TTEthernet
Encyclopedia
TTEthernet is a computer network
technology marketed by TTTech Computertechnik AG
for use in airplanes and other real-time applications.
with services to meet time-critical, deterministic or safety-relevant conditions. It claims to be compatible with IEEE 802.3
standards and integrate with other Ethernet networks.
Three message types are provided:
This compares to the eight quality of service
classes defined by the IEEE P802.1p task group in 1998 and IEEE 802.1Q
added to the standard protocol.
In 2008 the company announced Honeywell
would apply the technology to applications in the aerospace and automation industry.
In 2010 a switch-based implementation was shown to perform better that shared bus systems such as FlexRay
for use in automobiles.
and TTTech. First results were published in 2005.
The project proposed a preemptive switch and built a prototype for 100 Megabit/second links in 2007. This switch identified the reception of a time-triggered message based on an identifier within the message and preempted other messages under transmission to free the outgoing ports for the time-triggered message.
Research continued within a joint industrial development between TTTech and Honeywell
. TTEthernet was the industrial further development of the research. Objectives were extended towards scalable fault-tolerance and a finer classification of event-triggered messages into rate-constrained and best-effort traffic classes.
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
technology marketed by TTTech Computertechnik AG
TTTech
TTTech Computertechnik AG is an Austrian company that provides solutions in the field of time-triggered computer systems. TTTech’s technologies and products, based on TTP, TTEthernet and FlexRay, improve the reliability of networked computer systems in the transportation and automation industries...
for use in airplanes and other real-time applications.
Description
TTEthernet expands classical EthernetEthernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
with services to meet time-critical, deterministic or safety-relevant conditions. It claims to be compatible with IEEE 802.3
IEEE 802.3
IEEE 802.3 is a working group and a collection of IEEE standards produced by the working group defining the physical layer and data link layer's media access control of wired Ethernet. This is generally a local area network technology with some wide area network applications...
standards and integrate with other Ethernet networks.
Three message types are provided:
- Time-triggered messages are sent over the network at predefined times and take precedence over all other message types. The occurrence, temporal delay and precision of time-triggered messages are predefined and guaranteed. The messages have as little delay on the network as possible and their temporal precision is as accurate as necessary.
- Rate-constrained messages are used for applications with less stringent determinism and real-time requirements. These messages guarantee that bandwidth is predefined for each application and delays and temporal deviations have defined limits.
- Best-effort messages follow the usual Ethernet policy. There is no guarantee whether and when these messages can be transmitted, what delays occur and if messages arrive at the recipient. Best-effort messages use the remaining bandwidth of the network and have lower priority than the other two types.
This compares to the eight quality of service
Quality of service
The quality of service refers to several related aspects of telephony and computer networks that allow the transport of traffic with special requirements...
classes defined by the IEEE P802.1p task group in 1998 and IEEE 802.1Q
IEEE 802.1Q
IEEE 802.1Q is the networking standard that supports Virtual LANs on an Ethernet network. The standard defines a system of VLAN tagging for Ethernet frames and the accompanying procedures to be used by bridges and switches in handling such frames...
added to the standard protocol.
In 2008 the company announced Honeywell
Honeywell
Honeywell International, Inc. is a major conglomerate company that produces a variety of consumer products, engineering services, and aerospace systems for a wide variety of customers, from private consumers to major corporations and governments....
would apply the technology to applications in the aerospace and automation industry.
In 2010 a switch-based implementation was shown to perform better that shared bus systems such as FlexRay
FlexRay
FlexRay is an automotive network communications protocol developed by the . It is designed to be faster and more reliable than CAN and TTP, but is also more expensive...
for use in automobiles.
TTEthernet versus TT-Ethernet
The academic TT-Ethernet project was a joint research project between the Vienna University of TechnologyVienna University of Technology
Vienna University of Technology is one of the major universities in Vienna, the capital of Austria. Founded in 1815 as the "Imperial-Royal Polytechnic Institute" , it currently has about 26,200 students , 8 faculties and about 4,000 staff members...
and TTTech. First results were published in 2005.
The project proposed a preemptive switch and built a prototype for 100 Megabit/second links in 2007. This switch identified the reception of a time-triggered message based on an identifier within the message and preempted other messages under transmission to free the outgoing ports for the time-triggered message.
Research continued within a joint industrial development between TTTech and Honeywell
Honeywell
Honeywell International, Inc. is a major conglomerate company that produces a variety of consumer products, engineering services, and aerospace systems for a wide variety of customers, from private consumers to major corporations and governments....
. TTEthernet was the industrial further development of the research. Objectives were extended towards scalable fault-tolerance and a finer classification of event-triggered messages into rate-constrained and best-effort traffic classes.
See also
- Computer networkingComputer networkA computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
- Computer scienceComputer scienceComputer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...
External links
- www.tttech.com/ttethernet - TTTech Computertechnik AG
- realtime-ethernet.de - Comparison of realtime-ethernet solutions Explanations partly German, partly English
- NASA and TTTech partner on space network standards for network centric space operations Military & Aerospace Electronics magazine on TTEthernet