Inside Bristol’s urban 5G experience showcase

Layered Realities is a demo of "5G experiences" taking place in the UK this weekend. If reality is layered, then so is the technology stack.

This weekend, Bristol, UK, is playing host to live demonstrations of 5G “experiences”. The demos are hosted by the University of Bristol’s Smart Internet Lab, which received funding for its 5G test bed project from the UK government in July 2017.

The demos – called the Layered Realities Showcase – will allow the public to get an early taste of what 5G could enable.

Professor Dimitra Simeonidou, Director of the Smart Internet Lab at the University of Bristol, said, ” We took the decision from early on that in order to complete our mission we were not going to do a lab demo. We were going to bring the network out into the public, to be enjoyed by the public. So what you are seeing today is Britain’s first urban 5G network.”

Public showcase network

The square is covered by two types of WiFi, Nokia WiFi and Ruckus units, operated by the University of Bristol, fixed to six pillars. There is also dedicated LTE coverage from two Nokia LTE access points. These are served as one network to the end user.

The WiFi and LTE access points are being backhauled by CCS’ MetNet 26GHz self organising mesh units. All the fibre connects into the lab at the University hosting a Nokia packet core and Bristol University’s own cloud infrastructure and edge server.

The Two WiFi access points – and below them the CCS MetNet 26GHz backhaul node.

The WiFi nodes on left, CCS backhaul node below. Nokia LTE access point to right.









The trial use cases are being run within Bristol University’s edge server, stationed offsite in its lab, via a L2 edge switch.

The Zeetta Networks live network visualisation.

Services slicing control from Zeetta.

Zeetta Networks, a network software start-up spun off from the University of Bristol. is providing the orchestration layer and end-to-end control of network slicing. Simeonidou said this does not interfere with the packet core network slicing in the Nokia network, but sits on top and looks after integration of different network elements within the 5G network.


The demonstrations

There are three main demonstrations running. One is a crowd sourced content streaming app.

This is an AR app that lets users suggest and see how the square might look in 100 years’ time (for example). An animator on the edge platform captures that and in real time streams it back to the user’s phone.

Another demo is of live 360 degree video streams from helmet cams worn by cyclists – with virtualised video transcoding of the 360 degree feed taking place to enable facial detection. This allows the trial to bring the processing and computation very close to the user.

A third demo is a “constellation” demo/artwork that will create a live representation of the actual network data. The visualisation is created from data taken from Zetta’s controllers and creates a live image of the network. 

Bristol University Massive MIMO

This is operating in 3.5 GHz test spectrum that BT has.  Working with National Instrument, the university is demonstrating a 128 element antenna connected to 12 test UEs . 

The 128 element antenna array

The test UEs

128 connected radio heads

Professor Mark Beach said that the equipment can support 12 users simultaneously in the bearer channel where previously only one could be supported. The PHY layer can also provide very low link latency. The10-20x overall increase in capacity, plus low latency, can begin to address 5G business cases and use cases, he said.

Spatial multiplex processing

The spatial multiplex processing takes place in four FPGA cards in the rack.  Each antenna element is connected to its own radio transceiver, uniquely processed in DSP. Beach points out that this is possible as the test is using 20MHz channel, but digital signal processing would not (yet) be feasible at the higher bandwidths where there might be 250-500MHz of bandwidth available.

There are 128 Radio Heads connected to the antenna, generating that OFDMA (LTE-like) waveform across the air interface.

The development of the technology has taken five years from the original hardware concept, with the original paper being written in 2011.

Nokia 28GHz demo

Nokia  has brought its 28GHz 5GTF kit. This encompasses an EPC emulator, the AirScale baseband on the AirFrame blade connected over CPRI interface to the antenna, which is a 16×16, 256 element unit. The test UE is in the tent below. Due to the test license the system is deploying 2 component carrier aggregation, for a total of 200MHz channel bandwidth. That is generating throughputs of 700Mbps, a number slightly limited by the L3 protocol Nokia is using in the demo.

Nokia’s 28GHz 16×16 MIMO antenna looks down at the tent that houses its UE test terminal…

Side view of the Nokia antenna

 C’est magnifique, mais ce n’est pas la 5G?

Across the whole piece, there’s some very impressive technology, but… is it right to call everything here a 5G demo?

Taken piece by piece it looks like this. The massive MIMO is in 3.5GHz, a pioneer 5G band with test terminals.  But it is separate from the public experience demo. The Nokia 5GTF FWA deployment is of course a branch of early 5G so all good there but it is not providing any public connectivity (obviously). The WiFi and LTE links that the public will be accessing through their phones and that provide connectivity for the other apps are clearly not 5G NR.

The CCS backhaul? Undoubtedly the sort of thing required to support dense small cell deployments. But just as well suited to LTE, as in this demo, as 5G per se.

The edge core and server? This depends on your view of whether, just because 5G apps may well require an edge architecture, that makes edge computing “5G”. The network slice control – as above. Very smart and required for 5G but not exclusive as a 5G technology.

Bristol University’s Simeonidou was in no doubt, when asked if we should really be calling this a 5G demo, that we should. The important aspect for her is the 5G architecture – the edge core and network slice control that is enabling the “5G-like” low latency and high throughput user experiences . 

“True to the mission of 5G, it is a network of networks. It is a solution that is 5G ready and very close to what 5G should be doing in terms of providing mobility,” she said. “In this particular network the access element is not actually 5G, because we are providing a public experience. We wanted to provide a 5G experience to the public.”

“We are reaching with the 26GHz or fibre in the backhaul down to the WiFi, and then at 5GHz WiFi are giving very high capacity to the end user. What we are showing is that we understand what the radio could do. 

“But we could not do the demonstrations we are doing without the backhaul capability we have and without the MEC we are providing. 

“So our 5G proposition is very much an end-to-end proposition. 5G is not just about the radio. It is about the architecture – and we have implemented the architecture so that we can support flexible services slicing end to end.

“Nokia has an SDN controller which is for its own network and WiFi. We have more elements, for instance the 26GHz backhaul, the Ruckus WiFi. There’s Nokia’s MEC and our own OpenStack MEC solution – and we are co-oordinating services across them all of them, with Zeetta providing a live visualisation in real time of the whole network.

“To do this in nine months, it’s amazing. When we started I never believed that we could get to this point – to run the kind of applications we are running.”