7 types of network equipment: features, functions

In the world of mobility and speed information of particular importance. It is important to ensure its availability, reliability regardless of where the person is located. The level of technology allows a person to refuse access to information on landlines and to be truly mobile.

types

Wireless solutions have penetrated into all spheres of human activity. They are used in home, offices, public places, industrial enterprises. High-speed access to information provides Wi-Fi technology. Wireless mobile devices implemented using BlueTooth.

The brand Wi-Fi Aliance belongs to the association of manufacturers developing standards and equipment for Wi-Fi networks based on the IEEE 802.11 group of standards for data exchange regulation on radio.

Manufacturers sell 20 standards included in the 802.11 group. Modern equipment does not support all of them. 802.11 Each group has characteristic features used in various operating conditions.

Popular following versions:

• 802.11 a / b / g / n;
• 802.11 ad;
• 802.11 p;
• 802.11 y.

How do radio channel solutions at 802.11 has advantages and disadvantages. The advantages of rank:

• no need for installation of the cable system;
• mobility;
• a low level of radiation compared with cell phones.

The disadvantages include:

• speed reduction associated with the separation channel bandwidth for each connected client;
• relatively poor immunity from household appliances and industrial installations;
• reduction of the maximum communication range when encountering obstacles such as a wall or a metal partition.

Basic types of devices that implement the exchange of information over the air:

• routers;
• repeaters;
• routers for 4G modem;
• adapters;
• ADSL access point;
• Bluetooth adapters.

Wi-Fi routers

A router, or router, - a device that manages data flow between multiple network segments and defining a path for user traffic.

Widely distributed routers for home, office and public buildings. Industrial same solutions are supported by a handful of manufacturers in view of the increasing demands of reliability, extreme operating conditions and functional limitations associated with the production process.

The main functions of routers - provide a link with the points-clients and performing routing functions. However, modern equipment often is not so limited. Depending on the type of tasks and manufacturers equip additional functional tasks.

Routers are divided functionally into the following groups:

• for busy offices, public places and industrial premises;
• for home and small office.

The first group of routers addresses the functions of building Wi-Fi network with high performance and reliability. For the second group is characterized by the addition of additional options, not related to the routing process and the organization of interaction of "air".

Manufacturers routers complement the functionality of the following options:

• function in Internet access gateway;
• security features (Firewall, DMZ, IDS, «Parental control», Proxy);
• network services DNS, DHCP.

At the hardware level, built:

• additional connection to the Internet technology. In addition to Ethernet supports ADSL and GPRS;
• USB, supports the connection of a printer, disk drive, and 4G-modem.

It is worth noting a specialized Wi-Fi equipment using separate protocols 802.11:

• 802.11p used to exchange information between moving vehicles (buses, subway) and infrastructural objects;
• 802.11y transmits data up to 54 Mbit / s in the open countryside with a range of up to 5 km.

Since 802.11 implements a communication through a radio channel, technical parameters depend on the type of antenna. In appearance and functional tasks, the following types of radio antennas to the router:

• built-in;
• outer circumferential;
• an outward direction.

Built-in antenna is placed within the housing. The apparatus is stylish ergonomic design and the impossibility of dismantling the antenna. But because the internal antenna have low gain (up to 2 dBi), the action radius is rarely more than small-sized area of ​​the room or apartment.

External circular antenna is common in home and office use. She has a greater range than that of the built-in, and is used for the home, the average office or production facility. The gain depends on the make and reaches values ​​of 7-8 dBi.

Directional antennas operate on sector radiation diagram / receiving a radio signal and differ longer range (can be measured in kilometers) compared with circular. The gain depends on the make and the type of antenna. Such antennas are preferred in offices, in industry, for data transmission on open terrain.

The question arises, why a lot of router antennas. The functionally different routers with one or more (two - four or more) radio antennas? The fact is that one radio antenna works on transmission and on reception. To increase the speed or number of client expansion points the number of antennas increases.

Distributed two ways of using multiple antennas:

1. SmartAntenna MIMO (MultipleInputMultipleOutput) - Multiple radiovhod, multiple radiovyhod. This technology works on the simultaneous reception and transmission of radio signals;
2. Work router in several frequency bands. This technology reduces the "competition" customers when working with the router.

Wi-Fi adapters

Device for connecting computer or household appliances to a wireless network called Wi-Fi adapters. They are divided into two categories: integrated and connected. Many modern mobile devices such as smartphones, tablets and laptops are equipped with built-in (integrated) adapter.

Plug adapters are used to work on desktops. They differ in the type of interface used to connect to the system.

Basic types of interfaces for adapters:

• USB;
• PCI-E;
• PCI.

Adapters with a PCI-E interfaces and are connected to PCI stationary computers through respective interfaces to the system unit or motherboard. They are equipped with external antennas, which, if necessary, replaced by others with improved characteristics.

Adapter with a USB port can be connected to computers and household appliances, for example, to a television. This is only possible for the consumer electronics (TV, multivarka, air conditioning, washing machine, etc.), Which supports the activation of the function Wi-Fi via USB. Such adapters are implemented as a transmitter with an antenna inside. In some models to this form factor attach an external antenna to increase the signal level in the device.

Adapters with integrated SoftAP software and hardware function (software switch access points), create a computer access point. Setting is realized through software control interface adapter.

Wi-Fi repeaters

Amplifiers, repeaters, or signal repeaters are called Wi-Fi repeaters. Used to extend the area of ​​action 802.11. The basic function of the repeater is receiving a weak signal from the client device, its amplification and relay destination - the main device (access point or router). Repeaters use the same data transmission standards 802.11 as routers.

Amplifier signal as routers, are separated by application levels:

1. for home use and small offices;
2. office wide area, public spaces and industrial buildings.

According to the type and size of pets repeaters similar to a charger that is simply inserted into the socket. These models are equipped with built-in antennas.

Repeaters are used in multimeter office buildings or public places, extensive service coverage and provide the work of more concurrent clients, rather than domestic model. Such repeaters 802.11 implemented as separate devices with multiple external circular or directional antennas.

They work on MIMO technology, which was seen above.

Some models of home repeaters have an Ethernet port through which the computer connects with the purpose of use as a Wi-Fi adapter. Connection of repeaters to Wi-Fi routers and access points is performed using WPS technology (WiFiProtectedSetup) - standard for a secure home network.

ADSL access point

ADSL access point is a Wi-Fi router integrated therein ADSL-modem. ADSL (AsymmetricDigitalSubscriberLine) - Technology, a member of a group of xDSL standards.

These standards implement transmission over twisted pair data, including wired telephone lines public use. Especially the principle of asymmetric data transmission is to divide the bandwidth of the communication channel between the traffic of incoming and outgoing data. In this technology, the incoming traffic exceeds outgoing at times.

communication speed depends on the length of the line and its quality parameters. Limit values ​​for the information rate technology implemented on standard ADSL2 +, equal to 24 Mbit / s for the incoming traffic, and 3.5 Mbit / s outbound. In practice these values ​​are seldom achievable and the data rate is significantly lower.

This device does not require a power supply, and includes three connectors:

• external telephone line;
• ADSL-modem line;
• extension telephone line.

Solution with integrated ADSL-modem used to connect to home networks or small office to the Internet. ADSL-modem is used as a channel for the "last mile", i.e. the connection target device to the network over a telephone line in the absence of other possible ways of connecting wire.

Wi-Fi routers for 4G-modem

In addition to connecting to the internet via wired Ethernet channels and ADSL, developed routers that support external connectivity via 4G modems. These routers are used to connect to the networks of mobile operators.

4G - the marketing designation of wireless technologies relating to the fourth generation. These solutions provide a complete information transfer rate of 100 Mbit / s.

By the fourth generation technology include two standard data transfer:

1. LTE Long-TermEvolution (lie at the heart of mobile GSM / EDGE technology, UMTS / HSPA);
2. WiMax (IEEE 802.16m).

4G modems are compact, like a flash drive with USB connector. The spread of 4G modems got to connect to networks of mobile operators. The modem sends data on the LTE standard, for connecting to the mobile network operator additionally inserted USIM card with the appropriate mobile network operator.

Since 4G modem completes router for output to the external network, it is used as a backup or a backup link. To increase the speed of information exchange in the presence of two or more communications channels with unequal bandwidth can optimize data flows.

configure routers implement asymmetric communication. This outgoing traffic is transmitted on one channel, while the second input is received. Selecting the direction of data transmission channels based on traffic estimates and determining the amount of incoming and outgoing data.

Bluetooth adapters

Bluetooth - a specification for wireless personal use (WPAN). It intended for radio communication between devices (computers, printers, smart phones, etc.) over short distances. Authorization when connecting devices is performed on the PIN-based.

The market offers two types of Bluetooth:

• classical;
• high.

Bluetooth distinguishes a classic low-speed (up to 1 Mbit / s) and a small coverage of up to ten meters. This technology is used for transmission of information between mobile devices or computer and peripherals, and home appliances. Thanks to this the user gets rid of the large number of wires to connect to printers, headphone, mouse, keyboard and other devices are constantly used.

Bluetooth adapters are already integrated into the peripheral device, but personal computers are not always equipped with them. In order to use this technology is used Bluetooth-adapter. The device is implemented in a compact form factor flash connected to the USB connector.

The fastest Wi-Fi

A data transmission technique on a radio channel imposes a number of limitations. Which of the Wi-Fi technology is the fastest at the moment? The rate depends directly on the frequency. The higher speed is required, the greater the frequency of the transmitting radio signal.

Implemented technology designated standard 802.11ad (informal name WiGig), for transferring data at speeds up to 7 Gbit / s. To achieve this rate is used in the radio frequency range of 60 GHz.

Because of such high frequency radio signal transmitting restrictions imposed on the information transmission distance. Signal acts at a distance of 10 meters. For such radio frequencies is an insurmountable obstacle to any. Data transfer is possible only in the line of sight.

Because of data limitations WiGit does not apply to "wireless" routers. Niche of the solution is in the field of wireless communications with various devices as a substitute for a wired connection to a computer. Widespread this standard will receive when you connect to printers, portable data storage devices, monitors, and other peripherals.

Technology implemented in the standard, operates at frequencies in the band of 5 MHz and provides a data rate of hundreds of Mbits / s (433 Mbit / s per channel) and even Gbit / s.

Speeds in excess of 433 Mbit / s are provided through the use of MU-MIMO (MultiUserMIMO). MU-MIMO allows to transmit a plurality of data packets simultaneously to multiple users in the same frequency range. Theoretically, when using eight antennas may reach speeds close to 7 Gbit / s 802.11ad standard.