More Details Emerge on Samsung 28 GHz 5G Wireless Technology
Provides 1 Gbps connectivity at up to two kilometers
May 20, 2013
There was considerable press coverage of Samsung's announcement of “5G” 1 Gbps wireless technology
but few technical details. The technology works at 28 GHz and uses a 64-element adaptive antenna array to provide data rates of 1.056 Gbps over distances up to 2 km.
Looking for more details on how such a 28 GHz link would work, I found a paper that's scheduled to appear in the 2013 IEEE International Conference on Communications (ICC) June 9-13.
The paper 28 GHz Propagation Measurements for Outdoor Cellular Communications Using Steerable Beam Antennas in New York City
from Theodore S. Rappaport, and researchers at the Polytechnical Institute of New York University, describes a project sponsored by the Samsung DMC R&D Communications Research Team.
The NYU tests found that the maximum usable cell size in an urban environment was 200 meters and, as it notes, at these short distances rain fade will not be a problem. At 200 meters the attenuation of 28 GHz in heavy rainfall (some 1 inch/hour) is only 1.4 dB, with an increase to 6 dB of loss at a distance of 1 km.
The NYU propagation measurements were conducted using a 400 megachip-per-second sliding correlator channel sounder. At each location directional horn antennas were steered to find the best angle orientation with the highest received power. Note that these include non-line-of-sight paths.
The 64-element adaptive antenna would be able to find the best angle orientation faster and if MIMO techniques were used (one article
suggested a 64 element array could indicate 8×8 MIMO)
I can see why Samsung asserts that “The adaptive array transceiver technology, using 64-antenna elements, can be a viable solution for overcoming the radio propagation loss at millimeter-wave bands, much higher than the conventional frequency bands ranging from several hundred MHz to several GHz.”
This news from Samsung provides additional support for my previous assertion that by the time the FCC completes the Incentive Auction and allocates 600 MHz spectrum to wireless carriers, it will be about as useful for wireless broadband as low-band VHF is for digital TV today. While 600 MHz may be useful for serving rural areas--we've already seen examples of how TV white space devices can fill this need--it will be next to useless in urban areas where most users won't be satisfied with today's “4G” speeds at UHF frequencies. Samsung said it hopes to commercialize its 28 GHz “5G” technology by 2020, which is only seven years away.