MidART(tm) - Real-Time Communcation Middleware
Due to 1) network and processor technology advances, 2) cost considerations,
and 3) the desire for easy application construction, integration and evolution,
it is becoming ever more important to be able to use open, standard,
commercial-off-the-shelf (COTS) computers and network components to build
systems with real-time reuqirements.
MidART is a research project, lead by Dr. Chia Shen at MERL-CR , into the design and analysis of
network middleware services, protocols, message scheduling algorithms
and application programming interface so that
applications with real-time commumication requirements can be realized
on diverse types of commercial-off-the-shelf network environment.
The key question addressed in this project is:
Can and how much can real-time middleware communication services,
protocols, and message scheduling algorithms alleviate the undesirable
operational effects from the "best effort" nature of commonly used
operating systems and networks?
Our research so far has produced a real-time middleware software package
with a set of easy-to-use API for multimedia, data acquisition and control,
and message communication over UDP/IP. It allows rapid development of
multi-threaded concurrent communicating applications in a network
environment with Quality of Service provision. This marks the first stage
of this research project.
(1) A software-based reflective memory paradigm called RT-CRM (Real-Time
Channel based Reflective Memory) for data acquisition and
communication in a network environment. This reflective memory semantics
is achieved via an active data push agent mechanism.
(2) Selective Channels that allow applications to dynamically choose
the remote node(s) which data is to be viewed from or sent to
at run time.
(3) A variety of communication models including many-to-one, many-to-many,
and one-to-one are supported.
(4) Simple read and write type API functions
enable fast and reliable development of distributed applications.
Communication among processes or threads in an application is made easy.
Complex network level programming is eliminated since
network connections and data transport are entirely managed by
the middleware.
(5) MidART effectively
achieves the decoupling of the quality of service(QoS)
characteristics of data producers from the QoS needed by
data receivers. This decoupling offers flexibility to distributed
concurrent applications where every entity in the application is free
to choose the level of performance required.
(6) Various data push and data reception modes are supported, including
synchronous vs asynchronous data push, and blocking vs non-blocking
data reception. These modes can be effectively combined to achieve
many kinds of application specific tasks.
(7) Data are buffered and can be retrieved as most-recent item, or
last N items.
(8) Scalability is one key advantage of MidART. One can develop distributed
real-time systems of various scales -- systems from several nodes to
hundreds of nodes.
(9) MidART focuses on applications that have real-time requirements --- late data has no value
for many of the real-time applications. However, if desired, data logging
applications can be easily constructed using MidART APIs.
(10) Quality of Service with source rate control
-- rate based scheduling of message transmission and
admission control.
MidART Publications
Real-Time & MM Communication Publications
MidART Patents
"RT-CRM: Real-Time Channel-based Reflective Memory",
C. Shen and I. Mizumuma,
IEEE Transactions on Computers, Special Issue on Real-Time Resource Management, Vol. 49, No. 11, November 2000.
"CReMeS: A CORBA Compliant Reflective Memory based Real-time Communication Service"
S.-T. Chung, O. Gonzalez, K. Ramamritham, C. Shen,
In Proceedings of IEEE Real-Time Systems Symposium, Nov 27-30, 2000. Orlando, Florida, USA.
User Level Scheduling of Communicating Real-Time Tasks,
C. Shen, O. Gonzalez, Krithi Ramamritham, and Ichiro Mizunuma,
In Proceedings of IEEE Real-Time Technology and Applications
Symposium, June 2-4, 1999, Vancouver, British Columbia, Canada.
"Real-Time Communicating Tasks on COTS-based Distributed Platforms: Task Models and End-to-End Scheduling",
C. Shen and O. Gonzalez,
In Proceedings of IEEE Real-Time Systems Symposium Work-In-Progress, December 2-6, 1998. Madrid, Spain.
"Using Windows NT for Real-Time Applications: Experimental
Observations and Recommendations",
K. Ramamritham, C. Shen, O. Gonzalez, S. Sen, and S.B. Shirgurkar,
In Proceedings of IEEE Real-Time Technology and Applications Symposium, June 3 - 5, 1998. Denver, Co.
"RT-CRM: Real-Time Channel-based Reflective Memory",
Chia Shen, Ichiro Mizunuma,
In Proceedings of IEEE Real-Time Technology and Applications
Symposium (RTAS'97), June 9-11, 1997. Montreal, Canada.
"Implementation and Performance of MidART",
O. Gonzalez, C. Shen, I. Mizunuma, M. Takegaki,
In Proceedings of IEEE Workshop on Middleware for Distributed Real-Time
Systems and Services, December 2, 1997. San Francisco, CA.
"Middleware for Distributed Industrial Real-Time Systems on ATM Networks",
I. Mizunuma, C. Shen, M. Takegaki,
In Proceedings of IEEE Real-Time Systems Symposium, December 4-6,
1996. Washington, DC.
"Digital Audio and Video in Industrial Systems",
H.C. Lauer, C. Shen, R. Osborne, J. Howard, Q. Zheng, M. Takegaki, H. Shimakawa,and I. Mizunuma
NOSSDAV '95, April 18 - 22, 1995 Durham, New Hampshire.
"Adaptive-Weighted Packet Scheduling for Premium Service",
H. N. Wang, C. Shen and K. G. Shin,
ICC 2001 (IEEE International Conference on Communications), June 11-14, 2001. Helsinki, Finland.
"Tutorial:On ATM Support for Distributed Real-Time Applications",
C. Shen,
In Proceedings of IEEE Real-Time Technology and Applications
Symposium (RTAS'96), June 10-12, 1997. Boston, MA.
A Reliable, Adaptive Network Protocol For Video Transport,
P. Goyal, H. M. Vin, C. Shen, P. J. Shenoy,
In Proceedings of IEEE INFOCOM '96, March 24 - 28, 1996 San Francisco, CA.
"Real-Time Channel-Based Reflective Memory", U.S. Patent Number 5,987,496. 1999 (With I. Mizunuma)
"System and Process for Providing User Level Multiplexing of Two or More Application Channels to One Virtual Channel in Asynchronous Transfer Mode Network", U.S. Patent Number 5,818,841. 1998 (C. Shen)
MidART software, as well as its User Guide and Design Document are available for research purpose only. Signing of a license agreement is required.
Contact Dr. Chia Shen(shen@merl.com) for more information.
Chia Shen
(shen@merl.com)