FTTx variations for optical fiber access

In various technical means to achieve broadband access, the optical fiber access network is the most suitable for future development solutions, especially the ATM Passive Optical Network (ATM-PON) it is almost an economical and effective way to integrate broadband access. Outside China, china Southern Bell, France Telecom, British Telecom, CNET, Japan NTT, Germany Telecom, KPN, SwissCom, SBC, Telecom Italia CSELT and other international institutions have achieved remarkable results in the whole business access network research., system Level APON labs or commercial products based on ITU-TG.983 recommendations have been made.

Optical fiber access refers to the use of optical fiber as the transmission media between the local terminal and the user. Optical fiber access can be divided into active and passive optical access. The main technology of the optical fiber user network is the optical fiber transmission technology. At present, the multiplexing technology of optical fiber transmission has developed rapidly, and most of them are in practical use. The most widely used Multiplexing technologies include TDM, WDM, OFDM, and CDM. Based on the depth of the optical fiber into the user, it can be divided into FTTC, FTTZ, FTTO, FTTF, FTTH and so on.

Optical fiber access network structure

The three system structures of the access loop are FTTN, FTTC, and FTTH. Each structure has its own application and advantages during network development, every structure is a key link in the process of economic evolution to the whole business.

The benefit of FTTN is that it pushes fiber cables to user networks. It establishes a single access platform that provides voice, high-speed data, and video services to numerous families without the need to completely reconstruct access loops and allocate networks. You can add a plug-in at the optical fiber node as needed to provide the required services. Before the optical fiber nodes are moved to the roadside (FTTC or home (FTTH) due to service-driven or network reconstruction, FTTN will overlay and use existing copper wires to distribute the network.

The basic requirement of this network structure is to provide broadband or video services, and the distance between nodes and residential buildings should be within the range of 4000 to 5000 feet. Currently, the service distance of nodes is generally 12000 feet. Therefore, three to five FTTN nodes must be installed in each service area.

FTTC or FATH optical fiber (optical fiber is almost home) has several advantages over FTTN. When FTTC is used to reconstruct an existing network, the possible error caused by cable transmission can be eliminated. It makes the optical fiber more deeply into the user's network, which can reduce potential network problems and performance deterioration caused by field operations. Currently, FTTC is the most robust and "deployable" network. It is a network that can be evolved into FTTH in the future. It is also the most economical network construction solution for new and reconstruction areas.

A disadvantage of this network structure is that copper wire power supply systems need to be provided. A remote power supply system at the local end can provide power to 50 to 100 roadside optical network units. Each roadside node uses a separate power supply unit at a very high cost and cannot meet long-term business requirements in the case of persistent power outages.

As the final network form that provides fiber to the home, FTTH removes the entire copper wire facility: feeder, wiring, and wire introduction. For all broadband applications, this structure is the most robust and long-term future solution. It also removes all maintenance work required by copper wires and greatly prolongs the network life.

Residential Device

The connection end of the network is the user's residential device. In the user's home, a network terminal device is required to convert the bandwidth and data stream into a received video signal (NTSC or paled) or data connection (10G Ethernet ). There are two types of devices that can use non-forest digital user lines (ADSL and G. lite modem (for data services and INTERNET access) or VDSL Residential Gateway that handles broadband (for video and data services ).

Like the local HDT, the home gateway (RG) device is the same as that for all businesses in the home. It provides network connections and allocates all services to various residential network elements. The RG device is the network interface of all network structures (including fttn fttc and FTTH), so it can adapt to the smooth transition of various configurations.

Economical Optical Fiber strategy

No matter whether the network structure is FTTN, FTTC or FTTH, regardless of the actual application, optical fiber is the key to a successful network. To compete for new customers and maintain existing customers in a highly competitive market, it is necessary to deploy the entire business network to provide new businesses and win new profits.

Telephone companies make a lot of profits by using fiber-optic strategies to quickly provide machine frequency and data services. A cost-effective and efficient transition plan can be developed to win broadband users, create profits, and optimize customer groups.

Ethernet for optical fiber access

In the recent period, service providers have been selling high-density optical fiber backbone networks, and enterprise users are waiting for the submission of such high-speed services. Although the high-density optical fiber network that ensures the provision of massive available bandwidth has been built, the demand for network services is closed in the frame of the local loop Access Technology Based on time division multiplexing (TDM. Business users with changing bandwidth needs are dissatisfied with the need to wait several weeks to add a T-1 line or to wait several months to upgrade to a T-3 line.

A promising solution will enable the currently deployed optical fiber bandwidth to use software to replace hard-wired network access through rigid TDM infrastructure to configure multiple services, in addition, each service can have different service levels and the speed assurance of remote adjustment of software commands. This type of software tunable service is designed to meet the extra bandwidth needs of multiple services. It takes only a few days, not weeks, and configuration can be completed without high engineering costs or on-site upgrades, you can provide the required bandwidth exactly as needed.

Ethernet can achieve this goal. Ethernet is ideal for submitting software-adjustable bandwidth from an optical fiber network. It is universally available at a low price and can easily reach 1 Gbps and soon reach 10 Gbps. If the optical fiber cables connected to the home door currently support Ethernet technology, a connection line can reach any speed from 64 K to several gigabits per second and can be used to access all WAN services.

Such flexible services represent the current DSL and the next high-speed technology after the cable-based broadband service, which will allow enterprise users to ultimately use the optical fiber deployment in the core of the transmission infrastructure.

An Intelligent Optical Fiber access platform is required to submit Ethernet-based services. This platform enables service providers to migrate data packets from traditional TDM-based services to optimized data packet services, in addition, users can transmit multi-service and wide-area transmission streams such as IP voice over multi-service fiber connections that provide bandwidth assurance.