What exactly is a 3GPP submission?
As the name suggests, a 3GPP submission is a document that a company or some other entity submits to a 3GPP plenary or working group. The document, which is generally in Word or PowerPoint format, can have multiple objectives and range from being extremely technical to somewhat trivial. For clarity, it is helpful to examine submissions made at the June RAN plenary that we attended this summer.
Going into the June RAN plenary meeting there were 536 submissions – by the end of the four-day meeting the number of submissions had increased to 657 submissions for reasons that I discuss later in this article. Since the RAN plenary is primarily responsible for the management and oversight of its underlying working groups, many of the submissions came from these working groups. These submissions from the working groups primarily provide information to all attendees on the ongoing standardization activities of each working group, including accomplishments and potential issues that require resolution by the plenary. By having each working group provide these status updates, the plenary ensures everything remains on track and that the activities within each working group are aligned. From my perspective, these types of submissions are useful since we get a great overview of all ongoing activities without having to spend all our time attending other working group meetings.
External organizations, such as the IEEE or a consortium of radio broadcasters, for example, also make submissions. These types of submissions typically address a common area of interest where there is the potential for collaboration or where the external organization wants 3GPP to be aware of its views. For example, these organizations might have questions or concerns regarding how 3GPP intends to leverage new radio frequencies for LTE / 5G services or whether new capabilities and/or features might provide synergistic opportunities. These types of submissions from external organizations result in a formal response from 3GPP in the form of an outgoing liaison, or letter, which answers the external organization’s questions or concerns.
Last, but certainly not least, individual member companies or a consortium of companies make submissions to the standards body. Company submissions to a plenary meeting deal with a range of topics. Some submissions merely identify minor errors or inconsistencies in previously agreed-to specification documents. Other submissions are more interesting since they could provide insight into an operator’s long-term network strategy or they could eventually result in LTE / 5G having a new capability or feature, as well as clarify how the submitting company believes an already agreed-to feature should be implemented. Typically, the latter type of submission is more likely to occur at a working group meeting where the technical details are ironed out, although companies might still make high-level suggestions at a plenary meeting.
A quick review of my meeting notes from the last RAN plenary is helpful to provide some specific examples. Without naming names, several operators requested new combinations of LTE frequencies for carrier aggregation, not to mention new frequencies for existing LTE services, including NB-IoT. Turning to the vendors, many of the submissions fell into a couple of categories: a new “study item” or revisions to an existing study item and a new “work item” or revisions to an existing work item. It is worth noting that 3GPP doesn’t have time to treat all submissions during a meeting. Instead, it gives preferential treatment to those submissions which have a lot of co-sponsors. The rationale is that if only a single company is endorsing the submission then there may not be a lot of widespread interest. Conversely, a large number of endorsements suggests widespread support and a greater likelihood that 3GPP will be able to approve the submission.
What are study items and work items?
A study item is the first step in the process toward the introduction of a new capability or feature into an existing standard. At the extreme, a study item could involve the introduction of an entirely new standard, such as 5G. Before 3GPP decides to incorporate a new capability or feature, it must first determine there is a need for the feature and interest from the member companies. This step is followed by a multi-month research or study phase during which time the member companies, both individually and collectively, determine the best technical solution for meeting the specific objectives of the study item.
For example, several operators plus a few vendors might believe that the growth of video traffic is becoming problematic and they need a better means of supporting the high volume of data traffic. This common set of beliefs could result in a proposed study item to evaluate more efficient means of delivering video traffic over an LTE network. Most likely, even at this very early stage in the process there will be varying views on the best technical solution, resulting in multiple submissions for the same basic study item. For something like efficient video delivery, which is fairly broad in scope, there could be multiple study items exploring various facets of video delivery. When 3GPP is defining the study item, each corresponding submission identifies at a very high level a recommended solution along with some rationale, which validates the proposed approach. Inevitably, while there may be common agreement that the new feature or capability is needed, there won’t be common agreement on the best approach.
After multiple rounds of discussions and debates during a plenary meeting or potentially several meetings, 3GPP member companies will hash out the scope and timeline of the study item – if approved. As I have observed, many study items fall by the wayside, either due to lack of widespread support or more likely due to other study items which have higher priority. The document identifying the study item – actually a submission in itself – includes information on how the study item might impact the existing network and other specifications, a justification for the study item, as well as the objectives of the study. Lastly, the study item contains a schedule and identifies the working groups that have responsibility for doing the study.
A study item can be specific to one working group and involve a very discrete feature (e.g., uplink data compression) or it can be very broad. 5G is a great example of a very broad study item since until very recently everything done within 3GPP that pertained to 5G involved a 5G study item. Now that 5G has transitioned from being a study item to a work item, 3GPP can begin the real work on the new standard.
During the study item phase, companies evaluate various means of achieving a particular requirement. The actual requirement itself could also change in the event 3GPP determines the requirement is too difficult to achieve or that the scope of the study item doesn’t achieve the desired objectives. As companies propose and evaluate the technical merits of various solutions, they conduct modeling simulations to determine how well a solution might work if it was implemented. Keep in mind, at this point we are still literally years away from having a commercial product available that fulfills the objectives of the study item. Ultimately, there is healthy debate and compromise until ultimately 3GPP completes the study item.
The study item is just the first step in the standardization process since the work item follows. As an analogy, a hypothetical study item for a new energy-efficient house could conclude that solar power is best in the Southwestern United States and that wind turbines are more suitable on the Eastern seaboard. However, much of the detail regarding how the solar panels and wind turbines convert natural energy sources to usable energy would remain unanswered. Individual companies might be able to create an end-to-end solar power solution at the end of the study item phase, but there wouldn’t and couldn’t be a multi-vendor solution since each company would have a slightly [potentially vastly]different idea for how to do it.
3GPP is at this stage with 5G. Since the standards body has completed the initial 5G study item, it knows what it wants and it has a pretty good idea of how to implement it, but there still remain multiple unresolved implementation decisions.
Does 3GPP get really technical?
Although I do not necessarily consider the plenary meetings to be technical, they also are not a walk in the park. A better characterization of the plenary meetings is that it takes a 3GPP dictionary and thesaurus, as well as knowing the “secret handshake” to figure out exactly what is being discussed, let alone the implications.
For example, there has been a lot of press regarding the accelerated 5G schedule. Specifically, 3GPP agreed in March (after nearly 9 months of debate and multiple company submissions) to complete the “non-standalone (NSA)” means of deploying 5G while leaving the completion date for the complete phase 1 release of 5G unchanged, or June 2018. In simplistic terms, NSA means that the new 5G air interface will connect to an operator’s legacy LTE core network, or EPC; thereby, removing the need for an operator to also deploy a new 5G core network. The NSA option also negates the need for 3GPP to completely define a whole new set of interfaces between the radio and core network before an operator can begin deploying and using 5G.
In the plenary meetings when this topic was discussed, no one took the time to explain NSA since everyone assumed everyone else knew what it was. In fact, no one even called it NSA. Instead, they referred to the proposed architecture solution as “Option 3.” There is nothing technical about the term Option 3, but it sure as heck is a bit nebulous. Fortunately, I attended the June 2016 plenary in Korea where the term Option 3 originated. Side note – the term stems from a T-Mobile presentation in which the operator attempted to define all the various deployment options involving LTE and/or 5G. It is pure happenstance that 3GPP now calls it Option 3 versus Option C or Option 4. Suffice it to say, the typical person who attends a 3GPP plenary meeting has some sort of engineering background, but they are also more likely to have a friendly demeanor and personality than a pocket protector stuffed with pencils and a straight-edge ruler. After all, it generally takes a likeable personality and a hint of charisma to win over colleagues from competing organizations.
In working group meetings, the complexity of the discussions increases by at least an order of magnitude. I’ve sat in meeting rooms where people, in this case engineers with pocket protectors, debate the merits of different coefficients in complex mathematical equations while throwing around multi-letter and hyphenated acronyms with reckless abandon. To make matters worse, even if I figure out the full definition of the acronym, I still don’t know what it means or its implication in the context of a new air interface. I’ve been told that only a few dozen people in the world actually understand 5G channel modeling (essentially figuring out the expected behavior of a radio wave in millimeter wave frequencies) so I don’t feel too bad.
How does anything ever get done?
Slowly, but surely, 3GPP completes its assigned tasks, which primarily pertain to advancing the capabilities of existing standards (LTE evolving to LTE-Advanced and then LTE-Advanced Pro) as well as defining entirely new standards. On the one hand, companies have a vested interest to protect their own interests, meaning getting their ideas, and likely valuable IPR, introduced into the standard. On the other hand, these companies also don’t want to delay the standardization process since they want the overall industry to be successful. A rising tide raises all ships.
3GPP is a consensus-driven organization. This approach means while there is a lot of debate and a lot of disagreement, there are also a lot of compromises. When 3GPP approves something, be it a submission that identifies grammatical errors to a 3GPP specification or a 5G study item, it is never done with a voting process. The only time I ever voted at a 3GPP meeting was when I voted for the new RAN plenary leadership.
Instead of a voting process in which the majority rules, the consensus-based approach means that it is the absence of opposition that leads to approval. Yes, a single company can delay the standardization effort or at least the approval of a submission. Of course, you do so at the risk of ticking off your customer base or peers that you may need on your side in the future. Companies must figure out a mutually agreeable solution to move anything forward and achieving this objective is sometimes easier said than done. In some instances, the debate and discussion can extend for several quarters, as was the case with the accelerated 5G schedule that I discussed earlier in this article. At other times, the debate only takes a few minutes or a few hours (done during meeting breaks, etc.) so 3GPP can approve the item within the same meeting.
From what I have observed, the art of compromise is alive and well within 3GPP, although at times it can be a bit frustrating or even humorous. The frustrating part comes from spending tens of minutes dissecting and rearranging a few bullets and sub-bullets with a bit of wordsmithing thrown in for good measure. I even titled our March 2016 Signals Ahead report with this perspective in mind (“Potato, Potahto, Tomato, Tomahto, Let’s Call the Whole Thing 5G-NR”). The humorous part comes from recognizing that many of the debate participants speak English as a second language, yet their English language skills rival those of an American, Brit, or Australian.
Consensus and compromise also mean the best technical solution doesn’t always win. Politics can come into play and 3GPP may end up approving something – not because it was the best technical solution but because it was the only solution that everyone could accept, albeit begrudgingly. The consensus-based approach can also result in optional features or approaches being introduced into the standard. Personally, I think this happens fairly frequently although the implications may not be meaningful. If something is optional then it isn’t mandatory. Ultimately, market demand, which is driven by mobile operators, will determine the set of features which vendors implement into their LTE and 5G solutions.
SRG has been participating in 3GPP standardization meetings since September 2015 when the standards body held its first workshop on 5G. Prior to that initial 5G workshop, SRG closely followed the various standardization efforts since they provide great insight into the future capabilities of next-generation cellular technologies and the operator roadmaps. See 3GPP Fun Facts Part 1 for additional perspective from Michael Thelander of SRG.
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