In the Offline Finding Network(OFN), offline Bluetooth tags broadcast to the surrounding area, the finder devices receiving the broadcast signal and upload location information to the IoT(Internet of Things) cloud servers, thereby achieving offline finding of lost items. This process is essentially a Bluetooth low energy (BLE) neighbor discovery process(NDP). In the process, the variety of Bluetooth scan modes caused by the scan interval and scan window settings affects the discovery latency of finder devices finding the tag broadcast packets. To optimize the experience of searching for lost devices, we propose the CPBIS-mechanism, a certain proportion broadcast-intervals screening mechanism that calculates the most suitable two broadcast intervals and their proportion for offline tags. This reduces discovery latency in the BLE NDP, improves the discovery success rate, further enhances the user experience. To our knowledge, we are the first to propose a comprehensive solution for configuring the broadcast interval parameters of advertisers in BLE NDP, particularly for configurations involving two or more broadcast intervals. We evaluated the results obtained by CPBIS on the nRF52832 chip. The data shows that the CPBIS-mechanism achieves relatively low discovery latencies for multiple scan modes.

翻译：在离线寻物网络中，离线蓝牙标签向周围区域广播信号，发现设备接收广播信号并将位置信息上传至物联网云服务器，从而实现失物的离线寻找。该过程本质上是蓝牙低能耗邻居发现过程。在此过程中，由扫描间隔和扫描窗口设置导致的多种蓝牙扫描模式，会影响发现设备探测标签广播数据包的发现延迟。为优化寻找丢失设备的体验，我们提出CPBIS机制——一种特定比例广播间隔筛选机制，该机制可为离线标签计算最合适的两个广播间隔及其比例。这降低了BLE邻居发现过程中的发现延迟，提高了发现成功率，从而进一步提升了用户体验。据我们所知，我们是首个针对BLE邻居发现中广播方广播间隔参数配置提出全面解决方案的研究，特别是涉及两个或更多广播间隔的配置。我们在nRF52832芯片上评估了CPBIS获得的结果。数据显示，CPBIS机制在多种扫描模式下均实现了相对较低的发现延迟。