Page 41 - Intelligent Communication Systems

CHAPTER 4/ADVANCES IN COMMUNICATION NETWORKS 25
TABLE 4.1 Type of Channel in N-ISDN

FIGURE 4.2 Terminal-line interface in B-ISDN.

channel, which provides 8-, 16-, 32-, and 64-Kbps transmission services. The
D-channel is a control channel and provides 16- and 64-Kbps services. The H-
channel is a user's communication channel and provides 384-, 1536-, and 1920-Kbps
services. The B-, D-, and H-channel characteristics are shown in Table 4.1.

4.3 B-ISDN

B-ISDN provides the high-speed transmission of digital data through the network.
With B-ISDN, there are services such as an interactive service and a distribution
service. In the interactive service, a conversational service, a message handling ser-
vice, and an information retrieval service are provided. In the distribution service,
a broadcasting service, such as a radio or a television service, is provided. The UNI
of B-ISDN is specified as in Figure 4.2. Points T B, S B, and R are specified in this
figure. For example, analog equipment TE2, such as an analog television, is con-
nected to B-NT2 via B-TA. Digital equipment TE 1, such as a digital television, is
connected directly to B-NT2.