With the development of 5G, big data, Internet of Things, cloud computing and artificial intelligence, the data traffic is growing rapidly, and the market prospect of optical communication is bright. The function of the optical module is photoelectric conversion. Optical transceivers are widely used in various industries. Aerech Networks will use this article to introduce you to the application scenarios of optical transceivers.
Before introducing the application scenarios of optical transceivers, let me introduce you to the market segments of optical transceivers.
- Ethernet: Mainly used in local area networks, connecting network hardware devices by sending and receiving data signals.
- Fibre Chanel: Mainly used in Fibre Channel storage network links in data centers.
- Optical Interconnects: IP network using WDM transmission technology, mainly used for IP packets transmission. Telecom market
- CWDM/DWDM: Mainly used in the interconnection of switches within the data center and the front haul and backhaul of 5G networks.
- Wireless Fronthaul: Mainly used in the network between the baseband unit BBU and the remote radio unit RRU in the mobile base station.
- Wireless Backhaul: Mainly used in the network between the baseband unit BBU and the S-G W/MME in the mobile base station.
- FTTx: Fiber to the X, x can be home, building , etc. The technologies that realize FTTx include PON, EPON, GPON, etc., which are used to connect telecom operators and end users.
The application of optical transceivers is mainly telecommunications and data centers.
Data Centers
A data center is a place to manage (store, compute, exchange) data. Data center interconnection is the real-time mass exchange of information between data centers, and optical fiber communication can realize coordinated operation between data centers. Switching equipment needs to have higher speed, lower power consumption, and more miniaturization, optical transceivers play a major role. Because information networks are mainly based on optical signal transmission, while computation and analysis are based on electrical signals.
Optical transceivers can be divided into three categories according to the type of data center communication connection.
- Data center and users: End users access the cloud to browse web pages, send and receive emails, stream video, etc.
- Data center interconnection: mainly used for data replication, software and system upgrades;
- Data center internal: mainly used for information storage and generation.
According to Cisco statistics, data center internal communications account for more than 70% of data center communications. The construction and upgrade of data centers have increased the demand for high-speed optical transceivers, and also promoted the development of optical transceivers in the following three aspects:
- Growth in demand for transmission rates
- Quantity demand growth
- Growth in demand for transmission distance
The cost of the optical fiber link depends on the optical module and the optical fiber. Different distances have different network solutions. For the medium and long-distance interconnection required for data center communication, MSA has created two revolutionary solutions, PSM4 (Parallel Single Mode 4 lanes) and CWDM4 (Coarse Wavelength Division Multiplexer 4 lanes). Since the usage of PSM4 fiber is four times that of CWDM4, when the distance of the link is long, the cost of the CWDM4 solution is relatively low, and it is a better choice.
Mobile Communication Base Station
The core function of the mobile communication base station is to act as an intermediary device connecting wireless communication devices such as mobile phones to the wireless communication network. It is a form of radio station. It is a radio transceiver station that transmits information with information terminals such as mobile phones through a mobile communication switching center in some radio coverage areas.
For 4G network base station, there is mainly RRU and BBU equipment. To realize the interconnection of the two devices, optical transceivers and fiber jumpers are required to connect the link. The optical transceivers used for RRU and BBU equipment connection mainly include 1.25G SFP, 2.5G SFP, 6G SFP and 10G SFP+, etc.
Passive Wavelength Division System
Passive WDM systems are mainly used in metropolitan area networks, backbone networks, and wide-area networks. Passive WDM accounts for the highest proportion of the technical solutions used in 5G front-haul.
The passive wavelength division system consists of color light modules, multiplexers, and optical fibers. CWDM and DWDM optical transceivers are called color light modules, and conventional single-mode and multi-mode optical transceivers are called gray light modules.
The core principle of a passive wavelength division system is WDM technology, and connecting an external wavelength division multiplexer. A wavelength division multiplexer can couple optical signals of different wavelengths together and transmit them through a single fiber. The wavelength division multiplexer can separate these optical signals with different wavelengths at the receiving end, thereby saving fiber resources.
Taking the CWDM wavelength division multiplexing system as an example, insert the CWDM optical module into the switch, and use the jumper to connect the CWDM optical module and the CWDM wavelength division multiplexer or OADM to work.
SAN/NAS Storage Network
Due to the rapid development of the Internet and network applications, the types of data processed by the data information storage system have increased, and the data information storage system is facing enormous chall enges. NAS(Network Attached Storage) and SAN(Storage Area Network) provide the most effective solution for centralized data management. Because they can separate the data information storage device from the network and the host system, it manages information data centrally and has good scalability.
The function of the SAN/NAS storage network is to store data. Among them, the SAN network is mainly composed of servers, Fibre Channel switches, storage devices, and transmission carriers (optical transceivers, optical fiber jumpers); the NAS storage network is chiefly composed of NAS storage, switches, terminal equipment (computers), transmission carriers (optical transceivers, optical fibers) jumper). Please note that the SAN network uses Fibre Channel optical transceivers and needs to support the FC(Fibre Channel) protocol. The optical transceivers used in the NAS storage network are only required to comply with the Ethernet protocol.
5G Bearer Network
The arrival of 5G brings unlimited business opportunities to optical communication. Optical transceivers based on 5G base stations have become a research hotspot in the past two years. The 5G network consists of three parts, the access network, the bearer network, and the core network. The 5G bearer network is generally divided into metro access layer, metro aggregation layer, metro core layer/provincial trunk line, and realizes the front-haul and mid-backhaul functions of 5G services. The devices at each layer mainly rely on optical transceivers to achieve interconnection.
Typical application scenarios of 5G front-haul include optical fiber direct connection, passive WDM, and active WDM/optical transport network (OTN)/slice packet network (SPN).
Optical fiber direct connection scenarios generally use 25Gb/s gray light modules, which support dual-fiber bidirectional and single-fiber bidirectional types, mainly including two transmission distances of 300m and 10km. Passive WDM scenarios mainly include point-to-point passive WDM and WDM-PON, etc. Use A pair or one optical fiber to realize the connection between multiple AAUs and DUs, and 10Gb/s or 25Gb/s color light modules are required.
In active WDM/OTN scenarios, 10Gb/s or 25Gb/s short-distance gray light modules are required between AAU/DU and WDM/OTN/SPN devices. Dual-fiber bidirectional or single-fiber bidirectional color light modules with rates of N×10/25/50/100Gb/s are required between WDM/OTN/SPN devices.
In the outdoor working environment, the front-haul optical module must meet the industrial temperature range of -40°C to +85°C and be dustproof. The demand for 5G optical transceivers much exceeds that of 4G optical transceivers, especially front-haul optical transceivers, which may have very high demand, so cost control is also one of the issues to be considered.
5G backhaul mainly uses 25G, 50G, 100G, 200G, and 400G optical transceivers, which support CPRI, eCPRI, Ethernet, OTN, and other interface protocols and NRZ, PAM4, DMT, and other modulation formats.
5G mid-transmission can use the existing mature 25G optical devices and take PAM4 technology to double the bandwidth of optical devices. The transmission distance of 10km and 40km will cover more than 90% of the application scenarios, and the transmission distance of more than 80km will use coherent technology.
Conclusion
We introduced 5 Application Scenarios of Optical transceivers in this article, Data Centers, Mobile Communication Base Station, Passive Wavelength Division systems, SAN/NAS Storage networks, and 5G Bearer networks. What application scenario is your optical module used in?
Aerech Networks is a leading provider of optical transceivers, if any questions related to Application Scenarios of Optical transceivers, reach us freely.
