Conclusion

This paper presents the design, implementation, and evaluation of single-segment and multi-segment RETHER protocols. The major contribution of this work is a simple and efficient traffic control mechanism that turns commodity off-the-shelf Ethernet hardware into a network capable of providing delay/bandwidth guarantees, and thus makes it possible to deploy Ethernet to PLC networks used in industrial automation systems. Because RETHER is a software-only solution, no hardware modification is required. RETHER is also innovative because it supports both real-time and non-real-time traffic in a single framework, and because it is scalable to a large number of PLC nodes with its built-in end-to-end performance guarantee mechanism.

RETHER has also been extended to wireless LAN with roaming support [#!prashant!#]. In addition, we have also developed a new real-time Ethernet switch architecture called EtheReal [#!srinidhi!#], which takes one step further by providing bandwidth/delay guarantees without requiring any changes to both software and hardware on the host ends. We are currently developing a middleware based on the distributed shared memory abstraction and RETHER , with the goal to simplify the development of distributed real-time embedded systems. More up-to-date information about the RETHER project can be found in https://www.ecsl.cs.sunysb.edu/rether.html.