无线网络中的选择

　　无线网络中的选择

　　由于其扩展范围、易实现性和较小的代码尺寸，低GHz、低数据速率的无线网络通常是亚GHz专有协议的最佳选择。

　　设计者知道无线发送数据有多种选择。这些包括简单的命令和控制方案，如遥控钥匙（RKE）和车库门开启器，和更复杂的无线局域网。本文介绍了各种选择和它们的局限性，因为它们涉及到为工业应用选择无线网络。

　　RKE系统通常用于汽车锁定和解锁的门，提供了一个良好的例子，简单的命令和控制中的应用。在RKE应用，一个命令从钥匙到汽车接收机发送。响应一个正确接收的命令，汽车要么锁定要么解锁。

　　Receivers in similarly made automobiles can theoretically accept packets sent from any similar model key fob. However， the car will only accept commands from the unique key fob assigned to it. Security protocols like rolling code generators and security encryption are utilized to transmit a unique ID from the key fob to the car. In this way， a driver’s key fob is not able to unlock a similar model car.

　　In the case of automobile RKE， the key fob operator typically hears the locks being engaged. If this audible feedback “click” is not heard， the operator simply presses the button again， completing the feedback loop. To put it in simple terms， if you don’t hear the car unlock， you press the button again until you do.