包含大量设备。我们考虑采用两种协作方法的集群上行传输：首先，我们关注应用基于位置的信道知识地图实现协作的场景。其次，我们考虑传输中应用稀缺信道边信息的场景。在这两种场景中，我们还对错误信息的影响进行建模和分析。在性能评估中，我们应用了近期提出的数据导向型方法，该方法在短数据包传输领域已引起广泛关注。具体而言，该方法为小数据量传输引入了瞬态性能指标，其中数据量和可用带宽起着关键作用。结果表明，集群物联网设备间的协作可在增加覆盖范围方面带来显著优势。需要指出，在基于信道知识地图的协作中，性能严重依赖于静态信道分量的强度。基于信道边信息的协作对无线环境变化具有鲁棒性，但对信道边信息中可能存在的错误较为敏感。即使对于大型物联网设备集群，边信息错误也可能限制假设高可靠性和低延迟的服务的使用。分析结果通过仿真验证，在低概率水平下仅显示微小差异。