Modem transmission mode
- Release on :2018-09-07
Modem was originally only used for data transmission. However, with the continuous increase of user demand and fierce competition among manufacturers, more and more "two in one" and "three in one" Modem have appeared in the market. In addition to data transmission, these modems also have fax and voice transmission capabilities.
Faxing via Modem, in addition to the cost of saving a dedicated fax, there are many advantages: you can fax the files directly from the computer to the other party's computer or fax machine without first printing the file; you can receive the received file. Fax can be conveniently saved or edited; it can overcome the problem that the ordinary fax machine gradually disappears due to the use of thermal paper; because Modem uses error correction technology, the fax quality is better than ordinary fax machine, especially for graphic fax. This is the case.
2. Voice mode
The voice mode mainly provides telephone recording messages and full-duplex hands-free calling functions, which truly integrates the phone with the computer. Here, it is mainly a new voice transmission mode (DSVD (Digital Simultaneous Voice and Data). By using Digi Talk's digital voice and data simultaneous transmission technology, DSVD enables Modem to make calls while transmitting data on a normal telephone line.
The DSVD Modem retains 8K of bandwidth for voice transmission and the remaining bandwidth for data transmission. The voice is compressed before transmission and then combined with the data to be transmitted and transmitted to the other party through the telephone carrier. At the receiving end, the Modem first separates the voice from the data, and then decompresses the voice signal and performs digital/analog conversion, thereby realizing the simultaneous transmission of data/speech. DSVD Modem has broad application prospects in distance learning, collaborative work, and online games. Since the price of the DSVD Modem is more expensive than the ordinary Voice Modem, and the data/voice simultaneous transmission function is required, the other party also needs to use the DSVD Modem, which hinders the popularity of the DSVD Modem to some extent.