If you’ve been reading our blog for any length of time, then it’s no secret to you: Several components make up the infrastructure that supports your network – from cables to connectors – and they all have to follow appropriate standards, be well designed and be properly installed in order for your network to perform like you need it to.
Cable imbalance, which can lower immunity to interference – can increase alien crosstalk between adjacent cables to levels that are beyond recommendations, negatively impacting network performance. Every component of a cabling system has the potential to influence alien crosstalk performance and compromise cabling system quality. The cables and how they are connected can have a major impact on data transmission. This is one of many reasons why it’s important to use the appropriate cables and connectors.
Depending on the type of category cabling you use, alien crosstalk can be controlled by:
Ultimately, the best method is to use Category 6A cabling, which is designed to handle alien crosstalk.
As you can see from the list above, connectors matter in this performance equation. They say the worst thing you can do to a cable is put a connector on it – and that can be true if the connectors you use are poorly balanced. For example, the split pair in an RJ45 connector is a common source of imbalance in a structured cabling system. A well-balanced connector is designed to mitigate its effects.
A data signal is a differential signal, meaning that the voltage and current between each conductor of a pair is equal in magnitude and opposite in phase. Anything that disrupts this “balance” shows up in the form of a common mode signal.
If your system doesn’t have sufficient balance, then the unwanted common mode will propagate and find a path to ground – whether it’s through your data line, wires, shield or somewhere else. If this path is through your data lines, it becomes noise on the differential signal (the type of noise measured as alien crosstalk). This can cause unplanned downtime, financial loss and productivity decreases.
Good design and manufacturing are the only ways to ensure proper differential balance and mitigate issues with common mode; good balance (equal amounts of compensation) on the compensation network inside the jack is a necessity for high performance.
In an RJ45 pair 3-6, for example, if more compensation is added on pin 6 then on pin 3, this leads to unbalance. It could cause a common mode issue – or it could serve as a gateway for a common mode to enter the picture. If a common mode isn’t present, your network won’t have any problems; if a common mode is present, however, and you have imbalance in your compensation network, then problems will likely arise on your differential (“good”) signal.
So, if cable and connectivity manufacturing impact performance, how can you verify good cable and connector design? Confirm that your manufacturer offers:
Belden’s Category 6A cabling solutions are designed to handle alien crosstalk through a one-of-a-kind, truly unique design that maximizes performance and quality. Our newest Category 6A 10GXS cables are easier and faster to install, and help make the most of your space with a smaller diameter.
Ron joined Belden in 2016 to help define the roadmap of technology and applications in the enterprise. Prior to this, he developed cables and connectivity for Panduit and Andrew Corp. Ron Tellas is a SME in RF design and Electromagnetic Propagation and has BSEE from Purdue University, a MSEE from IIT, and a MBA from Purdue University.