May 1, 2012

Optimal Gigabit Data Transmission in Real-Time with Minimal Response Time

Real-Time – (not) just for the stock exchange floor

With its hardware implementation of TCP/IP, Fraunhofer HHI has moved the processing of communication protocols from software to hardware. Applied in areas like medical technology or high frequency trading, these embedded hardware systems enable transmission and processing of gigabit quantities of data in real-time – with minimal latency and optimal use of transmission capacity. Usage of full data throughput with simultaneous minimal latency is a hurdle that standard software-based approaches could never jump.

Communication protocols in embedded hardware systems

Conventional software-based TCP/IP processing in local Ethernet networks has now reached its limits as computing power fails to keep pace with the development of high-speed networks. Fraunhofer HHI has now found a way out of this impasse with its development of a hardware-based TCP/IP stack tailored to both 1 Gigabit and 10 Gigabit Ethernets. This protocol stack is a completely hardware-based implementation without any need for processors or software. This means that in times of high data traffic the full available network capacity can be used while reaction times are kept to the bare minimum.

Making the very best usage of transmission capacity

This is done by twiddeling two knobs on the hardware side. Correct hardware switching enables network lines to be operated with real usage of their theoretical data throughput capacity. The communication protocols are configured for each client/server hardware to give tangible reductions of reaction times and latency.

Minimizing Latency

Each signal has a certain delay time in a technical system which is known as its latency. This is why data transmission always involves delays in the processing and throughput of data. The root cause is the way the TCP/IP network protocols function. These protocols divide data up into packets and send them to the receiver one after the other. So it always takes a bit of time before receivers actually get all the data they have been sent.

Let's illustrate this with the example of the live broadcast of a football match. Packet-based processing and decoding of the picture content takes a certain time. This means that when a goal is scored viewers of digital TV will be up on their feet and roaring a little later than viewers with an analog signal. What might be just a slight personal disadvantage as in this case, in other scenarios results in serious financial losses.

High frequency trading and medical technology

Stock exchange computer systems cover the whole world. Late­ncy in data transmission here means that no company anywhere is in a position to have the same quotation simultaneously on all the world's stock exchange computer systems. And especially when it comes to automated types of securities trading like high frequency trading (HFT), a single millisecond can make all the difference between profit and loss.

Minimal reaction times for data throughput are also important in medical technology as when surgeons are remotely controlling instruments in the operating theater. It's absolutely vital that the medical robots controlled by the physician with a joystick react instantaneously to his or her commands.

The TCP/IP stack

The TCP/IP protocol stack is a conceptual architecture of communication protocols for data transmission. The individual protocols are placed on top of each other as layers in the stack depending on which functions they fulfill. What's really innovative about the solution developed by Fraunhofer HHI is that all layers have been implemented in hardware rather than software. The stack supports all conventional communication protocols such as Ethernet, ARP, IPv4, TCP and UDP as well as basic functionalities of ICMP, IGMP and DHCP. Two optimized versions of the stack are available one for 1-GbE and one for 10-GbE applications.