Full explanation of the Broadband Access Network Solution

The broadband access network solution is a problem that designers always need to think carefully. So I studied how to design an optimized broadband access network solution more rationally. I will share it with you here, I hope it will be useful to you. With the development of communication technology, telecom services have evolved from voice-oriented narrowband services to voice, DATA, VIDEO, and other multimedia broadband services. To achieve multimedia communication, public telecommunications networks must have broadband interactive access capabilities. At present, the main broadband access network solutions for achieving broadband interactive access include Copper Twisted Pair xDSL, copper cable HFCs, wired and optical fiber broadband access, and wireless broadband access. In particular, the passive optical network PON technology based on fiber broadband access is widely used with its economic and effective features.

FTTC, FTTB, FTTZ, and other technologies are connected to users through optical fiber networks and then Copper Twisted Pair wires to achieve access to user-side narrowband services, combined with Cable Modem and other technologies, it can economically access user-side broadband services. This is one of the commercial broadband service access technologies for users, namely, FTTC + HFCs ). The goal of Broadband Service Access Technology for users is to achieve FTTH at home through optical fiber, combined with the networking technology of PON in Passive Optical Networks and transmission technologies such as ATM and sub-carrier multiplexing SCM) and Dense Wavelength Division Multiplexing DWDM, develop an economic and efficient broadband service access system.

Features and development status of the Broadband Access Network Solution

Broadband optical fiber access technology mainly include FTTC + hfc-pon, ATM-PON, SCM-PON, DWDM-PON, super PONS-PON) and so on.

Technical Solution of FTTC + HFCs

The optical fiber is used as the trunk line of the CATV network, and a backhaul channel is added based on the original one-way downlink analog TV signal transmission to enable the integration of PSTN, DATA, and CATV, this is the so-called hybrid fiber-optic coaxial cable network (HFCs) technology. Due to the tree structure of the network, it has problems such as transmission reliability, noise, and backhaul channel congestion. With the digitization of telecom services and CATV, The FTTC technology combined with interactive digital transmission is the development direction of HFCs. Using the Cable modem technology to achieve broadband business access, the service is also one of the current broadband access solutions.

FTTC + HFCs is also known as the optical fiber splitter transmission technology. It uses FTTC to send interactive narrowband digital services to users and can be upgraded to broadband digital services in the future, the two use different optical fiber cables for transmission. CATV front-end HE) is generally configured in the central bureau, and the optical and node fn of the HFCs are configured together with the FTTC optical network unit ONU) or the remote module, and The ONU is powered by a coaxial cable. Use coaxial cables to connect analog broadband signals to your TV devices, and use twisted pair cables to connect interactive digital signals to your terminal devices. As the standards of digital broadband technology are not yet mature, FTTC is mainly used to transmit interactive narrowband digital services. The FTTC network can be upgraded to a broadband access network based on ATM.

The ATM-PON provides users with more flexible broadband access, the downlink rate can be 622 Mbit/s or 155 Mbit/s, the uplink rate is 155 Mbit/s. One Passive Optical Splitter OLT) can connect 16 to 32 ONU, and one ONU can connect dozens of user unit equipment CPE ), by configuring the ATM cross-connection module in the OLT, the ATM service module is configured in each ONU to provide interactive broadband services for users. The downstream direction uses the multiplexing technology based on ATM cells, while the upstream direction uses the TDMA control protocol to control user inbound traffic. The upstream and downstream ATM cells are enclosed in the ATM-PON group cell structure, that is, a byte header is appended to the header of each group cell to provide network synchronization and transmission-related functions, for example, The onu id of the upstream TDMA protocol. The network running and maintenance function OAM is transmitted through the physical layer cell PLOAM.

ATM-PON + xDSL technology

ATM-PON + xDSL is an economical use of the ATM-PON broadband access network solution, he will be the user test ONU configured in the user building cable allocation box near, in order to reduce the cost of ATM-PON broadband access network solution. ONU to the user through copper or copper twisted pair wire, using xDSL interconnection, each ONU needs to be responsible for the xDSL information structure and the conversion between the ATM-PON group cell structure, including reuse/demultiplexing between low-speed and high-speed information flows, the rest is the same as the above ATM-PON scheme. The XDSL Transmission Mode features that the transmission rate can be dynamically allocated based on user needs. You can use VDSL for ultra-high data transmission. The downstream speed of VDSL is 12 ~ 51 Mbit/s, the uplink speed is 1.6 ~ 26 Mbit/s, supporting a transmission distance of MB ~ 1.5 km. Multiple users who require broadband access share an ONU, which can reduce the access cost. At this stage, it is the initial stage of broadband access. Using the ADSL method can meet users' current needs for broadband access. The downstream rate of ADSL is 2 ~ 8 Mbit/s. The uplink speed is 640 Kbit/s, and the supported transmission distance is 3.7 km.

1. Discussion on the development direction of Access Network Technology
2. A detailed overview of the development of broadband access networks
3. Detailed design template for Broadband Wireless Access Networks
4. Summary on the technology of Optical Fiber Access Network
5. Common Access Network technical Practical Manual