E1 modem

For years, analog lines connected subscribers to telecommunications switches. For less than two decades, digital urban lines have been commercially available to subscribers. One of the disadvantages of analog city line is the restriction on making multiple calls to one line, which means that it is not possible to make another call with this line if we are talking to an analog line.

Now suppose an organization needs to buy 40 analog lines with different numbers to have a capacity of 40 calls at a time, although, with the possibility of rotary it is possible to introduce a number to customers, in fact, we receive incoming calls on 40 separate lines. And when making calls from inside the organization to outside, we actually make calls by using 40 separate numbers. Digital lines are commercially available to solve this problem and increase the capacity of a single number.

To connect a digital line from a telecommunications switch to a subscriber, we need two modems, one modem for the subscriber and one modem for the telecommunication switch. These E1 modems perform modulation of the analog-to-digital signal. As we know, the pair of telecommunication wires transmit the signal in analog form, so these modems are used to convert to a digital signal. As Internet modems are known as ADSL, E1 modems are known as SHDSL.