ZTE has announced the completion of commercial trials of its Combo PON solution in two local networks in Changzhou and Yancheng, in China's eastern Jiangsu province, conducted jointly with the China Telecom's Jiangsu branch and the China Telecom Beijing Research Institute.
ZTE stated that the commercial trial combined the in-service optical line terminations (OLTs) with its Combo PON cards to connect the legacy optical distribution network (ODN) and XG-GPON and GPON optical network units (ONUs) using the same Combo PON port.
The Combo PON solution is designed to utilise the system and flow of the carrier's existing element management system (EMS), OSS and resource management system, while implementing minor alterations to the attributes and performance statistics and alarms of the newly-added Combo PON cards. The solution leverages its advanced XG-PON smart gateway to provide a 1 Gbit/s connection supporting voice, 4K IPTV and smart home services for end-users.
ZTE noted that with the solution existing GPON FTTH ONUs are migrated under the Combo PON port, and inherit the existing integrated terminal management system (ITMS) flow to enable automated distribution and provision of FTTH services, thereby providing interoperability with GPON ONTs from multiple vendors.
The company observed that migration of 10 Gbit/s PON is necessary to enable 1 Gbit/s broadband in China, although lack of compatibility between 10 Gbit/s PON and existing EPON/GPON CO equipment and the ONUs in user premises needs to be addressed. The native ability to combine 1 and 10 Gbit/s EPON terminals under the PON port has led to 10G EPON being adopted in large-scale upgrades. However, as a 10 Gbit/s GPON port only supports 10 Gbit/s and not GPON ONUs, coexistence of 10 Gbit/s GPON and GPON requires wavelength combination.
ZTE stated that traditional external multiplexer solutions need to plan, construct and maintain both 10 and 1 Gbit/s GPON equipment and cards, resulting in more equipment and an additional 1.5 dB insertion loss, as well as requiring existing ODN to reserve redundant optical power of approximately 3 dB, which limits its applications. The Combo PON solution does not require additional space, does not incur insertion loss or require ODN transformation, and can support flexible access and compatibility for both 10 and 1 Gbit/s PON ONUs.
ZTE unveiled its Combo PON solution, based on the hybrid GPON and XG-PON optical transceiver module, in February last year; in June 2016 the Combo PON was first tested at the China Telecom Shanghai Research Institute.
