Sunday 19 October 2014

What is (pre-5G) 4.5G?

Before we look at what 4.5G is, lets look at what is not 4.5G. First and foremost, Carrier Aggregation is not 4.5G. Its the foundation for real 4G. I keep on showing this picture on Twitter

I am sure some people much be really bored by this picture of mine that I keep showing. LTE, rightly referred to as 3.9G or pre-4G by the South Korean and Japanese operators was the foundation of 'Real' 4G, a.k.a. LTE-Advanced. So who has been referring to LTE-A as 4.5G (and even 5G). Here you go:

So lets look at what 4.5G is.
Back in June, we published a whitepaper where we referred to 4.5G as LTE and WiFi working together. When we refer to LTE, it refers to LTE-A as well. The standards in Release-12 allow simultaneous use of LTE(-A) and WiFi with selected streams on WiFi and others on cellular.

Some people dont realise how much spectrum is available as part of 5GHz, hopefully the above picture will give an idea. This is exactly what has tempted the cellular community to come up with LTE-U (a.k.a LA-LTE, LAA)

In a recent event in London called 5G Huddle, Alcatel-Lucent presented their views on what 4.5G would mean. If you look at the slide above, it is quite a detailed view of what this intermediate step before 5G would be. Some tweets related to this discussion from 5G Huddle as follows:

Finally, in a recent GSMA event, Huawei used the term 4.5G to set out their vision and also propose a time-frame as follows:

While in Alcatel-Lucent slide, I could visualise 4.5G as our vision of LTE(-A) + WiFi + some more stuff, I am finding it difficult to visualise all the changes being proposed by Huawei. How are we going to see the peak rate of 10Gbps for example?

I have to mention that I have had companies that have told me that their vision of 5G is M2M and D2D so Huawei is is not very far from reality here.

We should keep in mind that this 4G, 4.5G and 5G are the terms we use to make the end users aware of what new cellular technology could do for them. Most of these people understand simple terms like speeds and latency. We may want to be careful what we tell them as we do not want to make things confusing, complicated and make false promises and not deliver on them.

xoxoxo Added on 2nd January 2015 oxoxox

Chinese vendor ZTE has said it plans to launch a ‘pre-5G’ testing base station in 2015, commercial use of which will be possible in 2016, following tests and adjustment. Here is what they think pre-5G means:


Alistair URIE said...

When 4.5G starts is not a significant issue and will depend upon marketing position (for example is CA counted as 4.5G?).

What Alcatel-Lucent was trying to explain at the 5G Huddle event was a more critical issue - when does 4.5G stop and hence when does 5G start?

Our argument is that lots of things that some players call 5G (SDN/NFV, access federation, dual connectivity, etc.) can be done with direct LTE evolution and so should be called 4.5G. 5G is therefore only really the things you can not do via direct LTE evolution.

Manoj Das (Via Het Net Linkedin Group) said...

Thanks Zahid, This is excellent to put things in black and white. While we can see, 4.5 G will start after deployment of Rel 13, some OEMs started marketing with less than 1 Gbps as their version of 5G without considering the latency, D2D, M2M, signalling congestion (due to D2D/M2M bursty signalling and low data transmission) and LTE group etc.

Dan W said...

Already, two comments in, we can see that even Zahid's post is causing confusion. So here are some facts:-

1. There is no definition of 5G yet. There is a lot of talk about what it might be, generally coming from two different view points - the 'hyper-connectivity' camp looking to enable M2M, and the 'R&D' camp looking at new RAN, massive per connection bandwidth and ultra-low latency.

A few industry bodies collated the requirements from each and made one long list, with a few industry aspirations chucked in for good measure. The result is a self-contradictory set of requirements (90% power reduction in a network delivering beam forming at 20GHz spectrum as an overlay of everything you already built, anyone?), that someone will have to sift through to see what actually flies. Hopefully NGMN are doing that. Then we all look to 3GPP and others to define some tech that actually meets the requirements, and then we can say it is 'defined'. 2018 maybe, and even then I predict a pretty compromised version of what we see as the aspiration today.

2. There is no definition of 4.5G either. If anything the rise of '4.5G' is muddying the waters further - some interim step along an as yet undefined path? Really? Some of the differentiators that people are pulling out - use of NFV, adoption of HetNet - these are things that are already deployed in some networks, so can all those networks already claim to have taken a half-generation leap forward even before that step was called out?

Consider NFV as an example. NFV can be applied to any network. You could virtualise MSC-Servers, SGSNs and GGSNs just as easily as you can virtualise IMS or EPC elements. So would a virtualised 2G EDGE network be 4.5G? No? There are plenty of networks in developing markets still building 2G coverage and capacity out, so if they choose to build with NFV-based kit, they are right on this bleeding edge surely.

Equally if you build a LTE-Advanced network using monolithic boxes, is that not 4.5G, but your competitor can claim 4.5G because his LTE-Advanced network is NFV-based? The performance for the end user will be the same, the device portfolio available to the customers will be the same, but one of you is 4.5G and the other isn't? Smells like a marketing spat and possibly even litigation to me.

The thing about all of this is that we don't need a generic badge for much of this. There is no consumer benefit from a lot of it, so why give it a consumer facing brand? Build your network on the basis of NFV, and say that is what you have done, rather than trying to tag it with an umbrella name that ultimately baffles your customers as to what they are getting extra over what they had before. The same for HetNet, small cells, even low power low throughput radio. These are all explicitly identifiable advances in network technology in their own right which need to be worked on independently of each other, to independent timelines, and hence independently of a catch-all brand. Stick it all in one bucket and we all end up arguing about whose flavour of 4.5G is best.

We do a disservice to the industry when we dumb this debate down to single labels for multiple advancements, and we potentially slow advancement down by tying independent innovations in common labels and associated timelines.

So before we start bragging rights about the interim step towards a nebulous next generation (which may just be the amalgamation of previous this generations), can we just let the requirements for 5G settle? Even then, I'll want to challenge them before I look at the path to how to meet them.

Don't stop working on everything we are working on, but please, have enough confidence in these individual technologies and their benefits to just say what they are and market them independently on their merits. We don't need a brand to understand them, so lets not use one.

Zahid Ghadialy said...

Dan, I agree that it may be a good idea to stop using the term 4.5G and not put everything in 5G either.

A better option may be to come up with some kind of branding to let the users know about the new advancements in the network/technology. An example would be to follow how SK Telecom has done.

Manoj Das said...

IMHO,there is never a "definition" of a decimal G. GPRS was called 2.5G, EDGE was called 2.9G, WiMAX was called 3.9G or sometimes 4G. Whatever convenient for industry, they gave a name. Similarly, before official 5G definition comes, whatever advancement in features of existing LTE framework could be called 4 dot any decimal G.

Joe Madden said...

Don't get so hung up on what each "G" means. The engineers will never agree with the market definition.

At the end of the day, the market will use terms like 4.5G and 5G to refer to any technology that forces the end user to buy a new device.

Cloud 4G said...

Several years ago, about twelve, 802.16d made first use of OFDM in a wide area network standard. I suggested to the standards group that what became known as WiMAX should integrate with Wi-Fi including seamless handshaking for data connections. That was a bit early to consider VoIP.. packets are packets if latency is suitable.
WiMAX's failure to turn the OFDMA+MIMO technology mainstream or force 3GPP to converge with mobile, was the difficulty of coverage and adoption of using the available higher frequency bands. Another mistake of WiMAX was not pursuing lower frequency bands which were available before LTE.

The approach made sense then and much more sense now that 'densification of the network' and smallcells have come into focus. This week I will be presenting to Asian operators including former WiMAX operators... many who have heard me talk about this years ago.

The old is new again.