What Are Small Cells & How Do They Work? An Overview

We’ll explain what small cells are, how they work, their different types, their pros and cons, and how private mobile networks can be an alternative.
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Network Infrastructure

We’ll explain what small cells are, how they work, their different types, their pros and cons, and how private mobile networks can be an alternative.

What is a small cell?

Small cells are low-power cellular radio access nodes typically installed within enterprise environments to extend public mobile network coverage and capacity to indoor facilities.

How do small cells work?

Small cells are literally smaller compared to macro cells in that they can be the size of a small pizza box. They provide less coverage and capacity compared macro cells on a per radio basis given the difference in design characteristics for indoor with small cells compared to city wide outdoor coverage with macro cells.

However, when used in a DAS system or RAN network, small cells smoothly bridge the gap from wide area coverage to focused localized cellular access. For example, 5G operates at a higher frequency, but suffers from poor signal propagation when broadcasting from outside to indoors.

Small cells are able to rebroadcast 5G signals from inside, allowing for better coverage and overall reliability. Organizations are able to arrange small cells in a way that guarantees coverage to indoor environments as needed per subscriber presence in specific locations.

Why small cells? Advantages & disadvantages

First, small cells are a supplement for—not a replacement of—macro cells. Here’s how small cells can help and what that requires.

Pros of Small Cells

Small cells extend coverage and add capacity to public mobile networks, especially in high-density areas like cities. They are an excellent supplement where a macro cell is struggling to keep up with growing demands, such as in dense residential, metropolitan, or commercial areas.

The size and flexibility of indoor cells makes them a more affordable option than using a Base Transceiver Station (BTS), and allow for quick and efficient deployments of public LTE coverage in localized areas.

With macro cells, all devices connect to the same central cell, meaning that devices that are farther away may suffer and nearby devices enjoy better performance. Since small cells are distributed across an area indoors, devices can enjoy a more consistent connection.

Small cells are used to efficiently distribute cellular signals that originate from cell towers miles away. This gives organizations a way to maintain precise control of their private LTE coverage, even when the public mobile network data centers are a large distance away.

Cons of Small Cells

Small cells require additional power, separate network backhaul, and proper placement of its dedicated radios to enable coverage for public mobile network indoors. They are installed next to existing private LTE, Wi-Fi based wireless LAN and other secure wireless infrastructure that might be in place within the enterprise. Thus building this separate small cell system to extend public mobile network coverage can cost time and effort, as well as additional money to deploy and maintain.

And there’s the issue of aesthetics. The industrial look of these small cells, which are often very visible when mounted on indoor walls and ceilings, makes it harder to sell the idea, and can cost additional effort to conceal or beautify the infrastructure.

The advantages and disadvantages of a small cell can depend on its type as well.

Types of Small Cells

There are three main types of small cells: femtocells, picocells, and microcells. These different options can be combined to build a small cell network in virtually any environment.

Femtocells

Femtocells have the lowest transmission power, shortest coverage radius, and smallest capacity for users. Femtocells only offer fiber or wired backhaul. Femtocells tend to be low-cost and are best suited for covering indoor areas.

Picocells

Picocells have a medium transmission power, medium range, and medium capacity for users. Picocells only offer fiber or wired backhaul. Picocells tend to be low-cost and can cover either indoor or outdoor areas.

Microcells

Microcells have more powerful transmission, longer coverage radius, and large capacity for users. Microcells offer fiber, wired, and microwave backhaul. Microcells tend to be more expensive and best suited to outdoor areas.

Compared to macro cells, microcells provide better consistency and reliability within their limited range. Microcells can use intelligent connections to overcome limited line of sight in challenging urban environments. This makes their infrastructure vital to the future of 5G networks.

Meanwhile, macro cells offer the most transmission power, longest coverage radius, and largest capacity via all types of backhaul. But they come at the greatest cost and are used primarily for large outdoor areas.

If you’re building a network for a large office building or corporate campus for an enterprise organization, here’s how these cells can help.

Small Cells for Enterprise Environments

Right now, small cells are largely used to cover residential, metropolitan, and commercial areas. But extending the public mobile network coverage within enterprise facilities is also a major opportunity for large enterprise organizations to cover large buildings, campuses, and more.

If your building or campus suffers “dead zones” where there is no wireless connectivity, small cells can be deployed to cover those areas. This is especially important if you require a reliable connection throughout a hospital building, factory floor, warehouse, or college campus. In the age of IoT devices more portable cells are crucial for ensuring a reliable connection from the sensor to the backend network.

In a network that hosts many devices that subscribe to public mobile networks, small cells can increase capacity to handle all those devices. This helps with high-density buildings like hotels and colleges. This capacity is even useful if you have mission-critical IoT devices that require public mobile network connectivity. These cells can overlap their coverage area to ensure a constant connection to devices that might be moving quickly between public macro cell and small coverage.

An Alternative: Single Enterprise-Ready Infrastructure for Public and Private Mobile Network Coverage

Today, with the advent of private spectrum options such as CBRS in the United States, enterprise organizations can build and operate their own private LTE and 5G networks. In conjunction with private Wi-Fi, companies can cover their buildings and campuses with their own private mobile networks using cellular technologies for those areas that Wi-Fi cannot serve.

Private cellular offers greater reliability for deterministic performance on key wireless applications, better coverage on a per radio basis, and superior performance in high density environments. For large organizations private LTE can help connect campuses, remote work sites, and satellite facilities to a single secure network for enterprise owned and staff operated mobile and IoT device infrastructure.

In addition, the same private LTE / 5G wireless network can be enabled to extend coverage for multiple public mobile networks within the enterprise environment - preventing the need to deploy separate small cell infrastructure. With the significant savings this entails, the return on investment (ROI) on the private mobile network can quickly be recognized.

The Celona Solution

Celona partners with businesses to seamlessly plan, deploy, and manage private LTE networks that integrate with existing infrastructure - that’s ready to support both public mobile network coverage indoors and satisfy private use cases.


If you are looking for an alternative to small cells and Distributed Antenna Systems (DAS) to extend public LTE / 5G coverage within your enterprise environment, Celona can help. See our solutions in action, or sign-up for a free trial to experience for yourself.

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