14.6. Access technologies on optical communication lines
14.6.1. FTTx Group Technologies
FTTx Technology Group (Fiber To The x - optical fiber up to ...)designed for use with ADSL and VDSL technologies and allows more efficient use of the bandwidth of these technologies by reducing the length of copper-cable communication lines. There are several options for implementing FTTx, the main ones include:
FTTH - Fiber To The Home (bringing fiber to the apartment);
FTTB - Fiber To The Building (bringing fiber to the building).
Options that essentially duplicate FTTH and FTTB with minor changes:
FTTN (Fiber to the Node) - fiber to the network node;
FTTO - Fiber To The Office (bringing fiber to the office);
FTTC - Fiber To The Curb (bringing fiber to the cable cabinet);
FTTCab - Fiber To The Cabinet (similar to FTTC);
FTTR - Fiber To The Remote (bringing the fiber to a remote module, hub);
FTTOpt - Fiber To The Optimum (bringing the fiber to the optimal point);
FTTP - Fiber To The Premises (bringing fiber to the customer's point of presence).
Separately, it is necessary to note the concept
FITB (Fiber In The Building) - organization of a distribution network inside a building.
The above technologies differ mainly in how close the optical cable is to the user terminal (Fig. 14.29).
Figure 14.29 - Technologies optical access FTTx
On this moment Interest in the deployment of optical access networks with cable laying to the building (FTTB), as well as directly to the subscriber (FTTH), is rapidly growing. To a greater extent, this situation is explained constant growth requirements for communication channel bandwidth, since there is now a boom in the development of “heavy” Internet applications, including online videos, online games and other services.
At the same time, the planned set of services and the bandwidth required to provide it have a direct impact on the choice of FTTx technology. Therefore, the higher the access speed and the larger the range of services provided to the subscriber, the closer the optical fiber should approach the subscriber terminal, i.e. you need to use FTTH technologies. In cases where the priority is to preserve the existing network infrastructure and equipment, FTTB is the optimal choice.
If we talk about today's realities, FTTB architecture prevails in new buildings and among large telecom operators, while FTTH is in demand in new low-rise construction (for example, in cottage communities in the vicinity of large cities).
Let's consider the features of the implementation and application of the most common technologies.
FTTN technology It is used mainly as a low-cost and quickly implemented solution where there is a distribution “copper” infrastructure and the installation of optics is unprofitable. Everyone knows the difficulties associated with this solution: the low quality of the services provided, due to the specific problems of copper cables lying in the sewer, a significant limitation on the speed and number of connections in one cable.
FTTC technology is an improved version of FTTN, devoid of some of its disadvantages. The FTTC architecture is primarily intended for operators already using xDSL or PON technologies and cable television operators. The implementation of the FTTC architecture will allow them to increase the number of users served, as well as the bandwidth allocated to each of them, at a lower cost. In Russia, this type of connection is often used by small Ethernet network operators. This is due to the lower cost of copper solutions and the fact that installation of optical cable requires highly qualified performers.
FTTB technologyassumes bringing fiber to the building, and has become most widespread, since when building FTTx networks based on Ethernet, this is often the only technically possible network construction scheme. In addition, in the cost structure of creating an Ethernet network, the difference between the FTTC and FTTB options is relatively small. Also, we should not forget that the operating costs of operating a FTTB network are lower and the throughput is higher.
It is advisable to use FTTB technology in case of network deployment in apartment buildings and business centers. Russian telecom operators are deploying FTTB networks so far only in major cities, but in the future it is planned to use this technology everywhere. With FTTB there is no need to lay expensive optical cable with a large number of fibers, as with FTTH.
With FTTB, optical fiber is brought into the home, usually in the basement or attic, and connected to an ONU (Optical Network Unit). On the telecom operator's side, an OLT (Optical Line Terminal) optical line terminal is installed. The OLT is the primary device and determines the parameters of traffic exchange (for example, time intervals for signal reception/transmission) with ONU subscriber devices (or ONT, in the case of FTTH). Further distribution of the network throughout the house occurs via “twisted pair” (Fig. 14.30).
FTTH technology is the most expensive, but at the same time the most promising, among all types of FTTx access. FTTH involves bringing optical fiber to the user’s apartment or private home. In this case, the optical fiber is brought into the house, usually in the basement or attic (which is more economically feasible) and connected to an ONU (Optical Network Unit) device. On the telecom operator's side, an OLT (Optical Line Terminal) optical line terminal is installed. The OLT is the primary device and determines the parameters of traffic exchange (for example, time intervals for signal reception/transmission) with ONU subscriber devices (or ONT, in the case of FTTH). Further distribution of the network throughout the house occurs via “twisted pair” (Fig. 14.31).
At first glance, building an FTTH network is a very labor-intensive and expensive process, but experience suggests that the main costs when deploying an FTTH network are construction work, and the cost of the fiber optic cable itself is relatively a small part. This means that if construction work is required, the amount of fiber optic cable installed is no longer of great importance.
Moreover, although life cycle FTTH networks and its electronic components is several years old, fiber optic cable and optical distribution network have more than long term service (at least 30 years).
Deployed FTTH network architectures can be divided into three main categories:
- “Ring” of Ethernet switches.
- “Star” of Ethernet switches.
- “Tree” using PON passive optical network technologies.
Now providers (Internet access service providers) offer several options for wired Internet access. The main technologies for accessing the World Wide Web are ADSL/ADSL2+ and FTTB. How not to get confused in the proposed technologies and choose what you need? This article aims to answer this question. Below we will describe each of the mentioned technologies, taking into account the advantages and disadvantages.
ADSL/ADSL2+ technology
This technology involves transmitting data over regular telephone wires. Because Data transmission occurs in a frequency range different from the frequencies for voice data; transmission of digital data together with voice is possible: i.e. You can talk on the phone and surf the Internet at the same time. To convert information into a form accessible for transmission over telephone wires, a device is used on the subscriber's side - DSL modem, and on the provider’s side, a device called DSLAM is used to reverse convert the information transmitted within the framework of this technology into digital form.
Due to historical circumstances, this technology is “tailored” to transmit data to the subscriber; the transmission speed of the outgoing stream is much lower than the downward one. And this is one of its main disadvantages. For ADSL technology, large providers, such as Rostelecom, MGTS and COMSTAR-Regions (MTS group of companies), offer speeds to the subscriber of up to 8 Mbit/s, and from the subscriber up to 800 kbit/s. In ADSL2+ technology, thanks to improvements, speeds have been increased, but the speed of the outgoing stream also remains low - up to 1 Mbit/s from the subscriber. The speed to the subscriber is up to 24 Mbit/sec.
The quality of communication for this technology largely depends on the quality and length of the telephone line: for example, for the technology, the possibility of providing the service is not guaranteed with a telephone line length of more than 5 kilometers, and with a length of 4 to 5 kilometers the maximum speed at which communication can be established An ADSL modem with provider station equipment (DSLAM) cannot exceed 2 megabits per second to the subscriber.
Despite the many disadvantages, this technology also has its advantages. These include the absence of the need to run a separate cable into the house if there is a landline telephone, provided that the telephone line is of sufficient quality and there are no errors in the connection circuit of the modem to the telephone socket - extremely high stability and reliability of the connection, many times greater than that which is achievable when connecting via more advanced FTTB technology.
Reliability is associated with the high fault tolerance of DSLAM, as well as the mandatory presence of guaranteed high-capacity power supply at the PBX (on which the provider’s DSLAM is located), which makes the operation of the Internet independent of the presence or absence of light at the point where the provider’s equipment is located. Also, an undoubted advantage of the ADSL family of technologies is the ability to connect to the Internet in private homes.
FTTB technology
FTTB technology stands for “Fiber-To-The-Building”(“Optics to the home”), and means that the provider supplies a fiber optic cable to an apartment building, which then goes into a switch (managed switch) - a device that “divides” the Internet among individual users. As a rule, the switch is installed in the entrance or in the attic, and a regular twisted pair cable (Ethernet cable used in office local networks) goes from it to subscribers.
Depending on the implementation of the technology, the Internet access speed can be up to 10 or 100 Mbit per second. In this case, the throughput speed of the fiber optic channel to the switch can be from 1 to 10 Gbit per second. This technology is now used by a huge number of providers, both small and very large, such as Beeline, Rostelecom, TTK, COMSTAR-Regions (MTS group of companies).
The qualitative difference between this technology and ADSL technologies is a symmetrical channel, i.e. the upload and reception speeds are equal, which is a big plus for those users who download torrents, upload large files to servers, or have their own website. Also, the advantages of FTTB include the absence of the need for additional equipment- to work, just insert the provider cable into the network card of your computer or laptop (you may also need to create a connection).
The main disadvantage of FTTB is the relative low reliability and the dependence of Internet access speed on the number of users connected to this switch: when large quantities subscribers may not have enough bandwidth of the fiber optic channel supplied to the home switch and it will be necessary to expand its capacity, which is not always done on time. The low reliability of FTTB is associated with the low fault tolerance of switches (usually due to the cheapness of the devices used), as well as the fact that they are usually not equipped with uninterruptible power supplies and at the slightest power outage at the point, users are left without the Internet. Another disadvantage is that FTTB technology is not available to users living in private homes.
If you doubt your ability to set up the Internet, ask for help! HELP - always helps!
Connection to the AzovInternetService and Internet networks is available to private and corporate subscribers using several modern high-speed technologies.
FTTH technology
“Fiber To The Home” - optical fiber to the home (apartment, cottage, office)
Using this technology, a fiber optic cable (FOCL) is laid from the signal source to the end user.
The advantages of FTTH architecture are:
- highest channel bandwidth;
- a fully standardized and most promising network option;
- FTTH solutions provide mass service to subscribers at a distance of up to 20 km from the communication center.
Connection using FTTH technology is made by connecting an optical cable at the end subscriber with the installation of a “media converter” - a device that converts the optical signal into an electrical signal for further distribution throughout the house using copper cable (UTP) or using Wi-Fi. Internet access can be provided at speeds of up to 1000 Mbit/s.
FTTB technology
The AzovInternetService company uses FTTB (Fiber To The Building) technology: an optical cable is supplied to the house and distributed to apartments using a copper Ethernet cable. This makes it possible to provide each apartment with high-quality Internet access at a maximum speed of up to 100 Mbit/s. Depending on the connection technology, the IP address can be external or internal. Today, FTTB technology is the most advanced. Its potential allows you to quickly increase network capacity in those places where it is needed to provide the highest quality data services. Additionally, FTTB ensures the same speed for data going in and out of a computer, unlike other technologies.
With the FTTB option, optical fiber is brought into the home, usually in the basement or attic (which is more cost-effective) and connected to an ONU (Optical Network Unit). On the telecom operator's side, an OLT (Optical Line Terminal) optical line terminal is installed. The OLT is the primary device and determines the parameters of traffic exchange (for example, time intervals for signal reception/transmission) with ONU subscriber devices (or ONT, in the case of FTTH). Further distribution of the network throughout the house occurs via twisted pair cable.
This approach is advisable to use in the case of network deployment in apartment buildings and middle-class business centers. Russian telecom operators are currently deploying FTTB networks only in large cities, but in the future this technology will be used everywhere. With FTTB there is no need to lay expensive optical cable with a large number of fibers, as with FTTH.
GPON technology
PON (passive optical networks) is a family of rapidly developing, most promising technologies for broadband multiservice access over optical fiber. The essence of PON technology follows from its name and lies in the fact that its distribution network is built without using active ingredients: branching of the optical signal in a single-fiber optical communication line is carried out using passive optical power splitters - splitters.
Structurally, any passive optical network consists of three main elements - the OLT station terminal, passive optical splitters and the ONT subscriber terminal. The OLT terminal ensures interaction of the PON network with external networks, splitters provide branching of the optical signal in the PON section, and the ONT has the necessary interfaces for interaction on the subscriber side.
Based on the PON architecture, solutions using a point-to-multipoint logical topology are possible. An entire fiber-optic segment of a tree-like architecture, covering dozens of subscribers, can be connected to one port of the central node. In this case, passive optical splitters (splitters) are installed in intermediate nodes of the tree and do not require power or maintenance.
The main idea of the PON architecture is the use of just one transceiver module in the OLT to transmit information to multiple ONT subscriber devices and receive information from them.
GEPON technology (Gigabit Ethernet Passive Optical Network) is one of the varieties of PON passive optical network technology and one of the most modern options for constructing communication networks, providing high speed information transfer (up to 1.2 Gbit/s). The main advantage of GEPON technology is that it allows optimal use of the fiber-optic resource of the cable. For example, to connect 64 subscribers within a radius of 20 km, it is enough to use only one fiber-optic segment.
The main advantages of GEPON are:
- Using standard 802.3ah mechanisms, which will significantly reduce the cost of equipment in the future;
- Increasing the transmission speed to 1 Gbit/s in both directions and providing more broadband services;
- Providing QoS using 802.1p/TOS mechanisms. It is possible to use strict traffic prioritization mechanisms using eight dedicated queues for each type of traffic. These mechanisms make it possible to provide services such as VoIP or VoD with a guarantee of quality;
- Possibility of connecting 64 subscriber devices per PON branch and efficient use of optical fiber;
- Full support for DBA (Dynamic Bandwidth Allocation) - a mechanism for dynamic redistribution of bandwidth in accordance with subscriber requests and the availability of free bandwidth in the PON tree. Thus, subscribers who are provided with a guaranteed bandwidth for data transmission, for example, 1Mb/s, can receive real speeds of up to 1Gb/s if the PON tree strip remains partially unused (similar to UBR traffic in ATM);
- Support for streaming video (IGMP Snooping);
- Easy to install and maintain.
FTTx technology from Rostelecom is one of the fastest and most reliable means for accessing the Internet. This connection is optimal for work large companies, who need a stable network connection to support digital telephony, send and receive large volumes of data, such as video recordings, and many other enterprise tasks. Rostelecom's FTTx technology is also not abandoned by individuals who want to get maximum opportunities and pleasure when using home boarding and interactive television, which has been gaining increasing popularity lately.
Rostelecom FTTx technology – what is it?
FTTx is one of the most promising Internet technologies that is being very actively developed by Rostelecom in large cities and beyond. The abbreviation stands for Fiber To The x, where x is any point, that is, your apartment, country house or office. In the Russian-speaking market, the technology often has a simplified name “”.
FTTx presents common name technology lines:
- FTTH (Fiber To The Home) – optical fiber is supplied directly to your home/apartment;
- FTTB (Fiber To The Building) - optical fiber reaches the building, and is then distributed to apartments using other technologies (Ethernet);
- FTTN (Fiber to the Node) – the fiber optic signal is distributed at the network node.
- FTTD (Fiber to the desktop) - the signal goes directly to the network user’s room (it is also called FTTS, where the last letter stands for Subscriber or subscriber in Russian).
What equipment is needed for FTTx Rostelecom
The Rostelecom provider in most cases installs FTTx equipment at nodes or in buildings, and then distributes the signal using switches via Ethernet technology. This option allows you to significantly reduce costs for the subscriber, but at the same time get a high connection speed. The FFTx line is capable of delivering multi-gigabit bandwidth and can thus provide every home user with a stable 100 Mbps connection. On the positive side This option, in addition to high speed and low cost, will also eliminate the need to install special equipment in your apartment.
The subscriber can easily start using the Internet by connecting the cord to the computer’s network card, or using a router to distribute the connection to several devices. In this case, the choice of router should be made based on its speed characteristics and the planned number of network devices. If you have computers and consoles (TV or game consoles) in your apartment that can be connected via an Ethernet cable, as well as devices that use Wi-Fi technology, you will need to purchase a router with wired routing capability and a built-in wireless access point. Such a device will allow you to organize a convenient home network based on FTTx technology from Rostelecom without complex configuration of a router and other equipment.
In cases where optical fiber is supplied directly to your apartment (FTTH), you will need to purchase a special modem that will allow you to decode the signal and transmit it to the Ehernet output. Further, the setup scheme will remain the same. When connecting fiber optics directly to the apartment, you can pay attention to modems, which immediately act as routers. This will free up space by getting rid of unnecessary network devices.
Setting up an Internet connection using FTTx technology
Depending on the type of FTTx, the connection setup from Rostelecom will be slightly different. In the case of FTTB, you will only need to order the service from the provider and rent or buy a router suitable for you.
When using, you will also need to have a fiber optic modem for setup. Usually, when laying the cable, the provider’s employees will install and configure the equipment themselves. It will be difficult to connect to a fiber-optic network without the help of a specialist, if only because crimping the laid cables can only be done with special equipment.
Thus, setting up FTTx connections from Rostelecom will differ significantly depending on the subtype and, of course, the equipment used.
Attention! Fiber optic modems are very expensive, so when connecting to FTTx Internet, the provider often offers equipment for rent or credit.
FTTx technology from Rostelecom is very new and promising. Its use is already actively underway in large cities and beyond. The process for connecting to fiber optic internet may vary depending on the subtype of technology.
Now we have reached a stage of providing users with access to the Internet, when many companies have begun to use advanced technologies, for example, FTTx. It is no longer as expensive and difficult as it was 5-6 years ago. The market is already saturated with offers of such services. Therefore, it is worth considering the concept of FTTx in more detail. What this is will become clear if you delve into the technology itself.
Peculiarities
For use by any new technology requires the involvement of certain resources, and in this case FTTx is no exception. What it is and how it works will be described below.
FTTx is a general term that denotes a general approach to how a network cabling infrastructure is formed, in which copper cable is stretched from to a certain point, designated as “x,” and then laid directly to the subscriber equipment. You can route the optics directly to a device or device operating on the Internet. Usually only considered physical layer when connecting FTTx. What is this? It's just the line itself. However, the concept itself implies the use of a number of channel and network level technologies. Thanks to broadband access, companies are able to provide customers with a whole range of services.
The main driver of development at the moment is the massive consumer demand for broadband access, which is incredibly difficult to provide using traditional ADSL. Optics has become more and more actively introduced in large cities, and now one can observe a trend towards the merger of operators of different levels. This technology is also actively used in villages where access to the Internet was initially built on the basis of an optical path.
Market development prospects
To better understand the essence of such technology, one should consider the prospects for the development of FTTx. What is this? On Russian territory, the formation of a market for such services depends not only on the demand for high-quality content, but also on the number of construction projects large sizes, as well as increased competition among broadband service providers. The dynamic development of the construction of apartment buildings has led to the fact that FTTx connections are carried out much more often than all other types. This is justified in an economic sense, and the presence of competition makes access to the network much cheaper. Not so long ago, operators looked exclusively towards corporate subscribers, but now they are increasingly showing interest in ordinary subscribers.
Construction Features
Until recently, FTTx technology was used by operators that did not have their own legacy infrastructure. But in last years All more companies are looking towards new networks. Among the reasons for this phenomenon are the opportunities to expand the range of services provided, the expansion of passive networks based on fiber optics (PON), as well as the spread of Metro Ethernet, reducing the cost of equipment, and the success of many operators in building networks of this type.
New type of content
Internet FTTx is becoming increasingly popular as today's users are attracted to new types of content with the highest quality graphics and high-definition video. The main catalyst for the growth in demand for such systems was the growing interest in video services. After the center of gravity shifted from group broadcasting to individual broadcasting, the needs of subscribers for dedicated bandwidth increased, which very soon will amount to up to 100 megabytes per second per household.
Nowadays, high-definition LCD TVs are actively selling, which creates a need to provide customers with access to television programs best quality than what analog television can offer. Many experts consider IP-TV to be the most logical stage of development. This will allow users to select films, programs and shows of interest, as well as the time when it is most convenient to watch them. That is why we can say that the mass connection of FTTx xPON is just around the corner. At the moment, any Internet provider is betting on investing in optical fiber, since this is an investment for decades to come, and the profit will exceed the costs many times over. This is the only way to explain such an active purchase of fiber optic lines, as well as many pilot projects, including such an innovation as laying optics directly to the subscriber’s equipment.
Existing risks
Connecting FTTx xPON in the coming years will not be the only option that guarantees the provision of broadband access services, but the potential of the fiber optic structure is so high that you can be absolutely sure of the return on your financial investment. Currently, the most active work is being done in the field of modernization of backbone networks, and the FTTx technology market, equipment and other components are being studied and gradually tested.
What architectures are there?
Rostelecom FTTx technology can operate using one of several types of architectures:
FTTN (Fiber to the Node) - optical fiber is laid to the network node;
FTTC (Fiber to the Curb) - optical fiber is extended to a microdistrict, block or several houses;
FTTB (Fiber to the Building) - optical fiber enters buildings;
FTTH (Fiber to the Home) - optical fiber is laid to the home.
Their difference lies only in the proximity of the optical cable to the user terminal. The first two solutions appeared the earliest. The first of them is still used now, but only as a budget option and quickly implemented where there is already a copper distribution infrastructure, and laying an optical cable is simply unprofitable. Everyone knows the difficulties that accompany such a solution: the low cost coupled with the special properties of copper cables, the limitation on the number of connections and speed in one cable. The second type is an improved and modified version of the first, which does not have these disadvantages. Laying copper cables in in this case is carried out exclusively inside buildings, so they are not subject to all sorts of destructive factors, and the length of the lines is not so great. All these factors make it possible to achieve improved speed in areas that do not use fiber. A similar offer is valid if an FTTx xPON connection is used. This is aimed at ADSL operators, as well as cable television operators. The implementation of such an architecture gives them the opportunity for significant savings when increasing the number of connected users. Each of them will be allocated more bandwidth. Most often in Russia this type is used by small network operators.
Factors
Issues related to the placement of equipment operating using this technology depend on a whole range of reasons:
Is there any alternative infrastructure, or has nothing been used before?
Is it possible to place active equipment in the house, or are there certain restrictions for this;
How many subscribers are expected to connect to the new network;
A set of less important factors.
FTTx terminal devices can be classified according to very specific criteria tied specifically to point “x”. The range of services offered by companies depends on the number and type of interfaces that the equipment uses, as well as the mechanism that manages traffic. If you need to preserve the existing infrastructure, then the best option would be to use FTTC/FTTB systems with an optical uplink interface. They are appropriate for use in large enterprises, business centers and residential complexes where there is previously used copper infrastructure. To do this, you will need to place an FTTx router at each device.
Conclusion
In economic terms, the organization of networks based on fiber-optic technology is most justified when there is a significant concentration of solvent subscribers or the construction of new residential complexes, when organizational issues regarding cable laying are at the stage of being resolved. The network must be designed so that the endpoint is as close to the subscriber as possible. It is best to accompany the construction of new areas by bringing it directly to the building, which will be convenient both at the beginning and in the future.
