LightCounting Archives - EFFECT Photonics

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August 31, 2023

The Future of 5G Fronthaul

The 5G network revolution promises to fulfill the capacity needs that previous cellular generations could…

The 5G network revolution promises to fulfill the capacity needs that previous cellular generations could no longer provide to the ever-increasing customer demands. This network generation is expected to revolutionize the concept of telecommunication and bring the most anticipated services of larger bandwidth, higher speed, and reduced latency as part of the modern cellular network. The upgrade from 4G to 5G has shifted the radio access network (RAN) from a two-level structure with backhaul and fronthaul in 4G to a three-level structure with back-, mid-, and fronthaul:

Fronthaul is the segment between the active antenna unit (AAU) and the distributed unit (DU)
Midhaul is the segment from DU to the centralized unit (CU)
Backhaul is the segment from CU to the core network.

Figure-backhaul-fronthaul — Figure 2: Simplified diagram that shows and compares the building blocks of 4G (left) and 5G (right) access networks and the links between these blocks.

5G promises to interconnect exponentially more devices than before, with higher speed and latencies. As a result, 5G edge network bandwidth requirements can reach up to 100 times more than 4G. These requirements will put more pressure on the existing fiber infrastructure, and mobile network operators are expected to deliver their 5G promises with relatively little expansion in their fiber infrastructure.

The initial rollout of 5G has already happened in most developed countries, with operators switching from 1G SFP transceivers and grey transceivers to 10G SFP+ or wavelength division multiplexing (WDM). Mobile networks must move to the next phase of 5G deployments, which will exponentially increase the number of devices connected to the network. These more mature phases of 5G deployment will require operators to scale capacity cost-effectively. The move to 25G tunable optics in fronthaul networks will enable this expansion in capacity in an affordable way and help promote a long-awaited convergence between mobile and fixed access networks.

Enhancing Mobile Fronthaul Capacity

The move from 4G to 5G networks saw many operators upgrade their 10G grey transceivers to tunable 10G transceivers and 25G grey transceivers to make the most of their fiber infrastructure. However, as the 5G rollout moves into a more mature phase, the demands of fronthaul networks will often require even greater capacity from fiber infrastructure.

These future demands are a key reason why South Korea’s service providers decided to future-proof their fiber infrastructure and invested in 10G and 25G WDM technology since the early stages of their 5G rollout. Over time, providers in other countries will find themselves fiber-limited and turn towards tunable technologies. These trends are why LightCounting forecasts that the 25G DWDM market will provide the most significant revenue opportunity in the coming five years.

These 25G tunable transceivers support a typical reach of 10 km. It can reach up to 15 or even 20 km with extra amplification and compensation. Maximizing the capacity of fronthaul fiber will not only be beneficial for mobile network providers and telecom business developers, system architectures, equipment manufacturers, and product developers.

Graph DWDM Annual Sales — Figure 2: Fronthaul tunable optics transceiver revenues. Source: LightCouting Next-Gen Access Optics Report (2021)

DWDM Solutions For Fronthaul Aggregation

The transitions to 3G and 4G relied heavily on more efficient use of broader RF spectrum blocks. These transitions were as simple for many cell sites as changing the appropriate radio line card at a base station unit. The same cannot be said about the transition to 5G. Particularly this second phase of 5G deployment will require a more profound restructuring of mobile network architecture. These mature 5G networks will use higher frequency bands, which require the deployment of more cell sites and antennas to cover the same geographical areas as 4G. In contrast, existing antennas must upgrade to denser antenna arrays.

The characteristics of this second 5G deployment mean that operators must deploy larger-bandwidth channels and more total channels due to the additional base stations. DWDM is an excellent fit for interconnecting these new smaller cell sites since it allows operators to quickly increase their number of channels without having to lay out new and expensive fiber infrastructure. Thanks to the 25G capacity, these additional channels can be easily aggregated into the fronthaul transport network without being limited by fiber infrastructure.

Figure-5g-frount-haul-deep-fiber — Figure 3. Comparison between 4G legacy fiber deployments in access networks vs. future deep fiber deployments in 5G. The latter needs significantly more fiber capacity and infrastructure that can handle this aggregation, such as DWDM.

The Dream of Fixed-Mobile Access

Carriers that provide both fixed and mobile network services may often have to deal with situations in which their fixed and mobile access networks compete against each other. Since these networks often use different technology standards and even transmission media (e.g., legacy coaxial networks in fixed access), these carriers often have to build additional and arguably redundant optical infrastructure.

These carriers have long dreamed of merging their fixed and mobile network infrastructures under the same standards and transmission pipes. Such solutions reduce the need to build and manage redundant infrastructure. The expansion of fiber infrastructure and WDM technology might finally provide them with the opportunity to do so.

Figure-metro-core-network — Figure 4: Simplified example of some critical technologies and network architectures that could be merged in a converged fixed-mobile access network solution. These include radio access networks (RAN) with DWDM technology and Common Public Radio Interface (CPRI) protocols, as well as passive optical networks that combine time-division multiplexing (TDM) and WDM technology.

Passive optical networks (PON) have become a popular solution to implement fiber-to-the-home solutions. These networks’ bandwidth and latency requirements are leading to the standardization of 25G PONs and WDM-PON technology. Now that both mobile and fixed access are considering 25G WDM solutions, it might be a good time to revisit the subject of convergence, as together, this network will offer various quality services such as communication, entertainment, and data acquisition without any terminal, application, network, and location limitation.

Takeaways

25G tunable optics will become an industry standard for mobile fronthaul in the coming years. They allow operators to make the most of their existing fiber infrastructure, maximizing bandwidth and increasing the network’s ability to aggregate more signals from smaller and more numerous 5G base stations. For certain carriers, they could enable a future converged fixed-access network that simplifies the installation and management of their infrastructure. As shown by the example of South Korean network operators, it pays off to anticipate all these future demands and invest in a future-proof network that can scale up quickly.

Tags: 5G, access, aggregation, backhaul, capacity, DWDM, fronthaul, Integrated Photonics, LightCounting, metro, midhaul, mobile, mobile access, network, optical networking, optical technology, photonic integrated chip, photonic integration, PIC, PON, programmable photonic system-on-chip, solutions, technology

Insights

July 28, 2023

The Next Bright Lights of Eindhoven

Paris may be the more well-known City of Light, but we may argue that Eindhoven…

Industrial Hardening: Coherent Goes Outdoors

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June 7, 2023

Industrial Hardening: Coherent Goes Outdoors

The global optical transceiver market is expected to double in size by 2026, and coherent…

The global optical transceiver market is expected to double in size by 2026, and coherent pluggables will play a significant role in this growth as they will constitute roughly a third of those sales. While coherent is now an established solution in data center interconnects and long haul networks, it is also expected to start gaining ground in the access networks that connect mobile base stations and their controllers to the rest of the Internet. LightCounting forecasts that by 2025, coherent modules will generate 19% of all sales revenue, in an estimated market of $827 million, for transceivers in back-, mid-, and front-haul network segments. This is an increase in market share from 6% in 2021, as operators are expected to replace some of their direct detect modules with coherent ones in the coming years.

*Figure 1: Transceiver sales revenue (in USD) forecast for coherent modules in back/mid/front-haul network segments. Source: LightCounting Access Optics Market Forecast – November 2020.*

The numbers for coherent sales will only increase in the coming decade for two main reasons. First, electronic and photonic integration are making coherent pluggables economically viable and smaller (see one of our previous article on the subject). Second, the increasing data demands require access networks to increase their capacity beyond what direct detect can deliver. However, for coherent devices to become established in access networks, they must learn to live outdoors.

Controlled vs. uncontrolled environments

Coherent devices have traditionally lived in the controlled environments of data center machine rooms or network provider equipment rooms. These rooms have active temperature control, cooling systems, filters for dust and other particulates, airlocks, and humidity control. In these rooms, pluggable transceivers operate at a relatively stable temperature of around 50ºC, and they only need to survive in ambient temperatures within the commercial temperature range (C-temp) of 0 to 70ºC.

*Figure 2: Temperature ratings required across different segments of a 5G network.*

On the other hand, access networks feature uncontrolled outdoor environments at Mother Nature’s mercy and whims. It could be at the top of an antenna, on mountain ranges, inside traffic tunnels, or in the harsh winters of Northern Europe. Deployments at higher altitudes present additional problems. The air becomes less dense, so networking equipment cooling mechanisms don’t work as efficiently, so the device cannot tolerate case temperatures as high as it does at sea level. Transceivers should operate in the industrial temperature (I-temp) range of -40 to 85ºC degrees for these environments. Optics are also available in the extended temperature (e-temp) range, which can operate as hot as I-temp devices (85ºC) but cannot get any colder than -20ºC.

*Table 1: Comparing the temperature ranges of different temperature hardening standards, including industrial and automotive/full military applications*

The initial investment has a longer-term payoff

An expensive challenge for a network operator is having a product that cannot perform reliably in the uncontrolled environments of 5G deployments. With more bandwidth and computing power moving towards the network edges, coherent transceivers must endure potentially extreme conditions in outside environments. Since i-temp transceivers are more robust, they will survive for longer, and operators will ultimately buy fewer of them compared to c-temp modules. Therefore, the initial, somewhat more expensive investment in I-temp transceivers will pay off in the long run.

In addition, the growth of Internet-of-Things (IoT) applications makes reliability even more important. A network connection drop could be disastrous in many critical and business services, such as medical and self-driving car applications.

The importance of standards

Making an I-temp transceiver means that every internal component—the integrated circuits, lasers, photodetectors—must also be I-temp compliant. EFFECT Photonics has already developed I-temp pluggable transceivers with direct detection, so we understand what standards must be followed to develop temperature-hardened coherent devices.

For example, our optical transceivers comply with the Telcordia GR-468 qualification, which describes how to test optoelectronic devices for reliability under extreme conditions. Our manufacturing facilities include capabilities for the temperature cycling and reliability testing needed to match Telcordia standards, such as temperature cycling ovens and chambers with humidity control.

*Figure 3: Examples of necessary verification tests for transceivers that will operate in harsh temperatures*

EFFECT Photonics transceivers also comply with the SFF-8472 standard that describes the Digital Diagnostics Monitoring (DDM) required for temperature-hardened transceivers to compensate for temperature fluctuations. Our proprietary NarroWave technology even allows network operators to read such device diagnostics remotely, avoiding additional truck rolls to check the devices on the field. These remote diagnostics give operators a full view of the entire network’s health from the central office.

Takeaways: going from Direct-Detect to Coherent I-temp

One of our central company objectives is to bring the highest-performing optical technologies, such as coherent detection, all the way to the network edge. However, achieving this goal doesn’t just require us to focus on the optical or electronic side but also on meeting the mechanical and temperature reliability standards required to operate coherent devices outdoors. Fortunately, EFFECT Photonics can take advantage of its previous experience and knowledge in I-temp qualification for direct-detect devices as it prepares its new coherent product line.

If you would like to download this article as a PDF, then please click here.

Tags: access networks, coherent, coherent optics, commercial temperature, fiber networks, I-temp, industrial temperature, Integrated Photonics, LightCounting, NarroWave, network operators, optical transceivers, photonic integration, Photonics, pluggables, Transceivers

Wafer Scale Photonics for a Coherent Future

Insights

May 5, 2023

Wafer Scale Photonics for a Coherent Future

The advances in electronic and optical integration have brought down the size and cost of…

The advances in electronic and optical integration have brought down the size and cost of the coherent transceivers, packing more bits than ever into smaller areas. However, progress in the cost and bandwidth density of transceivers might slow down soon. Electronics has achieved amazing breakthroughs in the last two decades to continue increasing transistor densities and keeping Moore’s Law alive, but these achievements have come at a price. With each new generation of electronic processors, development costs increase and the price per transistor has stagnated.

Figure 1. Evolution of foundry sale price per million transistors over successive electronic process nodes. Based on data from TSMC. Source: AI Chips: What They Are and Why They Matter, Center for Security and Emerging Technology (April 2020).

Due to these developments, electronic digital signal processor (DSP) chips will continue to improve in efficiency and footprint, but their price will stagnate and with it the price of optical transceivers. Without further improvements in the cost per bit, it will be difficult to achieve the goal of making coherent technology more accessible across the entire optical network. This will make it more difficult to provide the device volume and services needed by the growing 5G networks and cloud providers.

To make coherent transceivers more accessible, photonics has to step up now more than ever. With the cost of DSPs stagnating, photonic integration must take the lead in driving down the costs and size of optical transceivers. Integrating all optical components on a single chip makes it easier to scale up in volume, reach these size and cost targets, and ultimately provide faster, more affordable, and sustainable coherent transmission.

Size Matters

Full photonic integration allows us to combine active optical elements like the laser and the amplifer with passive elements, all on the same chip and enclosed in a simple, non-hermetic package. This process enables a much smaller device than combining several indivudally packaged elements. For example, by integrating all photonic functions on a single chip, including lasers and optical amplifiers, EFFECT Photonics’ pluggable transceiver modules can achieve transmit power levels similar to those of line card transponder modules while still keeping the smaller QSFP router pluggable form factor, power consumption, and cost.

Figure 2: Comparing transmit power, noise, size, and cost of line card transponders and different transceiver pluggable modules. Fully integrated QSFP-DD modules include lasers and amplifiers inside a single chip, so they can deliver high transmit powers at small size and low cost.

Full integration technology increases the transmit power by minimizing the optical losses due to the use of more efficient optical modulators, fewer material losses compared to silicon, and the integration of the laser device on the same chip as the rest of the optical components. The semiconductor optical amplifiers (SOAs) used in fully integrated devices can also outperform the performance of micro-EDFAs for transmission distances of at least 80km.

The Economics of Scale

As innovative as full photonic integration can be, it will have little impact if it cannot be manufactured at a high enough volume to satisfy the demands of mobile and cloud providers and drive down the cost per device. Wafer scale photonics manufacturing demands a higher upfront investment, but the resulting high-volume production line drives down the cost per device. This economy-of-scale principle is the same one behind electronics manufacturing, and the same must be applied to photonics.

The more optical components we can integrate into a single chip, the more can the price of each component decrease. The more optical System-on-Chip (SoC) devices can go into a single wafer, the more can the price of each SoC decrease. Researchers at the Technical University of Eindhoven and the JePPIX consortium have done some modelling to show how this economy of scale principle would apply to photonics. If production volumes can increase from a few thousands of chips per year to a few millions, the price per optical chip can decrease from thousands of Euros to mere tens of Euros. This must be the goal for the optical transceiver industry.

Figure 3: Modelling of photonic integrated chip (PIC) cost as a function of aggregate number of PICs produced per year. Exponential increases in production lead to an exponential decrease in cost. Source: Model and graph provided by Prof. Meint Smit, TU Eindhoven.

Full Integration Streamlines Production and Testing

Integrating all optical components on a single chip can make manufacturing and testing more efficient, sustainable, and easier to scale up. The price of photonic devices is not dominated by the manufacturing of the semiconductor chips, but by the device assembly and packaging. Assembling and packaging a device by interconnecting multiple photonic chips together leads to an increase in assembly complexity and therefore additional costs.

This situation happens frequently with the laser component, which is often manufactured on a separate chip and then interconnected to the other optical components which are on another chip. Integrating all components—including the laser—on a single chip shifts the complexity from the assembly process to the much more efficient and scalable semiconductor wafer process. For example, it’s much easier to combine optical components on a wafer at a high-volume than it is to align different chips together in the assembly process, and that drives down the cost of the device.

Testing is another aspect that becomes more efficient and scalable when manufacturing at the wafer level. When faults are found earlier in the testing process, fewer resources and energy are spent in process defective chips. Ideally, testing should happen not only on the final, packaged transceiver but in the earlier stages of PIC fabrication, such as measuring after wafer processing or cutting the wafer into smaller dies.

Figure 4: Package vs. die level testing. Manufacturers can find faults earlier by testing at the die level, which avoids wasting packaging materials.

Full photonic integration enables earlier optical testing on the semiconductor wafer and dies. By testing the dies and wafers directly before packaging, manufacturers need only discard the bad dies rather than the whole package, which saves time, cost, and is more energy efficient and sustainable. For example, EFFECT Photonics reaps these benefits in its production processes. 100% of electrical testing on the PICs happens at the wafer level, and our unique integration technology allows for 90% of optical testing to also happen on the wafer.

Takeaways

Photonics is facing the next stage of its development. There have been many great breakthroughs that have allowed us to take photonic devices from the lab to real-world use cases. However, to have the biggest possible impact in society, we need to manufacture photonic devices at very high volumes to make them accessible to everyone. This requires us to think about production volumes in the scale of millions of units. At EFFECT Photonics, we believe that the way to achieve this goal is by following the blueprint laid out by our friends in the electronics industry. By integrating all optical components on a single chip, we can shift more complexity from the assembly to the wafer, allowing production to scale more efficiently and sustainably. In our next article, we will elaborate on another key factor of the electronics blueprint: the fabless development model.

Tags: coherent, coherent optics, Density, Integrated Photonics, LightCounting, network operators, optical transceivers, photonic integration, Photonics, pluggables, Transceivers, Wafer Scale Photonics

Insights

April 17, 2023

When will the Network Edge go Coherent?

Article first published 27 July 2022, updated 12 April 2023. Network carriers want to provide…

Article first published 27 July 2022, updated 12 April 2023.

Network carriers want to provide communications solutions in all areas: mobile access, cable networks, and fixed access to business customers. They want to provide this extra capacity and innovative and personalized connectivity and entertainment services to their customers.

Deploying only legacy direct detect technologies will not be enough to cover these growing bandwidth and service demands of mobile, cable, and business access networks with the required reach. In several cases, networks must deploy more 100G coherent dense wavelength division multiplexing (DWDM) technology to transmit more information over long distances. Several applications in the optical network edge could benefit from upgrading from 10G DWDM or 100G grey aggregation uplinks to 100G DWDM optics:

Mobile Mid-haul benefits from seamlessly upgrading existing uplinks from 10G to 100G DWDM.
Mobile Backhaul benefits from upgrading their links to 100G IPoDWDM.
Cable Access links could upgrade the uplinks of existing termination devices such as optical line terminals (OLTs) and Converged Cable Access Platforms (CCAPs) from 10G to 100G DWDM.
Business Services could scale enterprise bandwidth beyond single-channel 100G grey links.

However, network providers have often stuck to their 10G DWDM or 100G grey links because the existing 100G DWDM solutions could not check all the required boxes. “Scaled-down” coherent 400ZR solutions had the required reach and tunability but were too expensive and power-hungry for many access network applications. Besides, ports in small to medium IP routers used in most edge deployments often do not support the QSFP-DD form factor commonly used in 400ZR modules but the QSFP28 form factor.

Fortunately, the rise of 100ZR solutions in the QSFP28 form factor is changing the landscape for access networks. “The access market needs a simple, pluggable, low-cost upgrade to the 10G DWDM optics that it has been using for years. 100ZR is that upgrade,” said Scott Wilkinson, Lead Analyst for Optical Components at market research firm Cignal AI. “As access networks migrate from 1G solutions to 10G solutions, 100ZR will be a critical enabling technology.”

In this article, we will discuss how the recent advances in 100ZR solutions will enable the evolution of different segments of the network edge: mobile midhaul and backhaul, business services, and cable.

How Coherent 100G Can Move into Mobile X-haul

The upgrade from 4G to 5G has shifted the radio access network (RAN) from a two-level structure with backhaul and fronthaul in 4G to a three-level structure with back-, mid-, and fronthaul:

Fronthaul is the segment between the active antenna unit (AAU) and the distributed unit (DU)
Midhaul is the segment from DU to the centralized unit (CU)
Backhaul is the segment from CU to the core network.

Figure 1: Simplified diagram that shows and compares the building blocks of 4G (left) and 5G (right) access networks and the links between these blocks.

The initial rollout of 5G has already happened in most developed countries, with many operators upgrading their 1G SFPs transceiver to 10G SFP+ devices. Some of these 10G solutions had DWDM technology; many were single-channel grey transceivers. However, mobile networks must move to the next phase of 5G deployments, which requires installing and aggregating more and smaller base stations to exponentially increase the number of devices connected to the network.

These mature phases of 5G deployment will require operators to continue scaling fiber capacity cost-effectively with more widespread 10G DWDM SFP+ solutions and 25G SFP28 transceivers. These upgrades will put greater pressure on the aggregation segments of mobile backhaul and midhaul. These network segments commonly used link aggregation of multiple 10G DWDM links into a higher bandwidth group (such as 4x10G). However, this link aggregation requires splitting up larger traffic streams and can be complex to integrate across an access ring. A single 100G uplink would reduce the need for such link aggregation and simplify the network setup and operations. If you want to know more about the potential market and reach of this link aggregation upgrade, we recommend reading the recent Cignal AI report on 100ZR technologies.

Cable Migration to 10G PON Will Drive the Use of Coherent 100G Uplinks

According to Cignal AI’s 100ZR report, the biggest driver of 100ZR use will come from multiplexing fixed access network links upgrading from 1G to 10G. This trend will be reflected in cable networks’ long-awaited migration from Gigabit Passive Optical Networks (GPON) to 10G PON. This evolution is primarily guided by the new DOCSIS 4.0 standard, which promises 10Gbps download speeds for customers and will require several hardware upgrades in cable networks.

To multiplex these new larger 10Gbps customer links, cable providers and network operators need to upgrade their optical line terminals (OLTs) and Converged Cable Access Platforms (CCAPs) from 10G to 100G DWDM uplinks. Many of these new optical hubs will support up to 40 or 80 optical distribution networks (ODNs), too, so the previous approach of aggregating multiple 10G DWDM uplinks will not be enough to handle this increased capacity and higher number of channels.

Anticipating such needs, the non-profit R&D organization CableLabs has recently pushed to develop a 100G Coherent PON (C-PON) standard. Their proposal offers 100 Gbps per wavelength at a maximum reach of 80 km and up to a 1:512 split ratio. CableLabs anticipates C-PON and its 100G capabilities will play a significant role not just in cable optical network aggregation but in other use cases such as mobile x-haul, fiber-to-the-building (FTTB), long-reach rural scenarios, and distributed access networks.

Towards 100G Coherent and QSFP28 in Business Services

Almost every organization uses the cloud in some capacity, whether for development and test resources or software-as-a-service applications. While the cost and flexibility of the cloud are compelling, its use requires fast, high-bandwidth wide-area connectivity to make cloud-based applications work as they should.

Similarly to cable networks, these needs will require enterprises to upgrade their existing 1G Ethernet private lines to 10G Ethernet, which will also drive a greater need for 100G coherent uplinks. Cable providers and operators will also want to take advantage of their upgraded 10G PON networks and expand the reach and capacity of their business services.

The business and enterprise services sector was the earliest adopter of 100G coherent uplinks, deploying “scaled-down” 400ZR transceivers in the QSFP-DD form factor since they were the solution available at the time. However, these QSFP-DD slots also support QSFP28 form factors, so the rise of QSFP 100ZR solutions will provide these enterprise applications with a more attractive upgrade with lower cost and power consumption. These QSFP28 solutions had struggled to become more widespread before because they required the development of new, low-power digital signal processors (DSPs), but DSP developers and vendors are keenly jumping on board the 100ZR train and have announced their development projects: Acacia, Coherent/ADVA, Marvell/InnoLight, and Marvell/OE Solutions. This is also why EFFECT Photonics has announced its plans to co-develop a 100G DSP with Credo Semiconductor that best fits 100ZR solutions in the QSFP28 form factor.

Figure : Comparison between QSFP-DD and QSFP-28 form factors for 100G applications. — Figure 2 : Comparison between QSFP-DD and QSFP-28 form factors for 100G applications.

Takeaways

In the coming years, 100G coherent uplinks will become increasingly widespread in deployments and applications throughout the network edge. Some mobile access networks use cases must upgrade their existing 10G DWDM link aggregation into a single coherent 100G DWDM uplink. Meanwhile, cable networks and business services are upgrading their customer links from 1Gbps to 10Gbps, and this migration will be the major factor that will increase the demand for coherent 100G uplinks. For carriers who provide converged cable/mobile access, these upgrades to 100G uplinks will enable opportunities to overlay more business services and mobile traffic into their existing cable networks.

As the QSFP28 100ZR ecosystem expands, production will scale up, and these solutions will become more widespread and affordable, opening up even more use cases in access networks.

Tags: 5G, access, aggregation, backhaul, capacity, DWDM, fronthaul, Integrated Photonics, LightCounting, metro, midhaul, mobile, mobile access, network, optical networking, optical technology, photonic integrated chip, photonic integration, Photonics, PIC, PON, programmable photonic system-on-chip, solutions, technology

Technologies and trends and their impact

Insights

April 14, 2023

Scaling Up Live Event Coverage with 5G Technology

Everyone who has attended a major venue or event, such as a football stadium or…

How To Make a Photonic Integrated Circuit

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November 9, 2022

Leveraging the Power of External Foundries in Photonics

Working with a world-class high-volume foundry makes scaling up from low to high volume as…

Working with a world-class high-volume foundry makes scaling up from low to high volume as easy as putting a purchase order in place. Instead of having to buy equipment, develop processes, and train operators over many years, a fabless photonics developer can leverage foundries who already have these capabilities and knowledge.

Thanks to wafer scale technology, electronics has successfully driven down cost per transistor for many decades. This allowed the world to enjoy chips that every generation became smaller and provided exponentially more computing power for the same amount of money. This scale-up process is how everyone now has a computer processor in their pocket that is millions of times more powerful than the most advanced computers of the 1960s that landed men on the moon.

This progress in electronics integration is a key factor that brought down the size and cost of coherent transceivers, packing more bits than ever into smaller areas. However, photonics has struggled to keep up with electronics, and now the optics dominate the optical transceiver’s cost. If the transceiver cost curve does not continue to decrease, it will be difficult to achieve the goal of making coherent technology more accessible across the entire optical network. This will make it more difficult to provide the services needed by cloud providers and the growing 5G access networks.

As we mentioned in our previous article, photonics manufacturing must move into wafer-scale territory to provide faster, more affordable, and sustainable coherent transmission.

However, most photonic chip developers don’t have human and financial resources to own and operate their own wafer-scale photonic foundries. Fortunately, electronic chip developers have shown a more viable and cost-effective alternative: the fabless model.

A Lower Upfront Investment

Increasing the volume of photonics manufacturing is a big challenge. Some photonic chip developers choose to manufacture their chips in-house within their own fabrication facilities. This approach has some strong advantages, as it gives component manufacturers full control over their production process. By vertically integrating the whole chip design, manufacturing, and testing process within the same company, it’s often easier to try out new changes and innovations to the product.

Figure 1: Simplified value chain diagram of a vertically-integrated optical transceiver developer. The developer handles the PIC design, manufacturing, and packaging

However, this approach has its trade-offs. If a vertically-integrated chip developer wants to scale up in volume, they must make a hefty investment in more equipment and personnel to do so. They must develop new fabrication process which not only need money, but also time to develop and train personnel. Especially in the case of an optical transceiver market that is not as big as that of consumer electronics, it’s hard not to wonder whether that initial investment is cost-effective.

Electronics manufacturing had a similar problem during their 1970s boom, with smaller chip start-ups facing almost insurmountable barriers to enter the market because of the massive capital expenditure (CapEx) required. Electronics solved this problem by moving into what we call a fabless model, with companies designing and selling the chips but outsourcing the manufacturing.

For example, transceiver DSP chip developers design the chip, but then outsource the actual fabrication to a large-volume manufacturing plant (usually called a foundry). This business model works by leveraging the design, research, development, and distribution networks of the fabless company, and the specialized manufacturing skill of the chip foundry.

Figure 2: Simplified value chain diagram of a vertically-integrated optical transceiver developer. The developer handles the PIC design, manufacturing, and packaging.

This model reduces the capital expenditure burden on the DSP developers, because instead of spending all the time and energy in scaling up their own facilities, they can work with a foundry that already did that investment and has the required manufacturing volume. In other words, instead going through a more costly, time-consuming process, the troubles of scaling up are outsourced and (from the perspective of the fabless company) become as simple as putting a purchase order in place. Furthermore, the fabless model also allows companies to concentrate their R&D resources on the end market. If photonics is to move into million-scale volumes, this is likely the way forward.

Economies of Scale and Operating Expenses

Even if an optical transceiver developer could move forward with the CapEx required for its own large-scale fab and a vertically-integrated model, market demand and operational expenses become the next pain point. Transceivers are a B2B market, and their demand is significantly smaller than of B2C consumer electronics. For example, LightCounting estimates that 55 million optical transceivers will be sold in 2021, while the International Data Corporation estimates that 1.4 billion smartphones will be sold in 2021. The latter figure is 25 times larger than that of the transceiver market.

The smaller demand of transceivers means that even if a vertically-integrated transceiver developer upgrades to a larger-scale manufacturing facility, it will likely have more manufacturing capacity than what their customers need. In such a situation, the facility could run at a reduced capacity. However, fabs are not only expensive to build, but also to operate. Unless they can be kept at nearly full utilization, operating expenses (OpEx) will become a drain on the finances of the facility owners.

This issue was something the electronics industry faced in the past, during the 1980s. Integrated electronics manufacturers had excess production capacity, and this situation paved the way for the fabless model too. The large-scale manufacturers ended up selling that excess capacity to smaller, fabless chip developers. Ultimately, the entire electronics industry relied increasingly on the fabless model, to the point where pure play foundries like the Taiwan Semiconductor Manufacturing Corporation (TSMC) appeared and focused entirely on manufacturing for other fabless companies.

In this scenario, everyone ended up winning. The foundries serviced multiple companies and could run their facilities at full capacity, while the fabless companies could outsource manufacturing and reduce their expenditures.

Working with the Best in the Business

The other advantage of pure play foundries is that they not only have state-of-the art equipment but also the best personnel and technical expertise. Even if a vertically-integrated developer transceiver can make the required CapEx to scale up their facilities, developing processes and training people inevitably takes years, delaying the return on investment even further.

By working with an established and experienced foundry, fabless companies take advantage of the highly trained and experience personnel of these facilities. These operators, technicians, and engineers have worked day in, day out with their equipment for years and already developed processes that are finely tuned to their equipment. Thanks to their work, fabless transceiver developers do not have to reinvent the wheel and come up with their own processes, saving valuable time and many, many headaches.

Takeaways

To make transceivers more accessible to world and connect more people together, transceiver developers need to reach production scales in the millions. At EFFECT Photonics, we believe that the way to achieve this goal is by having photonics follow the blueprint laid out by the electronics industry. Using a fabless model, we can reduce the capital expenditure and scale up more quickly and with fewer risks.

Working with a world-class high-volume foundry makes scaling up from low to high volume as easy as putting a purchase order in place. Instead of having to buy equipment, develop processes, and train operators over many years, a fabless photonics developer can leverage foundries who already have these capabilities and knowledge.

Tags: coherent, coherent optics, external foundries, foundries, Integrated Photonics, LightCounting, optical transceivers, photonic integration, Photonics, photonicwafer, pluggables, Transceivers, wafer

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November 4, 2022

The Growth of Business Ethernet Services

The increasing use of data and fiercely price-conscious and multimedia-hungry business subscribers can limit revenue…

The increasing use of data and fiercely price-conscious and multimedia-hungry business subscribers can limit revenue opportunities for the network provider industry. Providers must therefore look elsewhere to grow their customer base, open new revenue streams, and boost margins. So how can they adapt their business strategies and achieve growth objectives?

Just as operators scale up high-capacity data center interconnects to cope with these needs, providers can add Ethernet services for high-capacity services. These can offer a differentiated and competitive service to corporate customers, ranging from 1G to 100G and beyond. Not only will Ethernet services add a cost-effective alternative to existing services, but they also ensure business Ethernet offerings are set up to complement wide area networks and hybrid network services.

According to Ovum, the global enterprise Ethernet services market will grow at 10.7% CAGR, exceeding $70bn by 2020 (Ovum’s Ethernet Services Forecast, Sep 2015), and is now the de facto wide-area network data connectivity technology. Ethernet will be a significant portion of the data service market driven by enthusiasm for higher bandwidth services. This growth will continue as we adopt more cloud-based applications and enterprises embrace digital transformation. Business Ethernet solutions can be further boosted with tunable DWDM transceivers.

Towards Carrier Ethernet

With applications and data volumes exploding in organizations of all types and sizes, there is an increasing need for 1GbE+ connections, with 10GbE+ connectivity for company headquarters and even 100GbE+ connections for data center connectivity. Specifically, demand is being driven by the proliferation of bandwidth-hungry applications. An MRI scan, for example, can be a 300GB file, which would take around 7 hours to download over a 100Mbps connection. Over a 10GbE link, that time falls to just 4 minutes and 28 seconds on a 100GbE link – this can be the difference between life and death when a consultant needs to make a time-critical decision on how to treat their patient best.

Enterprises know all about cost-containment and budget constraints. Virtual private networks (VPNs) based on legacy MPLS protocols have their place when delivering wide-area connectivity. These VPNs can offer any-to-any connectivity and scale to thousands of sites – but, at the higher speeds needed for high-bandwidth applications, they can be significantly more expensive than business Ethernet to deploy and maintain.

In addition, the MPLS routers needed for IP VPN have acquired more and more protocols and complexity over the last few decades. The cost of implementing all of these protocols, and securing them against attack, has driven leading service providers to demand a radically more straightforward way of building networks.

With business Ethernet, the network infrastructure and management can be unified under Ethernet protocol, making the network easier to plan, deploy and manage at scale. This means fewer routers, more remotely programmable services, and fewer truck rolls resulting in a lower cost per bit than comparable VPN solutions. These savings scale across 1GbE, 10GbE, and 100GbE connections with less CAPEX investment, helping to increase the predictability of delivery costs over time. WDM solutions can further boost this capacity.

Towards a Coherent Upgrade with 100ZR

Almost every organization uses the cloud in some capacity, whether for development and test resources or software-as-a-service applications. While the cost and flexibility of the cloud are compelling, many IT executives overlook the importance of fast, high-bandwidth wide-area connectivity to make cloud-based applications work as they should.

These needs might require businesses with huge traffic loads to upgrade to 25G, 100G, or even 400G speeds. These capacity needs would require coherent technology. Fortunately, advances in electronic and photonic integration have miniaturized coherent line card transponders into pluggable modules the size of a large USB stick.

Many of these business applications will require links between 25 Gbps and 100 Gbps that span several tens of kilometers to connect to the network provider’s headend. For these sites, the 400ZR pluggables that have become mainstream in datacom applications are not cost-effective when utilization is so low. This is where 100ZR technology comes into play.

100ZR is currently a marketing term for a short-reach (~80 km) coherent 100Gbps in a QSFP pluggable. Targeted at the metro edge and enterprise applications that do not require 400Gbps, 100ZR provides a lower-cost, lower-power pluggable that also benefits from compatibility with the large installed base of 50 GHz and legacy 100 GHz DWDM/ROADM line systems.

Self-Tuning Makes Management Easier

Businesses that need to aggregate many sites and branches into their networks will likely require tunable transceiver solutions to interconnect them. The number of available channels in tunable modules can quickly become overwhelming for technicians in the field. There will be more records to examine, more programming for tuning equipment, more trucks to load with tuning equipment, and more verifications to do in the field. These tasks can take a couple of hours just for a single node. If there are hundreds of nodes to install or repair, the required hours of labor will quickly rack up into the thousands and the associated costs into hundreds of thousands. Self-tuning modules significantly overcome these issues and make network deployment and maintenance more straightforward and affordable.

Self-tuning allows technicians to treat DWDM tunable modules the same way they would grey transceivers. There is no need for additional training for technicians to install the tunable module. There is no need to program tuning equipment. There is no need to obsessively check the wavelength records and tables to avoid deployment errors on the field. Technicians only need to follow the typical cleaning and handling procedures, plug the transceiver, and the device will automatically scan and find the correct wavelength once plugged. This feature can save providers thousands of person-hours in their network installation and maintenance and reduce the probability of human errors, effectively reducing capital and operational expenditures (OPEX).

Takeaways

With business Ethernet, one can set up super-fast connections for customers and connect their locations and end-users with any cloud-based services they use. Business Ethernet solutions can be further boosted with tunable DWDM transceivers. If business future-proof their networks with upgrades like 100ZR transceivers, they can scale up connectivity seamlessly to ensure that applications always provide an excellent end-user experience. That connectivity is never a limiting factor for customers’ cloud strategies. As the business sector seeks to upgrade to greater capacity and easier management, tunable and coherent transceivers will be vital in addressing their needs.

Tags: 5G, access, aggregation, backhaul, capacity, DWDM, fronthaul, Integrated Photonics, LightCounting, metro, midhaul, mobile, mobile access, network, optical networking, optical technology, photonic integrated chip, photonic integration, PIC, PON, programmable photonic system-on-chip, solutions, technology

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November 3, 2022

How to Increase Bandwidth Density in Photonics

In the past, optical transceivers were too bulky, too expensive, and not efficient enough, so…

In the past, optical transceivers were too bulky, too expensive, and not efficient enough, so they could only be used for long-haul telecom networks or data centers with massive bandwidth requirements. Electronic and photonic integration broke this paradigm, miniaturizing optical transceivers to the size of a large USB stick and reducing their cost. Through these advances, optical component manufacturers could pack exponentially more bandwidth into a smaller transceiver area within the last decade. Thanks to this exponential progress, component manufacturers managed to keep up with the exponentially-growing worldwide demand for data.

*Figure 1: Exponential growth of bandwidth density over time through the evolution of types of transceiver module standards.*

However, the next wave of innovative network services—autonomous vehicles, the Internet of Things, Industry 4.0—demands even more bandwidth and other requirements. Optical links that connect 5G controller units to the rest of the network must upscale from 10G to 100G. The links from metro networks to datacenters must upscale from 100G to 400G or 800G, and the links within datacenters must operate at Terabit speeds. These services require not only more bandwidth but also lower latencies and more reliability. Further electronic integration cannot keep up by itself; photonic integration must also continue pushing the envelope on bandwidth density.

In our previous articles and videos, we have already discussed one way to increase the bandwidth density through coherent transmission. Coherent technology can pack more bits into a laser signal because it encodes data in the laser light’s amplitude, phase, and polarization. The use of digital signal processing in these devices improves the reach and bandwidth of the signal even further. Coherent transmission allows network operators to reach higher bandwidths without upgrading their existing optical fiber infrastructure. Conserving and reusing existing fiber infrastructure is also a sustainability measure because it avoids spending additional energy and resources on manufacturing more fiber and laying it down on the roads.

However, another way to improve the bandwidth density is by moving to full photonic integration. Let’s use an analogy from electronics to explain what this means.

*Figure 2: Example of integrating a laser to other photonic components through different integration approaches.*

Before 2020, Apple made its computer processors with discrete components. In other words, electronic components were manufactured on separate chips, and then these chips were assembled into a single package. However, the interconnections between the different chips produced losses and incompatibilities that made the device less efficient. After 2020, starting with Apple’s M1 processor, they now fully integrate all components on a single chip, making the device more energy efficient and reducing its footprint.

Full photonic integration achieves something similar to Apple’s approach, but with optical components instead of electronic components. By integrating all optical elements required for optical transmission (lasers, detectors, modulators, etc.) into a single System-on-Chip (SoC), we can minimize the losses and reduce the chip’s footprint, transmitting more bits over the same chip area. Furthermore, as we discussed in a previous article, a fully integrated system-on-chip reduces materials wastage while at the same time ensuring increased energy efficiency of the manufacturing, packaging, and testing process.

Coherent transmission and full photonic integration approaches must synergize to achieve the highest possible bandwidth density. For example, EFFECT Photonics taped out a fully-integrated coherent optical System-on-Chip (SoC) last year. This device can push hundreds of Gigabits per second within a chip that fits inside your fingertip, and we want to turn this breakthrough into a world-class coherent product. We believe it is the next step in packing exponentially more data into optical chips, allowing the world to keep up with the exponential increase in data for years to come.

In the coming weeks, we will discuss more photonic integration and how to implement it in larger volumes to make coherent transmission more widespread around the world.

Tags: bandwidth, coherent, coherent optics, Density, fiber networks, increase bandwidth density, Integrated Photonics, LightCounting, network operators, optical transceivers, photonic integration, Photonics, pluggables, Transceivers

Insights

September 19, 2022

How Many DWDM Channels Do You Really Need?

Optical fiber and dense wavelength division multiplex (DWDM) technology are moving towards the edges of…

Optical fiber and dense wavelength division multiplex (DWDM) technology are moving towards the edges of networks. In the case of new 5G networks, operators will need more fiber capacity to interconnect the increased density of cell sites, often requiring replacing legacy time-division multiplexing transmission with higher-capacity DWDM links. In the case of cable and other fixed access networks, new distributed access architectures like Remote PHY free up ports in cable operator headends to serve more bandwidth to more customers.

A report by Deloitte summarizes the reasons to expand the reach and capacity of optical access networks: “Extending fiber deeper into communities is a critical economic driver, promoting competition, increasing connectivity for the rural and underserved, and supporting densification for wireless.”

*Figure 1: Comparison between legacy and future deep fiber deployments in access networks. Yellow lines represent copper links, blue represents coaxial, and the green represents optical fiber.*

To achieve such a deep fiber deployment, operators look to DWDM solutions to expand their fiber capacity without the expensive laying of new fiber. DWDM technology has become more affordable than ever due to the availability of low-cost filters and SFP transceiver modules with greater photonic integration and manufacturing volumes. Furthermore, self-tuning technology has made the installation and maintenance of transceivers easier and more affordable.

Despite the advantages of DWDM solutions, their price still causes operators to second-guess whether the upgrade is worth it. For example, mobile fronthaul applications don’t require all 40, 80, or 100 channels of many existing tunable modules. Fortunately, operators can now choose between narrow- or full-band tunable solutions that offer a greater variety of wavelength channels to fit different budgets and network requirements.

Example: Fullband Tunables in Cable Networks

Let’s look at what happens when a fixed access network needs to migrate to a distributed access architecture like Remote PHY.

A provider has a legacy access network with eight optical nodes, and each node services 500 customers. To give higher bandwidth capacity to these 500 customers, the provider wants to split each node into ten new nodes for fifty customers. Thus, the provider goes from having eight to eighty nodes. Each node requires the provider to assign a new DWDM channel, occupying more and more of the optical C-band. This network upgrade is an example that requires a fullband tunable module with coverage across the entire C-band to provide many DWDM channels with narrow (50 GHz) grid spacing.

Furthermore, using a fullband tunable module means that a single part number can handle all the necessary wavelengths for the network. In the past, network operators used fixed wavelength DWDM modules that must go into specific ports. For example, an SFP+ module with a C16 wavelength could only work with the C16 wavelength port of a DWDM multiplexer. However, tunable SFP+ modules can connect to any port of a DWDM multiplexer. This advantage means technicians no longer have to navigate a confusing sea of fixed modules with specific wavelengths; a single tunable module and part number will do the job.

Figure 2: Example of a point-to (multi-)point system with fullband tunable modules. Each of the 10G SFP+ modules is a full C-band tunable covering ITU channels 14 to 61. This link uses the different wavelengths for up-and downstream transmission, allowing for a full-duplex transmission across a single fiber and multiplexer.

Overall, fullband tunable modules will fit applications that need a large number of wavelength channels to maximize the capacity of fiber infrastructure. Metro transport or data center interconnects (DCIs) are good examples of applications with such requirements.

Example: Narrowband Tunables in Mobile Fronthaul

The transition to 5G and beyond will require a significant restructuring of mobile network architecture. 5G networks will use higher frequency bands, which require more cell sites and antennas to cover the same geographical areas as 4G. Existing antennas must upgrade to denser antenna arrays. These requirements will put more pressure on the existing fiber infrastructure, and mobile network operators are expected to deliver their 5G promises with relatively little expansion in their fiber infrastructure.

*Figure 3: Simplified diagram that shows and compares the building blocks of 4G (left) and 5G (right) access networks and the links between these blocks.*

DWDM solutions will be vital for mobile network operators to scale capacity without laying new fiber. However, operators often regard traditional fullband tunable modules as expensive for this application. Mobile fronthaul links don’t need anything close to the 40 or 80 DWDM channels of a fullband transceiver. It’s like having a cable subscription where you only watch 10 out of the 80 TV channels.

This issue led EFFECT Photonics to develop narrowband tunable modules with just nine channels. They offer a more affordable and moderate capacity expansion that better fits the needs of mobile fronthaul networks. These networks often feature nodes that aggregate two or three different cell sites, each with three antenna arrays (each antenna provides 120° coverage at the tower) with their unique wavelength channel. Therefore, these aggregation points often need six or nine different wavelength channels, but not the entire 80-100 channels of a typical fullband module.

With the narrowband tunable option, operators can reduce their part number inventory compared to grey transceivers while avoiding the cost of a fullband transceiver.

Synergizing with Self-Tuning Algorithms

The number of channels in a tunable module (up to 100 in the case of EFFECT Photonics fullband modules) can quickly become overwhelming for technicians in the field. There will be more records to examine, more programming for tuning equipment, more trucks to load with tuning equipment, and more verifications to do in the field. These tasks can take a couple of hours just for a single node. If there are hundreds of nodes to install or repair, the required hours of labor will quickly rack up into the thousands and the associated costs into hundreds of thousands.

*Figure 4: Short description and comparison of different approaches to DWDM tunable modules.*

Self-tuning allows technicians to treat DWDM tunable modules the same way they treat grey transceivers. There is no need for additional training for technicians to install the tunable module. There is no need to program tuning equipment or obsessively check the wavelength records and tables to avoid deployment errors on the field. Technicians only need to follow the typical cleaning and handling procedures, plug the transceiver, and the device will automatically scan and find the correct wavelength once plugged. This feature can save providers thousands of person-hours in their network installation and maintenance and reduce the probability of human errors, effectively reducing capital and operational expenditures.

Self-tuning algorithms make installing and maintaining narrowband and fullband tunable modules more straightforward and affordable for network deployment.

Takeaways

Fullband self-tuning modules will allow providers to deploy extensive fiber capacity upgrades more quickly than ever. However, in use cases such as mobile access networks where operators don’t need a wide array of DWDM channels, they can opt for narrowband solutions that are more affordable than their fullband alternatives. By combining fullband and narrowband solutions with self-tuning algorithms, operators can expand their networks in the most affordable and accessible ways for their budget and network requirements.

Tags: 100G, 5G, 6G, access, access networks, aggregation, backhaul, capacity, coherent, DWDM, fronthaul, Integrated Photonics, LightCounting, live events, metro, midhaul, mobile, mobile access, mobile networks, network, optical networking, optical technology, photonic integrated chip, photonic integration, Photonics, PIC, PON, programmable photonic system-on-chip, solutions, technology, VR, WDM

Sub-Assemblies: pITLA

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Sub-Assemblies: pITLA

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Sub-Assemblies: pITLA

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LightCounting

Enhancing Mobile Fronthaul Capacity

DWDM Solutions For Fronthaul Aggregation

The Dream of Fixed-Mobile Access

Takeaways

From Matches to the Light Bulb Factory

From ASML and Photonics Research to Philips

Bringing Photonics into the Real World from the Lab

Controlled vs. uncontrolled environments

The initial investment has a longer-term payoff

The importance of standards

Takeaways: going from Direct-Detect to Coherent I-temp

Size Matters

The Economics of Scale

Full Integration Streamlines Production and Testing

Takeaways

How Coherent 100G Can Move into Mobile X-haul

Cable Migration to 10G PON Will Drive the Use of Coherent 100G Uplinks

Towards 100G Coherent and QSFP28 in Business Services

Takeaways

A Higher Bandwidth Experience

New Ways of Interaction

Strengthening the Transport Network

Takeaways

A Lower Upfront Investment

Economies of Scale and Operating Expenses

Working with the Best in the Business

Takeaways

Towards Carrier Ethernet

Towards a Coherent Upgrade with 100ZR

Self-Tuning Makes Management Easier

Takeaways

Example: Fullband Tunables in Cable Networks

Example: Narrowband Tunables in Mobile Fronthaul

Synergizing with Self-Tuning Algorithms

Takeaways

Sub-Assemblies: pITLA

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Contact Us