TABLE OF CONTENTS The basband is the information content (channel) that is used to modulate or encode a transmission medium. When used with radio signals, the high frequency component is called the broadband channel.
The EVDO system uses a relatively short packet length. This allows the EVDO system to efficiently prioritize packets for time sensitive applications (such as IP telephony or streaming audio).
To transfer packets through the EVDO system, IP data packet encapsulation is used. This allows the EVDO system to integrate well with other types of systems such as frame relay, SONET, and Ethernet.
The transmission length of the forward physical layer packet is 256, 512, 1024, 2048, 3072, or 4096 bits and the transmission length of the reverse physical layer packet is 256, 512, 1024, 2048, 3072, or 4096 bits. The format (field structure and coding method) varies based on the type of channel and chosen data rate for which it is transmitted. The control channel packet is always 1024 bits.
To ensure each bit receives the same amount of RF energy, the RF output of the access terminal increases as the data transmission rate increases.
Data packet encapsulation is the process of inserting the entire contents of one packet (header, control, and data) into the payload of another packet. Packet encapsulation is used to transparently transfer packets from one packet communication system over the packets of another communications system.
Figure 1.10 shows an example of how IP packets (datagrams) can be...
