typical hfc nodeFrom the beginning of the CATV industry, engineers developed a coaxial network that has remarkably enabled the best platform for network convergence. Today’s hybrid fiber coaxial (HFC) network provides a path for efficient powering and signal transport. It’s a robust and relatively low-cost system that has tendrils extending from high-density urban environments into suburban and rural subscriber markets. The key point here is that these networks exist in many populous areas prime for small cell deployment.

What exactly is a small cell, and how does it differ from current cellular networks? First, let’s define cell: a geographical area that is covered by a radio system. A macro cell is the common servicing approach used today, where a large footprint (often a radius of a few miles) is serviced by a single radio system on a cell tower. There are many devices all sharing the bandwidth being provided; too many devices accessing it can result in calls not going through or data service interruption. A small cell services a smaller footprint, approximately a third of a mile radius or about one radio for every six to eight utility poles. The small cell’s reduced geographical area can provide the same amount of bandwidth as a macro cell, but the radio will be shared by fewer users. This enables large size portions of that bandwidth to each device. 

While some people are developing future IoT technology, others are converging their HFC networks with wireless small cell radios. These small cells will become essential to enabling the progression of IoT, like autonomous services. While most people are thinking about IoT in terms of technology services like smart security systems and thermostats, the technology-minded are thinking about other things like fully autonomous postal and package, school bus, sanitation, and grocery delivery services. All these autonomous services have a common need for bandwidth to operate as efficiently as possible by status reporting and updated directives. 

CLICK TO TWEETHere's why HFC networks are so important in a small cell world, according to CommScope. 

For example, imagine an autonomous school bus traveling through a neighborhood -- no driver, yet it knows where to pick up a child based on a wireless device the child wears. The bus assigns the student a seat when they get on and provides a review of the day’s schedule or any other information that may be important. The inside of the bus is constantly recorded so in the event of an incident it can be reviewed by school officials. The wireless device the students wear lets the home automation system knows to adjust the thermostat, set the lighting, and what materials are needed for homework. 

The possibilities become limited only by the technologies available. The only constant is the need for wireless bandwidth, but it doesn’t mean the network is wireless. It only relates to the user being untethered, wirelessly connecting to the network. That wireless network still requires a radio which needs power and a data pipe. This is where the HFC network comes in play. It can provide up to 90 Volt AC power over the coaxial cables and a huge bandwidth pipe over the fiber. 

fiber deep with small cellsFrom a cost narrative, coaxial can be less expensive than equivalent power capacity copper cables. The coaxial cable enables distributed power to multiple small cell radios, reducing power meters and power supplies needed, and it does not require specialized electrical workers to install and maintain. To be as efficient as possible with powering, some segments of the existing HFC network may require installing a larger size coaxial cable to replace a segment of smaller coaxial cable. Fiber deeper into the network will also be beneficial as it enables deployment of Node 0 and Remote PHY that can reduce latency and increase bandwidth by moving signal processing close to the user. It also permits the use of lower cost and more efficient digital laser systems than the current analog laser systems being used today.

As Node 0 architectures are implemented, (AKA fiber deep), additional power is made available through the removal of the RF amplifiers that were previously used. This excess power now means that small cells can piggyback on the existing network powering scheme without the costly and time-consuming need for permitting, power meters installations, cabling, electrical work, pole attachment agreements and the like. Select the location for the small cell, cut the coaxial cable and drop in a power inserter to power the radio, splice the radio into the fiber network, and you are up and running that quickly.

The future for HFC is looking bright, so pass the sunscreen.


About the Author

Chris Gemme

Chris Gemme is Regional PLM for CommScope, a global leader in communications networks and infrastructure solutions. Gemme has more than 20 years’ experience in telecommunications. Prior to his current role, he served as director field applications engineering and as product manager of coaxial cables. Before joining CommScope, he worked at Time Warner Cable. Gemme earned his bachelor of science degree from Troy State University and his MBA from Regis University. Gemme is a member of the Society of Cable Telecommunications Engineers (SCTE). He has also served on the SCTE Engineering Committee, which is responsible for all standards and recommended practices activities of the Society.

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