With some mobile operators and vendors promising to launch 5G cellular as early as next year, it's easy to assume that 4G now has one foot in the grave. Wrong, for several reasons.
For example, new and forthcoming versions of 4G -- such as Release 13, now branded as LTE-Advanced Pro -- will keep it viable for at least another decade by improving efficiency, speed and capacity. Some of the new features also address the Internet of Things' (IoT) unique wants and needs, such as sensors that can run entirely on batteries for the better part of a decade.
"In Release 13, they're looking at more efficient modules that will last longer in the field because they have lower battery usage," says Chris Pearson, president of 5G Americas.
In the process, LTE also will pioneer many of the technologies and concepts that will go into 5G. Release 12, for instance, lets devices communicate directly with one another instead of always through a network. Meanwhile, 5G aims for latencies of 1 to 5 milliseconds, so it could build on 4G's work to support delay-intolerant applications such as vehicle-to-vehicle communications for driverless cars.
Another example is higher orders of multiple input, multiple output (MIMO) antenna systems. Higher orders than today's 4x2 require more tower space than some cell sites can accommodate. But 5G will use millimeter-wave bands, which enable physically smaller antenna elements, so it can take 4G's MIMO work to the next level.
"LTE is the foundation for 5G networks," Pearson says.
Market Momentum Continues
Another reason why LTE won't disappear anytime soon is that many operators also are still upgrading from 3G, so they're in no rush to make another big, expensive migration to 5G. Currently there are about 480 commercial LTE networks in 157 countries.
"We expect to hit more than 500 by the end of this year," Pearson says. "We expect LTE subscriptions to go over 1.5 billion in 2016. By the time we get to 5G in 2020, there will be 3.6 billion LTE connections."
It will take a decade or more for those connections to migrate to 5G, especially the IoT ones -- such as utility smart readers -- that have refresh cycles spanning 10 years or longer. LTE's enormous installed base also means it's well down the cost curve, whereas 5G chipsets, devices and infrastructure won't start their slide until sometime long after 2020. So although 5G is being designed partly to meet IoT's unique requirements, LTE's relatively low cost will give it a significant competitive edge deep into the next decade. And for some IoT applications, such as telematics, LTE also will be attractive for its footprint, which 5G won't be able to match for years.
LTE also could find new life in unlicensed bands. Currently most operators and vendors focus on LTE Licensed Assisted Access (LTE-LAA), which aggregates signals from licensed and unlicensed bands. But there's also growing interest in creating a version that uses only unlicensed spectrum. Money is a big part of the appeal for potential users such as cable companies: They're spared the expense of spectrum licenses and they get to leverage LTE's mature cost structure.
— Tim Kridel, Freelance Contributor. Follow him on Twitter @TimKridel. Special to The New IP