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VoIP Telephone Systems in the Studio Environment
Published in Steve Church, Skip Pizzi, Audio Over IP, 2012
ISDN-BRI (Basic Rate Interface) lines offer two B channels, supported by one D channel. (As noted above, B channels carry audio payload “speech”, while D channels carry signaling; this is sometimes referred to as a “2B+D” configuration.) These were intended as a residential replacement for POTS lines or for small businesses. One application envisaged by its inventors was to allow a simultaneous voice call and data connection. With DSL providing much higher data rates, ISDN-BRIs are moving ever closer to obsolescence. Nevertheless, when they are available, they could be useful for small installations that need only a few lines. Most VoIP gateways have cards to interface with these lines. As with PRI lines, take care to set the gateway's configuration to match the type of signaling that your line uses.
Telecommunications Networks
Published in Andy Bailey, Network Technology for Digital Audio, 2013
A monitoring capability is provided by using the D-channel on DSL. The D-channel provides a data rate in the region of 16 KB/s using the X.25 protocol within the upper layers. The D-channel can be used for low speed packet data, whilst also relaying call-processing information. This can be aggregated with the highspeed packet service to obtain the maximum data rate.
ISDN
Published in Steve Heath, Multimedia and Communications Technology, 1999
The D channel is used for messages and control information between the terminal and the network. The LAPD frame format used is shown in the diagram. It provides a wrapper around a block of data describing its destination, some control information and a CRC value for error correction.
Isotopic effects of the N(2D) + H2 → NH + H reaction: a quantum time-dependent wave packet investigation
Published in Molecular Physics, 2020
N(2D) + D2 reaction’s values are in general agreement with the experimental data at the collision energy below 0.15 eV. The deviations from the experiment at the threshold may indicate that the PES reported by Li et al. [17] underestimate the barrier height. When the collision energy is above 0.15 eV, large discrepancies are observed between theoretical and experimental data. The experiment is based on the detection of D atom form, as suggested by Liu [10], N(2D) + D2 reaction is dominated at the collision energy below 4 kcal/mol (0.17 eV), whereas, OH + D2 reaction also generates D atom at the collision energy above 4 kcal/mol. This can explain why the theoretical values lower than the experimental data at collision energy above 0.15 eV. Thus, to achieve enhanced comparability, further theoretical and experimental studies are required. N(2D) + HD reaction’s ICSs of the two channels increase monotonically with the collision energy and ICSs of ND + H channel are larger than those of NH + D channel in the examined collision energy range.
The quantum and quasi-classical dynamics calculations of the Au++HD → AuH+/AuD++D/H reaction
Published in Molecular Physics, 2021
The reaction probabilities of the Au+ + HD reaction at several selected J values are displayed in Figure 4(a) (AuH+ + D channel) and Figure 4(b) (AuD+ + H channel), respectively. It is very clear that the threshold increases with the increasing J values due to the emerging of centrifugal barrier . Furthermore, we can also find that AuD+ + H channel has relatively large threshold than that of AuH+ + D channel for a fixed J value. It is because that AuD+ + H channel has a small reduced mass than that of AuH+ + D channel. In addition, more partial waves are needed to get convergent results at high collision energies.