The situation: Small cells meet 4G network demands


By John Spindler, vice president of product management at TE Connectivity

Mobile operators around the world are rolling out LTE networks to deliver high capacity services to bandwidth-hungry consumers. Small cell architecture makes sense for these operators as it brings mobile signal closer to the customer and divides the customer base into smaller groups so that each individual receives more bandwidth, enabling a build-as-you-grow strategy to bring service where it's needed.

To keep pace with capacity and coverage demands, service providers have been adding or splitting cells, or using Distributed Antenna Systems (DAS) to provide effective 3G services (especially for dense user populations). This trend will accelerate as 4G services are being deployed. Small cell architecture offers the opportunity for wireless service providers to provide excellent service quality.

Another reason why small cells play a role in 4G network rollouts is that macro base stations have virtually saturated most markets, and there is rising community resistance to more big towers in cities and suburbs based on concern about RF emissions, environmental clutter or visual pollution. Municipalities (especially in residential neighbourhoods) often block and delay cell site construction. Mobile operators, in many cases, can't add more macro towers even if they want to. Small cells will fill the gaps.

There are five key advantages to using DAS for small cell architecture:

Coverage DAS can be installed inside buildings, in tunnels or underground areas to bring clear and consistent mobile coverage to the user. Some mobile signals won't properly penetrate buildings or underground areas, so having the signal emanate from inside these areas solves the coverage problem. DAS are being installed in buildings but also urban and suburban areas where macro tower coverage is spotty. Weak signal strength will impede data performance.

Capacity Small cells increase the network capacity available to each user by dividing the user population into smaller segments. With fewer customers using bandwidth, each customer receives a proportionally larger amount. LTE networks promise from five to 14 megabits of data service on the downlink. It is unreasonable to provide adequate capacity to large swaths of the population when using macro towers alone.

Frequency Management Spectrum is limited, and small cells make it much more critical to re-use frequency efficiently. DAS can help by expanding the size of one base station's coverage area, enabling digital simulcast and extending the station's capacity to multiple antenna points, thus directing the capacity where it is needed most. And as those capacity needs change over time, the network adjustments can be made to the simulcast configuration without physical hardware changes in the network.

Capital Expenses Small cell products are quicker to deploy (requiring less physical material and real estate than macro cells), scalable and incrementally cost far less than macro cells, so service providers can deploy them with a strategy that maximises return on investment. For example, a service provider can start out by covering portions of an urban core where the concentration of early 4G adopters will be higher, and then move out from there as demand grows.

Operating Expenses To reduce field service time and cost, DAS can extend signals out from centrally located base station hotels. This minimises real estate needs and costs and provides the service provider with one place to make network changes and manage maintenance versus disperse sites throughout a market. The DAS itself requires little maintenance and is easily monitored through the network operations centre (NOC) with other network elements.

DAS-based small cell networks solve many of the key challenges in rolling out LTE networks. DAS makes it possible to precisely extend LTE service to specific areas, such as urban cores, stadiums, and airports, where high value LTE customer density is highest. DAS solves the technical problems of coverage and capacity that make LTE rollouts different from 3G rollouts.

TE Connectivity is a global, $12.1 billion company that designs and manufactures over 500,000 products that connect and protect the flow of power and data inside products that touch every aspect of daily life.


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