GPON, XG-PON, and XGS-PON, which PON technology is right for your network?
XGPON and XGSPON both belong to the GPON family, and it can be said that XGSPON is the technical evolution of XGPON. Both technologies belong to 10G PON, but the main difference lies in the rate symmetry. XGPON is an asymmetric PON, whose PON port upstream and downstream rates are 2.5G and 10G respectively; while XGSPON is a symmetric PON, whose PON port upstream and downstream rates are both 10G.
Currently, GPON and XGPON are the mainstream PON technologies, and they are asymmetric PON. because user upstream and downstream data usually shows asymmetry, for example, in first-tier cities, the upstream traffic of OLT only accounts for about 22% of the downstream traffic, so the asymmetric PON technology basically meets the user’s needs. In addition, the uplink rate of asymmetric PON is relatively low, which also makes the cost of the sending component in the ONU lower, thus reducing the price of the equipment.
However, with the growth of services such as live streaming and video surveillance, the user demand for uplink bandwidth is increasing. As a result, some scenarios require the provision of circuits with symmetrical uplink and downlink rates, which is driving the development and growth in demand for XGSPON technology.
Ride-On has XGSPON COMBO OLT SFPDD, XGSPON COMBO OLT SFP+, XGSPON OLT SFP+, XGSPON ONU SFP+, and XGSPON STICK SFP+ series of optical modules with single-mode and SC connectors, with transmission distances of up to 30KM, Tx1577/Rx1270nm Tx1577/Rx1270nm and Tx1490/Rx1310nm wavelengths, operating temperature commercial grade and industrial grade can be selected, which greatly meets the needs of different scenarios in the enterprise.
1, XGSPON and XGPON coexistence
Similar to XGPON, XGSPON also use the broadcast method to realize the downlink communication, and TDMA method to realize the uplink communication.
Because XGSPON and XGPON have the same downlink wavelength and rate, XGSPON’s downlink cannot distinguish between XGSPON ONUs and XGPON ONUs, and the splitter broadcasts the downlink optical signals to all XGSPON and XGPON ONUs connected to the same ODN link. each ONU chooses to receive its own signals and discards the others.
The XGSPON uplink carries data over time slots. each ONU sends data within the time slot allocated by the OLT. the OLT dynamically allocates time slots based on the traffic demand and type of the ONU (XGPON or XGSPON). When the time slot is allocated to an XGPON ONU, the data transmission rate is 2.5 Gbps; while when the time slot is allocated to an XGSPON ONU, the data transmission rate is increased to 10 Gbps.
In summary, XGSPON inherently supports mixed access to XGPON and XGSPON ONUs, achieving more efficient fiber network communications.
2.Coexistence of XGSPON and GPON
Given the different wavelengths of XGSPON and GPON, in order to realize compatible sharing, XGSPON adopts the Combo scheme.XGSPON Combo optical module integrates GPON, XGSPON and WDM combiner.
In uplink transmission, the optical signal enters through the XGSPON Combo port, separates the GPON and XGSPON signals through the WDM filter, and sends them to their respective channels.
In downlink transmission, the GPON and XGSPON signals are mixed after WDM multiplexing and transmitted to the ONUs through ODNs. due to the different wavelengths, different types of ONUs can select the desired wavelengths to receive the signals through internal filters.
XGSPON Combo solution supports mixed access of GPON, XGPON and XGSPON ONUs and naturally supports coexistence with XGPON. Therefore, the XGSPON Combo optical module is also known as a triple-mode Combo optical module, while the XGPON Combo optical module is known as a dual-mode Combo optical module due to its support for mixed access to GPON and XGPON ONUs.
Original link：https://yingdapc.com/gpon-xg-pon-and-xgs-pon-which-pon-technology-is-right-for-your-network/
