Defining Small Cell in Wireless Industry Networks

"Small cells" is one of the more recent developments in the wireless industry. In a wireless network, small cells provide both coverage and capacity, indoors and outdoors. Their function in the wireless network is to increase capacity and to achieve higher radio density.

What Is a Small Cell?

Also known as a small cellular base station, small cells incorporate a few different technologies, but perhaps they are best described as anything that is not a standard macro site. It is the function they play in the wireless network that defines them Their function is to add capacity by shifting traffic away from the macro network. Small cells are about network densification, because they are used to resolve issues of network capacity in relatively small areas, such as hotspots, or other subset zones of the overall macro site coverage.

Besides helping provide seamless connectivity, small cells occupy less space. In crowded urban areas, operators can replace or enhance large cell sites using small cell solutions. This way, operators can effectively support more users by shrinking, or breaking, the size of each cell. The result is consistent data speed and fewer blocked calls in densely-populated metropolitan areas.

The following are methods of deploying small cells to expand capacity:

Distributed Antenna Systems (DAS)

Passive DAS are typically considered to be the original small cell solution. A DAS takes a donor feed from the macro-cell and uses fiber to distribute it to an outside space, or throughout a building. Active DAS has its own dedicated radio base station, which guarantees both capacity and coverage, thus enhancing the quality of both data and voice services.

DAS supports new traffic in areas that were not previously covered, and it also takes traffic away from the macro network in areas where coverage overlaps. DAS has become a highly efficient and effective method for eliminating dead zones and distributing wireless connections within large buildings.

Active DAS is typically considered for large areas like airports, malls, campuses, and so on, where Passive DAS with its bi-directional antennas and non-fiberoptic cabled connections is limited in terms of scalability. Either way, DAS achieves a wider reach because optical electrical signals are converted into optical signals via an optical repeater. These optical signals are then translated back into EMF waves.

We're also seeing low-power radio technologies like micro base transceiver stations and integrated pico being tested for fixing coverage and localized capacity.

Integrated Metro-cells.

Metro-cells are mini macro sites. They are capable of boosting network capacity. They are cost effective, and they can be installed quickly. In dense urban areas, they tackle most issues associated with macro cell site deployment by reducing zoning and site acquisition problems. Metro-cells are aesthetically pleasing because they are usually concealed by being affixed to street furniture, like lamp-posts.

Multibeam Antennas and Sector Splitting.

This is where one antenna is used to provide double the capacity. By using multibeam or twin-beam antennas, a sector is split in two, thereby doubling the capacity. This solution is used in high data traffic areas, where sectors in macro sites need to increase capacity, cover a large outdoor area, or penetrate a large building.

Because of the availability of the above solutions, it is not difficult to understand why small cells have become so popular, especially when operators are forced to deal with challenges like site acquisition and the ever-increasing growth of high usage areas where there’s an urgent need to increase capacity.

In today's world where customer loyalty is determined by the quality of service delivered, it has become even more vital for wireless network operators to have access to a range of solutions to cover these issues.