How operators can overcome the challenges of 5G NSA multi-vendor anchoring

For many operators, the journey to 5G begins with non-standalone (NSA) mode, where the 5G network is built on top of a 4G infrastructure. Since 5G is not yet available nationwide, 5G NSA is critical for facilitating national coverage, as it enables the seamless handover between 4G and 5G that is required for effectively compensating for coverage holes.

Moreover, with the rollout of 5G cells being a cost-intensive venture, NSA networking enables operators to launch 5G without having to endeavor full-scale investment in a 5G core network. With NSA they can ensure economic viability by optimizing the existing infrastructure and extending the life of their 4G equipment as they accelerate time to market.

How dual connectivity is essential for 4G to 5G handover

For 5G services and data speeds to run on a network that is still primarily 4G, dual connectivity is a must. That is, both the LTE Master Node Evolved Node B (MN-eNB) and the 5G New Radio (NR) Secondary Node gNodeB (gNB) need to have a fixed connection. Otherwise, the user equipment (UE) won’t be able to leverage the benefits of 5G NR while enjoying the stability of 4G.

Yet, as essential as dual connectivity is to 5G NSA, it can be challenging. There are cases in which synchronization between the 4G and 5G networks must be precise, balancing traffic can be difficult, and certain preconditions must be in place, such as:

• The UE must support 5G as well as the two LTE/5G bands simultaneously.
• The 5G UE must be able to camp on the 4G cell.
• The 5G signal strength (SS) must be above the defined threshold.

But even when all these conditions are in place and challenges are overcome, dual connectivity is not possible without anchoring, which poses its own set of challenges.

Anchoring — The 5G NSA enabler

Simultaneous LTE eNB and 5G gNB connections in 5G NSA require anchoring. This means the 4G LTE network is defined as the anchor link, where:

• The connection between the LTE and NR nodes is defined, so they can communicate with each other. 
• Mobility between the LTE source cell and the target 5G cell is defined.
• The 5G and LTE specifications to be measured are defined.  
• ENDC is activated on the eNB for specific LTE cells and the gNB.

Accomplishing these tasks effectively and efficiently is a complex undertaking. 

For example, when there is radio frequency (RF) overlap between LTE and NR cells, it is difficult to know which should be selected for anchor activation to optimize performance and avoid wasting resources. Additionally, it’s not always easy to know what the minimal required level of overlapping is between the two cells that should be defined.

Another challenge arises from LTE hardware that is limited in its ability to support 4G-5G time synchronization. Since 5G employs a timing mechanism that differs from that which is used by LTE, an accurate time synchronization definition is needed for ensuring efficient node-to-node communication and 5G signal acquisition. 

The multi-vendor challenge when rolling out to 5G

The third — and most demanding — challenge to 5G NSA anchoring is the multi-vendor network where, in some cases, the underlying 4G network is comprised of equipment from vendor X, but the 5G NSA equipment that is optimal for the operator is provided by vendor Y. In this kind of network, a multi-vendor anchor will need to be defined to allow for inter-working between the two. This translates into provisioning that is profoundly more complex. 

First, a greater number of managed objects than ever before — sometimes more than 15 — need to be deleted, changed and added. And all this needs to be done on multiple operations support systems (OSSs) from multiple vendors. This entails a long and cumbersome back-and-forth process of continually switching between OSSs, since new 4G and 5G managed objects can’t be defined and added before deleting the old parameters on the 4G vendor’s equipment.

Moreover:

• There is a very specific order for these changes that must be followed;
• Every deletion, modification and addition must align with the operator’s policy;
• All the dependencies among the various managed objects must be accounted for;
• There is more manual work, since the definitions of managed objects that are typically automated by the OSS, can’t be automated in intra-vendor anchoring.

That said, many 5G NSA operators may not be able to afford not overcoming the multi-vendor anchoring challenge. Without doing so, they may not be able to deliver the 5G experience that customers expect and could miss out on the 5G monetization opportunity.

So how can operators roll out 5G NSA with the vendor of their choice, avoid the multi-vendor anchoring challenge, and accelerate 5G time to market?

The key is a combination of vendor agnostic, AI-driven configuration automation, and programmable provisioning.

How the Qualcomm Edgewise Suite can help roll out 5G NSA

The Qualcomm Edgewise Suite simplifies the complexities of multi-vendor anchoring, so network operators can have the freedom to choose any vendor for any layer, while avoiding the costs of 4G rip-and-replace when opting for a different 5G equipment vendor.

Qualcomm Edgewise Suite helps users to overcome logic, dependencies and other limitations, which not only makes deleting, adding and modifying definitions more seamless, but also facilitates alignment with the operator’s policy. It manages complex multi-vendor decisioning — automatically detecting and resolving inconsistencies in existing vendor anchoring definitions to make new ones — without any of the customization complexities that inter-vendor logic typically entails.

With a broad portfolio of anchor definitions that are compatible with the equipment of leading vendors, users can manage interdependencies and flows in multiple vendor combinations, regardless of the hardware and logic involved. And with programmable provisioning, the Qualcomm Edgewise Suite enables the local deployment team to be independent in defining the provisioning flow for each inter-vendor scenario. 

In this manner, Qualcomm Edgewise Suite has activated hundreds of thousands of 5G NSA cells and counting, and will continue to enable Tier-1 operators all over the world to activate their 5G NSA sites.

When seeking to simplify the deployment of 5G on top of another vendor’s 4G equipment, vendor agnostic, AI-driven configuration automation with programmable provisioning is the key to simplified and effective multi-vendor anchoring — and to accelerating 5G rollout for realizing the connected intelligent edge.