Ethernet , as we know it today, needs at least two twisted pairs of wires to transmit data at 10 or 100 Mbit/s, and even four twisted pairs at 1000 Mbit/s. While the rigidity, cable diameter and weight of 4-pair cables are acceptable in offices. Data centers and at home, these parameters are a major problem in industry, particularly for sensors. Actuators and automobiles. For example, several hundred meters of cable are installed in a vehicle, so every tenth of a millimeter in diameter and every gram less weight counts. Likewise, it is often a problem in industry to connect and control a small sensor with a thick and bulky LAN cable.
There is another major challenge in industry. Classic Ethernet via 2- or 4-pair copper data cables only works over distances of around 100 meters. Some cable manufacturers do offer solutions that support slightly longer distances. But sensors and actuators distributed over large-scale industrial plants in particular require much longer cables than would be possible with classic cables due to the high attenuation with wire diameters of up to AWG22. Instead of the classic 100 meters. Industry requires distances of at least 1,000 meters, which is completely beyond the scope of classic Ethernet in the LAN. Another requirement of industry is that remote powering of devices . Similar to Power over Ethernet ( PoE ). Must be possible. Since the digital sensors and actuators must still draw their power from the data lines.
In order to get to grips with the diverse challenges. Various working groups in standards committees are working on solutions. This article focuses on the part of structured cabling. Solutions for the automotive industry are only mentioned in passing here. But all solutions have one thing in common: Ethernet is only transmitted via the so-called ” Single Pair Ethernet ” or “SPE” for short. I.e. via a single pair of wires.
SPE standardization in ISO/IEC and IEEE
The first push for SPE was made by the groups responsible for industrial cabling in the standards committees for cabling. The first idea was to be able to transmit Ethernet over a simple, single-pair cable Lithuania Phone Number List over a distance of at least 1,000 meters in order to replace analog sensors and actuators and to be able to integrate their digital successors into the “Ethernet world”. It soon became clear that there were many more interesting applications for SPE than “just” the 1,000-meter application for industry.
The office and data center groups quickly came forward with ideas for using SPE in their environments. Applications in the office environment could include connecting end devices using thin and light cables and small connectors or even LED lighting via Ethernet (control and power supply). Here, SPE would not replace the classic 4-pair cabling, but would be a useful addition. SPE could open up the possibility of using “normal” 4-pair cabling to go to a collection point or to the subscriber connection box and then supply 4 end devices with SPE from there. However, there are still a few points to be clarified regarding the remote power supply of end devices – these are explained in more detail below under the topic of ” PoDL ” (“Power over Dataline”).
SPE applications
In the data center, for example, it would be interesting to operate monitor lines for switches and servers via SPE for cost and space reasons. These connections do not require high data rates. So SPE is completely sufficient. Another application for which SPE is very interesting in both the office and data center as well as the cell phone number listing home is building control and monitoring. There are already a large number of competing transmission protocols here, but none of them are compatible with each other. From the end user’s point of view. A common transmission protocol would make it much easier to integrate devices such as controls for doors. Blinds, heaters and air conditioning systems.
In addition, the automotive industry is working
On SPE in vehicles up to 15 and 45 meters, although this is not an application for classic structure cabling. This application is nevertheless mention here because the professional association IEEE defines its own transmission standards for it.
The Technical Report ISO/IEC TR 11801-9906 was the Bulk Database first ISO/IEC document to be publishe in 202., Describing a first part of the variants for structur SPE cabling. At the same time, IEEE is working on the corresponding transmission standards. In this Technical Report (TR), ISO/IEC focuses exclusively on the applications planne by IEEE. The new report is intende to help users who have to plan SPE routes specifically for the Ethernet variants mention in Figure 1. In a further step. ISO/IEC will publish an amendment in which ISO/IEC11801-1 will be expand with generic cabling classes for single-pair cabling. Figure 2 shows the current status of the draft standard.
