Читать книгу Wireless Connectivity - Petar Popovski - Страница 33

1 1 The term broadcast outside of information theory is used to denote the message that is sent to all devices within the range. In that sense, the term multicast is used when the message is sent to a subset of two or more devices within the range. Hence, in this sense a broadcast is a special case of multicast. On the other hand, broadcast in an information-theoretic sense means that the transmission of a device is received by multiple devices, regardless of who the intended receiver of the message is. Thus, we can say that a transmission over a wireless medium is a broadcast, but the actual message sent may be intended as a unicast to a specific device or multicast to a group of devices.

2 2 Here we conservatively assume that a device sends a reservation packet even if it has no data to send.