Monday, 19 December 2016

It’s all in the details when it comes to understanding 5G field trials!

The fact that 5G tests and trials are going on all over the United States and the world should be encouraging to all of us. Problem is, for some of us, the results all start to run together, like a stream of ones and zeros without any real standouts.

Turns out, it’s not that easy to point to specific 2016 trials that triggered a collective “Wow, that’s amazing!” across the industry. There is general agreement that achievements in speed and latency are impressive, but those tend to be all over the place as well: 1 gigabit per second and above here, 14 Gbps to a single user there. There’s been demonstration of data speeds of more than 2.5 Gbps with a mobile device and moving vehicle, and Ericsson and Telia achieved peak data rates of 15 Gbps and latency of less than 3 milliseconds. But after a while, it all just starts to run together and lose meaning. Part of the problem in deciphering what’s what is you need to know exactly what took place.

“It’s all the details that are really important here: what spectrum was used, how much, what air interface, base station architecture, etc.,” said Peter Jarich, VP of consumer and infrastructure services at Current Analysis.

Of course, these are the very details that vendors and operators like to keep close to their vest. And there’s no shame there; this is a hypercompetitive industry, and people are going to be very careful about what and how much they reveal about what they’re doing, even as the industry tries to write the standards for what everybody ultimately wants to be doing. Plenty of people want to talk about speeds, but how impressive are these speeds when you’re doing tests and trials in a spectrum that is wide open? Often the trials we hear about are not being done in dense, urban areas. And as for latency, how low do you go? That seems to be closely tied to use cases, which need to be identified and better explained.

Notably, in boasting about his own company’s achievements and plans for 5G, T-Mobile CTO Neville Ray called Verizon’s grand vision to compete as a fixed broadband player a “double yawn.” Verizon deserves serious kudos for all it has achieved and continues to do with fixed wireless, yet I can’t help but wonder if it doesn’t sound a heck of a lot like what the old AT&T tried to do with Project Angel way back in the day. Sprint CTO, John Saw, was asked about that since he was part of the team working on Angel before we even heard of WiMAX, and he affirmed that much of what we are talking about today is along those same concepts.

Back then, it was about putting pizza box-sized dishes on the sides of people’s houses in order to offer high-speed internet and phone services and take on the big established wired phone companies. Now it sounds a lot like that, only wireless companies are talking about taking on the established cable companies, which in turn want to increasingly play in the wireless space.

Go figure. As for a few of the more impressive trials, it’s probably no surprise that one announced at Mobile World Congress 2016 in February still stands out to some analysts like Daryl Schoolar at Ovum.

Good old Samsung talked about how it had concluded a series of fixed wireless 5G tests delivering multi-gigabit per second speeds at Verizon’s Basking Ridge, New Jersey, headquarters, including live streaming of 360-degree virtual reality content using Samsung Gear VR. During the trial, Samsung also showed off 4K UHD video content transmission over the air while in a moving vehicle using automatic beamforming multiple-input and multiple-output (MIMO) technology. Interestingly, Alok Shah, VP of strategy, business development and marketing at Samsung’s networks division in Richardson, Texas, stated all that in the 2013-2014 timeframe, Samsung really felt it was important to push the envelope around speed, and it was able to demonstrate 7.5 Gbps in a stationary environment in 2014 in what was then deemed the fastest-ever 5G data transmission rate. It also achieved an uninterrupted and stable connection at 1.2 Gbps in a mobile environment from a vehicle traveling more than 60 mph. Once that was demonstrated, Samsung’s team kind of pivoted—they’d already been heavily into 5G R&D for a few years by this time—and started to think more about the path to commercialization. More recently, Samsung has done a lot of testing and demonstration around other pieces of millimeter wave technology that are necessary to actually reach the commercialization stage. “Throughput and data speeds are kind of nice headlines, but at the end of the day, the path to market and the path to commercialization requires that we figure out all these other factors, and we feel comfortable that we’ve already validated the speed question,” Shah said. It’s also important to remember that 5G will require a lot of small cells and getting the miniaturization and economics to pencil out will be key so that gear can fit on street “furniture” wherever it’s installed. Miniaturization tends to be a gradual process and much can be expected to happen in that area before the Winter Olympics in South Korea in February 2018. Samsung has been a long-time collaborator with educational institutions like NYU Wireless, which also has done important work in millimeter wave, which will be one critical component of 5G. This past summer, Ted Rappaport, NYU Tandon professor and founding director of NYU Wireless, and his team conducted research outside his mountain home in Riner, Virginia, using the 73 GHz band, where they were able to cover remarkable distances—something that even they were surprised to be able to show.

Another achievement of particular interest was Ericsson and China Mobile’s ability to show the world’s first 5G-enabled drone prototype, where a drone was flown using the operator’s cellular network with 5G-enabled technologies with handovers across multiple sites. Conducted in Wuxi, in China’s Jiangsu province, it was impressive not only because it involved drones but also included handover, multi-use networks and low latency due to edge computing. And there’s a lot here that will be important going forward, Jarich said. Building on some of their previous work, Germany’s Deutsche Telekom and Huawei conducted an autonomous end-to-end network slicing implementation to add dynamic and real-time slicing of the 5G radio access network (RAN) and data center, as well the interconnecting transmission network. That demo, conducted in Deutsche Telekom’s 5G:haus lab based in Bonn, Germany, shows how different network slices can be created automatically in an optimized way on a shared RAN, core and transport network.

Everyone knows network slicing will be critical in 5G, but if setting up slices is super time consuming or only touch one part of the network, that’s a problem, Jarich said. “Touching the RAN, core and transport networks is a different story—and what we have here,” he said According to Joe Madden, principal analyst at Mobile Experts, significant progress was made during 2016 in mobility testing and validation of Massive MIMO in the field. Samsung has done some leading tests of mobility using a 28 GHz link and Huawei has “leaped ahead of other vendors” with deployment of Massive MIMO in LTE networks, proving the real-world benefit of Massive MIMO prior to deployment of 5G, he said. As for the next challenges that need to be addressed, Madden said there’s been anticipation of some problems with heat dissipation in 28 GHz radios that transmit 60+ Watts of power.

“The efficiency of amplifiers at 28 GHz make this a challenging hardware problem … so we’re hoping to see some demonstrations of high power transmitters without air conditioners during 2017,” he told FierceWirelessTech. Generally speaking, testing 5G as a mobile application has been done, but it’s taken place in an open area. Mobile handover performance in a crowded urban environment has not yet been demonstrated, and of course, the urban environment is key for the 5G business scenario, he said.

With any luck, in the coming year we’ll hear a lot more details about what operators are experiencing as they gain more understanding about exactly what can and can’t be done in millimeter wave spectrum, as well as how it will dovetail with low- and mid-band spectrum.