I was sitting on modems, then the time came for satellite asymmetric connection, to which, thank you, there were three fates that did not change, as it could.
How many satellites and providers have changed is no longer safe.
And all through - the evil guys-providers did not want to pull the wire to my heel through the private sector, as if they were unacceptable.
But the situation has changed dramatically - our local university, LLC Telecom, has taken on the difficult task of providing services.
What can we earn in the first place?
That's right - unstitch, the signs are coming, and where the very same telephone line is laid, which we are so terribly exposed to.
Have you unstitched it?
Did you notice what bolts you need to approach the telephone box that is located in the hallway?
That's it, let's see.
I respect that such a “lokshina” axis is the best that can be installed for ADSL, so don’t harm it.
Now the time has come to lay our “twisted pair” - carefully, with force, not to twist the wire at the loop - you don’t like a twister.
Oh, now we’ve done everything we can to protect ourselves from failures and difficult times in accessing the Internet.
As soon as it becomes a rapt, we can now press the provider, and our conscience will be clear.
The recipe for my writings is for those who are afraid of obvious problems with ADSL, and it is also recommended that advertisers contact them quickly. Turn over - the fluidity and stability will decrease.
I lost contact with people who helped me with setting up an ADSL connection. Tse:
Khodun Yuriy Ivanovich- Chief engineer of LLC Telecom.
A very patient and literate person.
Balikov Oleksandr Timofiyovich
- Director of LLC Telecom. A person who lives up to her words. Having promised ADSL to people - having bought it. I respect you. Trusin Oleksiy
The remaining time is to guard against the growth of services symmetrical to DSL access in the corporate sector.
The greatest hope is placed on the standardized 2001 rub. The International Electrical Union ITU-T uses SHDSL technology, which, due to its parameters, greatly surpasses other symmetrical systems.
For subscriber access, asymmetric systems are most often used. Among them, the greatest expansion is ADSL and ADSL2+. VDSL transmission systems can be either symmetrical or asymmetrical. Connecting to the Internet via a telephone line is organized as follows (division 1). The telephone signal, passed through a 4 kHz filter, is connected to the computer signal that passes through the modem.
The combined signal (from the telephone and from the computer) enters the subscriber line and is transmitted to the university connection. There, in its own way, the telephone signal is seen by a low-pass filter (4 kHz) and is fed to the telephone switch, and the computer signal is sent to the modem and then directly into the multimedia network. Thus, to connect home subscribers using DSL technology, a standard telephone system can be used. DSL technologies are most suitable for Russian subscriber lines, since they directly go from the telephone jack to the communication node. It is important to note that in many countries there is another approach: the line from the telephone exchange will end near the booth and the home on the multiplexer.
DSL modems differ from telephone modems with a much larger frequency range.
Since telephone modems operate on a standard telephone channel (0.3-3.4 kHz), the frequency range associated with DSL becomes hundreds of kilohertz - a few megahertz.
- Obviously, for the implementation of DSL systems, it is necessary for cables to ensure the transmission of such frequencies.
- Who has the power, and has wide access.
Depending on the method of transmitting the linear signal, it is necessary to differentiate (see table 1): DSL systems with serial transmission of signals under the name “single carrier modulation systems” (Single Carrier Modulation, SCM), the coding methods 2B1Q, CAP and so on are used; systems with parallel transmission of signals at many non-carrying frequencies, so-called “systems with multi-carriers” (Discrete Multitone, DMT).
Їх zastovoyut in asymmetric DSL. Symmetrical DSL technologies, such as HDSL, SDSL, SHDSL, are single carrier systems (SCM). Asymmetrical DSL, such as ADSL, ADSL2, ADSL2+, uses multiple carrier modulation (DMT).
As already mentioned, the VDSL system can be both symmetrical and asymmetrical, and there is a difference between different views modulation.
The main parameters of the DSL system are capacity and line life.
Accessibility
The enhanced HDSL system will provide transmission mode with a speed of approximately 2 Mbit/s on both sides over one or two pairs of wires for a distance of up to 10 km. ADSL, however, is intended for asymmetric transmission with speeds of 6-8 Mbit/s - at each subscriber and 840 Kbit/s or less - at each node. RADSL differs from other technologies in that it supports either a symmetrical mode with a speed of approximately 1 Mbit/s or an asymmetric mode with a speed of up to 8 Mbit/s to the subscriber.
SDSL usually means symmetrical transmission over one pair;
IDSL – modification of ISDN (
digital measure
with integration of services). This report will look at two of the most vulnerable technologies – High-bit-rate Digital Subscriber Line (HDSL) and Asymmetric Digital Subscriber Line (ADSL). is divided into 256 subchannels and digital streams are transmitted through the skin of them.
As a matter of fact, the methods are different, and to ensure normal functioning, it is necessary to ensure that the presence in subscriber lines works consistently for one and the same system. From now on ADSL technology
was developed for the “video-on-demand” service and was intended to transmit an uninterrupted stream.
The alternative for the Internet is to add ADSL to computer communication protocols.
Now let's use the ADSL equipment. Ascend (a subsidiary of Lucent Technologies) produces a highly stocked series of DSL systems..
In addition to the ADSL2+ protocol (exchange speed up to 24 Mbit/s), it supports primarily ADSL (up to 8 Mbit/s) and SHDSL (up to 4.6 Mbit/s), equipped with two Gigabit Ethernet ports and 10/100BaseTX/FX ports. The smaller Corecess 6804N multiplexer has a capacity of 192 subscriber lines, supports the protocols themselves, including Gigabit Ethernet ports and 10/100/1000BaseT, and 10/100BaseTX/FX. As a matter of fact, the capacity of both systems is sufficient to serve a large number of apartment buildings, as well as an entire microdistrict.
Different protocols are supported by the multiplexer so that the operator does not have to identify the subscribers who are using modems in older systems.
Gigabit Ethernet ports provide output to the ASDL2+ provider in the MAN and WAN Ethernet networks.
In the remaining hours, DSL access will be quickly completed.
The standard for ADSL2+ was recently adopted, and in 2005. The International Electrical Union ITU-T has introduced the VDSL2 standard (Very-High-Bit rate DSL).
To cancel your digital subscriber line (DSL), you need to get a primary line.
A typical subscriber line consists of several wires from the telephone socket to the junction box;
From here, there is a cable running to the split coupling and the shawl, which is usually laid out directly above;
Another number of inconsistencies is the connection to the subscriber line (not shown on baby 2). The above is called a section of betting rotations, which is connected in parallel to the subscriber line and open at the end. These are established during the operation of subscriber lines as a result of additional connections. The result consists of cross-cutting wires and a power supply of torsion pairs. Let's take a look at the parallel connection: there is an additional telephone socket, which is usually present in every apartment.
Such outputs are especially cheap because they are located near the input of the DSL modem. In this situation, the signal that is received is small, but the signal coming out of the output is, however, large. The shortest method
Plug in the inflow of similar leads - eliminate unconnected sockets from the leads.
U to the extreme vile hvil's support.
The main effect of line irregularity lies in the appearance of broken signals. These signals, by their nature, sense re-reflections at points of other inhomogeneities. Thus, the line experiences a lot of irregularities that directly interfere with the main signal. The “following flow” that results in a real loss of transmission clarity and leads to a loss of smoothness of the frequency characteristics of the line and the appearance of a “tail” in the main signal.
Another important parameter for the transmission of signals is the active suppression of the line.
Before the stationary current cross-codes, the appearance of which is due to the normal operation of these cross-codes - connecting pairs of the same cable and other closely connected cables, as well as radio stations, line ій power transmission.
Non-stationary processes include transient processes in the life cycles of automatic telephone exchanges and in power transmission lines, atmospheric agents (blinkers), etc. This group transitions to a sudden sequence of short impulses with great effort;
They are also called pulse transcodes.
For a twisted bet, the initial ones are the external ones.
This class of modern cross-codes can especially be called transient, because the fragments of the signal can be the most influx in the transmission of signals.
CABLES FOR DSL
Before the parameters of the flow between two pairs lie: transition to the near end (Near End Crosstalk, NEXT);
transitional extinction at the far end (Far End Crosstalk, FEXT);
near-end burglary (ACR);
long-range theft (ELFEXT).
The values of these parameters are shown in Figure 3. Figure 4 shows the adjustment of the NEXT parameter for the telephone cable TPPep 10x2x0.5 and specially divided to support the DSL cable MVPV 25x2x0.5, which is produced by the Elix-Cable company. Both cables have a copper core diameter of 0.5 mm and approximately the same time the extinction goes out, but generally disappears after the transient extinction.
- Please note that the TPPep 10x2x0.5 cable is a “ten-pipe” cable, which is most often used for residential units.
- The electrical characteristics of the cables must ensure transmission of one pair of cables, which meets the recommendations of ITU-T G992.1;
- 2;
- 3;
- 4 and 5, including up to 20 Mbit/s for ADSL2+;
- up to 52 Mbit/s for VDSL2+, offending parties;
- Due to electromagnetic properties, it is necessary to allow the operation of ADSL and VDSL systems in a high-speed mode with a speed of 155.52 Mbit/s;
- The maximum DSL line must be no less than 1500 m;
- number of pairs on cable – from 2 to 50;
- conductor diameter – 0.5; 0.64; 0.9 mm;
28.01.2009 vicoristic and porous insulation;
the cable must be laid in a telephone sewer, directly near the ground, in the middle of a telephone, and to protect against rodents (in necessary situations);
The design of the cable is responsible for the latent penetration of moisture;
Non-stationary processes include transient processes in the life cycles of automatic telephone exchanges and in power transmission lines, atmospheric agents (blinkers), etc. This group transitions to a sudden sequence of short impulses with great effort;
electrical characteristics of the cable on
postynomu struma
The cables are intended for the tonal (low frequency) range.
At a frequency of 1 kHz, the transient attenuation between pairs can become less than 70 dB.
At higher frequencies this parameter is not standardized, which complicates the design of digital lines.
This is one of the most common types of cables, and is not entirely compatible with DSL. Often the twisted pairs are twisted differently, which improves the efficiency of cable filament, which is far from optimal in terms of noise immunity, which ensures minimal leakage between pairs in the low-frequency range i. Subject to the “Rules for the laying of cables with metal conductors”, approved by the Ministry of Bonding in 2006, this product is liable to satisfy even the lowest possible demand. One of the main reasons is that the frequency content of the extinction, and the breakdown of the frequency of the distribution is due to the effects of the transmission system in which the cable is vicorized. Characteristics of mutual influx: amniotic asymmetry, transient influx at the near end and loss at the far end in a given frequency range - it is necessary to communicate the connection to the possible system.
Groups of pairs of symmetrical cables are twisted into a core behind a single circuit (either a coil or a bundle). Tie the bunches of the guilty mother with color indication., and for wide access.
The noise is similar to that of traditional SCS cables, but their scope has been extended to the DSL area. The parameters of these cables support DSL capabilities in the range up to 4 MHz. The letter “E” denotes shielded structures.
For example, the MVPVE/E-5 brand means a Category 5 trunk cable with twisted pairs and a polyvinyl chloride sheath with individually shielded twisted pairs and a shield.
Their characteristics were matched by the AnCom A-7 adapter from the Analyst-TS company.
These recently released cables are much better suited for DSL and lower CCIs, which are widely used.
To equalize, the characteristics of transient extinction at the near end (NEXT) have been adjusted for cables EKS-MVPV 25x2x0.52 and TPPep 10x2x0.5 with 0.5 mm conductors and approximately the same extinction.
It can be seen that there is a lot of security in the transfer of code to the MVPV cable, not even the widened “ten-pair” TPPep.
Power supply is often a problem: how many twisted pairs can a high-pair cable have to connect to DSL systems? Standards have been established for transient extinction at the near end (NEXT) between pairs in a number of pairs in a multi-pair cable. Apparently, with an increase in the number of pairs that are vicorized for DSL, the norms increase and with 10 pairs become 75-80 dB depending on the code that is vicorized. Rozrakhunki was collected in the Leningrad Galuzev NDI connection (LONIIS), in the laboratory of digital line connections. This is the basis for estimating the number of couples for whom it is possible to organize a full-time DSL connection via a local telephone line.
Analysis of the parameters in the flow, the results of the Loniis fakhivtsy, showing what is in the cables of the Chamber of Commerce and Industry that are being tested for DSL, it is necessary to specially select the pairs that are relevant for the organization of DSL. For the cables of the Elix-Cable company, the assessment is more optimistic: in fact, any combination of pairs will ensure a shift in the norm of electromagnetic capacity, so that the smell is entirely suitable for organizing DSL.) , but they will provide a range of 100 m, even as VDSL2 technologies are insured for transmission (for these very speeds) with a winding up to 300 m. Telephone communication cables (TPP and others) for frequencies higher than 2-4 MHz were not considered.
Therefore, cable supply for VDSL2 will require special investigation. Dodatkovo respectfully, scho frequency plans for VDSL2 different, different for ADSL2+..).
As a result, the mastery of the frequency range by VDSL2 systems is being carried out in stages: initially the frequency is up to 8 MHz, then up to 12 MHz, and in Western America there is a tendency to expand to 30 MHz.
The cables are tightened in parallel with the passage of frequency up, as it happened at the drop in the SCS (admirable article by the author in
“Journal of Merezhevikh Solutions / LAN” for the spring of 2004.
For installation in small spaces with plenty of space, optical fibers with a different radius are used, as described in the recently adopted G.657 standard.
Class A includes fibers with a permissible radius of 20 mm; The smell is wrapped up with the G.652D standard. Up to Class B fibers are carried, for which the permissible radius must be greater than 15 mm, but this is not compatible with G.652D fibers.
This arrangement involves high costs at the point of welding G.652D and G.657B fibers, so it is not recommended to grow them. Multi-mode fibers are significantly more expensive than single-mode fibers. The main area of their stagnation is local measures
(SKS).
For SCS, the use of multi-mode fibers together with electron-optical components is obvious, since the fragments are cheaper than those required for single-mode systems.
As a result, gradient fibers 50/125 µm (core with a diameter of 50 µm, optical shell 125 µm), as well as gradient fibers 62.5/125 µm, are produced.
The protection of optical cables from the external laying from the penetration of moisture is achieved by filling the empty core with sealant.
In a number of optical cables, instead of a hydrophobic sealant, water-blocking materials or water-blocking powders are used, which are more expensive than hydrophobic sealants.
As a rule, optical cables are coated with a polymer coating on top of the core. Since the operating conditions allow for the cables to be near water, changes in transverse diffusion are achieved by the sealed barrier with a ball of metal, structurally formed around a metal-polyethylene shell. Optical cables should be laid in cable ducts or dry plastic pipes, laid directly in the ground or suspended between supports or booths.
When laid in a cable duct, the cables should be of the simplest design. The steel-polymer shell protects against rodents. If the cable is laid in tunnels or collectors, then by increasing the fire safety, the sheathing is prepared with a composition so that the cables do not differ from each other.
The cable, which is laid near the ground, is equipped with an armored cover made of galvanized steel rods (div.).
The main connections will be made with metal cables (div.).
In the near future, this system is unlikely to change, so let’s take a look at the metal cables for internal wiring. Coaxial cables. Similar outliers have already been seen in the author’s articles (div., for example, in the Serpnevo issue for 2005 and in the Serpnevo issue for 2006).“Journal of Merezhevyh Solutions/LAN”
), here we are talking about cables that are produced in Russia.
Over the next 10-15 years, significant changes took place: the replacement of cables with copper conductors began to vibrate from the current conductor made of aluminum foil. The insulation design also has innovations: modern coaxial cables are insulated with porous polyethylene from physical spun. It is said that they are more connected with such furnishings.
First of all, such cables are lighter and cheaper.
Regardless of those who spend a little more in them, cables with copper screens and aluminum become thicker and wider. The optical cable, as it was usually meant, is laid from the connection node to a group of boxes or adjacent boxes (div.).
At the end, an electron-optical converter (media converter) and a switch are installed, from which the wiring around the house is completed using an additional symmetrical cable (div.). In this way, an Ethernet network is formed, which allows the distribution of information. Chotiriohparny cable,
base component
SCS, descriptions in many articles and is published by a whole range of cable factories in Russia, together with popular enterprises “Elix-Cable”, “Kirskabel”, “Saranskkabel” (10 small ones).
These products are similar and similar to Categories 5e and 6, differing in the quality of materials and the accuracy of preparation.
Some modifications have no screen (UTP) or armor.