A star puts all intelligence in the center. Each end device needs only to reach the hub, which simplifies the device firmware, keeps latency predictable and makes it easy to reason about where a failure occurred. Wi-Fi access points, cellular cells and LoRaWAN gateways are all stars; LoRaWAN is sometimes described as a star of stars, since many gateways feed one network server.
The weakness is the single point of failure and the hard limit set by radio range: a device that cannot hear the gateway is simply offline, with no neighbor to relay for it. Long-range radios compensate with a large link budget, which is why LPWAN systems can stay star shaped. Short-range technologies such as Zigbee and Thread instead switch to a mesh network to extend coverage.
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