Abstract: Triple play refers to the convergence of telecommunications networks, radio and television networks, and the Internet. During the development and evolution of the next generation telecommunications network, the next generation radio and television network, and the next generation Internet, the network functions tend to be the same, and the business scope tends to be the same, all of which can provide users with a variety of services such as making calls, surfing the Internet, and watching television. The essence of tri networks integration is that the future telecom network, radio and television network and Internet can all carry multiple information services and create more diversified integration services, rather than three networks combining into one network. Therefore, tri networks integration is not tri networks integration. The possible development directions of triple play integration are shown in the following figure, including technology integration, business integration, and industry integration

Triple play refers to the convergence of telecommunications networks, radio and television networks, and the Internet. During the development and evolution of the next generation telecommunications network, the next generation radio and television network, and the next generation Internet, the network functions tend to be consistent, and the business scope tends to be the same, all of which can provide users with a variety of services such as making calls, surfing the Internet, and watching television. The essence of tri networks integration is that the future telecom network, radio and television network and Internet can all carry multiple information services and create more diversified integration services, rather than three networks combining into one network. Therefore, tri networks integration is not tri networks integration. The possible development direction of triple play integration is shown in the following figure, from technology integration, business integration, industry integration to the final terminal integration and network integration.

 

Figure 1 Possible development directions for the integration of three networks

IPTV/CATV is the starting point and key to the integration of the three networks

The key to the integration of the three networks lies in the integration of telecommunications and broadcasting services. Telecom operators and broadcasting operators will penetrate each other’s businesses and become full service operators, competing for customers through full service binding and pricing strategies; Telecom operators, on the other hand, provide IPTV services by laying ultra bandwidth metropolitan area networks to compete with cable TV operators for TV services. Cable TV operators may enter the mobile field of traditional telecom operators through self built or MVNO methods, competing across all services. Both sides face unprecedented competitive pressure, and compete in all aspects based on all services. IPTV/CATV is the starting point and key to the integration of the three networks.

At present, the network carrying IPTV still faces many difficulties: firstly, the current network does not meet the requirements of end-to-end speed increase: high-definition home entry requires 10-20M, and the current home bandwidth is generally less than 4M. To achieve end-to-end speed increase, some access devices, BRAS, and core routers need to be modified; Secondly, the service experience is difficult to guarantee: the vast majority of the traffic of broadband IP MAN is Internet services, and the current network planning, design and construction basically do not consider the bearing of IPTV services, while the switching of IPTV channels is worse than the traditional TV experience, and is very sensitive to packet loss, which seriously affects the user experience; Thirdly, there is a lack of end-to-end management methods: the operation and maintenance of the carrier network involves IPTV business systems, carrier networks, and set-top boxes. The operation and maintenance department involves multiple departments in multiple fields, making it difficult to quickly define and locate them; Finally, having multiple network layers can become a bottleneck in quality. Currently, metropolitan area networks generally have 5 hops, and it is difficult to deploy IPTV related bearer technologies uniformly. If this architecture is directly used to carry IPTV, it will bring greater problems in network construction costs, network business control, network service quality, and other aspects. Therefore, the integration of the three networks has put forward new requirements for access networks.

Flat development of access networks

Firstly, there is the integration and unification of access networks, with a shift from separate networks to integrated access for multiple services. PON networks provide the possibility for unified access for small and medium-sized enterprises, building micro base stations, and residential users. The integration of services and equipment further promotes the integration of FTTX networks, reducing network nodes, simplifying network layers, and lowering network TCO costs; Secondly, for the full business management of operators, the current network maintenance is managed by different vertical business departments for their respective devices. In the context of three network integration, a unified OLT must face the management of different departments and achieve virtualization of management. Finally, to cater to the differentiation of end-users, OLT devices must face a two-dimensional network, which includes different businesses and customer groups, providing different QoS guarantees to truly achieve customer differentiation.

Faced with the integration of the three networks, the access network needs to develop towards a flat trend, as shown in the following figure. The point by point transformation architecture of the optical copper withdrawal network is a 5-level architecture with numerous network nodes; The new technology combination architecture of Guangjin Copper Withdrawal is a three-level architecture, reducing the number of nodes by 80%; Large capacity and fewer stations have become industry consensus. With the improvement of PON technology, larger bandwidth, greater spectral ratio, and longer communication distance have become the trend of access technology development.

 

Flat development of transmission networks

The development trend of flattened access networks has also brought about some changes in transmission networks. Firstly, the consumption of fiber resources has increased. OLT/DSLAM direct connection to BRAS/SR requires a large amount of fiber, which will lead to insufficient fiber resources in some areas; In addition, OLT comprehensively carries home services (including voice, video and other services), requiring high security network protection; And BRAS requires higher security backup. In the future, BRAS hot backup and OLT uplink will require more fiber consumption, and different cables are required for working and protecting fiber. At the same time, BRAS/OLT also has the need for long-distance lasers; On the other hand, for large customer dedicated lines, fiber optic direct connection to SR is required, which results in low fiber utilization and lack of protection, and the security cannot meet the requirements of large customers. Therefore, it is necessary to develop the transmission network towards flattening, as shown in the following figure:

 

Figure 3 Trend of Flat Development of REB670 1MRK002820-AC Transmission Network

DWDM/OTN conforms to the trend of network flattening and directly connects to the service layer through the STM-1/4 interface to provide small particle services. Therefore, FiberHome Communications has proposed the “OTN+PTN” solution, as shown in the following figure. The backbone transmission layer: builds a large capacity OTN transmission network to carry the backbone layer IP services, while cutting the existing trunk layer broadcast services to the OTN network as a unified transmission platform for IP services and broadcast video services. Provide ultra large bandwidths of 196 * 100G and 96 * 40G, with a ring topology as the main approach to increase network security, while supporting 10G/40G/100G mixed transmission. Utilize ultra long distance transmission technology to achieve wide coverage. Metropolitan Convergence Layer: Due to the lack of WDM networks in most metropolitan areas, PTN can be used instead of SDH networks and 1550nm networks to transmit broadcast video services. The main network is the GE/10GE PTN network, which intersects with the access layer network and the backbone layer OTN network to complete the aggregation and convergence functions of services.

 

Figure 4 OTN+PTN construction of transmission network

OTN sinks to the aggregation layer to build a three network integrated transmission network

As OTN sinks to the aggregation layer, the metropolitan aggregation layer utilizes OTN devices to achieve uplink transmission and aggregation of broadband access network OLT, solving problems such as bandwidth, fiber optic, distance pulling, and efficient protection. Provide T-level cross capacity, wavelength level, and sub wavelength level multi particle cross scheduling, as shown in the following figure:

 

Figure 5 OTN sinking trend

Metropolitan core layer: The topology is in the shape of MESH, and a large number of GE services for IP metropolitan area networks or large customer dedicated lines need to be scheduled and quickly opened, so it is necessary to build high-capacity OTN cross devices.

Provincial trunk line and national trunk line: Construct a high-capacity OTN transmission network to carry backbone layer IP services, while cutting off existing trunk layer broadcast services to the OTN network as a unified transmission platform for IP services and broadcast video services. Provide ultra large bandwidths of 96 * 100G and 96 * 40G, with a ring topology as the main approach to increase network security. At the same time, support 10G/40G/100G mixed transmission, and utilize ultra long distance transmission technology to achieve wide coverage. As shown in the following figure:

 

Figure 6 Construction Plan for Integrated Transmission Network of Radio and Television Three Networks

FiberHome Communications has been tracking and developing OTN technology since 2002. After several years of effort, it has gradually led the development of OTN technology in China. Currently, it has launched a full range of OTN products, forming end-to-end solutions. The products cover the core layer, backbone layer, aggregation layer, and access layer. Its product series includes new generation OTN transmission platforms such as FONST 5000, FONST 4000, FONST 3000, FOSNT 2000, and FONST 1000. Once launched, OTN products have gained recognition from customers and have now gained a large number of commercial applications in various operator markets across the country, including primary, secondary, and local metropolitan area networks, which have gained mature and stable applications.

In the above scheme, due to the downward trend of OTN devices, the latest FONST 1000 devices are applied to the access layer or edge aggregation nodes of the metropolitan area network. Multiple GE devices from the same access point or different access points are multiplexed to a single wavelength, and multiple wavelengths are converged to a single fiber through WDM, thereby improving fiber utilization and saving fiber resources, to solve the problem of increasingly tight line fiber resources in the metropolitan area network. This is because there is a large amount of GE uplink business from these access points to the aggregation point, including DSLAM, MSAN, OLT and other access aggregation devices, which all have GE business uplink requirements.

The FONST 1000 of FiberHome Communication has a compact structure with a height of 2U. REB670 1MRK002820-AC is suitable for scenarios with limited computer room conditions, and supports sub frame stacking and wall mounted installation; This device adopts the standard G.709 interface, supports OTU1 and OTU2 granular scheduling, and has flexible multi service access capabilities, such as SDH service (STM-1/4/16/64), Ethernet service (FE/GE/10GELAN/WAN), SAN storage service (FC100/200/1200), OTN service (OTU1/OTU2), video service and other types of service access. As an access and aggregation layer device, FONST has a large capacity and intelligent business scheduling capability, with a maximum transmission capacity of 40/48 × 10G in the system; By adopting MINI EDFA technology, the optical transmission distance is effectively extended. The customer side and line side interfaces all use pluggable optical modules, which can be flexibly configured into OTM and OADM, providing a unified OTN product platform for urban convergence and urban access applications. The efficient and secure OTN system architecture provides multiple network level protection methods for customers to choose from flexibly; Provide flexible networking capabilities to support point-to-point, chain, and ring networking, and can be mixed with FONST3000/4000 for networking.

summary

The full service support of the three network integration brings large business traffic and requires support from a large system capacity. OTN does not impose any restrictions on the exchange bit rate, and can increase the exchange bit rate and upgrade the system capacity according to the growth of business (line) speed in the three network integration, which is the guarantee of the full service support of the three network integration.

REB670 1MRK002820-AC