What the modem is used for

The router distributes packets of data to the devices via a pre-installed DHCP server that assigns its own IP address to the connected devices. With these addresses, the router determines what should be routed and where.

What a modem is for – what it's made of and how it's constructed

In today's world internet users get information, explore the space of the internet without thinking why they can do it. Almost always users confuse the router with what is a modem. In this article, let's take a look at what it is.

The ancestor of the current data communication device appeared in 1962. Its its creator is AT and T. At that time, the data exchange rate was only three hundred bits per second. Then in 1991, this data increased to fourteen kilobits per second.

What is a modem

A modem is a device for to receive and send information through the telephone system. Streams of information enter it, where they are converted into the necessary signal, which passes through the telephone line. It goes to the other end of the wire, where another such device already demodulates the signals, turning them into computer signals, and they arrive at the computer and then and then displayed on the screen user. The word itself came from an abbreviation of two English: modulator and demodulator.

Modems are used to connect to the Internet via a telephone line. This device is a kind of bridge between the Internet and home or office equipment. Modern models can be used as a router, sharing the Internet between several devices.

It is worth noting that it can not fully replace the router, as there is no possibility to receive the Internet via rj45 from the provider.

From the history

The first modems began to be used quite a long time ago. It is believed that the first modem was launched in the middle of the last century by American scientists. The first modems were used on military bases. Scientists of those times believed that the devices of such plan were able to provide reliable and secure communication in comparison with the classic phones. The first device for the PC was the Micromodem II. The developers created the device especially for Apple. The first modem could work at a very low speed – up to three hundred bps. Today, such an indicator will not be able to satisfy the needs of any modern person. But at that time, transmitting information even at that speed was the pinnacle of progress. Gradually, with the development of technology the world saw new devices which we use today. What does a modem do? To receive, convert and transmit signals.

Classification

The definition of a modem is now very clear, so it is worth paying attention to the varieties of these devices.

According to the general classification, modems can be internal or external:

• Internal modem – such a device does not function as a separate device, it must be inserted into the system unit of the computer in a specially allocated slot. This is a completely inconspicuous device, made in the form of a small board. Another advantage of such modems is that they do not require power supply. The cost is an affordable option. The devices are very easy to use. Interface circuits, indicators and, accordingly, the housing are not provided in such models. As for the disadvantages, they also exist: such modems are highly susceptible to interference, much stronger than external devices. Due to the lack of light indicators, it will be difficult for the user to determine the modem's operating mode. In addition, it is worth considering that the disadvantage is the way to install such a device. To install or remove the internal modem, you will have to open the system unit. This procedure requires skills and experience in working with the "iron". Therefore, beginners in this regard may have difficulties. If the internal modem begins to slow and hang up, only a global reset of the computer can solve the problem, but not the modem device itself.
• External modem. Such models, unlike the previous variants, are equipped with their own case and have a separate power supply unit. They work independently from the computer. In this case, there are light indicators that indicate in which mode the device is working. Models of previous generations could be built into the motherboard of the PC. Modern devices allow the user to reset at any time in case of incorrect operation or failure. In terms of cost, such modems will cost more than internal models.

According to the way the devices are connected, they are divided into two classic types:

Types of modems: type of data processing

Modems are divided into separate groups according to the format of the networks to which they are connected. The first modems used telephone lines to gain access to a global network. Today, this type of Internet transmission can be found in ADSL modems from Rostelecom. With the development and introduction of new technologies and communication standards, access to the Internet has become possible through the networks of cellular operators.

They are connected to them by portable modems, which are different:

It is this type of modems is in high demand among users, which is due to its versatility, convenience and reliability of operation.

Types of modems according to the type of connection

According to this feature, network modems are divided into such groups:

1. Analog devices. A large group of models designed to build networks using telephone lines.
2. Cable models. Information is transmitted through special cables. They are used in the organization of information exchange in television systems.
3. Radio modems. It is used for receiving and transmitting data using radio channel.
4. The fax modem. A separate group of techniques ensuring reception-transmission of text or pictures in fax format.

A popular group of cellular modems transmits and receives arrays of information through the mobile network 3G, 4G LTE.

Types of 3G/4G modems

What are the differences between 3G/4G modems? There are not so many key differences that you should rely on when buying.

Supported frequencies

Let's start with the most important one. If a modem doesn't support the frequency your service provider operates on, you simply won't have internet. So avoid shopping abroad. You should not order a modem from China, even if it is half the price of a nearby store. The problem is that different countries use different frequencies for mobile communications. And because of this, even the most expensive, wonderful and high-quality modem ordered from abroad will be a useless piece of plastic somewhere near Moscow.

Suitable for Russia modem must support accepted communication frequencies in our country:

It is not necessary to support all frequencies without exception, but make sure that the operator you choose works in one of the frequencies supported by the modem. But, of course, the best choice would be a model that works with all "Russian" frequencies. The list of bands in which the device works is always listed in its specification on the package.

Data transmission speed

The modem device implies the presence of an upper limit on the speed of the Internet, and this limit is different for 3G and 4G standards. Ideally, it should not be less than the maximum speed offered by operators in your area, and better still with a reserve, so that the modem does not have to be replaced in a year or two, when the real speed of the Internet will rise. Even now it is definitely not worth to take models limited to 7.2 Mbit/s (although you can still find them on sale, such as Huawei e303).

Now the best choice is a modem with 3G speeds up to 45 Mbit/s, and 4G speeds up to 150 Mbit/s.

The ability to connect the antenna

For a stable and fast connection to the Internet, not only the specifications of the modem, but also the peculiarities of the territory – namely the location and signal strength of the towers. There are problems with this even in large cities, and in secluded corners and in rural areas it is everywhere. To avoid loss of speed, you should choose a modem with the ability to connect an antenna. It will be able to catch a weaker signal.

Modem for home and cottage

For stationary use, usually choose a modem that meets the following characteristics:

• A maximum 4G speed of at least 150 Mbps. 3G is not so important, because it is unlikely to be used;
• for dacha are obligatory connectors for the antenna, in urban housing you can do without them;
• work with all SIM cards;
• no Wi-Fi module.

But, of course, they may vary depending on your personal preferences or conditions of the area.

Types and types of modems

There are several types of these devices. In particular, you are already familiar with half of them. For example, we have already considered all the well-known aDSL modem. This device is connected exactly to the telephone line. At first sight this transmitter is very similar to the router, but there is one difference – this DSL port, which already has not 8 wires as on a usual network port, but only 6.

An analogue can be an aDSL card which is inserted inside the computer. They are not as popular because only one computer can be connected in this way. That is why they are more often used on servers.

There are also combined and separate devices. For example, the picture below shows a separate modem that connects to the telephone Internet. From the local port goes the cable to the router, which in turn distributes the traffic.

But there are also the combined devices aDSL routers as in the picture below. That is, there are all in one: modem, router and WiFi with antennas.

The next type is 3G, LTE, 4G modems, which look like a flash drive and are connected to the USB port. They convert the mobile radio signal into a digital one. To connect you also need a SIM card and a paid tariff from the mobile operator. Let me remind you that such a modem is already built into any modern cell phone or smartphone.

The most popular modems

Initially, the most popular modems were exactly aDSL. Since there were quite a lot of telephone lines. But now the telephone line is being replaced by optical fiber. It is a type of cable that allows you to transmit a lot more information. It is called optical – because the information is transmitted by a beam of light. The disadvantage of the same aDSL technology is that telephone cables are not designed to transmit this kind of information at all.

They are also not shielded. Shielding is necessary to ensure that the information transmitted is not affected by external factors, particularly electromagnetic waves, which can create interference. As a result, information is transmitted with errors. And of course the main disadvantage is that the speed of such a network is quite small.

Of course now aDSL is still in use, but in the near future they will completely go to rest. To date, the most popular modems are: 3G, 4G, and LTE (mobile flash drives). This technology allows you to connect to a mobile network and enjoy all the benefits of the global network almost anywhere in the city or region.

Now, while holding the phone in your hand, you are also holding the modem. But as I said earlier, you can use a modem separately and connect computers, laptops, and other devices. In addition to a regular modem, there are combined with routers that can simultaneously distribute Wi-Fi.

3G and 4G are different generations of mobile Internet. The letter "G" is short for "generation," which translates to "generation." "Bigger" generation is distinguished by higher speed and stability of communication. At the moment, the most popular network is 3G, as it has a farther range.

Popular modem manufacturers

Since 2009, on the market of modems manufacturers in the major roles played by Chinese firms. Huawei company occupies 45% of the world market of USB-modems, its competitor ZTE has 21%.

The list of device manufacturers is very large. The most popular now are the following:

A new type of modem has recently appeared on the market. They help provide access to the Internet for all the surrounding devices that have the ability to use Wi-Fi networks. Such a device is the Mi-Fi model manufactured by Novatel;

The Mi-Fi modem functions as a portable (mobile) router

ZyXEL Keenetic DSL modem provides Internet access to all the devices in your home Wi-Fi network

ASUS DSL-AC52U modem ensures Internet availability by switching operators

The modem Huawei E3372h will provide access to the Internet within the coverage area of a mobile operator

Choice, connection and ADSL-modem setting

Most often when connecting to telephone networks, ADSL-modems are used.

The cheapest option is a modem with a USB interface. Such devices are small and easy to set up. Unfortunately, not all computers are compatible with such modems.

Modem with USB-interface is characterized by the convenience in use.

Modems equipped with Ethernet-port are universal and can be connected to all computers and notebooks. If you intend to use a desktop computer and there is no need for an internal Wi-Fi network, it makes sense to choose such a device.

The most popular are modems with Wi-Fi. They provide for both wired and wireless device connection. Such a modem can operate as a bridge or router. It has a provision for distributing Internet via Wi-Fi network. It is such multifunctional devices are worth choosing to use. The main evaluation criterion in their choice is the power you need. The price of the modem and the range of the Wi-Fi signal depends on it. Accordingly, the cheaper variant is enough for small rooms, in the case of requirements to cover a large area, you need to choose a larger power.

Setting up such devices requires information from the provider – DNS and IP-address, PVC, login and password assigned to the subscriber. These parameters are entered manually. Many carriers provide a disk with the necessary settings. In such cases, no special knowledge and skills are required to configure the modem.

If the modem has been used before, the best solution is to reset it to the factory settings. This function is mainly used when changing the provider or if you lose the access password.

How it differs from a router

Contrary to what most users think, modem and router are different devices. They differ in how they work. A modem is used to convert the signal it receives from digital to analog and vice versa. That is, its task is to receive, convert and further transfer information. It provides Internet access only on one computer and does not distribute it to other devices.

A router is used to distribute the incoming Internet signal to all the devices connected to it. You can do this both through a cable connection and wirelessly. It has a built-in DHCP server function that gives each device its own IP address.

This allows the router to identify which gadget is connecting to it and to which address it needs to send the information. The pluses of such a network include the ability to exchange data within it.

Types and types of modems

Modern devices differ from each other in the type of connection to a PC or laptop. Some are used exclusively within the home or office, while others are used anywhere within the mobile network coverage area. Let's talk more about each of them.

Combined and separate

Combined ones combine a modem and a router, which means they can both convert the signal and distribute the Internet. They are equipped with one DSL and four LAN ports, as well as an antenna and a Wi-Fi module. The DSL connects the telephone cable, while the LAN ports and Wi-Fi network connect all the devices in the house. An example is the D-Link DSL 2640U.

The latter have only one DSL and one LAN port each. The first one has a telephone cable, and the second one has a network cable that connects the modem to the PC. Internet distribution in this case is done by connecting a router to the device. To do this, the cable coming from the LAN port of the modem is connected to the WAN port of the router.

ADSL .

The working principle of their devices has already been described, so we will not dwell on it in detail. We can only say that these devices are equipped with a DSL port, which instead of the standard 8 wires has only 6. To connect it, the RJ-11 cable is used. The disadvantages of these devices include low bandwidth, i.e. limited data transfer speed.

Built-in ADSL modem is represented by a card that is inserted into the motherboard of the PC. It provides Internet access to only one device, so it is not as popular as the combined modems.

Modem device functions

The main task of the device is to provide communication, which involves the exchange of coded data. What is the purpose of a modem? The equipment is created for coding, receiving and transmitting a signal. Modules which provide connection to the Ethernet network are the most demanded among the ordinary users.

Initially, the converters were used to form a computer network as part of the telephone line. What does a modem do? Since the information in the PC is in digital format and is transmitted in analog format, the module connects the mobile device to both ends of the network.

Varieties of modern modems

To date, various types of equipment are produced, differing from each other depending on the functionality, connection method, purpose and principles of operation. For example, it can be a modem for a car, computer or TV, 4G modem. The devices can be part of other devices, or connected to the COM, USB or Internet ports of the PC.

Initially modules were used to provide communication via telephone cable. Today the most demanded devices are USB ones. What is the USB modem used for? The device allows the mobility of the serviced device.

According to the way of use, converters are divided into the following groups:

• internal, which is an expansion board;
• integrated. What is an integrated modem? It is an element of the PC or laptop that cannot be removed;
• external (stand-alone modules);
• group, which are several interconnected devices;
• portable ones, designed to work with mobile devices.

Of all the variety, the most interesting for the average user is the modem with an antenna, which provides wireless access to the Ethernet network in the signal coverage area.

The most popular models

There are a huge number of different Internet modem companies on the market, the list of which is constantly updated with new names. Some of the most famous are:

• ASUS DSL-N16. It transmits data through both telephone and fiber optic networks. It is tamper-proof and Wi-Fi enabled, and connection speeds can reach 100 Mbps. However, it functions only in one channel (2.4 GHz), and therefore interference in operation is possible, in addition, sometimes this model can automatically reboot, which takes a very long time.
• Huawei E8372. This is a 4G Internet modem, which can not only guarantee a decent speed Internet connection, but also to act as a router and distribute Internet within a radius of fifteen meters. The working principle of the modem is simple, and it does not need any configuration.
• Zyxel LTE7240-M403. This device is equipped with a jack for fiber optic connection, a LAN port, a slot for a SIM card and Wi-Fi.
• ZTE MF823D. It is a portable model that supports LTE, third and fourth generation mobile communications. The maximum bandwidth is one hundred megabits per second.
• D-Link DSL-2500U. To connect it uses technology The device has a single LAN port, the bandwidth of which is limited to ten megabits per second.
• Zyxel AMG1001-T10A. An ordinary Internet modem that connects to the telephone channel and provides an Internet connection on a single PC.

How to choose a good modem

Now that you know what the different types of modems are used for, you can tell which one is suitable for you personally.

If you need a portable USB modem, then you should pay attention to the following criteria when choosing one:

• Data transfer speed.
• The type of network to be supported. At the moment, 4G and 5G Internet modems are popular. They give a more stable and faster Internet connection, unlike the same 3
• If you want to connect a portable Internet modem to your router, it makes sense to check if your devices are compatible. You can find out on the router manufacturer's official website by looking at the list of all the devices it supports.
• If you are often in areas with low signal strength, you may want to consider having an antenna attached to your device to increase the reception strength and speed of your Internet connection.
• Make sure Wi-Fi is available if you have a need to distribute the Internet. It's also good to find out about the range of the wireless network and the maximum number of gadgets that can connect to it.

If you want an ADSL Internet modem, then first determine the type of connection. There are models, which are connected to your computer via Ethernet port, there are variants, which for this purpose address to the USB slot, and there are devices, which can be connected to via Wi-Fi.

The first type is the most universal and easy to use. The second is not supported by all devices, but it has a number of advantages: small size, convenience and easy setup. The third type of connection is easy to use, but it can be difficult to configure. To use an Internet modem with Wi-Fi you may need some information from the provider, such as DNS, PVC, etc.

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