Optical Transceivers Solution for 5G Fronthaul/Backhaul Bearer Network

Date: 2020-04-30 774

With the commercially available of 5G technology, the development of 5G mobile and wireless networks has progressed at a rapid pace. The significant increase in base station density, along with demands on latency, bandwidth and network flexibility, have placed higher requirements on the 5G network architecture and associated transmission solutions. Thus elevating the quality of the pluggable optical transceiver modules applied in 5G networks. For 5G bearer network, FIBERSTAMP provides a complete optical transceiver solution, including industrial-grade 25G/100G transceivers for 5G fronthaul and carrier-grade 100G/200G transceivers for 5G backhaul.

5G Fronthaul Solution

FIBERSTAMP's 5G fronthaul transceivers are designed to support the eCPRI interface that is considered as an optimal choice for 5G fronthaul, to meet the strict requirements of bandwidth and latency (below 100µs). Considering the convenience and efficiency of network construction, the initial 5G fronthaul connection is based on fiber direct connection, which is supplemented by passive WDM connection and active WDM/OTN/SPN connection. Among them, fiber direct connection is easy to maintain but will consume more fiber resources. As a supplementary solution, WDM connection can save fiber resources and support a longer transmission distance than fiber direct connection. Luckily, FIBERSTAMP's 5G fronthaul transceivers support all the connections mentioned above.

Fiber Direct Connection

The fiber direct connection is used to link each AAU and DU, which can be deployed easily. FIBERSTAMP's industrial-grade 25G grey light optical transceivers, including SR, CSR, LR, ER Lite and BiDi options, will be the dominance of the direct connection in 5G fronthaul transmission. These optical transceivers support dual-fiber transmission up to 40km and single-fiber bidirectional transmission up to 10km.

Passive WDM Connection

Passive WDM connection can multiplex several wavelengths and transmit them on a pair of optical fibers or a single fiber to connect multiple AAUs to DUs to save the optical fiber resource. FIBERSTAMP's industrial-grade 25G colored light optical transceivers, including CWDM and DWDM options, support this connection up to 10km over dual single-mode fibers.

Active WDM/OTN/SPN connection

Active WDM/OTN/SPN connection needs to deploy OTN devices (such as WDM Mux/Demux, OADM, EDFA, OEO, etc.) between the AAU site and DU equipment room. It also utilizes WDM technology and provides multiple AAU-to-DU connections by using a pair of optical fibers or a single fiber. FIBERSTAMP's industrial-grade 25G grey light optical transceivers with a short transmission distance can be applied for connecting AAU/DU with WDM/OTN/SPN. And the connections between WDM/OTN/SPN network devices can be achieved by FIBERSTAMP's industrial-grade 25G/100G grey light optical transceivers. Compared with the passive WDM connection, the active WDM connection is more flexible, cost-effective, easily deployed, and is likely to be gradually used by the 5G operators.

Considering the budgets of the network, 10G optical transceivers might be applied for network deployment in the 5G fronthaul by some network service suppliers. Nevertheless, the industry prefers to use 25G optical transceivers due to that the network granularity is 25Gbps. That is to say, 25G and 100G may be the optimal choices for 5G fronthaul. For 5G fronthaul, FIBERSTAMP has launched a series of industrial-grade 25G/100G transceivers as shown in the table below.

Product Name Part Number Reach
100GE/eCPRI QSFP28 SR4 (IT) FST-100G-SR4-I 100m
100GE/eCPRI QSFP28 ESR4 (IT) FST-100G-ESR4-I 300m
100GE/eCPRI QSFP28 4WDM-10 (IT) FST-100G-4W10-I 10km
25GE/eCPRI SFP28 SR (IT) FST-25G-SR-I 100m
25GE/eCPRI SFP28 CSR (IT) FST-25G-CSR-I 300m
25GE/eCPRI SFP28 LR (IT) FST-25G-LR-I 10km
25GE/eCPRI SFP28 ER Lite (IT) FST-25G-ERL-I 40km
25GE/eCPRI BiDi SFP28 1270nm-Tx 1330nm-Rx 10km (IT) FST-25G-23B10-I 10km
25GE/eCPRI BiDi SFP28 1330nm-Tx 1270nm-Rx 10km (IT) FST-25G-32B10-I 10km
25GE/eCPRI CWDM SFP28 1270nm 10km (ET) FST-25G-27C10-E 10km
25GE/eCPRI CWDM SFP28 1290nm 10km (ET) FST-25G-29C10-E 10km
25GE/eCPRI CWDM SFP28 1310nm 10km (ET) FST-25G-31C10-E 10km
25GE/eCPRI CWDM SFP28 1330nm 10km (ET) FST-25G-33C10-E 10km
25GE/eCPRI CWDM SFP28 1350nm 10km (ET) FST-25G-35C10-E 10km
25GE/eCPRI CWDM SFP28 1370nm 10km (ET) FST-25G-37C10-E 10km
25GE/eCPRI CWDM SFP28 1470nm 10km (IT) FST-25G-47C10-I 10km
25GE/eCPRI CWDM SFP28 1490nm 10km (IT) FST-25G-49C10-I 10km
25GE/eCPRI CWDM SFP28 1510nm 10km (IT) FST-25G-51C10-I 10km
25GE/eCPRI CWDM SFP28 1530nm 10km (IT) FST-25G-53C10-I 10km
25GE/eCPRI CWDM SFP28 1550nm 10km (IT) FST-25G-55C10-I 10km
25GE/eCPRI CWDM SFP28 1570nm 10km (IT) FST-25G-57C10-I 10km
25GE/eCPRI DWDM SFP28 C18 1563.05nm 10km (IT) FST-25G-18D10-I 10km
25GE/eCPRI DWDM SFP28 C19 1562.23nm 10km (IT) FST-25G-19D10-I 10km
25GE/eCPRI DWDM SFP28 C20 1561.42nm 10km (IT) FST-25G-20D10-I 10km
25GE/eCPRI DWDM SFP28 C21 1560.61nm 10km (IT) FST-25G-21D10-I 10km
25GE/eCPRI DWDM SFP28 C22 1559.79nm 10km (IT) FST-25G-22D10-I 10km
25GE/eCPRI DWDM SFP28 C23 1558.98nm 10km (IT) FST-25G-23D10-I 10km
25GE/eCPRI DWDM SFP28 C24 1558.17nm 10km (IT) FST-25G-24D10-I 10km
25GE/eCPRI DWDM SFP28 C25 1557.36nm 10km (IT) FST-25G-25D10-I 10km
25GE/eCPRI DWDM SFP28 C26 1556.55nm 10km (IT) FST-25G-26D10-I 10km
25GE/eCPRI DWDM SFP28 C27 1555.75nm 10km (IT) FST-25G-27D10-I 10km
25GE/eCPRI DWDM SFP28 C28 1554.94nm 10km (IT) FST-25G-28D10-I 10km
25GE/eCPRI DWDM SFP28 C29 1554.13nm 10km (IT) FST-25G-29D10-I 10km
25GE/eCPRI DWDM SFP28 C30 1553.33nm 10km (IT) FST-25G-30D10-I 10km
25GE/eCPRI DWDM SFP28 C31 1552.52nm 10km (IT) FST-25G-31D10-I 10km
25GE/eCPRI DWDM SFP28 C32 1551.72nm 10km (IT) FST-25G-32D10-I 10km
25GE/eCPRI DWDM SFP28 C33 1550.92nm 10km (IT) FST-25G-33D10-I 10km
25GE/eCPRI DWDM SFP28 C34 1550.12nm 10km (IT) FST-25G-34D10-I 10km
25GE/eCPRI DWDM SFP28 C35 1549.32nm 10km (IT) FST-25G-35D10-I 10km
25GE/eCPRI DWDM SFP28 C36 1548.51nm 10km (IT) FST-25G-36D10-I 10km
25GE/eCPRI DWDM SFP28 C37 1547.72nm 10km (IT) FST-25G-37D10-I 10km
25GE/eCPRI DWDM SFP28 C38 1546.92nm 10km (IT) FST-25G-38D10-I 10km
25GE/eCPRI DWDM SFP28 C39 1546.12nm 10km (IT) FST-25G-39D10-I 10km
25GE/eCPRI DWDM SFP28 C40 1545.32nm 10km (IT) FST-25G-40D10-I 10km
25GE/eCPRI DWDM SFP28 C41 1544.53nm 10km (IT) FST-25G-41D10-I 10km
25GE/eCPRI DWDM SFP28 C42 1543.73nm 10km (IT) FST-25G-42D10-I 10km
25GE/eCPRI DWDM SFP28 C43 1542.94nm 10km (IT) FST-25G-43D10-I 10km
25GE/eCPRI DWDM SFP28 C44 1542.14nm 10km (IT) FST-25G-44D10-I 10km
25GE/eCPRI DWDM SFP28 C45 1541.35nm 10km (IT) FST-25G-45D10-I 10km
25GE/eCPRI DWDM SFP28 C46 1540.56nm 10km (IT) FST-25G-46D10-I 10km
25GE/eCPRI DWDM SFP28 C47 1539.77nm 10km (IT) FST-25G-47D10-I 10km
25GE/eCPRI DWDM SFP28 C48 1538.98nm 10km (IT) FST-25G-48D10-I 10km
25GE/eCPRI DWDM SFP28 C49 1538.19nm 10km (IT) FST-25G-49D10-I 10km
25GE/eCPRI DWDM SFP28 C50 1537.40nm 10km (IT) FST-25G-50D10-I 10km
25GE/eCPRI DWDM SFP28 C51 1536.61nm 10km (IT) FST-25G-51D10-I 10km
25GE/eCPRI DWDM SFP28 C52 1535.82nm 10km (IT) FST-25G-52D10-I 10km
25GE/eCPRI DWDM SFP28 C53 1535.04nm 10km (IT) FST-25G-53D10-I 10km
25GE/eCPRI DWDM SFP28 C54 1534.25nm 10km (IT) FST-25G-54D10-I 10km
25GE/eCPRI DWDM SFP28 C55 1533.47nm 10km (IT) FST-25G-55D10-I 10km
25GE/eCPRI DWDM SFP28 C56 1532.68nm 10km (IT) FST-25G-56D10-I 10km
25GE/eCPRI DWDM SFP28 C57 1531.90nm 10km (IT) FST-25G-57D10-I 10km
25GE/eCPRI DWDM SFP28 C58 1531.12nm 10km (IT) FST-25G-58D10-I 10km
25GE/eCPRI DWDM SFP28 C59 1530.33nm 10km (IT) FST-25G-59D10-I 10km
25GE/eCPRI DWDM SFP28 C60 1529.55nm 10km (IT) FST-25G-60D10-I 10km

Notes: The "IT" in the brackets means the Industrial operating Temperature range of -40℃ to +85℃ and the "ET" in the brackets means the Extended operating Temperature range of -20℃ to +85℃.

5G Backhaul Solution

FIBERSTAMP's 5G backhaul transceivers support both 5G midhaul and 5G backhaul. Since the requirements of bandwidth and networking flexibility are basically the same for 5G midhaul and 5G backhaul networks, they can utilize the same technology for transmission, like IPRAN (Internet Protocol Radio Access Network), PTN and OTN technology, etc. Two connecting methods for 5G backhaul network are presented below.

OTN & IPRAN Connection

The packet-enhanced OTN equipment with routing and forwarding functions are applied for the 5G midhaul transmission, while 5G backhaul network continues to adopt BGP protocol for routing and forwarding between IPRAN and OTN devices. In order to meet the demand for large capacity and network slicing of 5G, IPRAN will introduce high-speed interface technologies such as 25G, 50G, and 100G, or consider adopting new interface technologies such as FlexE (flexible Ethernet) to achieve physical isolation and offer better quality assurance for 5G transmission.

End-to-End OTN Connection

End-to-End packet-enhanced OTN network devices are applied for 5G midhaul/backhaul transmission. Compared with the above solution, it has strong networking capabilities and end-to-end maintenance capabilities to avoid the issues of interoperability and cross-professional coordination between OTN and IPRAN.

In addition, 5G midhaul/backhaul networks cover the access layer, aggregation layer, and core layer of the MAN (metropolitan area network), and the optical transceivers used in the core layer are similar to those used in existing transmission networks and data centers. Among them, the 25G/50G/100G grey light or colored light optical transceivers will be mainly applied for the metro access layer network, and the metro convergence and core layer network will mainly use 100G/200G/400G DWDM colored light optical transceivers. For 5G midhaul/backhaul, FIBERSTAMP has launched a series of carrier-grade 100G/200G transceivers as shown in the table below.

Product Name Part Number Reach
100G QSFP28 CWDM4 (IT) FST-100G-CW4-I 2km
100G QSFP28 4WDM-10 (IT) FST-100G-4W10-I 10km
100G QSFP28 LR4 FST-112G-LR4 10km
100G QSFP28 ELR4 FST-112G-ELR4 20km
100G QSFP28 ER4 Lite FST-112G-ER4L 40km
200G QSFP56 FR4 FST-200G-FR4 2km
200G QSFP56 EFR4 FST-200G-EFR4 10km
200G QSFP56 LR4 FST-200G-LR4 10km
200G QSFP56 ELR4 FST-200G-ELR4 20km
200G QSFP56 ER4 FST-200G-ER4 40km

Currently, with the population of the 5G applications, there are multiple optical module technologies and solutions for the 5G bearer network, which poses huge potential and great challenges for the optical transceiver market. Since there is a large demand in the market for 5G optical transceivers, and the development of 5G optical transceivers is difficult at this moment, the prices might be a little expensive in the short term. It is believed that with the continuous maturity of 5G technology and applications, the price of 5G optical transceivers will gradually decrease in the future and the market is still promising.