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Projects - Fundamental Research

PrioMAC

Prioritized Medium Access Control
CISTER/RF02/2005
5 years (Jul 2005 to Aug 2010)


Summary:	A prioritized Medium Access Control (MAC) grants the right to access the medium to the computer node with the highest priority. Such a protocol was originally created for wireline networks; Controller Area Networks (CAN) is the most known one, and is currently deployed in 700 million units. We are transferring this idea to the wireless domain as well and exploring it to solve problems in real-time communication and collaborative distributed computing (wireless/wired sensor networks and cyber-physical systems). The research in prioritized MAC protocols has triggered a number of research initiatives and frameworks, listed below. WiDOM WiDOM or WiDOM-SBD is a prioritized MAC protocol for wireless networks. It is an adaptation of the dominance protocols (used in the CAN bus) to a wireless channel. WiDOM-MBD This extension to WiDOM, supports multiple broadcast domains, resolves the wireless hidden terminal problem and allows for parallel transmissions across a mesh network. Arbitration of messages is achieved without the notion of a master coordinating node, global clock synchronization or out-of-band signalling. WiDOM-MC We are also exploring the development of a simple globally prioritized multi-channel medium access control (MAC) protocol for wireless networks. Such a protocol should provide "hard" pre-run-time real-time guarantees to sporadic message streams, exploit a very large fraction of the capacity of all channels for "hard" real-time traffic and also fully utilize the channels with non real-time traffic when hard real-time messages do not request to be transmitted. WiSe-CAN We have been using CAN for efficient distributed computation of aggregated quantities. The use of such a prioritized MAC protocol is proposed to be in a way that priorities are dynamically established during runtime as a function of the sensed values involved in the specific distributed computation. Exploitating Prioritized MAC for Data Aggregation and Data Dissimination In a dominance-based MAC protocol the computer node contending with the highest priority (lowest number) is granted access to the medium. This election procedure can also be used to compute the minimum value of sensor readings distributed on different computer nodes and, remarkably, this computation can be performed with a time-complexity that is independent of the number of computer nodes. This procedure forms an important building block for other useful calculations; for example, it is possible to efficiently extract an interpolation of sensor readings and this can be performed with a time-complexity that is independent of the number of computer nodes. This is a crucial asset for addressing problems in future Large-Scale Dense Sensor Networks for Cyber-Physical Systems (CPS). A prioritized MAC protocol can be used to efficiently disseminate data when the topology is unknown. We are studying the problem of disseminating data from an arbitrary source node to all other nodes in a distributed system. We assume that nodes do not know the topology and that wireless broadcast is used. We propose new protocols which propagate data faster and uses fewer broadcasts.

CISTER Project Information:	http://www.hurray.isep.ipp.pt/activities/PRIOMAC/MainPage.ashx

Journals

Efficient Computation of MIN and MAX in Multihop Networks (by exploiting a prioritized MAC protocol) HURRAY-TR-080901
Nuno Pereira, Björn Andersson, Eduardo Tovar, Paulo Carvalho (Apr 2009)
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Lecture Notes in Electrical Engineering, Vol. 38, Intelligent Technical Systems, 2009.

A Scalable and Efficient Approach to Obtain Measurements in CAN-based Control Systems HURRAY-TR-061102
Björn Andersson, Nuno Pereira, Wilfried Elmenreich, Eduardo Tovar, Filipe Pacheco, Nuno Cruz (May 2008)
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Published in IEEE Transactions on Industrial Informatics (TII), Volume 4, Issue 2, May 2008, pages 80-91 (Revised in November 2007 and January 2008) This document was previouly entitled "Using a Prioritized MAC Protocol to Efficiently Compute Aggregated Quantities in a Single Broadcast Domain");

WiDom: A Dominance Protocol for Wireless Medium Access HURRAY-TR-070512
Nuno Pereira, Björn Andersson, Eduardo Tovar (May 2007)
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Published in IEEE Transactions on Industrial Informatics, Volume 3, Issue 2, May 2007 Page(s):120 - 130

Conferences and Workshops

Elements of Scalable Data Processing HURRAY-TR-100510
Björn Andersson, Paulo Gandra de Sousa, Filipe Pacheco, Vinny Reynolds, Pedro J. Marrón, Panayiotis Andreou, Pedro J. Marrón (27, May, 2010)
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The paper has been published at the 9th International Workshop on Real-Time Networks RTN'2010 (http://rtn2010.das.ufsc.br/) on July 6, 2010, Brussels, Belgium, in conjunction with the 22th Euromicro Intl Conference on Real-Time Systems, July 7-9, 2010, Brussels, Belgium

New Schedulability Analysis for WiDom HURRAY-TR-100507
Maryam Vahabi, Björn Andersson (25, May, 2010)
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WiP session of 22nd Euromicro Conference on Real-Time Systems (ECRTS 2010), Brussels, Belgium, July 6-9, 2010.

Using a Prioritized Medium Access Control Protocol for Incrementally Obtaining an Interpolation of Sensor Readings HURRAY-TR-090704
Björn Andersson, Nuno Pereira, Eduardo Tovar, Ricardo Gomes (29, Jul, 2009)
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in Proceedings of the 7th Workshop on Intelligent Solutions in Embedded Systems (WISES'09), Ancona, Italy, June 25-26, 2009.

Improving the Reliability of WiDom in a Single Broadcast Domain HURRAY-TR-090610
Nuno Pereira, Björn Andersson, Eduardo Tovar, Paulo Carvalho (8, Jul, 2009)
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Published in proceedings of the IEEE Symposium on Industrial Embedded Systems (SIES'09) - WIP Session, Lausanne, Switzerland, July 8 - 10, 2009.

Using a Prioritized Medium Access Control Protocol for Incrementally Obtaining an Interpolation of Sensor Readings HURRAY-TR-090601
Björn Andersson, Nuno Pereira, Eduardo Tovar, Ricardo Gomes (Jun 2009)
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Proceedings of the 7th Workshop on Intelligent Solutions in Embedded Systems (WISES'09), Ancona, Italy

Efficient Aggregate Computations in Large-Scale Dense WSN HURRAY-TR-081101
Nuno Pereira, Ricardo Gomes, Björn Andersson, Eduardo Tovar (13, Apr, 2009)
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Proceedings of 15th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS'09)

Highly Scalable Aggregate Computations in Cyber-Physical Systems: Physical Environment Meets Communication Protocols HURRAY-TR-090203
Eduardo Tovar, Björn Andersson, Nuno Pereira, Mário Alves, Shashi Prabh, Filipe Pacheco (16, Jun, 2008)
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Proceedings of the 7th International Workshop on Real-Time Networks (RTN'08), Prague, Czech Republic, July 1, 2008

Localizing Objects in Large-Scale Cyber-Physical Systems HURRAY-TR-080502
Björn Andersson, Shashi Prabh (25, May, 2008)
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Invited Paper in the International Workshop on Cyber-Physical Systems Challenges and Applications (CPS-CA'08), Santorini Island, Greece, June, 2008.

Exploiting a Prioritized MAC Protocol to Efficiently Compute Interpolations HURRAY-TR-070630
Björn Andersson, Nuno Pereira, Eduardo Tovar (May 2007)
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Published at the 12th IEEE International Conference on Emerging Technologies and Factory Automation (ETFA'07), Patras, Greece, September 25-28, 2007.

Static-Priority Scheduling over Wireless Networks with Multiple Broadcast Domains HURRAY-TR-070118
Nuno Pereira, Björn Andersson, Anthony Rowe, Eduardo Tovar (May 2007)
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Published at the 28th IEEE Real-Time Systems Symposium (RTSS'07), Tucson, Arizona, USA, 2007.

Exploiting a Prioritized MAC Protocol to Efficiently Compute Min and Max in Multihop Networks HURRAY-TR-070502
Björn Andersson, Nuno Pereira, Eduardo Tovar (25, Mar, 2007)
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Published at the 5th Workshop on Intelligent Solutions in Embedded Systems, Madrid, Spain, June 2007