On 5G millimetre wave technology and why wireless is the new wired

Last  month I presented to Tech UK on 5G millimetre wave technology for fixed wireless access, particularly looking at the demands and challenges of advancing throughput speeds for urban connections.

Current state

If we look at the current state of web connectivity – I’ve used the US as an example due to both its huge population and it being in the top 5 of average broadband speeds globally – there are approximately 92 million broadband subscribers in the country, with cable providers vastly dominating the market there. Ookla’s data from H1 2016 states its average fixed download speeds are 55.0 Mbps (up 42 per cent year on year) and upload speeds (now (18.9 Mbps up) have increased by “over 50% since last year.” The country’s regulator, the FCC, has set a target speed of 25 Mbps down, 3 Mbps up and 10% of Americans lack access to these speeds – and unsurprisingly 39% in rural areas.

However, as Ookla’s report put it: “While this average speed is more than sufficient for typical activities like browsing the web and streaming video content, 50 Mbps is a small fraction of the speed offered from gigabit fibre optic internet.” And much of this increase in average speed has come from providers being pushed to offer faster non-fiber speeds. Indeed, gigabit rate provision stands at just 1 in 10,000 homes, albeit this is growing rapidly.

But is fibre to the home the right way?

Rolling out fibre optic cable to the home is expensive and companies need to – for want of a better term – sweat their legacy copper connections.

For the short and medium term, technologies like G.Fast are enabling speeds of up to 500 Mbps (300 Mbps at 300m) through copper. Three semiproviders already offer services here and, moving back across the Atlantic, the roll-out of G.Fast is already happening. Here in the UK, BT’s Openreach is among the first to trial the technology and last week Swisscom, Switzerland’s leading ISP, announced it was the first to roll it out, with 1,000 customers already using it.

And looking further forward, at the same time, consolidation is happening in the xDSL semi market, meaning innovation is less likely to happen.

Millimetre wave spectrum as the alternative

Back in the US, a recent announcement by the FCC means that over 40 GHz of bandwidth (up from 7 GHz)  is available for millimetre wave applications. The EU is following suit, adding to its existing 9 GHz of unlicensed spectrum.

Putting this into perspective, the total existing bandwidth for LTE is less than 2 GHz. The strongest 5G candidate (the 28 GHz band) alone provides more than this and mmWave can provide over 60 times LTE’s bandwidth. This means the apparent need for last-mile technologies to be rolled out can be replaced with easier to upgrade wireless options.

Again, in the US, the NSF (National Science Foundation) has announced $400 million to subsidising 5G last mile innovation. And Verizon’s 5G fixed wireless access last-mile should be introduced from next year. To do this, Verizon will use the licensed 28 and 39 GHz mmWave spectrum made available in July, and it is anticipated that this will deliver 500 + 500 Mbps over 300 (plus) metres – this is run in partnership with Cisco, Nokia, Samsung and Ericsson. And these projects are certainly not the last we’ll hear of this.

As stated above, Verizon is using the licensed spectra to do this, however I would also expect applications using the unlicensed band to be adopted soon too. The below table summarises these two approaches.

 

Licensed 28 & 39 GHz Unlicensed 57 – 71 GHz
3GPP OFDM air interface
100 MHz channelization
Up to 64QAM modulation MIMO: 2×2 to 8×8 support
Data rates:
800Mbps (64QAM2x2MIMO)
3200Mps (64QAM8x8MIMO)
WiGig (IEEE 802.11ad) & IEEE802.11ay air interface
1760 MHz channelization
QPSK to 64QAM modulation Optional MIMO (XPIC)
Data rates:
2500Mbps (QPSK (no MIMO))
8000Mbps (64QAM (no MIMO))

Fig 2: comparing licensed and unlicensed approaches

Summary

The FCC’s new millimetre wave spectrum, coupled with the demand for gigabit broadband is driving innovation in the USA. The UK and Europe (possibly no longer the same thing now) need to take a similar approach to deliver these speeds for customers and maintain our fourth place in the world’s average league table for web speeds.

We already have companies, like ourselves, developing leading millimetre wave technologies but investment needs to continue to be strong if the UK based operators, OEMs and IP rich technology companies are to continue to thrive in this sector.