It's All About Time: Time-sensitive Networking

February 7, 2019 at 8:00 AM

 

In today’s fast paced world, we’ve all got places to go – and quickly. Thus, the demand for reliable transportation has grown along with urbanization and transit companies’ desire for efficient and cost-effective business. Previously, we’ve discussed how technology is changing transportation and modern day wireless railways. Today, we’re going to take a closer look at another technology changing transportation: time-sensitive networking.

 

Time-sensitive networking (TSN) is an extension and update to the IEEE Ethernet standards 802.1 and 802.3 that are intended to standardize Ethernet technology for control systems. TSN is a groundbreaking technology that offers deterministic, timed messaging over Ethernet for train-to-ground communication. It is centrally managed and ensures delivery with reduced jitter by utilizing time scheduling for real-time applications that require determinism. This technology will allow operations networks to utilize the benefits of traditional Ethernet while also fulfilling the timing and control demands of control and measurement applications.  

 

TSN eliminates the need for multiple networks by leveraging existing Ethernet networks to prioritize transmissions that are critical to safety over non-critical data. This feature provides enhanced interoperability and cost savings by reducing the amount of physical network components needed. Though TSN is not a protocol, but an extension of the Ethernet standard, it benefits from growing improvements in Ethernet security, bandwidth and additional capabilities to hold an advantage over standard and specialty Ethernet protocols.

 

Some of the biggest advantages of TSN include safer rides for both passengers and rail operators by allowing real-time delivery of safety messages. Clearer communication and accurate delivery of information allows for trains to run more efficiently and move more passengers. In addition to faster, safer rides, passengers will have a better trip experience with TSN’s reliable Ethernet network to keep them connected during the ride.

 

In addition to rail transportation networks, there are other applications and industries that could benefit from TSN. These include test cells and distributed monitoring which require sensor readings from multiple locations, all of which need to be linked in time. Hardware in the loop (HIL) could also use TSN since it often needs closely coordinated measurements in addition to distributed closed loop control. Machine control systems also use control networks that need synchronized measurements and actions that are highly time-sensitive. Additionally, auto makers are beginning to integrate Ethernet into vehicles to deliver more bandwidth and quicker response, and media networking can use TSN to transmit audio and video data that requires a stringent timing schedule.

 

As the world of rail and transportation and Ethernet networks continue to evolve, TSN has much to offer to help advance operations and usher in the next age of Ethernet technology.

 

802.3ca Ethernet Passive Optical Networks

January 24, 2019 at 8:00 AM

 

Today, passive optical networks (PONs) are commonly used as a cost-effective way to deliver optical broadband services to many users. This technology is comprised of point-to-multipoint networks that use an optical line terminal at the central office connected to multiple optical network units placed inside the user’s home via a feeder fiber and an optical splitter. The IEEE has already standardized PONs in the 1 Gbps to 10 Gbps range, Gigabit Ethernet PON (G-PON) and 10 Gigabit Ethernet PON (10G-EPON), now it is setting its sights on standardizing 50 Gigabit Ethernet PON (50G-EPON) with the development of the 802.3ca standard.

 

The goal of 802.3ca is to support the subscriber access networks that use point-to-multipoint arrangements on optical fiber. This standard will provide specifications for physical layers that operate over one single-mode optical fiber (SMF) strand. It will support symmetric and/or asymmetric data rates in these ranges:

  

  • ·       25 Gbps in downstream and 10 or 25 Gbps in upstream (25G-EPON)
  • ·        50 Gbps in downstream and 10, 25 or 50 Gbps in upstream (50G-EPON)

 

802.3ca will also support legacy PON technologies such as 10G-EPON and 10 Gigabit-capable symmetric PON (XGS-PON). Originally, 100 Gbps speeds were going to be an objective of this standard, but that was deemed to be too technically challenging, not economically feasible and not needed for 10 years, so 50 Gbps wavelengths were chosen to be a better technical solution.

 

The IEEE has begun the process of developing 802.3ca by organizing a task force with the mission of determining the specific protocols for the standard. This process is currently underway and is expected to complete in the 2nd quarter of 2020. So, even though we’re a ways out, there is still much to look forward to as the 802.3ca standard evolves.

 

802.3bu - Power Over Data Lines (PoDL)

October 25, 2018 at 8:00 AM

 

In the realm of IEEE standards, 802.3 has some pretty good tricks up its sleeve. There is 802.3bt which expanded the capabilities of Power over Ethernet (PoE), 802.3bv brought you Power over Plastic Optical Fiber (POF) and 802.3bz which delivers 2.5 Gbps and 5 Gbps speeds data over copper. Now, the IEEE has unveiled 802.3bu – a standard for Power over Data Lines (PoDL).

 

Initially, single-pair Ethernet was created to help meet a demand in the automotive industry for Ethernet connectivity in vehicles. 802.3bu defines the specifications and standards for delivering power over single twisted-pair to connect Data Terminal Equipment (DTE) with IEEE 803.2 interfaces. This standard also extends the wattage range to up to 60 Watts of power, which is more power over a single cable than the PoE standards 802.3af and 803.2bt. With this PoDL standard, the most recent physical layers of single twisted-pair Ethernet are supported, including 100BASE-T1 and 1000BASE-T1, while using unshielded twisted-pair cables. This results in a lower cost and lighter weight solution, which is always good news. It is targeted for use in automotive, industrial automation, air and rail transportation, and other applications that use 100BASE-T1, 1000BASE-T1 or any single-pair data or non-data entity protocol. The IEEE 802.3bu standard also opens itself up for the possibility of additional applications across a variety of industries in need of solutions to adapt to the Internet of Things (IoT) expansion.

 

The goal of the 802.3bu standard is to specify a power distribution technique for use over a single twisted-pair cable that will allow for operation if data is not present. This standard is designed to deliver power that supports multiple voltages and classes of power at each voltage level. Plus, it has the capability of fault protection and detection to identify device signatures and communicate directly with devices to ensure precise and safe power delivery. PoDL supports fast startup operation with predetermined voltage configurations and the option of operation with run-time voltage configuration. It ensures compatibility with the IEEE 802.3bp standard. However, it is not compatible with Ethernet applications that operate over 2 or 4-pairs of twisted-pair cable.

 

With the introduction of 802.3bu PoDL, not only is the wattage delivery increased and intuitive, the possibilities of power delivery are increased as well.

 

Next Generation PoE - What You Need to Know

August 23, 2018 at 8:00 AM

 
What’s better than Power over Ethernet? More Power over Ethernet (PoE), of course – and that is exactly what PoE++ is delivering. PoE++ expands upon the traditional PoE benefits of delivering data and power over a single Ethernet cable, it increases power capabilities and extends PoE’s reach into new industries and applications. Here, we’ll tell you exactly what gives PoE++ those two extras plus signs.
 
First, let’s look at a numbers comparison. The first ratified PoE standard 802.3af supports 15.44 watts of power, but power dissipation usually lowers that number to a reliable 12.95 watts. Then PoE+ was introduced and bolstered power to 30.8 watts with the 802.3at standard, though power dissipation usually takes its toll and lowers power to 25.5 watts. PoE++ (the 802.3bt standard) will be capable of supplying more than 3 times the power of PoE+ with up to 100 watts (Type 4) of DC power and the ability to support 10 Gbps connections.
 
Traditionally, PoE has been used in networking applications. With PoE++, the technology’s reach is extended to include healthcare, point of sale, financial and surveillance industry applications. PoE++ utilizes all four twisted pairs of an Ethernet cable for optimal power transmission. It consists of Mode A and Mode B, and combines them to reach higher voltage levels. Mode A is also referred to as Type A, Type 3 or 4-pair PoE. It is specified for 60W, 50W reliable, and is able to support technology such as access controls, point of sale readers, IP cameras and nurse call devices. Mode B is also known as Type B, Type 4 or higher-power PoE. It is designed for 100 watts of power, 80 watts after power dissipation, and increases the capabilities to also include support of videoconferencing systems, laptops, desktops and televisions.
 
PoE++ is slated to bring more power, more conveniently to more devices than ever before. With all of the speed, convenience and capabilities that this new technology offers, it’s no wonder that PoE++ earned those extra plus marks.

802.3bv - The Power of Plastic Optical Fiber

August 16, 2018 at 8:00 AM

 

In the realm of IEEE standards, 802.3 is bringing a lot to the table for today’s newest innovations. This standard includes several iterations that support ground breaking technology, including 802.3at and 802.3bt that support Power over Ethernet (PoE), 802.3bz that delivers 2.5 and 5 Gbps speeds over copper and now we can add 802.3bv to that list. 802.3bv was developed to support Power over Plastic Optical Fiber (POF) and it’s slated to deliver groundbreaking speed and performance.

 

First, let’s take a look at plastic optical fiber and all of its capabilities. It is a large core, step-index optical fiber capable of speeds of up to 1 Gbps. It is easy to install, cost effective, durable and is an ideal choice for networks reaching 80 meters with infrastructure that connects to switches and/or wall plates. POF will be able to meet the higher bandwidth demands of developing technology and can be used in new applications for home, industrial and automotive networks. Thus, there has been a push for the development of 802.3bv to support all of the possible POF applications.

 

The IEEE 802.3bv standard is an amendment to the 802.3 standard that allows 1000 Mb/s speeds, allowing POF to meet the increased bandwidth needs of those automotive, industrial and home network connectivity applications. 802.3bv delivers Gigabit Ethernet operation over POF and defines physical layer specs for home, industrial and auto industries. With 802.3bv, POF Ethernet networks will have the support of a robust and reliable media option. Automotive applications will have operation over a minimum of 15 meters with 4 POF connections, and distances of at least 40 meters with zero POF connections. Home and industrial applications will be able to achieve lengths of at least 50 meters with one POF connection.

 

There are three physical layer specifications in this amendment, specifically designed for the industries targeted. All use 1000BASE-H encoding over duplex POF cable and red light wavelength transmission.

 

  • ·        1000BASE-RHA – 1000 Mb/s speeds for home network and consumer applications 

 

  • ·        1000BASE-RHB – 1000 Mb/s made for industrial applications

 

  • ·        1000BASE-RHC – 1000 Mb/s rates designed for automotive applications

 

With the development of 802.3bv, yet another layer of power and possibility has been added to the realm of IEEE standards, ensuring that the world of technology has no intention of slowing down.

 

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