Finally, the contract provides for Discontinuation, which covers how and when the slice should be discontinued. This is important to release committed resources to ensure that old slice components (so-called “zombies”) do not proliferate and consume network resources.  Unfortunately, this is a problem already in existence today. There are many things running in our networks and infrastructures that were started years ago. Nobody knows what they do, but people are afraid to turn them off. Most of these things just consume resources while doing nothing productive, or worse. Having a requirement for specific terms for discontinuation can go a long way toward avoiding the proliferation of more such zombies.

Umbrella Data Model

Now that we have a negotiation framework, how do the NFOs communicate? The default can be text strings, but it will be much easier if it is possible to communicate by simply referencing objects in a data model. But where does the data model come from? It turns out that there are many forces working on data models in the CSP context. A number of different standards organizations have developed different and sometimes overlapping data models. In an effort to differentiate their products, vendors have developed different data models. And different CSPs have developed their own, too. It is tempting to retreat to an older paradigm and set out to create a single data model for all, but that is both impractical and will create a serious roadblock to 5G slicing. What we really want to do is enable 5G slicing now, not put roadblocks in the way.

The more that is left up to negotiation, the more agile the whole system will be. So, the choice of data model can itself be the subject of negotiation. A common well-thought-out way to start might be to use the Umbrella Information Model (UIM) promulgated by 3GPP SA5 and TMF. The UIM is a Meta Model derived from the previously existing standards of the underlying data models of the two organizations, and those of participating vendors and CSPs. 

The Umbrella Model was developed in response to a set of requirements generated by NGMN (Next Generation Mobile Networks—an industry association comprising the largest cellular providers). The development of requirements for the extensions to the Umbrella Model could be similarly supported by an industry group started earlier this year called ZSM (Zero-Touch Service Management).

The UIM was intended to support provisioning and configuration of wireless and wired network elements. To this operational base, we would need to add SLA and Settlement data objects. Those extensions can be done initially with text strings. Thus, while some models are developed in standards organizations, multiple compliant models could evolve in practice. However the umbrella model evolves, there are likely to be a number of versions of the model. So, early in a negotiation, the NFOs could start by bidding model versions until they reach agreement. This way, as the models evolve, the overall system can take advantage of them without significant disruption.

Now, inside the CSPs, there are still likely to be different data models in use. There will have to be a translation capability (sometimes called a Bridge) inside the NFOs to translate to the underlying different model(s). These models reflect the views of each CSP on its day-to-day operations. As an aside, there may be a range of different models in use inside a given CSP and a range of different layers of orchestrators with different bridges. In any case, it will not be necessary to translate all of the vendor-specific, domain-specific, and CSP-specific data models. Only the parameters related to the subjects of negotiation need to be available to the NFOs.

Some people have suggested that we fix certain portions. For example, a common suggestion is that we fix the use of blockchain and a particular crypto-currency for settlement. This is dangerous. A few years ago, we didn’t know that blockchain and crypto-currencies were coming. We can’t predict what will appear in a few years. But we can say with a high level of confidence that something we don’t know about now and which will have the potential to affect settlement will come. So, if, for example, we restrict settlement to a blockchain process using Etherium today, it is likely to be overtaken tomorrow. By leaving it up to the negotiation process, if a CSP wants to use blockchain and Etherium, it can bid it. If the other NFOs have set up this option and it supports their objectives in this slice, they can bind to that. 

Over time, a set of widely employed options will emerge. This set of widely used options will also slowly evolve as technology develops. At the same time, CSPs that have close partner relationships may develop specific sets of data models and processes that are tailored specifically for their unique situations.

Thus, by focusing on making standards to support 5G slicing agile and easy to implement, the full economic promise of 5G can be realized.  And we have seen how focusing the standards efforts on the negotiation framework and umbrella models is the best way to maintain that agility, enabling near-term deployment of 5G slicing.