Tag: 5G

25G WDM-PON for 5G Fronthaul Transmission

With the rapid development of mobile Internet, mobile data traffic and connected devices grow explosively. In response to the challenges brought by the network growth, 5G is under construction. 25G WDM-PON, combines the WDM technology and the PON topology, effectively bring high bandwidth, low latency, plug-and-play ONU (Optical Network Unit), simple OAM (Operation Administration and Maintenance) and low-cost advantages to 5G fronthaul transmission. Therefore, it has attracted widespread attention in the industry. This article describes 25G WDM-PON for 5G fronthaul transmission.

Technical Requirements for 5G Fronthaul Transmission

Compared to 4G architecture, the 5G RAN (Radio Access Network) architecture will evolve from the formal BBU (Base Band Unit) and RRU (Radio Remote Unit) two-level architecture of LTE to the three-level structure of CU (Centralization Unit), DU (Distribution Unit) and AAU (Active Antenna Unit). Therefore, the bearer network is also divided into front haul, middle haul, and backhaul. 5G base station fronthaul requires a bandwidth up to 25Gbps. However, as the number of base station increases, the cost of the base station to the fiber infrastructure networks and deployment will be higher. In this case, employing a Centralized Radio Access Network (C-RAN) architecture for 5G fronthaul holds great appeal for operators, but the current dark fiber solution for the C-RAN architecture requires a large number of mobile backhaul fibers. Most operators are still seeking an optimal solution to meet the needs of 5G fronthaul.

altTechnical Requirements for 5G Fronthaul Transmission

25G WDM-PON Solution for 5G Fronthaul Transmission

In the C-RAN architecture of 5G network fronthaul, the functionality of the 5G BBU will be reconstructed into two functional entities — CU and DU. The CU primarily includes the non-real-time part of wireless upper-layer protocol stacks and supports the distribution of some core network functions and the deployment of applications at the network edge. The DU mainly handles physical-layer functions and real-time transmission-layer functions. In order to save the transmission cost and reduce the transmission bandwidth between the RRU and the DU, some functions of the physical layer are moved down to the RRU implementation. 25G WDM-PON is a solution for transmission between DU and RRU. In the network architecture of WDM-PON 5G fronthaul, WDM-PON OLT and ONU are connected with DU and RRU respectively. The transparent business transmission between DU and RRU is realized by the adoption of the wavelength position multiplexing technology and AMCC (Auxiliary Management and Control Channel) technology. The OLT devices carry the midhaul service between DU and RRU at the same time that the OLT devices realize the fronthaul service between DU and RRU.

alt 25G WDM-PON Solution for 5G Fronthaul Transmission

Advantages of 25G WDM-PON for 5G Fronthaul

25G WDM-PON has advantages like high bandwidth, low latency, and low-cost. These all make 25G WDM-PON a better choice to satisfy 5G fronthaul requirements.

Reduce Capex

In the 5G construction, operators are faced with the pressure to reduce the number of sites and leased equipment rooms. In this case, employing a centralized radio access network (C-RAN) architecture can significantly reduce capital expenditure (Capex) on sites and equipment rooms. The 25G WDM-PON OLT can utilize an Access Office (AO) to deploy a centralized distributed unit (DU) pool. Thus, wireline and wireless AOs can be co-located if the condition permits.

Reduce Deployment Cost

The 25G WDM-PON 5G fronthaul solution allows for sharing of the existing fiber infrastructure, making it suitable for densely populated urban residential areas. The 5G network requires a large number of fiber resources. A network architecture based on the point-to-multipoint tree topology of a 25G WDM-PON can save a lot of fibers. The existing FTTx networks have rich lines and port resources in a wide range of deployments. 25G WDM-PON can completely reuse these resources to reduce 5G network deployment costs, avoid overlapping investments and improve 5G network coverage.

Conclusion

The 25G WDM-PON optoelectronic devices belong to the world’s leading edge, which requires high technology, chips, research and development capabilities. Overall, the 25G WDM-PON industry chain is basically mature, but it still needs continuous investment from all aspects of chips, transceiver modules (SFP, SFP+, SFP28), equipment and systems, to develop key technologies, reduce core device costs, establish a unified standard, and accelerate the productization process.

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5G Deployment Ushers In New Opportunities for 25G Optics Market
5G Is Coming – the New Wireless Revolution to Change Our Life

Talk About 2.5G And 5G

Network technology is developing rapidly. To keep up with the trend, data centers are required to upgrade constantly, from 10G to 40G, 40G to 100G and even 100G to 400G. However, for some small business data centers with 1G infrastructures, directly migrating from 1G to 10G is a little fast. Is there any slower Ethernet standards to fill the gap between 1G Ethernet and 10G Ethernet speeds? The answer is Yes—2.5 Ethernet and 5G Ethernet. This article will talk about 2.5G and 5G.

Overview of 2.5G And 5G

The physical (PHY) layer transmission technology of IEEE 802.3bz is based on 10GBASE-T but operates at a lower signaling rate. By reducing the original signal rate to  1/4 or  1/2, the transfer rate drops to 2.5 or 5 Gbit/s, respectively. The spectral bandwidth of the signal is reduced accordingly, lowering the requirements on the cabling, so that 2.5GBASE-T and 5GBASE-T can be deployed at a cable length of 100 meters on unshielded Cat5e cable and Cat6 cable, respectively. The following figure shows the comparison of twisted pair based Ethernet technologies.

comparison of twisted pair based Ethernet technologies

Cons And Pros of 2.5G/5G Ethernet Standards

As 2.5G and 5G Ethernet standards came out after 10G Ethernet standards, there are mixed reviews for them. This part will focus on cons and pros of 2.5G/5G Ethernet standards.

Cons of 2.5G And 5G

When 2.5G Ethernet and 5G Ethernet standards came out, many people didn’t think much of them. They commented that:

  • 5GBase-T and 5GBase-T are going to be used for wifi rollouts. And they are pretty much strictly for enterprise wireless deployments.
  • 10GbE is getting pretty cheap. Lots of new desktop motherboards now have 10G NICs inside them and the premium seems to be less than $100 too, which isn’t too bad. What’s missing is a bunch of 10G home switches and routers.
  • As for availability, the 10G has 2 models out while the 2.5G and 5G are both “coming soon”. Due to the economies of scale and the penetration, 10G already has IMO. While 2.5G and 5G will never be widely adopted or supported.
  • There are not that many chip sets that support 2.5G Ethernet and 5G Ethernet yet as they really only got finalized. Also, most cards that support them right now support 10Gbe.
Pros of 2.5G And 5G

What exists is reasonable. One estimate is that there are 70 billion meters of Cat5e and Cat6 cabling have been sold between 2003 and 2014. With such a significant amount of existing infrastructure at stake, it’s hardly surprising that most enterprises want to extend the existing cabling, component and equipment investments in the standard Ethernet wireless closet. Therefore, it is not difficult to find that 2.5G Ethernet and 5G Ethernet standards have their advantages.

  • Cat5 and Cat6 cabling can’t support 10G Ethernet up to 100 meters, but they will be able to support the emerging 2.5Gbps and 5Gbps standards, thereby preserving the value of the existing copper cable plant.
  • Adopting new 2.5G and 5G can satisfy the need of increasing data rates of wireless networking. The new 802.11ac Wi-Fi standard increases wireless bandwidth, supporting Ethernet speeds of 1.7 Gbps to 2.5 Gbps. With the coming of the next generation of wireless networking, 802.11ac Wi-Fi Wave 2, wireless network speeds could increase to as high as 6.8 Gbps.
  • Besides the need from the Wi-Fi industry, a 2.5G/5G version will also aid in other applications such as enterprise infrastructure, cellular Wi-Fi offloads, small cells, security cameras, multiple industrial uses and PoE technology.
  • These two new Ethernet standards have plenty of attributes to ensure success, such as ease of use, backward compatibility, faster speeds without requiring a cable upgrade, incremental speed upgrades, multi-vendor interoperability, not to mention optimized cost and performance.
Conclusion

From the above content, we can conclude that 2.5G/5G Ethernet standards have both pros and cons. For those who want to upgrade cabling system to 10G, 2.5G/5G is not useful. For small business and home network, 2.5G/5G is a cost-effective solution. No matter what your cable plant is, choosing a suitable migration path is the most important thing. FS.COM can provide high quality components for your cable plant, such as Cat5e cable, Cat6 cable, wireless access point and PoE switch. For more details, you can visit our site.