There is no uniform demand for the load-bearing scheme of the forward transmission network. According to the different access conditions and scenarios, the optical fiber direct drive, passive WDM, active WDM / OTN and semi-active schemes can be selected flexibly. For the medium and return networks, the bandwidth, networking flexibility, network slicing and other aspects of the bearer network are basically the same. Therefore, a unified bearer scheme can be adopted. This paper mainly introduces the medium and return bearer schemes based on OTN technology.
Metro OTN network architecture includes backbone layer, convergence layer and access layer. Metro OTN network architecture matches the bearing requirements of 5g uplink / backhaul. The backbone / convergence layer corresponds to 5g backhaul network, and the access layer corresponds to the uplink / forwarding.
With the introduction of Ethernet, MPLS-TP and other packet switching and processing capabilities, OTN evolves to packet enhanced OTN, which can well match 5g IP Bearer requirements.
The WDM capability of packet enhanced OTN integration can realize long-distance transmission to suburban counties, and increase the bandwidth capacity of transmission links as required.
In order to meet the requirements of flexible networking for medium / return, it is necessary to consider enhancing the routing and forwarding function on the basis of MPLS-TP technology supported by packet enhanced OTN.
The 5g bearer scheme based on OTN is suitable for operators' demand for integrated service carrying. It provides low-cost bandwidth and high-quality bearer services for FTTx fixed broadband, 5g mobile broadband, high-quality government enterprise dedicated lines, etc., which can simplify the network equipment level and help to reduce cpaex and OPEX.
