Next-Generation Transport and Broadband: Challenges and Solutions


June 29, 2023


A guest post from Emir Halilovic, Research Director of Telecom Technology & Software Group at GlobalData.

Operators are facing external challenges that also affect their network buildouts and service development plans.

The pace of telecom network transformation has accelerated in recent years, driven by the much increased adoption of high-bandwidth consumer services, the introduction and evolution of 5G in mobile networks, the expanded use of cloud-based applications, and the digitization of various enterprise verticals.

This accelerated pace of change has increased the focus on development and transformation of practically all domains of telecoms infrastructure.

In parallel with these drivers of network transformation, operators are also facing a set of external challenges that also affect their network buildouts and service development plans. Increasing energy prices and a general focus on sustainability have opened the way for building business cases for network development with a strong sustainability angle. The pace of change has accelerated as well, underscoring the need to build networks capable of quickly scaling up and down or serving different customer segments and use cases all at once. 

In optical transport and fixed access, this set of traditional and new requirements can roughly be divided into three sets of complementary challenges that operators face in developing their networks:

  • Sustainable capacity scaling: Until recently, optical transport and fiber-based broadband access scaling challenge was usually tackled by usual means. The first step was usually adding more wavelengths, in the case of optical transport, and reducing contention ratios and boosting user download/upload speeds in the case of FTTx. The second step usually involved deploying new technologies – higher line rates for optical transport, or new PON technologies for fiber access. However, with incessant traffic growth in transport, and fiber access supporting new use cases and applications, operators will likely need to add other methods to their operational practices to ensure not only that capacity scaling is in line with traffic and application demands, but also to increase the sustainability of their network infrastructures.
  • Multi-service capabilities: Despite the efforts to break down operational “silos” in telecom networks – operational stacks linking services to specific network domains or whole networks – very few operator domains today effectively support multiple diverse services or service families. In transport, the network capabilities required for multi-service support are constantly developing. Some service types – most importantly related to 5G use cases – benefit from precise timing and synchronization, and some require reduced and/or deterministic latency. Advanced enterprise services, such as optical private lines, usually require encryption capabilities, and put a premium on reliability. In fiber access, use cases beyond home broadband, like enterprise connectivity, wholesale, or mobile xHaul require not only higher bandwidth, but also increased service reliability and availability, as well as control over bandwidth and latency. Additionally, the most demanding new services in fixed access will require stringent time and phase synchronization, as well as improved latency and low jitter.
  • Enhanced visibility, automation capabilities: Multi-service support, but also the operational demands of network automation require next-level network visibility and control. The new control systems deployed in optical transport and access need to be developed with capabilities allowing per-customer and per-service QoS insights linked with network element and sub-system visibility. Coupled with that, operators need control mechanisms allowing for versatile and flexible network management and administration plus evolving automation support to augment network management staff effectiveness and reduce operational costs.  

This set of challenges and requirements network operators face in developing their infrastructures defines the evolving demands in fixed access and transport technology development and adoption. The main difference compared to the situation operators faced in the recent past is the addition of emphases on sustainability, efficiency, and flexibility. These requirements translate into the following set of new technology and operational capabilities:

  • Evolved optics for spectral and power efficiency: With per-wavelength performance of optical networks nearing the Shannon limit, operators and vendors are looking at increasing the capacity of transport networks through expanding addressable optical spectrum. Current state-of-the art optical line systems enable the use of Super-C and Super-L bands. Future developments will address the S-spectrum band as well. The use of advanced optics – advanced amplifiers, WSS, or all-optical OXC – can improve power efficiency and system performance significantly.
  • Transport-access integration: Sustainable capacity scaling in optical access can be achieved by streamlining customer speed upgrades through the targeted use of flexible PON line cards concurrently supporting different technologies, from legacy GPON to future 50G PON. This allows operators to expand their service offerings while at the same time avoiding forklift upgrades. On the transport side, overall network efficiency and performance can be improved by introducing OTN transport links, thus directly integrating fiber OLTs as OTN nodes into optical transport. 
  • In multi-service environments, operators need to consider deploying technologies that allow for the most demanding projected use cases to be served. 5G and 5G Advanced use cases, for example, dictate end-to-end system timing and sync performance that, in turn, requires much increased timing and sync precision of transport or backhaul domain.

One technology that can ensure precise control on connection parameters is the OTN Optical Service Unit (OSU), which combines OTN features with capability to set up small granularity connections. At the same time, traffic growth requires capacity to increase. Finally, both transport and access domains need to support network slicing to be able to cater to services requiring isolation and guaranteed QoS. Operators intending to streamline their transport and access networks by supporting multiple types of traffic to coexist need to approach these functionality requirements strategically and build their networks with a clear view of desired outcomes, making technology choices that will allow maximum flexibility and versatility of their transport and access networks. 

  • Advanced Control, Management, Orchestration: Operators deploying multi-service transport and access networks need to consider the use of advanced software functionality from day one. Multi-service operations require expanded network and service visibility and QoS control, and greatly profit from automation capabilities like zero-touch provisioning, self-service mechanisms, or predictive maintenance. Advanced visualization and QoS control, the ability to precisely monitor ODN parameters in real time, or using digital optical labels in metro optical networks can be used to enable the end-to-end automation of optical access or the transport service lifecycle. Using this software functionality, operators can achieve much greater service velocity and shorter time-to-market and serve diverse customer segments with differentiated QoS.  

The evolving nature of customer demand and operator services dictates the directions for the evolution of optical transport and fixed access networks. Additionally, operators should look for ways to build their networks sustainably. Sustainability, however, needs to be considered in a multi-dimensional fashion. That means considering factors beyond power efficiency or space requirements. For example, building networks using technologies with a long development roadmap ahead will likely result in less need for upgrades in the future – which increases both the environmental and financial sustainability of the infrastructure.

Operators should also reflect their overall strategy in the development of their transport and access networks. In addition to increasing capacity, operators should develop multi-service capabilities of the network through expanding features like network slicing, or automation, in addition to exploring ways to enhance performance on latency, timing precision, and network reliability. Following these principles should ensure the design of telco networks fit for the next generation of services and use cases, and therefore provide secure foundation for sustainable growth and new service revenue.

Learn more about Huawei’s Converged Transport Networks.

Disclaimer: Any views and/or opinions expressed in this post by individual authors or contributors are their personal views and/or opinions and do not necessarily reflect the views and/or opinions of Huawei Technologies.

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