Small Cell Densification

- Small Cell Densification

Small cells began to augment coverage and capacity in both 3G and 4G deployments, the term "densification" was introduced. With 5G, unlike its predecessors, a different set of frequencies will be used to implement new services. Sub-6-GHz will be used worldwide as the basis for city-wide mobile connectivity, while higher parts of the spectrum (millimeter wave frequencies of 24 GHz and above) will be used for high-bandwidth coverage. This new higher-band spectrum inherently has more significant distance coverage limitation. Thus, densification takes on an entirely new meaning.

- Small Cell Densification Is Becoming A Must

Next generation 5G wireless networks will run applications requiring high demand for data rates. One of the solution to solve the data rate requirement is to allow densification of network by deploying small cells. Small cell densification of LTE and 5G networks is a major priority for mobile network operators (MNOs) around the world. To densify MNOs' networks is not only a logical step to improve geographic coverage while adding much need additional capacity, it’s also a significant step to address changing end-user demands. Using small cells to make cellular networks more dense is becoming a must amidst the demand for quality-of-service expectations associated with 5G. 

5G small cells is a hot area for service providers worldwide, but small cell densification is not a new operational trope. However, in the past, it has been a matter of competitive advantage, allowing MNOs to publish higher coverage statistics than their direct rivals. In the 5G age, it is less a “nice to have” and more of an operational “must-have” in order to achieve the quality of service that consumers and enterprise customers expect. 

MNOs are now referring to their radio usage heat maps to see the geographical areas of high LTE usage to plan their 5G small cell strategies. Places like busy city centers, highways and train routes, airports and shopping malls are all candidates.

[Base Station Site - EverythingRF]

- Network Densification and Small Cells 

While 5G opens up a world of new use cases, it also comes with a number of important implications. One that represents both a challenge and an opportunity, particularly for MNOs, is network densification. That is, to realize the higher data rates and area traffic capacities promised by 5G, MNOs will need to deploy much denser network topologies using small cells. The transition needs to be made from today’s networks, which are larger composed of macro cells, to 5G networks with the targeted deployment of small cells. 

For eMBB (Enhanced Mobile Broadband) applications, for example, small cells will likely be deployed in both mid-band and mmWave bands depending on the type of environment. mid-band (e.g., 3.5 GHz) small cells are best suited for dense urban areas, whereas mmWave (e.g., 28 GHz) small cells will typically be deployed in extremely high traffic areas such as stadiums, airports and pedestrian zones. In addition, mmWave small cells may also be deployed for FWA or flexible use deployments, serving both fixed and mobile subscribers. In contrast, 600 MHz will most likely be deployed at macro sites to provide wide area and in-building coverage.

- Small Cell Densification and Optical Fiber

5G requires at least a 10-fold increase in the density of cellular antennas within the same geography, as 5G begins to flood the airwaves with higher-bandwidth signals in the coming years, the entire goal of wireless technologies will be to move the signal over an air interface and onto fiber as quickly as possible because that is the only way to achieve the strict latency and delay requirements of 5G.  

The role of physical network infrastructure is only going to grow as 5G rollouts continue. More and more small cell connections will call for an enormous amount of fiber optics. 5G network designs dictate the use of more fiber because in order to improve network coverage, capacity, and overall quality, MNOs are adopting small cells, which place radios closer to users. It is preferable to backhaul these small cells over fiber whenever possible because other options, like copper and wireless backhauling, cannot scale to the incredible amount of backhaul demand that will be generated by 5G. In the 5G era, fiber optic lines must be deployed in the antenna at the top of the tower as a fronthaul connection in the RAN as well as at the base station for backhaul to the mobile core. 

Optical fiber is the preferred medium for existing wireless backhaul networks, and even in networks where this is not the case, the wireless backhaul eventually needs to connect into a fiber backhaul. Fiber will also be preferred for fronthaul, connecting the dense mesh of 5G small cells. Increased speeds with lower attenuation, immunity to electromagnetic interference, small size, and virtually unlimited bandwidth potential are among the many reasons why fiber is the right choice. 

[More to come ...]