How new is the 5G New Radio MIMO

How new is the 5G New Radio?

As the first commercial roll-outs of 5G systems are beginning to gain momentum world-wide, there seems to be a growing interest among the general public what will the benefits (and risks – look out for an upcoming article on that on our page…) of the new system be. An understanding seems to emerge that 5G will bring even higher data speeds, better coverage and lower latencies, therefore (finally) fulfilling the GPRS’s “always on” promise, and with a significantly better approach to QoS guarantees. And (at least at first sight) it seems that the improvements are a result of a much better radio concept than anything before. The 5G New Radio enters the stage to the sound of fanfare, and with the glow of an enormous spotlight directed at it. Which makes it natural to feel a lot of curiosity – how is it that this new radio is much more potent than our existing (and, actually, pretty satisfactory…) LTE?

LTE Evolution

The need for high throughput for the rapidly evolving bandwidth-hungry data services has been identified quite some time ago, resulting with a lot of research and development going into new radio concepts. The step from CDMA-based UMTS to OFDM-based LTE was aided by the already well-rooted (also OFDM-based) technology of WiFi. But it was not only the choice of that particular transmission and multiplexing technique that made the 4G radio more efficient than the earlier 3GPP systems. Over time, a big number of LTE Radio Features has been defined and deployed, significantly adding to the transmission speeds.

Carrier Aggregation. A fairly straightforward idea… The LTE radio resources have pre-defined “sizes”, placed on a part of the radio spectrum of a certain width. Why not bunch these pre-defined radio resources, creating therefore a much wider radio resource, allowing for a lot more information to be transported to/from a certain device on 2, or on 3 component carriers?

Dual Connectivity. A similar concept, really… Allocate resources for a particular device from two radio network “towers” simultaneously, enabling a double throughput.

Multiple Input Multiple Output, MIMO. Why not take a number of transmitters or receivers (from the same “tower”) and use them to transport information to/from a certain device? If the transmitters are satisfactorily far apart from one another (we are looking at centimetres here) the transmitted signals will be distinctive enough for the receiver to interpret them separately.

How new is the 5G New Radio MIMO

These, and other radio network features have been developed in the process of the evolving the LTE radio. Basic LTE (3GPP R8), then LTE Advanced, LTE Advanced Pro: more carriers that could be aggregated, more antennas in the MIMO antenna array… As the numbers grow, so do the throughputs.

New features of the New Radio

So, how can the 5G New Radio improve even more? Can we increase the throughputs with some smart new solutions? The obvious first step is to continue with the evolution of the previously defined features… More Carrier Aggregation? Yes! Wider carriers? Yes! Dual Connectivity with LTE radio? Yes! That would be Inter-Rat Dual Connectivity… Even more antennas in the MIMO antenna array? Yes! That would be Massive MIMO…

How new is the 5G New Radio carrier aggregation CA

In other words – yes, the 5G New Radio gives increased throughputs – but that is really a continuation of the 4G radio’s evolution path, not an actual breakthrough new concept. On top of that, though, there exists a rather obvious solution for increasing throughputs: adding more frequencies to the defined licensed radio spectrum. Standardising more allowed resources on the radio spectrum can be the biggest throughput-booster. The only problem is that the more attractive parts of the spectrum are already in use for other purposes, which leaves the ITU-R with the less attractive parts of the spectrum to open up for 5G usage. This “less interesting” part of the spectrum is higher up, where the frequency of the wave increases (and its length shortens), making the wave less resilient to obstacles on its way. What’s worse, the shorter the wave, the smaller objects become obstacles – from mountains being an issue for the traditional GSM carriers to wet leaves becoming a problem once we start using higher parts of the spectrum currently defined for LTE usage.

An ITU-R congress in October and November this year (in Sharm-el-Sheikh, Egypt) will finalise the spectrum allocation for 5G. Currently it is expected that the newly allocated frequencies might go all the way up to 100 GHz, meaning we will be using millimetre waves (mmWaves) to transport data over the 5G NR. That high up in the spectrum we can only expect reasonable signal propagation for very short distances, but within this area a significant throughput boost will be achieved.

And that is really the major improvement the 5G NR will bring – additional radio spectrum to increase the capacity. All the rest of the NR features are basically a continuation of the LTE evolution. It just seems 3GPP realized that calling the next evolution step “LTE Advance Pro +” is a bit of a tongue twister – and ended up call the 5G new radio “New Radio”. Which might become awkward one day, when a 6G system is born New Radio might be old technology…

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