18Apr 2018

5G is the evolution of the present LTE wireless network that carriers are beginning to deploy later this year. 

Yes, it will be a Global network, with every geography around the globe utilizing it at some point in the future. 

Yes, it will have Great capabilities, from streaming videos with very little if any delay, and seamlessly handle a large number of connected devices such as sensors.

Yes, it will Galvanize a new set of applications that may have not even been conceived of yet. Just imagine what the previous generations did to promote social networks, video, and other such uses that were not possible a decade ago.

Yes, it will have Grave consequences on the battery. The demands that the network places on the devices, in particular, the handset or smartphone, are significant. Early results show that the power consumption in the chipsets that run smartphones are higher by as much as 25 to 50%.

Yes, the effort will be Grueling to improve the battery’s performance and safety.

Much has been written about 5G and its planned deployment. Unfortunately, the coverage tends to be centered on the benefits of 5G and neglects the impact on the battery. If anything, it can be misleading in promising a longer battery life, contrary to the present data.

The figure below (courtesy of Verizon Wireless) highlights three main thrusts of 5G. At the low frequency bands, typically between 600 MHz and 900 MHz, 5G will continue to provide mobile broadband, similar to 4G / LTE connectivity on your smartphone or handset device. At these frequencies, the network will be limited by physics to maximum data bandwidths on the order of a few hundred Mbits per second.

 

 

5G introduces a new set of frequency bands that will go as high as 6 GHz where data rates can reach one or more Gbits per second. These higher data rates will provide new services that have much faster connectivity, or as Verizon Wireless calls it, enhanced Mobile Broadband.

The last frequency tranche is above 24 GHz where data rates can now reach 10 Gbits per second or higher.

There are three key observations to make here in relation to the battery. 

First, there will be a substantial increase in the amount of data traffic with 5G. Each bit of data consumes a small amount of battery charge. While electronics are getting incrementally more efficient in power usage, this efficiency is no match to the massive increase in data traffic, anticipated to be 1,000X higher than present-day volumes. This, unquestionably, will be the first strain on the battery requirements necessitating higher battery capacities and energy densities.

The second observation is more subtle but potentially more potent. The 5G networks provide new applications that are time and mission critical with a very low latency. In other words, the time that it takes the data to make a round trip from one device to another, and back to the original device (what engineers call latency) will decrease from a present-day value near 100 ms (milliseconds) to less than 10 ms. 

Who cares, you might ask! Imagine two autonomous vehicles on the highway traveling at 65 mph (105 km/h). In 10 ms, the vehicle would have traveled nearly one foot (about 30 cm). In 100 ms, the distance is ten feet or nearly three meters. This is the difference between avoiding a collision or a potentially tragic accident. 

But low latency means that the apps processor (or CPU) will be getting far less idle time that it does today. You see, battery-operated devices rely on the electronics being asleep (not drawing power) for a good portion of the time in order to save battery. So when the processor needs to be awake a longer duration of time, it will have a substantial impact on power consumption, and consequently the battery. 

The third and last observation relates to the new higher frequency bands at 3 – 6 GHz and greater than 24 GHz. Physics tell us that power consumption increases linearly with frequency. So just by going from the 900 MHz band to the 6 GHz band will incur up to 5X increase in power. 

Additionally, waves at these frequencies do not travel very far and tend to be greatly attenuated by physical obstacles like buildings and trees. This limited propagation requires that network carriers (like AT&T and Verizon) install far more antennas more densely. This large capital outlay will most certainly take time. Consequently, handsets operating at higher frequencies will most certainly need to increase the transmission power to overcome the attenuation. Once again, the battery suffers.

Of course, it is fair to expect that the power utilization in 5G networks will improve over time and manufacturers will derive improvements in efficiency. However, it is highly unlikely that 5G power requirements and impact on battery will be similar to those of 4G/LTE. The demands on the battery are certain to increase and put more constraints on battery performance and safety.