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Explore various MAC protocols like S-MAC, T-MAC, B-MAC, TRAMA, and PEDAMACS in sensor network applications to optimize power usage, reduce delays, and enhance network performance. Discover their unique features and applications in different scenarios.
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Sensor Network MAC protocol & Applications KIRAN KUMAR REDDY V LENIN THUMMALAPALLI
802.11 Network Delay Power Used Sensor Application 802.11 time
S-MAC • Identified that radio is consuming more power. • Made radio sleep some duration of frame. Network Delay S-MAC 10% Power Used Sensor Application 802.11 S-MAC time • S-MAC 100% is equivalent to 802.11
T-MAC • Why radio should do idle listening for 10% of frame length. • used a small time out. Network Delay Power Used Sensor Application 802.11 S-MAC T-MAC time • Under homogenous traffic T-MAC is equivalent to S-MAC
B-MAC • Radio is using Threshold mechanism for Clear Channel Assessment. Due to environmental variations, noise is considered as channel is idle. • For efficient CCA outlier is used instead of threshold. Network Delay Power Used Sensor Application B-MAC 802.11 S-MAC T-MAC time • In a scenario where threshold doesn’t give false negatives, B-MAC and T-MAC are equivalent
Change in Trend • What S-MAC, T-MAC, B-MAC are doing? • Trying to minimize idle listening as much as possible. • Why radio should listen the channel? • To minimize collisions. • How can we make collision free without listening the channel? • TDMA • TDMA is not adaptable to Network changes where as CSMA is adaptable to network changes. • Combine the best features of CSMA and TDMA, introduced “schedule based protocol”. • How can we do Time synchronization? • External GPS reciever can be used.
TRAMA • TRAMA is schedule based protocol. • Frame consists of two periods Random Access period, Schedule Access period. Random Access Period (CSMA based) Schedule Access Period (TDMA based ) To adapt to Network Changes To transfer data collision free
TRAMA Network Delay Power Used Sensor Application 802.11 S-MAC T-MAC B-MAC TRAMA time If we can’t provide Time synchronization externally TRAMA is not applicable.
Consider the following scenario Data initiators Forwarders Base Station • What Forwarders are doing? • Just routing data to base station. Forwarders have to wake up for longer time, it may lose its power quickly. • If one Forwarder is dead, initiators choose a path of longer • distance. It will be difficult to replace the dead motes in sensor field
PEDAMACS • Provided solution to above scenario. • Deploy extra motes outside network field. Supply unlimited power to these extra motes Access Point
PEDAMACS Network life time with PEDAMACS depends on optimal placement of Access points Network Delay Power Used Sensor Application PEDAMACS 802.11 S-MAC T-MAC B-MAC TRAMA time • In an application where no scope to deploy Access points, PEDAMACS is same as TRAMA. In PEDAMACS Access point provides Time Synchronization.
Conclusion • Sensor application can be designed using 802.11 also. But Network life time will be in terms of hours. • Some amount of delay can be accepted in sensor applications. So, researchers are trying to minimize the power usage by increasing delay. • An ideal MAC protocol is one which makes power usage almost zero with an acceptable delay. • “ Habitat monitoring” Application can be redesigned using PEDAMACS to achieve greater network life time. But “Military surveillance” application cannot use Access points. For matter of stealthiness GPS receiver. B-MAC is suggestable.
Counter sniper Application Acoustic signals, such as muzzle blasts and shock waves provide the easiest and most accurate way to detect shot. Applicable MAC : S-MAC, T-MAC, B-MAC, and TRAMA. TRAMA is best suitable.
Marine Microorganism Detection Regions of sharp temperature change in oceans (thermoclines) are a breeding ground for certain marine microorganisms. Applicable MAC S-MAC, T-MAC, B-MAC. B-MAC is best suitable.
Volcanic Eruption Detection Volcanic Earthquake radiates acoustic waves into atmosphere and seismic waves into the ground. Applicable MAC S-MAC, T-MAC, B-MAC, TRAMA and PEDAMACS. PEDAMACS is best suitable.
Military Surveillance system : • Detecting Vehicles in restricted area based on the magnetic distortions caused by the vehicles Applicable MAC : S-MAC, T-MAC, B-MAC, TRAMA
Traffic Monitoring System : • Based on the magnetic distortions generated by the Vehicles. Applicable MAC : PEDAMACS, S-MAC, B-MAC, T-MAC, TRAMA. Best suitable: PEDAMACS.