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FCC Committee Gives Go-Ahead To Investigate 5G Spectrum and Technologies

October 18, 2014 - Written By David Steele

We reported at the beginning of the month that the Chairman of the American agency, the Federal Communications Commission (FCC), had asked his fellow members to investigate how best to deploy next (fifth) generation wireless services with research at and above the 24 GHz frequency range. We are now hearing that all five members he contacted have agreed to start research into the technologies. The committee are to explore how spectrum can be licensed; if it can be managed on a regional basis for exclusive carrier use via auctions or if it will be offered on a non-exclusive (or unlicensed) basis and relying on carriers and manufacturers to figure out the necessary frequency coordination. There are many unanswered questions, which is not surprising given that we do not expect next generation networks to be deployed until 2020 (with trial networks coming in 2018) and also Samsung have already demonstrated super high speed data access using spectrum at the 28 GHz point as Joseph covered here. In this demonstration, Samsung’s technology allowed a data transfer speed of 7.5 Gbps when stationary, dropping to a stable 1.2 Gbps in a van moving at 62 mph. Current LTE networks allow for a theoretical 300 Mbps and 802.11ac WiFi allows up to 1 Gbps.

It’s a topic we cover quite frequently here at Android Headlines, but I need to draw readers’ attention to the high network frequency of these two projects. The higher the frequency, the greater the potential speed but the quicker the signal strength drops. This means that high frequency signal does not penetrate buildings, walls and other solid objects as well as lower frequency signals. This means that next generation networks are going to have to work smarter if they’re to avoid having a base station every couple of hundred feet, because increasing the power output of a mast is not a viable solution! Current mobile networks use frequencies from 700 MHz to 2.7 GHz depending on the network type: my current (UK) networks offer service at the 800 MHz, 900 MHz, 1,800 MHz and 2,100 MHz points but these networks are based on line of sight; in other words, the two-way signal takes a straight line from my device to the mast. There are a number of ideas in circulation that could be used such as how spectrum can be ricocheted and received by multiple receivers, to be put back together to form a usable data signal; our devices could actively communicate with multiple masts rather than just the one. Current technology limits the number of masts that our device can actively communicate with as one per SIM card, although it is aware of other masts in the vicinity and will communicate with multiple masts at the point of handoff from one to another. The idea of using massive arrays of antenna with beam-shaping systems is not new and is already being used (Sprint use eight antenna arrays for the Spark network and T-Mobile USA uses four antenna arrays).

At this juncture, we can but speculate as to how next generation networks will be shaped. My suspicion is that we will see many different techniques employed, from large array main masts to many smaller masts being put up onto street furniture such as signs and lampposts. The carriers will need to get smarter in their mast deployment, too.