How 5G Works


5G and Millimeter Wave Tech
A robot introduces 5G technology to a visitor during the Mobile World Conference 2017 in Shanghai. VCG/VCG via Getty Images
A robot introduces 5G technology to a visitor during the Mobile World Conference 2017 in Shanghai. VCG/VCG via Getty Images

Radio signals are measured by their wavelengths. The shorter the wavelength, the higher the frequency. 5G signals will use wavelengths (between 30 and 300 gigahertz) that are measured in millimeters. That's why 5G is considered a millimeter wave technology [source: IEEE]

The very high frequency of these signals is important to note. It means that 5G will be capable of incredible data bandwidth, so that many people will simultaneously send and receive nearly unfathomable amounts of data.

The downside? High frequencies have short range, and 5G may only be able to span a few blocks of any given area. That means 5G may not project over long distances. Smaller frequencies also don't penetrate obstacles very well, so everything from concrete walls to tree leaves may disrupt signals. That makes it a line-of-sight technology – your wireless modem or phone will need to be close to a base station for best transfer speeds.

In addition to better bandwidth, 5G should have reduced latency, or delay, between the devices it connects. 4G has a latency of around 70 ms (milliseconds); 5G should have less than 1 ms [source: Mobile Foresight]. That means less frustration and more productivity, and in some scenarios, it's a lifesaver. With driverless cars, for example, the vehicles must be able communicate on a nearly instantaneous basis to prevent accidents.

5G's infrastructure rollout will be different, too. In the past, communications companies typically build big cell phone towers to propagate cell signals throughout a geographical area. 5G may alter this paradigm. Rather than constructing towers, service providers will just install their equipment (called small cells) on existing telephone lines and buildings. The cells may have a range of around 250 meters (820 feet) [source: IEEE]. To tap into the signal, customers will use wireless modems (or phones) to connect. In turn, that could mean you no longer need that cable-based internet service.

Because millimeter wave 5G signals have weaker propagation compared to 4G, service providers will have to create a denser infrastructure to ensure consistent service. As with WiFi, 5G will require more base stations in closer proximity to serve many people.

A few mobile carriers are launching "pre-5G" versions of 5G that would lead you to believe that 5G is already a well-defined standard. It's not. In fact, no one really knows just yet what 5G will be like because the standard for 5G won't even be finalized until 2018 [source: Frenzel].

A lot of what 5G really will entail is still in the realm of speculation. One thing's for certain: 5G will be an improvement over 4G in terms of speed and capacity. If there's a drawback, it's that the upgrade process will be expensive. Service providers will blow billions (perhaps as much as $21 billion) to make the jump from 4G to 5G [source: Real]. And consumers will have to pay up too.

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