By: Slavko Djukic
There’s continuous work being done to get more out of the currently used frequency spectrum. Mobile operators are always looking for more spectrum in order to expand bandwidth and provide their users with faster LTE service. Once they have extracted all they can out of new cell sites, splitting sectors, and carrier aggregation, the next step is to look at the unlicensed spectrum. LTE-U, LAA, and MulteFire are all terms that describe approaches to unlicensed spectrum that will deliver more from current technology.
LTE Technology Guide
|LAA||License Assisted Access||
3GPPP standardization of LTE use
in Wi-Fi bands
|LTE-M||LTE for Machines||
Short-range LTE designed
for M2M applications
|LTE-U||LTE Unlicensed||LTE using unlicensed frequency bands|
|MulteFire||N/A||LTE using unlicensed frequency bands|
While 5G standards are not fully developed, 5G is being tested outdoors with 28-30GHz frequencies. Those frequencies do not propagate well in indoor environments. Thus mobile operators will need lower frequencies for indoor 5G use, where, after all, 80 percent of mobile traffic originates and where 5G will see a wide range of use cases.
So how will these unlicensed frequencies converge onto 4G and 5G? While it’s too early to tell when and how 5G will be used in buildings (2020 is a possible target date for widespread implementation), the path to adding unlicensed frequencies for LTE use is fairly clear. Chip makers like Qualcomm (which favors MulteFire) must produce cellular transceivers that can operate in the 3-6 GHz bands, and these chips must be implemented in phones, tablets, and other devices. Networks at these frequency bands must be built.
At some point, users’ devices will implement both licensed and unlicensed frequencies for LTE use and mobile operator networks will decide, for any given environment, what works best for the user to get to the highest throughput.
From what we can see today, LTE protocol deployed for IoT applications is LTE-M, which is a licensed, short-range LTE designed for machine-to-machine applications. Some mobile operators are already deploying LTE-M in their networks. At the same time, LTE-M will be one of several wireless standards used for IoT implementations. Wi-Fi, ZigBee, Bluetooth, and others will also provide support for the coming Internet of Things.