A slave device may only start transmitting on an odd numbered slot, following a message from the master which was directed specifically to that slave.
而在主设备定向发给从设备的信息的指引下，从设备也只能在偶数时隙上开始传输。
2
Adding or deleting a slot is easy in Self: you just send the _add_slot message.
在Self中添加或删除slot很简单：只需要发送_add_slot消息。
3
But thanks to a well-organised mobile-notification system (which informs visitors of their time slot via text message), I was able to while away time at the nearby beach bar.