Cell phones have become deeply integrated into modern life, enabling us to stay connected and access information at a moment‘s notice. But without an extensive network of cell phone towers and antennas to receive and transmit signals, these pocket-sized devices would be useless.
As carriers begin rolling out super-fast 5G networks, an influx of new cell tower infrastructure is required to support the technology and deliver its promised speeds and capabilities. Upgrading this critical equipment is no small feat.
So how exactly does a network like 5G come together? What types of cell towers power our phones, and how are they evolving for the future? This guide explores the six main varieties of cell towers driving mobile innovation now and into the 5G era.
A Brief History of Cell Towers
Before diving into the different tower types, it helps to understand how we got here. The first commercial cell phone networks emerged in the 1980s using analog technology powered by large "macrocell" towers.
Early macrocell sites had limited capacity and covered expansive areas. As more users came online, carriers had to deploy more macro towers while also developing smaller "microcell" sites to support increased demand in dense urban areas.
The 1990s saw the rollout of second-generation (2G) digital networks enabled by improvements in infrastructure hardware as well as new coding techniques to transmit more data. This kicked off an ongoing cycle of new mobile technology standards, each requiring upgrades to existing equipment.
Today‘s 4G LTE networks laid the groundwork for our current world of mobile apps, streaming, and more. Now 5G is poised to unlock new possibilities with exponentially faster speeds, massive device capacity, and near-instant response times. But these perks cannot happen without major cell tower innovations across the board.
Macrocell Towers: The Original Workhorses
The most visible presence of cell networks are those tall towers dotting landscapes across the country. Known as macrocells, these high-power base stations provide coverage across wide regions and serve as the backbone of nationwide mobile communication.
A large macrocell tower. Image source: Wikimedia Commons
Macro towers can reach 200 feet tall and are typically placed on high ground for maximum coverage. Their height and power allow signals to travel farther and overcome obstacles like buildings and terrain. Originally designed for analog signals, these sites now transmit multiple cellular standards including 5G.
However, 5G‘s higher frequency bands have shorter ranges than previous generations. Upgrading macrocells for 5G therefore requires adding new equipment so they can broadcast on additional spectrum. More macro sites are also needed overall to provide ample coverage.
Other innovations like MIMO (multiple input, multiple output) antenna arrays help macrocells handle greater 5G capacity and speed. But smaller supplements are still necessary in busy areas. This is where microcells enter the picture.
Microcell Towers: Extra Capacity for Urban Zones
As the name suggests, microcell towers are smaller versions of macro ones. They function similarly but transmit at lower power levels and cover more modest footprints. Microcells are used to infill mobile networks, boosting capacity in dense urban locations or patches of poor coverage.
Rooftop microcell installation with multiple antennas. Image source: Wikimedia Commons
Since microcell towers are compact, they can be mounted in more places like building roofs or utility poles. This flexibility allows carriers to target high traffic areas. 5G microcells function similarly to macro ones, providing extra capacity on new 5G frequencies. More fiber backhaul connections are also needed to handle additional data flows.
Picocell and Femtocell Towers: Indoor/Local Coverage
Beyond macro and microcells are even smaller base stations designed for indoor settings. Picocells provide wireless access within confined public spaces like offices, malls or train stations. The tiny femtocell is made for residential use in homes or apartments.
A femtocell provides localized coverage inside a home. Image source: Wikimedia Commons.
These low-power units connect to a broadband modem and offload data traffic from wider cellular networks. This helps ease congestion while providing better signal quality in hard-to-reach indoor areas.
Picocells and femtocells are also being upgraded with 5G radios and antennas. Their compact form factors plus reliance on IP networking makes software/hardware upgrades simpler compared to larger cell sites.
DAS: Focused Signal Boosting
An alternative to traditional towers are distributed antenna systems (DAS). Rather than one tall tower, DAS uses many smaller antennas linked together to provide coverage across buildings or confined zones.
DAS networks contain centralized radio equipment connected to optical fiber cables leading to distributed antenna nodes. Custom antenna placement provides precise, high-capacity mobile signal exactly where it‘s needed – similar to how Wi-Fi access points work on a local scale.
A distributed antenna system uses many compact nodes. Image source: Wikimedia Commons.
DAS is popular in stadiums, corporate campuses, hospitals, and other large buildings to bolster indoor wireless rather than relying solely on macrocell signals from outside. Like other infrastructure, DAS requires upgrading to handle 5G frequencies. But it‘s a cost-effective way to cover confined areas with fast, consistent mobile data.
COWs: Deployable Relief
Finally, cell towers don‘t always need a permanent foundation. Cell on wheels (COW) sites are essentially cell towers installed on vehicles for easy transport. Mobile carriers dispatch COWs to provide expanded coverage at large events or disaster response when infrastructure is impaired.
A mobile COW deployment. Image source: Wikimedia Commons.
Truck-mounted COWs contain all the usual tower equipment to light up cellular service anywhere needed. They serve an important role for early-stage 5G as well by providing hotspot-style coverage on next-gen networks where permanent towers aren’t yet available.
The Road Ahead
This crash course demonstrates the diversity of infrastructure underlying our mobile world – and how upgrading each piece is integral for unlocking 5G capabilities. From towering macrocells to compact indoor femtocells and deployable COWs, all these technologies combine to fuel the promise of 5G speeds, responsiveness and capacity.
Ongoing 5G deployments mean even more cell towers, small cells and antennas will continue propagation. And future innovations in areas like software-defined infrastructure, drone and balloon-based platforms may yield entirely new approaches to keep everyone connected. The only thing certain is that wireless infrastructure will remain just as important as the devices we carry.
