5G hasn’t been around very long and is launching all around the world at record speeds.
In the modern world, dominated by terse, character-limited Twitter, and text communication, we have become quite fond of abbreviations and acronyms. Perhaps the hottest such buzz-term this year is 5G. It’s quicker, and just rolls off the tongue better than “the fifth-generation mobile communication network.”
There’s quite a bit packed into those two characters, too – including a lot of history. Now that 5G is becoming a reality, it’s worth exploring some of that history.
From Car Phones To Smartphones
The first generation (not actually referred to as “1G” until much later) of wireless networks in the US was installed in the early 1980s and was limited to voice calls. Coverage was sparse, and the towers relied on analog FM radio signals, subjecting them to frequent interference. The first phones on the network required bulky power and support equipment, so they were initially restricted to phones hard wired into vehicles, or heavy but portable “suitcase” phones. Despite these early limitations, the popularity of mobile communication grew rapidly as people saw it’s potential.
The 2G network launched just in time for the emergence of the internet in the early 1990s. The biggest significance of 2G over 1G was its institution of communication standards which supported digital data transmission over the voice bands. Digital voice calls were much higher in quality. 2G also marked the birth of text messaging and mobile email as well as some very limited mobile internet connectivity, changing the whole concept of telephone usage. Phones themselves were finally small, portable, and cheap enough to be practical for the general public.
In keeping with the trend of a mobile network upgrade about once a decade, 3G started to take shape in 2001. Third-generation standards built upon 2G to support much higher data transmission rates. This resulted in an explosion of mobile applications, allowing multimedia streaming and full mobile Web functionality. Although there were some 2G smartphones, 3G made it possible for them to become the norm. With these technological innovations and improvements also came dramatic increases in the cost of network infrastructure, services, and devices.
MIMO and 4G
In the mid-1990’s while 2G was still in its adolescence, Stanford engineer Greg Raleigh developed a mathematical theory for the transmission and reception of signals using an array of antennas – instead of a single transmitting and a single receiving one. Although it took years to develop into a practical technology, it promised to drastically improve the speed and reliability of wireless signals. This multiple-input multiple-output (MIMO) technology became the basis of the current 4G mobile network.
The first networks meeting the 4G standard, including the Long-Term Evolution (LTE) standard, began to emerge in 2009. The increase in data rates allowed by MIMO antenna arrays enhanced network performance in ways that are still being realized. Real-time applications requiring constant connectivity and high-definition streaming are commonplace on 4G networks. But the ten-year average life span of wireless generations is still holding true, and 4G is about to give way to the new kid on the block.
The 5G Upgrade
Although 5G will not be the first network standard to employ MIMO, it will do so to much greater effect and use beamforming (aiming a signal to reduce interference) for up to ten times the data rates that 4G provides. The low latency, or delay between transmissions, along with the increased connectivity of 5G’s dense, MIMO antennas is expected to result in the proliferation of connected, autonomous devices. 5G will run on top of, and in conjunction with, the existing 4G infrastructure but to be used to its full potential requires additional, closely spaced “small-cell” antennas in its service areas.
The other distinguishing (and controversial) feature of 5G is its use of signals in the ultra-high frequency millimeter wave band. Mobile communication frequencies have increased with each successive generation to allow more information to be transmitted and have been in the microwave band for decades. Millimeter waves have been used before – in airport body scanners and military crowd control devices – but they will be ubiquitous in areas with full 5G coverage. There is growing concern that the long-term health effects of these high frequencies are unknown – causing many to call for more study before deploying 5G antennas near homes and schools.