Jarich: 4.5G – What's the big deal about half a "G"?

Current Analysis Peter Jarich

     Peter Jarich

We've talked a lot about 5G in the past year or so.  And in saying "we," I mean nearly everyone in the wireless industry.  Analysts.  The press.  Vendors.  Operators.  Talking dogs.  Everyone.

A quick scan of these 5G discussions, however, might leave you confused.  On the one hand, you have announcements, demos, and innovations suggesting that 5G matters in the here and now.  On the other hand, you have operators and vendors reminding us that 5G won't likely be a commercial reality for, at least, another five years.  How do you reconcile this?  Split the difference and start talking about 4.5G!

(Marketing-savvy readers will know that the term "4.5G" is being largely used by one specific vendor.  Here, the term is being used broadly, without referencing that vendor.  Really, the term is pretty generic--so that just makes sense.)

The concept of a "half-G" isn't new.  Back in the GSM days, GPRS was often referred to as "2.5G" with EDGE called out as "2.75G."  The same dynamic played out with 3G, where UMTS was followed by HSPA and HSPA+.  It's not surprising, then, that we're talking about 4.5G in the run up to 5G deployments.  Yet, where GPRS/EDGE delivered substantial value over initial 2G deployments and HSPA delivered a real performance bump over UMTS, it's clear that these evolutions were more than just incremental improvements – and that we need to be thinking (and talking) about 4.5G more than we have been.

·        What's The Point of a Half-G?  If fractional-G stepping stones have been around for a while, you'd assume they serve some sort of purpose.  The cynical among us might claim it's all about marketing – getting new buzz from an existing technology.  Looked at another way, it's about extending the capabilities of a technology before jumping to a completely new generation (with a new architecture and/or air interface), all while ensuring backwards compatibility.  Once a 2G foundation was established, for example, it could be built upon in order to deliver new capabilities and functionalities via GPRS and EDGE.  The same holds for HSPA.  Of course, where spectrum is doled out for specific technology generations, fractional generations are key for getting the most performance from RF frequency allocations without running afoul of regulators who might not allow existing spectrum to be used for a new technology.

·        What is 4.5G?   Imagine that this was a multiple choice quiz; the answer options might be: (a) the wireless technologies between 4G and 5G; (b) 3GPP R12/13 enhancements to LTE Advanced (LTE-A); (c) a collection of LTE-A technologies including tighter cellular-WiFi integration, device-to-device comms, massive carrier aggregation, new modulation schemes, and virtualization; (d) all of the above.  For those of you who instinctively put down (d) if you don't know the actual answer, congratulations – the strategy paid off.

·        Is this Half-G Any Different?  We've been through this before.  2G evolved into 3G, with intermediate technologies delivering important performance gains.  3G begat 4G with a similar progression.  This is the way technologies and standards work.  4.5, then, would seem to business as usual.  Move on people.  There's nothing to see here.  Right?  Not quite.  The move to 3G was largely about delivering a better mobile data performance.  4G delivered greater improvements and the move to IP networking.  5G, however, comes with a much broader set of requirements. It's about data rate improvements and spectral efficiency improvements, sure.  But, it's also about latency improvements, network density improvements, and accommodating IoT use cases with low-speed solutions and battery life improvements.  Yep, it's asking a lot.  Accomplishing all of this will take a diverse set of technologies.  Come 2020, they may all be standardized and ready to roll.  Who knows?  In the run-up to 5G, the requirements that get commercialized as part of 4.5G will depend on vendor assets, operator priorities, and expectations of what can be reasonably commercialized in the near-term.  In other words, this half-G is much more up for grabs than any in the past.

·        What is a Half-G Really Worth?  The implication of the last point is pretty clear.  Vendors interested in benefitting from the near-term and medium-term evolutions of LTE-A need to message its value – if only to drive operator thinking around the technologies they're actually in a solid position to develop and deploy.  However, there's another reason for everyone to care; a lot of money is on the table.  Think five, maybe ten years of investment.  As operators plan for how to evolve their LTE and LTE-A networks, they'll have to think about the roles of both 5G and 4.5G.  Do they want to wait until 5G features and technologies are fully baked or move on upgrades earlier?  It's not a completely either/or question; many foundational network investments will feed into tomorrow's 4.5G and even 5G futures.  Regardless, if 5G is positioned as a major break (especially where it involves new air interfaces), operators will need to understand why they can't afford to wait for it.  This is a question that will be top of mind while waiting for 5G commercialization in the 2020 timeframe, and even after the first 5G networks go into operation.  It's a question that will shape network spending and vendor revenues for some time to come.  

Peter Jarich is the VP of Consumer and Infrastructure at Current Analysis. Follow him on Twitter: @pnjarich.

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