November 19, 2020

Bringing 100G DWDM to the Network Edge

Network operators are under more pressure than ever to boost the performance of their existing fiber networks. With the rise of 5G and the Internet of Things (IoT), which are causing an exponential growth in the amount of data created and processed all along today’s optical networks, the need for 100G DWDM at the edge is rising. Yet, for a long time, network operators have had to make hard choices when looking to boost the performance of existing fiber in this way. They have had to sacrifice at least one of the following to achieve 100G: use of the QSFP28 form factor, ability to leverage DWDM, maximum capacity or transmission distance.

Now, our Advanced Engineering Group is on the cusp of putting an end to that with our new PAM4 Access Reach (P4AR™) transceiver. In this blog, we look at how the needs of businesses and consumers are impacting network operators. Then, we show you why P4AR™ is now the ultimate solution for operators looking for performance, cost savings and scalability when leveraging 100G DWDM in their networks.

Trends Challenging Current Fiber Infrastructure

Networking technology is evolving at a rapid rate as businesses and individuals generate and share growing amounts of information. The IDC says that, by 2025, the world will have generated a whopping 175ZB of data. Central to this growth is the rise of edge computing, which describes the shift in data gravity away from a network’s core, such as a major hyperscale data center, to where the data is created. The edge is not formally defined. It could be as far as the endpoints in an autonomous vehicle (AV), a micro-edge data center in a Tier 3 market, or even a bigger facility in an area with dense fiber connectivity options. Edge computing is a vital networking paradigm that supports a myriad of new technologies like AVs, HD streaming, the Internet of Things (IoT), 5G and greater adoption of the cloud.

Despite its benefits, however, edge computing places more responsibility on underlying infrastructure, as CBI Insights notes. In fact, the rise of 5G demonstrates this point nicely. By 2025, 5G networks are expected to carry half of our mobile data traffic. In August 2020, T-Mobile lit the first standalone 5G network in the U.S. Other carriers have already been rolling out 5G services using existing 4G infrastructure. As we have noted in a previous blog, 5G has a connection density of 100,000 devices per square kilometer. With a peak data rate of 10 GB/s, increased adoption of 5G (which edge computing supports) demands fiber networks that can support extremely low latency connections between endpoints, data centers and the cloud.

Overcoming Network Bottlenecks: 100G DWDM Solutions and Equipment

It is safe to say that edge and cloud computing as well as 5G will demand greater capacity and speeds at the periphery of modern networks. As the edge continues to proliferate even further away from traditional cores, transmission distance and cost also become critical. For network operators, this poses a challenge – fiber exhaustion. However, it is costly for network operators to simply add new fiber on an ongoing basis. In urban areas, pre-existing infrastructure is often dense, making it difficult to install more. In rural areas, the economics of adding new fiber can make even the wealthiest of network operators take pause. The advent of 100G posed a successful solution to this challenge.

When it comes to implementing 100G in a network, the main question has always centered around transmission distance. Because of this, the market for 100G optical modules separated into two general taxonomies – CFP and QSFP28. For their part, CFP (C form-factor pluggable) modules are geared toward long-distance transmission for distances greater than 10km but potentially measured in the hundreds of kms. Compared to QSFP28 optics, CFP modules are much larger and require more power. In contrast, QSFP28 modules are the preferred solution, especially in the cloud and data center industries, for sub-10km applications. Yet, as adoption of edge architectures and cloud computing continues to rise, the need for 100G at longer distances has also increased.

Instead of running long haul transport between end-users and a core, network operators are now bringing fiber to the edge. This means connecting multiple data centers and enterprise campuses at distances above 10km with networks capable of supporting ultra low latency, multi-directional traffic flows. For the cloud and data center verticals, doing so while being able to use the QSFP28 form factor has been critical to keeping expenditures reasonable. To achieve networks that offer high speed and capacity at the edge, network operators have come to rely on the following QSFP28 longer distance options:

  • QSFP28-100G-LR4 with duplex LC single mode fiber (up to 10km)
  • 100G QSFP ER4 (40km)
  • 100G QSFP28 ZR4 (80km)

Though they leverage the QSFP28 form factor, the above solutions only offer a maximum capacity of 100G. However, as businesses and consumers use increasingly data-intensive and latency-dependent applications, network operators need optics that enable greater capacity with existing fiber assets. For network operators looking to up capacity through the application of DWDM on existing fiber, ER4 and ZR4 do not help in that regard as they cannot be multiplexed together and require dedicated fiber.

In 2016, the market widened one step further with the rollout of a DWDM QSFP28 module based on PAM4 modulation that gave network operators 4Tbps of capacity in a single fiber pair. This QSFP28 DWDM DCI solution was billed as the answer for connecting edge data centers without the need for a dedicated transport layer – and thus costly monthly fiber rentals. However, what has often been overlooked in this discussion is the need for external components to ensure quality of data transmission.

Introducing P4AR™: The Next Step in Streamlining Adoption of 100G DWDM at the Edge

To put it simply, the existing QSFP28 DWDM DCI solution currently on the market requires external components such as erbium-doped fiber amplifiers, dispersion compensation modules (DCM), filters and other transport equipment to reach the data transmission distances it claims. That means significant capital expenditures for network operators trying to deliver high speeds and capacity at the edge of their networks. That is where P4AR™ comes in: it is the only commercial 100G DWDM, QSFP28 switch pluggable product that does not require DCM (or other equipment) for transmission up to 40km. As a result, it is a complete game changer.

In many ways, our Advanced Engineering Group built this product specifically to meet the evolving needs of our customers. As Chris Page, our CTO says, “the P4AR, with its 4TB max capacity, 40km reach without external equipment, QSFP28 form factor, and bidirectional capabilities, is the only product that checks off all of the boxes.” Here is what it can do for you:

  • Provides high capacity with high speed at the edge while eliminating the need for external transport equipment, amplifiers or filters for distances up to 40km
  • Allows those leveraging expensive dark fiber routes to join multiple sites to simplify network architectures and save on costly duplex fiber rental fees
  • Enables network operators to leverage single fiber multiplexed solutions. Most coherent solutions need two fibers due to transceiver cost and technical challenges. Just one fiber with P4AR™ can support 2Tbps of traffic in a 40-channel filter system.
  • Moves past 1310nm 100Gbps solutions to achieve the bandwidth needed to future-proof optical networks for 5G, IoT, the Internet of Everything (IoE), etc.
  • Achieves reduced latency with cost savings. For a transport distance of 40km on 1 fiber pair with 40 DWDM wavelengths, P4AR™ yields upwards of 76% of CapEx savings, more than 8.5 kW of power savings and 10RU of rack savings.
  • Avoids costly expenditures on new switches or routers because of PAM4™’s use of the QSFP28 form factor

As you can see, P4AR™ represents the pinnacle of 100G DWDM QSFP28 solutions for network operators adjusting to the challenges of edge computing, cloud computing, 5G and a host of other new technologies that will arrive in the decade ahead. The Precision OT team will begin offering initial demonstrations of these transceivers in late Q1 of 2021.

If you’d like to learn more, visit our product page here. Or contact us and someone from our Advanced Engineering Group would be happy to talk to you about what P4AR™ can do for your networks.

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