December 05, 2023
ForewordHi everyone, I'm Mr. Lin, what's triple game? How to build a triple game. How much do you understand? Text1. What is Triple Play?
Three networks in one (i.e. three-network integration) - mutual penetration, mutual compatibility and gradual integration of telecommunications networks, radio and television networks, Internet into a single information and communication network, of which Internet is core. To implement functions of television, Internet and telephone, it is necessary to introduce only one of three networks, and network resources will be fully used.
The so-called Triple Play technology is designed to provide an ideal low-cost FTTH or FTTB (data, voice and cable) access solution. The Triple Play Optical Switch is designed for emerging Ethernet-based FTTx Triple Play. The 3-in-1 fiber optic switch provides various network management methods using a standard RS-232 interface, a web browser, a command line interface (CLI), and a network management platform based on Simple Network Management Protocol (SNMP). System administrators can easily configure features, monitor performance, and troubleshoot switches.
A typical EPON system consists of OLT, ONU and ODN. The OLT is located in central computer room, and ONU is user terminal equipment. ODN is an optical distribution network that mainly connects OLT and ONU with one or more optical splitters. Its function is to distribute downstream data and concentrate upstream data. OLT is not only a switch or router, but also a multi-service platform that provides fiber optic interfaces for passive fiber optic networks.
In addition to providing network concentration and access functions, OLT can also perform bandwidth allocation, network security, and management configuration according to different QoS/SLA requirements of users. An optical splitter is a simple device that does not require a power source and can be placed in all weather conditions. Typically, an optical splitter has a separation rate of 2, 4, 8, 16, and 32, and can be connected in several stages. In EPON, distance between OLT and ONU can be up to 20km. If fiber optic amplifiers (active repeaters) are used, distance can be increased, but now there is no need to add amplifiers because rural areas are now mostly completely covered. .
The biggest benefit of Triple Play is resource integration.
Second, general terms and definitions of triple game
Before we can understand triple game, we need to understand definitions of some commonly used terms that are also often used when building a triple game.
1. Passive optical network. A multipoint network consisting of passive optical devices such as optical fiber, optical splitters and optical connectors, called PON.
2. Passive optical network system: a signaling system consisting of optical line terminal OLT, passive optical network PON (or optical distribution network ODN) and optical network unit ONU, < /strong> PON system for short. According to adopted signal transmission format, it can be called xPON, such as APON, BPON, EPON and GPON.
3. Optical Distribution Network: Another name for a passive optical network, a multipoint optical distribution network, consisting of optical feeder cables, optical splitters and optical branch cables, called ODN.
4. Feeder: in optical distribution network, fiber optic channel from OLT side of optical line terminal, located closer to outside of S / R interface, to input connector of main optical port of first optical splitter.
5. Drop line: fiber optic link from drop port of first layer optical splitter to R/S interface on line side of ONU in optical distribution. net. When a multi-level optical splitter is used, other optical splitters other than first layer optical splitter are also included.
6. Cold Fusion Splicer: An optical fiber splicer that quickly realizes butt splicing of bare optical fibers by mechanical means.
7. Optical splitter: a passive device that can split one optical signal into multiple optical signals and perform opposite process called OBD.
8. Optical Splitter Box (Frame): A box or frame specially designed for mounting optical splitters. It contains accessories such as fiber splice trays and active fiber connectors. Certain dust-proof function. The box type can be divided into floor type or wall type, and frame type can be installed on a standard 19" rack.
9. Junction Box A86/Panel A86: general purpose wall outlet 86mm long and wide, consisting of a junction box and a panel.
10. Integrated information block: installed at final floorThe user, it is an active information distribution unit with extensive connectivity features for phone, data, cable TV and other networks.
11. User Optical Cable Terminal Box: Provide an optical fiber protection box so that optical cable can reach user for termination, usually equipped with optical connectors.
12. Home optical cable: optical cable inserted into user's building.
13. Leather Optical Cable: This is a non-metallic optical cable with a small bend radius optical fiber and a low smoke, halogen-free, flame retardant outer jacket. for internal dark pipes, trunking, laying methods such as nails.
3. FTTH network construction mainly provides services
1. General planning
Referring to broadband access network development requirements of Chinese market, combined with characteristics of current GPON products and deployment specifics of existing network, it is recommended to adopt FTTH construction mode, which has ability to provide end users with ultra-high bandwidth, and also provide end users with IP network + cable TV + landline phone and other multifunctional business models and better business experience.
PON FTTH Triple Play Shared Network Solution
2. FTTH network area division
The FTTH network belongs to category of access networks and should be consistent with idea of access network planning. Through regional division, planning is carried out in units of sub-regions. Typically, access network service area is a planning sub-area. The access network service area is area covered by one access network backbone network service. Typically, end office is center of service area. This may be a service area covered by a single office, or a service area covered by a dual office. After planning of FTTH network and ODN network elements in each access network service area is completed, a comprehensive review should be carried out throughout entire local network, and planning and economic evaluation of network resources and other content should be carried out.
3. Main services provided by FTTH network
The FTTH system can be used as an end-to-end access method to provide high bandwidth and guaranteed quality of service, and can also provide a variety of services, including Ethernet/IP services, voice services, video surveillance, etc. play. It can provide access to voice, data, video, monitoring and communication:
Data service: FTTH can provide more than 30M bandwidth, which can meet needs of Ethernet/IP based data services for a long period of time, such as Internet access, P2P, download files. , Various services and applications such as online games.
Voice service: An FTTH system can provide voice services, including soft-switched voice telephone (and various value-added services) using VOIP and traditional telephone with 64 kbps channel emulation. From point of view of technological development trend, soft-switching mode will become an implementation mode that should support FTTH.
Cable TV Service. Including digital cable TV and high-definition cable TV, effective GPON bandwidth occupancy can greatly increase video uplink bandwidth occupancy, as well as provide a higher video level. downlink bandwidth.
For public customers:mainly provide voice, data and video services;
For large clients. Business customers mainly provide voice, data and monitoring services.
Fourth, FTTH network planning
1. OLT Equipment
On one hand, OLT equipment combines signals carrying different services and sends themto access part in accordance with a certain signal format for transmission to end user. On other hand, signal is from end user. Service types are sent to each service network respectively.
The OLT must be able to flexibly combine similar services among its users; for all Ethernet/IP services, it must support differentiation over different upstream ports and use different VLANs over same upstream port, etc. to distinguish between .
OLT configuration method: The OLT is configured centrally at end office to facilitate centralized equipment management and save transmission resources required for uplink. With introduction of light inputs and copper outputs, piping resources can accommodate a large number of optical cables in future. The material cost of optical cable is a small part of pipeline cost. As cost of optical devices decreases further, difference between construction cost of large-core optical cables and small-core optical cables will become smaller and smaller. evident. Centralized settings at end office can significantly reduce investment in access points. Centralized maintenance management can reduce maintenance costs. This time it is recommended to use centralized mode of target office.
2. ONU/ONT equipment
ONU is responsible for communicating with OLT and can provide users with access through built-in or external user network interface devices.
ONU equipment performance requirements: ONU equipment must comply with relevant technical system. The ONU can be configured with different user interfaces to suit different applications.
ONU configuration and power supply:ONU should be configured according to application mode and business requirements of FTTH network:
You can install ONU in various places, such as building corridors or shaft cabinets, outdoor optical transmission boxes, etc. In principle, ONU adopts local power mode and tries not to use remote power mode. In order to ensure normal development of voice services during a power failure, power failure protection of ONU can be provided if necessary.
3. Planning an ODN
a, ODN Infrastructure Framework
The Passive Optical Distribution Network (ODN) connects OLT and ONU and provides the transmission media; ODN includes all optical cables, passive components and line accessories between OLT and ONT.
The ODN mainly has a tree structure, including a feeder section, a distribution section, and a home section. The optical tap point in middle is an optical distribution point and an optical user access point. The incoming ODN section extends from OLT central office to each distribution point, distribution section extends from distribution point to each access point, and home entry section extends from access point to each user and ends at user's access point. room or directly The drop cable is connected to ONU.
For FTTH applications, ODN distribution optical cable section may have 2-3-layer wiring, sometimes 4-layer wiring; for FTTB/C applications, optical distribution point can also be used as user's optical access point. The household optical cable segment can be set by default.
The means of passive optical distribution used in ODN network mainly include:
1) Central office wiring facilities: optical distribution frame, etc.
2) Optical distribution devices: optical distribution frame, optical distribution box, optical distribution box, optical splitter, optical distribution box, etc.
3) Optical user access point objects: optical splitters, optical junction boxes, optical terminal boxes, optical junction boxes, etc.
4) User terminal connection means: user terminal smart box, information panel with fiber optic cable.
b, ODN Optical Distributors
Optical distribution board, optical distribution box
Optical distribution frame (ODF) is used for wiring equipment between optical communication equipment and optical cables in central office, and distribution of optical feeder cables and distribution optical cables in indoor optical distribution points or distribution optical cables and distribution optical cables line to connect device. Optical junction boxes are generally used for connecting outdoor wiring, large buildings may also have optical junction boxes for indoor wiring.
The outdoor light transmission box should be installed as close as possible to permanent building.
Optical junction box, optical terminal box
Optical junction box and optical terminal box are used to connect indoor wiring equipment other than this function. When user does not temporarily open optical fiber service, optical junction box / terminal box with function of terminating optical fiber can be used to terminate distribution optical cable in box, and then connect home optical cable to user end when user applies for service.
Optical split junction box
Optical junction box is generally used for outdoor wiring connection (fixed direct fusion connection). Generally speaking, each spur junction box can provide protection splice and fiber distribution for 2 to 8 optical cables.
User terminal smart box, fiber optic information panel
The smart user terminal box mainly provides functions of ONU installation and auxiliary user terminal, power supply, home line optical cable termination, optical/cable storage and protection. The fiber optic information panel provides a protective termination for home optical cable, but fiber optic connector is easily damaged by external factors.
The residential ONU should be installed in smart box of user terminal as far as possible, and fiber optic cable should be connected directly to box to strengthen protection of fiber optic connector. For office buildings that implement FTTO technology or buildings that require competition, you can set up a fiber optic information panel to terminate home optical cable, and then connect to ONU via a pigtail when you need to open a service.
An optical splitter (fiber splitter), also known as "non-wavelength selective optical splitter", is a fiber optic device used to realize power splitting and redistribution of optical signals in certain wavelength ranges.
Optical splitters can be used as independent devices in OLT nodes, optical distribution points and user access points, and can also be placed in other central office electrical installations, optical distribution points and user access points (integrated design or removable) to use.
c. Deploying an Optical Splitter
Optical splitters are mainly divided into two categories. One of them is Fusion Double Cone (FBT) optical splitters, which are produced by traditional optical passive device manufacturers using traditional double cone process. The other is a planar light guide (PLC) splitter based on optical integration technology. Below is a comparison of fused cone couplers and planar optical waveguide couplers.
In optical splitters, devices with planar optical waveguides should be used, and in case of low separation factors (1 × 4 and below), devices with a cone connection can be considered.
It is recommended to use a planar waveguide optical splitter in a low temperature working environment, and it is not recommended to use a conical alloy optical splitter.
If there are special optical power distribution requirements due to different ONU transmission distances, an optical splitter with uneven optical separation can be used in ODN, and at present, a fused conical optical splitter should be used.
Deploying an optical splitter and comparing separation methods
The PON network should use one-level optical separation, try not to exceed two-level optical separation. Optical splitters can be appropriately dispersed to be as close to user as possible. The light split point should be closer to user and located in distribution box of building.
4. Optical cable planning
(1) The base-layer optical cable can have a ring and mesh network structure to maximize use of existing optical cable resources. In principle, particles of GE IP services and above are transmitted by IPover WDM. When building a new system, throughput of a pair of optical fibers should not be lower than 10GE.
(2) The fiber optic cable in aggregation layer should have a ring structure, and existing optical cable resources should be used to maximum extent possible according to factors such as length of optical cable, fiber core resources, and business requirements. In principle, optical fiber can be used for transmission. With urban data transmission equipment descending to aggregation layer, it can also be transmitted over IPover WDM. When building a new system, throughput of a pair of optical fibers should not be lower than 10GE.
(3) The optical cable from aggregation node to base station is main optical access cable, and ring structure must be main one. In case of limited geographical conditions and fiber resources, chain structure can also be used. The number of cores of backbone access optical cable should be reasonably set according to scale of user. In principle, throughput of a pair of main optical fibers in a new system should not be lower than 1G.
(4) Optical cables from base station to various customers are end-access optical cables, which can be flexibly formed into ring, chain and star shapes, and plan number of cores of optical cable according to distribution of customers and business needs. .
5. Integrated Service Access Area Planning
One or two integrated services access points and multiple fiber distribution points should be reasonably installed in integrated services access area.
1) Integrated services access point: As a central service aggregation point in integrated services access area, it should be co-located as much as possible with metropolitan transmission network convergence node. , and own ownership or long-term lease of computer room.
The integrated service access point is intersection point of backbone optical cable and optical distribution cable, backbone of optical fiber physical network, and center of full service access area. Trunk and wiring jumper is done through installed ODF.
2) Fiber distribution point. The location of ODF racks (boxes) on user's side, such as in buildings, residential areas, distribution rooms, and wireless base stations, is called a fiber distribution point. fully functionalonal access zone. Intelligently adjust fiber distribution point according to demand. In principle, it should be located at base station for base station's internal fiber cabling. Considering factors such as network security, construction cost and serviceability, internal and external distribution of optical fiber. can also be carried out near base station.
6. Optical cable selection and optical cable connection
1) Optical cable selection
In an FTTH network, all new optical cables must use G.652 single-mode optical cables. The optical cables in ODN network of FTTH system are divided into outdoor optical cables, indoor optical cables, and indoor and indoor optical cables. Dual purpose outdoor optical cables according to working environment: Outdoor optical cables should be used outdoors.
Indoors, in addition to indoor optical cables of various designs specified by YD/T1258, you can choose hanging optical cables ("8-inch optical cables"), frame ribbon optical cables, etc. When optical cable enters room outside, indoor and outdoor dual-use optical cable can be used to directly enter room.
2) Optical cable connection
Connection via optical cable includes two methods:
Fixed and active connections. For fixed connections, two methods can be used: welding and mechanical connection (cold connection). A fixed connection can reduce number of ODN jumpers and reduce optical link losses; active connection is more convenient for flexible wiring of optical cables.
Active connections can also be used between ODN optical cable segments, but number of active connections should be strictly controlled and number of active connections from OLT to one ONU should not exceed 7.
3) Classification of fiber optic connectors:
According to different designs, it is divided into:FC (round head screw), SC (square head plug), ST (round head bayonet), LC (small square head plug)
Pin face classification:APC (8° beveled physical contact), UPC (polished physical contact), PC (spherical physical contact), EUPC (improved ultra-polished physical contact). contact ) please wait.
The fiber end of active connector is typically UPC type; if FTTx network carries analog cable television signals, all fiber optic connectors must use an APC-type endcap.
V. General Network Management Plan
1. Positioning of PON network management function
Therefore, when building a PON optical access network, it is necessary to simultaneously and centrally build an EMS network management system for new PON equipment, in order to realize centralized monitoring and centralized management of PON network. The processing module and data service processing module are managed centrally and unified, at same time it provides information convergence function such as alarms and performance. PONEMS must also be connected to BOSS and other network management services (such as softswitch network management, IP MAN network management, etc.) through north interface. It performs remote configuration and management of basic service information such as VLAN.
The positioning of PON network management in entire network is as follows:
The entire PON access network, including OLT and various ONUs, must be fully managed by PON Network Management System (EMS). Its functional positioning basically looks like this:
Manage PON network and equipment layer, configure physical link and be able to batch preconfigure, and simultaneously populate public configuration attributes related to business management of PON network during network deployment phase. When user service is opened, user equipment and peripheral equipment associated with PON network are auto-configured or zero-configured to shorten opening time. Provision and control of services can be performed by various professional network administrators (for example, authentication and rate limiting of broadband services are implemented through BRAS, and provision and activation of voice services is carried out on soft switches and SHLR equipment, etc.).
PON Network Management is responsible for data configuration, operation and management of PON access network, and detecting various failures caused by edge devices. At same time, it can manage passive optical access network (ODN), and quickly and efficiently detect and measure various faults caused by passive equipment such as optical fibers, optical cables and logs.
For IAD embedded in ONU, PON network management is responsible for managing related equipment, and PON network management for PON terminal part and central office equipment is managed by PON network management. Voice service management can be done by PON network management or VoIP network management, and for FTTH application scenarios can also be managed by home network management platform. In a specific project, you can choose appropriate control method according to actual network situation and user plans.
Implement a unified GPON and EPON network management solution that can fully meet requirements of PON network management,
Comprehensive management of all network devices, including network topology, fault management, performance management, configuration management, system management and other functions. In addition, unified north interface implements interfacing with operator's existing BOSS system and integrates management and operation of PON network into the existing management process.
6. EPON Complete Solution
This solution is a two-way PON-based network for optical path extension and perfect FTTH integration. In terms of EPON structure, its key advantage is that it greatly simplifies traditional layered overlay network structure. Main Features:
●ATM and SDH levels are eliminated, reducing initial and operating costs;
●The downlink data rate can reach 1Gbps, which can support more users and higher bandwidth;
●Simple equipment, no need for external electronic equipment, which simplifies installation and deployment;
● A large number of chips can be used with advanced Ethernet technology, which is relatively easy to implement and inexpensive;
● Improved flexible channel assignment and service provisioning and reconfiguration capabilities;
● Provide layered security mechanisms such as VLAN, closed user group, and VPN support.
The uplink and downlink wavelengths of EPON technology specified in IEEE802.3ah are 1310nm and 1490nm, uplink and downlink speed are 1.25Gbps, transmission distance is 10/ 20 km, and division ratio is 32/16, main business data and voice. After adding 1550nm television broadcast wavelength, it becomes so-called triple business package of voice, data and television services. EPON is a good solution for transferring a single Ethernet business.
1. Data service
Broadband data service is most basic service that an EPON system can provide. The system can provide high-speed user access. All user data services are connected to BAS through an optical port in central office. Management procedures such as billing and authentication are same as those of traditional broadband to maximize use of existing network resources and maintenance process .
There are two bandwidth provisioning methods that can be used in projects: fixed bandwidth provisioning and DBA bandwidth provisioning.
The fixed bandwidth allocation method is a traditional broadband provisioning method that places an upper limit on bandwidth for each user. This method's bandwidth provision is not flexible, but it can make efficient use of existing network resources and service methods, and is relatively easy to implement.
The DBA method can dynamically allocate bandwidth for each user according to a specific policy, as shown in figure below.
2. IPTV Service
With popularization of broadband access, number of IPTV services is also growing. High bandwidth FTTH is very suitable for providing IPTV services. If you need to solve IPTV services in FTTH solution, you can use solution shown in figure.
In development of IPTV business, main function of access network is to provide an uninterrupted broadband channel. Provision of this channel requires not only that line speed be sufficient to support video stream, but that access network equipment also should not have bottlenecks in data transmission. The system's GE full line card connection is clearly different from other access products in industry, and can well support large-scale IPTV service traffic. The system provides good support for multicast and managed multicast, and provides good support for large-scale development of IPTV services, and has been fully verified in a large number of real projects.
3. Cable TV Business
Cable Antenna TV-CATV is a broadband image transmission using optical fiber and coaxial cable. The system transmits high quality TV image signals to user terminals on floor through a fiber optic distribution network.
4. PSTN Voice
The so-called Public Switched Telephone Network (PSTN) is telephone network commonly used in our daily lives. As we all know, PSTN is a circuit switched network based on analog technology. Among many WAN connection technologies, PSTN connection has lowest communication cost, but its data transmission quality and transmission speed are also worst, and PSTN network resource utilization is also relatively low. By transforming integration function of three networks, resource utilization efficiency will be effectively improved. Save your optical soldering resources as much as possible.5. Reliability and business security
The EPON platform provides robust data protection capabilities. ONUs are logically isolated at second layer. Without special settings or other layer 3 devices, ONUs cannot communicate with each other, that is, ONUs will not be exposed to threats such as attacks from within system; and EPON devices are layer 2 devices, ONU device information is terminated at OLT in central office, and its MAC address and other information will not be transmitted outside network, so security is better. If a higher level of security is required, our system also supports business encryption.
Because EPON downlink data is implemented by TDM broadcast, it can be intercepted and received by individual users. In this case, our internal EPON standard requires EPON system to encrypt downlink data. AES-128 standard encryption algorithm or encryption algorithm is flexibly selected in EPON series products, which can effectively protect user data from theft.
6. Residential Fiber Scenario (FTTH)