As its name suggests, Single Pair Ethernet (SPE) cabling uses only one pair of wires to transmit data, as opposed to the two pair that have long been standard in the majority of Ethernet cabling in use worldwide.

The potential benefits of reducing the “guts” of a cable by upwards of 75% are fairly intuitive: reduced weight, reduced cost, smaller footprint, easier installation, etc. Of course, the potential drawbacks can be equally intuitive—less internal cable structure can mean shorter range and lower data rates.

Fortunately, there are some applications where shorter range and lower data rates are not a concern, and it was in one such application—wiring automobiles to carry sensor and diagnostic information and on-board communications—where single pair Ethernet was first proven out successfully. Indeed, a modern automobile can have thousands of wired connections collectively weighing hundreds of pounds, so replacing these connections with lighter ones has paid huge dividends to the industry in reducing manufacturing costs and improving performance. Since these connections tend to run short distances under th  e hood and within the car body, and data demands tend to be minimal, there are often few to no disadvantages. Similar applications for Single Pair Ethernet—cabling within robots, inside walls and floors for building automation, and inside trains and buses for example—are also emerging in the shorter term.

Constant improvement opening up new opportunities

Single Pair Ethernet technologies are standards-based technologies, and it is the first two IEEE standards out of the gate—802.3bw and 802.3bp—that are driving pioneering applications such as the in-car innovations described. These are 100BASE-T1 and 1000BASE-TI technologies respectively, offering 100 Mbps/15m and 1 Gbps/40m speed and distance limits respectively—well within the demands of these and similar applications.

ISD Ethernet Blog July 10 ImageJust as with traditional Ethernet, Single Pair is not a static technology, and dynamic improvements like these are emerging all the time. Proudly, Belden presented test samples of some of the most advanced SPE cable yet developed to industry experts at European trade fairs a few months ago. And, we continue to work in partnership with IEEE to help create standards that will achieve longer distances and data rates that will double the latest standard.

New products designed for Single Pair Ethernet

In the even shorter term, a number of companies are working on creating the products that will bring the promise of current and emerging Single Pair Ethernet standards to reality. Where there is new cable, there of course needs to be new infrastructure to support it, including connectors, switches, I/O modules, cordsets and more. And, in conjunction with developing the most advanced cable on the market, Belden is also investing in developing complementary infrastructure. We will ultimately provide industrial customers with a complete SPE solution—in transportation, in robotics, in building automation, and ultimately, in even the most data- and distance-intensive applications in the process industry and on the factory floor.

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