Nokia and Japanese telecom giant NTT DoCoMo are testing 5G technology using extremely high millimeter wave (mmWave) spectrum for high-bandwidth, low-latency services like virtual reality (VR) and augmented reality video.
The tests will use a phased-array RF chip and antenna platform from Nokia’s Bell Labs division to support 5G transmissions in the 90 GHz spectrum band. That spectrum band is significantly higher than most current 5G tests using mmWave spectrum, which are typically in the 28 GHz and 39 GHz bands.
According to physics, the higher the spectrum band, the more difficult it is for that spectrum to penetrate obstacles like walls or foliage. This also impacts the reach of that spectrum, which in turn requires operators to deploy more cell sites to gain adequate coverage.
Industry trade group 5G Americas recently released a white paper that aligned these high mmWave spectrum bands as being “suitable for certain applications, mainly outdoor hot spot and indoor micro and pico-deployment environments.”
As part of the tests, the companies are looking at coverage characteristics of the mmWave spectrum to provide multi-gigabit speeds in support of planned 5G use cases. The tests are important in that carriers have spent billions of dollars on mmWave spectrum licenses that they hope to use to bolster 5G deployments.
Nokia and DoCoMo will also be testing dynamic offloading of data traffic and coverage in a 5G core. The initial tests are being conducted at this week’s Brooklyn 5G Summit. The companies plan to continue the tests at DoCoMo’s labs in Japan.
Daryl Schoolar, practice leader for next generation infrastructure at Ovum, said the deal is significant for Nokia as DoCoMo “has a reputation for being very demanding of its partners.”
“For Nokia, having public support from NTT on a very difficult network solution to implement is a strong public endorsement of the vendor,” Schoolar said.
Specifically to the test plans, Schoolar noted that the low latency focus was more impressive than the speeds, explaining that “low latency will be harder to implement but is needed to support new industry vertical solutions.”
DoCoMo late last year partnered with Chinese vendor Huawei on a long-range coverage trial using 5G technology and mmWave spectrum in the 39 GHz band. The test showed data speeds of more than 3 Gb/s at a distance of just less than a mile and speeds of more than 2 Gb/s at just over a mile.
Speaking on the DoCoMo trial with Huawei, Roger Entner, founder and president at Recon Analytics, said the numbers were impressive.
“It’s definitely impressive that they have been able to achieve that level of speed at nearly a mile in range,” said Entner. “And even more so since this is really just the beginning of the work on developing greater range and not the end. They might be able to get even more down the road.”
However, he did note that improving mmWave performance will be challenging. “Range and speed are related when it comes to spectrum,” Entner said. “It’s really the same physics for everyone on this.”
Domestically, Verizon has been trialing mmWave spectrum in the 28 GHz and 39 GHz bands as part of its 5G plans in a handful of markets. Entner noted the carrier has been seeing speeds up to 800 Mb/s at a range of 1.2 miles.
Speaking at an investor conference last year, Ronan Dunne, EVP and group president of Verizon Wireless, indicated the trials are looking at very basic issues with mmWave technology.
“Yeah, I think some of the propagation has probably been better,” Dunne said.
In its field tests, Verizon is looking at “not what’s the maximum throughput, but it’s what’s the minimum throughput in certain experiences,” Dunne said. The company is looking at propagation in certain weather conditions such as snow and heavy rain.
Dave Wolter, assistant vice president for radio technology and strategy at AT&T, said the carrier has seen more than a gigabit-per-second in speed at a distance of 250 meters using the 28 GHz band. In terms of outright coverage, Wolter said AT&T has not yet focused on pushing the limit in its mmWave trials. The carrier has so far tested at a maximum range of around 500 meters.
“We are making some propagation measurements and will probably make adjustments as we move along,” Wolter said.
Nokia’s 5G Progress
The latest trial builds on Nokia’s recently signed deal with DoCoMo. That deal calls for DoCoMo to use Nokia’s 5G New Radio (NR) gear as part of the carrier’s network plans. Nokia and DoCoMo have been jointly testing 5G technology since 2014, and Nokia has supplied equipment to DoCoMo for the company’s 3G and 4G LTE networks.