Kamis, 07 Mei 2015


Definition, Functions and Types of Modem ~ Did you know that the name modem? I'm sure you know it. Yes modems are used to receive and send data at any time we want online in cyberspace. Without modem we may not be connected with each other through the internet. Thus the role of the modem is enormous in every time an Internet connection. But do you know the modem?

Understanding the general modem
Modem is short for modulator and demodulator. Modulator has a function to process the data in the form of signal delivers the information to the signal (carrier) to be sent to users through a particular medium. And this process is commonly called the modulation process. In this process the data from the computer in the form of a digital signal is converted into an analog signal.
Demodulator has a function as a process to recover the data sent by the sender. In this process the data will be separated from the high frequency and the data in the form of an analog signal is converted back into digital signals that can be read by a computer.

Modem functions in general
Modem function is to change the two-way communication of digital signals into analog signals or vice versa. A digital signal is sent from the computer is converted into an analog signal in advance by modem and transmitted over a telephone line to a computer delivered to the other and vice versa.
Currently modem also has developed a technology to add voice modem facilities which can serve as a channel radio, telephone conversations and other audio.

Specifically modem function
To minimize the error rate when transmitting a signal, and the modem will also check whether the information received is damaged or not by the method checksum if damage occurs then the data is sent back to the place of origin.

The type of modem types in circulation
Many types of modems that exist at the moment, can be distinguished by the type of modem and network installation. based installation known modem internal modem and an external modem, while jikberdasarkan modem network can be divided into a cable modem with the media and with the media without the cable modem.

Internal Modem is a network device that is located on the expansion board mounted on the motherboard slot. This is the advantage modem installation means simple and relatively cheaper price. The internal modem is also known as On-Board Modem

External modem is a modem that is attached outside the computer, usually plugged in a USB slot and a LAN cable. The advantages of this modem is that it can be easily carried or moved elsewhere.

Cable modem is the hardware that uses wired media as intermediary media, eg, cable TV and telephone network. Cable TV network can be used for internet connection up to maximum speed 27 Mbps for download, and upload speeds up to 2.5 Mbps.

Without a cable modem, this modem uses wireless media to intermediaries, eg GSM modem, CDMA modem. Disadvantages of this type is the speed of the modem can be weakened if the surrounding weather is not favorable. The surplus is easily portable and easily moved as desired.

Based on the technology or the type of connection, the modem can be divided into several types, as follows.

1. The analog modem, is a modem that receives data in the form of analog signals via a data transmission network and then convert it into digital data to be transmitted to a computer, or vice versa. This modem is usually used for dial-up connection through the telephone network, and then called a dial-up modem. Analog modems are available in various speeds, for example 14.4 kbps, 28.8 kbps, and 56 kbps with a range of brands, for example.

2. Modem DSL (Digital Subscriber Line), ie the modem to receive and transmit data with digital technology through a dedicated network (dedicated line - a dedicated network that is constantly available for internet purposes, who are physically unable to use a phone cable). In this technology the data received / sent DSL modem in the form of digital data, making Internet access faster than analogue modem.
There are two types of DSL, which is ADSL (Asymmetric Digital Subscriber Line) faster download speeds than upload and SSL (Symmetric Digital Subscriber Line) is equal to the download speed upload speed.

3. The cable modem, is a modem that receive and send data through the internet cable TV networks. Data received and sent also in the form of digital data with equal speed DSL modem.

4. The CDMA modem, dial-up modem is a wireless technology that works with CDMA (Code Division Multiple Access), for example, CDMA USB modem or can also use CDMA mobile phones.

5. Modem GSM mobile wireless modem that works on GSM mobile telephone communication lines. This modem supports GPRS / EDGE or 3G services. Examples such as USB GSM modem or can use a GSM mobile phone that supports GPRS / EDGE or 3G.

Thus the definition, function and type of modem types, may be useful.