- Modem are used for data transfer from one computer to another computer network through telephone lines.
- Modem is abbreviation for modulator and demodulator.
- It is a hardware device that connects a computer or router or a broadband network.
- The first modem known as Dataphone was first released by AT&T in 1960.
Operation:
- Modulator converts the information from digital mode to analog mode at the transmitting end.
- Demodulator converts the analog to digital at receiving end.
- When an analog facility is used for data communication between two digital devices called data terminal equipment (DTE), modems are used at each end. DTE can be a terminal or computer.
Types of Computer Modems:
1. Onboard Modem:
- Modem built onto the computer mother board.
- These modems can't be removed, but can be disabled through a Jumper or CMOS setup.
2. Internal Modems:
- Modem that connect to a PCI slot inside a newer desktop computer or ISA slot on an older computer.
3. External Modem:
- Modem with in a box that connects to the computer externally, usually serial port or USB port.
4. Removable Modems:
- Modem used with older laptops PCMCIA slot can be added or removed as needed.
Speed of Modems:
- Modem speed is measured bps and kbps.
- Which is the speed modem can send and receive data.
Features:
- Auto answer: Modems ability to automatically answer the phone after the phone rings a set amount of times.
- Data/voice: Modems with voice capability that can switch between a voice and data communication.
- Fax: Fax modems can send and receive a fax with proper software.
- V-90: The standard that the modem uses also allows it to communicate at an optimal speed.
Advantages:
- It converts the digital to analog signal and vice versa.
- Not expensive.
- Access the internet.
- Higher transmission speed.
Disadvantages:
- External modem does not allow you mobility with laptop but it does provide faster connection and less power uptake.
- Internal modem allow you mobility to use wire less internet at hotspot but connection is slower and power uptake greater.
