Modulation protocols determine how modems convert digital data into analog signals that can be sent over a phone line. The first modulation protocols were Bell 103 and V.21, which allowed transmission at 300 bps. However, it is impossible to transmit more than 600 bps by converting a single bit into a single signal. By combining digital data into more complex signals, it is possible to transmit at higher speeds. How this is done is determined by other protocols, such as V.32bis and V.34. The suffixes "bis" and "ter" indicate that protocols are further versions of previous protocols. Thus, the 19.2 V.32terbo is an improvement over the 14.4 V.32bis, which is itself an improvement over the 9600 V.32 protocol. The latest modulation protocol is V.34, which allows transmission at 28.8 kbps.
Articles in this section
- How can I use one phone line for both voice and data?
- How do V.92 modem speeds compare to ISDN, ADSL and Cable speeds?
- Does the Model 3090A modem have lights or a speaker ?
- Where can I learn more about modems and V.92/V.44?
- What makes a Zoom V.92 modem faster than V.90?
- Synchronous vs. Asynchronous Data Transfer
- IRQ Settings
- COM Port Settings (DOS/Windows)
- UARTs and Data Buffering
- Flow Control