To some, 5G sounds like an abstract quest for the Holy Grail; a far-off dream, an unnecessary addition or perhaps a marketing ploy to sell more cell phones. But 5G is about more than new mobile devices.
WNCG faculty research, including that of Dr. Jeffrey Andrews and Dr. Robert Heath, pushes the current boundaries of mobile data and calls for drastic changes to the structure of mobile networks.
Since 2008, mobile traffic across the globe has increased at a rate of roughly 100 percent per year, while the available bandwidth, or spectrum, for data use has remained largely unchanged. During peak hours, wireless networks in major cities often reach a point of failure. With the explosion in online video traffic, which is predicted to occupy 66 percent of mobile traffic by 2017, the industry is scrambling to find a solution.
Other factors also strain the current 4G and LTE systems. With the increase of cloud computing, machine-to-machine communications, multiplayer gaming and the spread of HD video, the 4G Network, still in an early stage of deployment, will not be able to keep up.
According to Andrews, the Federal Communications Commission’s (FCC) boldest plans are too low. At best, the FCC’s plans call for a 50 percent increase in the available spectrum, which is about 1 GHz across both cellular and WiFi. For 5G to become an effective solution, Andrews believes it should support machine-to-machine communications, support extremely high access point density, and increase the network’s available spectrum by at least a factor of 10 over the current 1 GHz.
Both Andrews and Heath are proponents of the usage and refinement of millimeter-waves to transmit signals and develop the 5G Network.
“Increased spectral efficiency is not enough to guarantee high per-user data rates,” Dr. Heath states. “The alternative is more spectrum. Millimeter-wave cellular systems appear to be a promising candidate for next-generation cellular systems by which multiple gigabit per second data rates can be supported.”
Current research undertaken by the WNCG faculty demonstrates that a millimeter-wave network has the benefit of large bandwidth and greater density, while often exceeding the current coverage of microwave networks.
Many questions must first be answered before millimeter-waves can be widely used. Though these waves can be precisely steered to direct signals, they sometimes create brittle links. Objects and barriers, such as tinted glass, can interfere with the connection of these wavelengths from transmitter to receiver. According to Andrews, models are still needed for judging the efficacy and cell performance of millimeter-waves in dense networks. Both researchers are searching for solutions that will transform the use of millimeter-waves into an effective 5G global solution.
“5G cellular systems will be extremely dense, highly integrated networks of many different spectral bands and types of devices,” Dr. Andrews says. “Increasingly, data traffic will be routed through a combination of picocells, femtocells and WiFi offloading, all of which are more amenable to millimeter-wave spectrum and provide large cell-splitting gains.”
The path to 5G will take time, however. With many research hurdles yet to overcome, Andrews predicts the final rollout for 5G will not occur until after 2020.