三軸加速度計是一個常用的感測元件,通常我們會利用無線模組將感測到的資料送到後端的伺服器上,本實驗室已經建置了一套基於IEEE 802.15.4e TSCH的無線感測網路,每個配置三軸加速度計的感測節點可以週期性的感測資料並傳回伺服器,然而就算是加上了功率放大器,傳輸的距離還是無法太遠。為了要延長無線感測網路與伺服器之間的距離,我們設計了一個混合型的無線感測網路,於gateway加上了LORA模組。無線感測網路內的資料傳遞還是基於IEEE 802.15.4e TSCH以達到省電的目的,而gateway到伺服器的連線則是採用LORA技術,如此一來,無線感測網路就可以佈建於離伺服器較遠的場域中。總結來說,提出的混合型感測網路利用整合兩種無線傳輸技術來達到同時滿足兩個設計目標。
3-axis accelerometer is a widely adopted device for applications such as fall detection of the elders, kinematic analysis, building/bridge/landslide monitoring, and so on. To retrieve the sensing data in real time, one may use a wireless module to forward those data to a gateway or server. We have implemented an IEEE 802.15.4e TSCH based wireless sensor network (WSN) in our lab. A sensor node, equipped with a 3-axis accelerometer, can periodically transmit data to the server. However, the transmission distance is still limited even after a power amplifier is added. To extend the distance from the WSN to the server, we design a hybrid WSN by integrating a LORA module for the gateway. The transmission within the WSN is still based on IEEE 802.15.4e TSCH to achieve high power efficiency, while the link between the WSN gateway and the server is based on LORA such that the WSN can be deployed in a distance field. In summary, the proposed hybrid WSN can satisfy two goals by incorporating two wireless technologies.