Intelligentes Gebäude

Comparing 3 Powering Options for DAS Connectivity

Ron Tellas
Back in January, our What to Expect in Terms of Connectivity with a DAS System blog introduced you to distributed antenna systems (DAS) and other types of radio access nodes that provide service to mobile-network subscribers. At that time, we promised to cover the different options available for powering in distributed antenna systems.

This follow-up blog explains your powering options for DAS connectivity: Power over Ethernet, DC power and Digital Electricity.


To support increasing numbers of network-connected people and devices, fifth-generation wireless (5G) is projected to be the technology of choice to address high cellular demands.



With 5G, up to 1 million connected devices per 0.38 square miles can be supported. In comparison, approximately 2,000 connected devices per 0.38 square miles can be supported with 4G. 5G will increase wireless throughput at rates that are 20 to 100 times faster than today’s rates and deliver connections with low latency.


DAS systems will enable 5G technology, ensuring that facilities have the coverage and capacity levels needed for constant, reliable cellular signals.


Like almost any building system, a DAS relies on the transfer of data and power. In enterprise spaces, Power over Ethernet (PoE) has been the technology of choice to deliver data and power. But, to support DAS connectivity, there are three options to consider.


Option No. 1: Power over Ethernet (PoE)

PoE technology sends power and data through one cable. Because power requirements of network devices are growing, IEEE 802.3bt was recently ratified to provide up to 100W of DC power to each PoE port (up to 71W of power for each device). Now PoE can carry up to 100W of power over a data cable for up to 100 m.


Running these higher power levels running through a cable may cause performance issues by making the cable warmer. When a cable gets hotter, insertion loss increases, which increases the possibility of downtime and may cable damage.


To prevent cable temperature rise, look for Category 6A cables with insertion loss margin to maximize channel reach at higher temperatures.


Option No. 2: DC Power Source

This type of system is widely used in telecom systems. A centralized DC power source provides power to end devices through copper conductors varying from 12 AWG to 20 AWG.


The required delivered voltage and distance of the end device from the central location determines the number of pairs and gauge size of the copper conductors. For distances greater than 100 m, consider hybrid cabling, which melds the benefits of fiber for data and copper for power together in one cable.


Option No. 3: Digital Electricity™

Digital Electricity is the safe deployment of high power voltages over long distances. A complete system requires transmitters and receivers.


The transmitter (which looks like a server) takes an AC or DC power source and sends it out on individual electrical circuits. From there, Digital Electricity Cable can distribute the power. The receiver "receives" the electricity packets sent from a transmitter and converts the energy packets into the required form (i.e. 57 VDC or 120 Vrms).


Digital Electricity can carry up to 2,000W for up to 2,000 m. In simple terms, Digital Electricity offers 20 times the power and 20 times the distance currently available through PoE. That’s enough power to support an entire building’s wireless system, including DAS, ONTs, PoE switches, IoT devices, etc.


Making the Smartest Powering Choice

When your DAS system components aren’t located near a local power source, a remote power solution is needed. The two most common solutions – PoE and remote DC power – are limited in terms of the amount of power they can provide and the maximum distance at which the power can be provided.


In these cases, Digital Electricity is the most obvious answer, sending high levels of power over long distances. Belden Digital Electricity Cables are designed to support DAS connectivity even when the environment doesn't easily support traditional cable lengths. The cables are available in hybrid copper/fiber to transfer power and data over long distances through a single cable run.


Belden can help you lay the groundwork for successful, reliable, high-performance delivery of data and power. Whether you choose PoE, DC power or Digital Electricity to deliver power for DAS connectivity, we can ensure you've got copper, fiber or hybrid cabling infrastructure to support these systems and provide always-on connectivity.