Discussion

We discuss some limitations and future work below:

Network Size Estimation: As mentioned in Section 4.2, CosMAC’s satellites rely on the knowledge of IoT device locations to estimate and broadcast the number of devices in their footprint. In today’s IoT networks, these locations are easily maintained by the network operators and configured at setup time. Managing device locations will likely become more difficult for networks with decentralized ownership and/or high mobility. Some recent work [50, 54] and potential future work can facilitate to better configure CosMAC’s overlap aware uplink protocol through estimating the distribution of IoT devices in different regions of the Earth.

网络规模估计

如第4.2节所述，CosMAC协议中的卫星依赖于物联网设备的位置信息来估算并广播其覆盖范围内的设备数量。在当今的物联网网络中，这些位置信息可由网络运营商轻松维护并在设备设置时配置。然而，对于所有权分散和/或设备具有高移动性的网络，管理设备位置可能会变得更加困难。一些近期的研究[50, 54]以及潜在的未来工作，可以通过估算地球不同区域物联网设备的分布情况，来更好地配置CosMAC的重叠感知上行链路协议。

Reliable Data Transfer: Today’s IoT-picosat networks do not ensure reliability and lack the ability to send per-packet acknowledgments. Therefore, IoT data is delivered in a best effort manner and can be lost. Enabling reliable data transfer, under the resource constraints of picosats, is a challenging and interesting research problem.

可靠数据传输

当今的物联网微型卫星网络不保证数据的可靠性，并且缺乏发送逐包确认（per-packet acknowledgments）的能力。因此，物联网数据以“尽力而为”（best-effort）的方式传输，可能会发生丢失。在微型卫星资源受限的条件下实现可靠的数据传输，是一个具有挑战性且有趣的研究问题。

Ground Station Backhaul: Although CosMAC provides an effective means of coordinating communication between IoT devices and the ground stations, we have not explored its effects on backhaul from the ground station to the cloud. On the backhaul side, fault tolerance of ground stations may be a key factor to consider, especially in a distributed ground station network where most ground stations have a low hardware complexity. In this scenario, it may even be helpful for IoT satellites to transmit multiple copies of the data to multiple ground stations under its footprint.

地面站回传

尽管CosMAC协议提供了一种协调物联网设备与地面站之间通信的有效方法，但我们尚未探讨其对从地面站到云端的网络回传（backhaul）的影响。在回传方面，地面站的容错能力可能是一个需要考虑的关键因素，特别是在一个分布式地面站网络中，其中大多数地面站的硬件复杂性较低。在这种情况下，让物联网卫星将其数据的多个副本传输到其覆盖范围内的多个地面站，甚至可能是有益的。