With the emergence of new multimedia services and the growing demand for broadband access, the existing EPON, GPON technology may become the bottleneck of development. Therefore, it is necessary to start the next generation PON technology research. The main development direction of PON technology is: multi wavelength network. Such as WDM-PON technology, single wave growth bandwidth trend. Such as 10g GPON, 10g EPON Technology. WDM-PON is a long-term evolution scheme based on the new optical network, which needs to be redeployed. And 10g GPON is a medium-term evolution scheme. On the basis of compatibility with the existing GPON ODN, the transition to 10g GPON is achieved by extending the GPON standard.

1. System structure of 10G GPON
System structure of 10G GPON. 10g GPON is still a typical topology of GPON in system structure, which is composed of optical line terminal (OLT), optical network unit (ONU) and optical distribution network (ODN) supporting 10g rate. In the uplink direction, TDMA mode is adopted to enable multiple onus to share the trunk channel capacity and channel resources 141. The transmission of uplink data is controlled by 0lt. Each ONU field 1 10ggpon's topology field transmits user data according to the time slot allocated by OLT. Different 0nu uses different time slots, so the uplink data generated by each 0nu will not conflict. In the downlink direction, the OLT transmits the frame composed of data packets to each ONU through the passive optical brancher in the broadcast mode. Each ONU receives all data streams, and then extracts specific packets according to the media access control address of ONU.

2. Principle of 10G GPON

10G GPON Principle Downward schematic

10G GPON Uplink schematic

3. Technical advantages of 10G GPON

① It is compatible with the existing GPON, has enough bandwidth to support a variety of new services, and can be flexibly deployed. It can configure both 10g / 10g uplink and downlink symmetrical rates and 10 (3 / 2.5G uplink and downlink asymmetric rates).

② 10g GPON and GPON have more power. Longer coverage. Therefore, it is not only suitable for laying in dense urban areas, but also in more remote rural areas. In addition, it can transmit more distance, so a central office can be used to manage more sparse users in rural areas to maximize the cost.

③ 10g GPON has the advantage of full service access guaranteed by QoS. In addition to data services, operators also include a large number of voice and video services. The service quality assurance requirements are relatively high, so the advantage of multi service QoS guarantee will provide customers with high quality. Rich personal media experience.

④ As the upgrade of GPON, 10g GPON runs on the currently deployed GPON network. It realizes the smooth upgrade from GPON to 10g GPON. Therefore, it has the advantage of cost and the feasibility of technology. If WDM-PON is used, the old ONU must be replaced. It costs a lot. Therefore, 10g GPON can provide appropriate bandwidth at a lower cost.

10G GPON is the next generation PON technology. It can not only meet the needs of the emerging high bandwidth network applications, but also achieve 10Gb / s bandwidth access with less cost. It is the development trend of next generation access network technology. In this paper, the key technologies of 10G GPON are studied, and a new scheme of hybrid system of up and down symmetric 10g GPON and GPON is proposed. It uses the existing optical devices on the basis of the original mild upgrade to get 10Gb / s uplink rate. It is also compatible with the existing GPON system and realizes smooth evolution, so it has cost advantage and practicability. It provides a reference for 10G GPON to become access network. On the one hand, with GPON occupying more market share than EPON in the world, it is hoped that the next generation PON technology can be compatible with the deployed GPON; on the other hand, with the continuous increase of user broadband services, it is believed that 10g GPON will become the mainstream of the next generation PON Technology, will become the most critical technology for operators to speed up the broadband access network.