1. Sensor Network MAC protocol & Applications KIRAN KUMAR REDDY V LENIN THUMMALAPALLI

2. 802.11 Network Delay Power Used 802.11 Sensor Application time

3. S-MAC Network Delay Power Used 802.11 Sensor Application  Identified that radio is consuming more power.  Made radio sleep some duration of frame. S-MAC  S-MAC 100% is equivalent to 802.11 S-MAC 10% time

4. T-MAC Network Delay Power Used 802.11 Sensor Application  Why radio should do idle listening for 10% of frame length.  used a small time out. S-MAC  Under homogenous traffic T-MAC is equivalent to S-MAC T-MAC time

5. B-MAC Network Delay Power Used 802.11 Sensor Application  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. S-MAC  In a scenario where threshold doesn’t give false negatives, B-MAC and T-MAC are equivalent T-MAC time B-MAC

6. 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.

7. 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

8. TRAMA Network Delay Power Used 802.11 Sensor Application S-MACT-MAC time B-MAC TRAMA If we can’t provide Time synchronization externally TRAMA is not applicable.

9. 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

10. PEDAMACS  Provided solution to above scenario.  Deploy extra motes outside network field. Supply unlimited power to these extra motes Access Point

11. PEDAMACS Network Delay Power Used 802.11 Sensor Application S-MACT-MAC time B-MACTRAMA Network life time with PEDAMACS depends on optimal placement of Access points PEDAMACS  In an application where no scope to deploy Access points, PEDAMACS is same as TRAMA. In PEDAMACS Access point provides Time Synchronization.

12. 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.

13. 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.

14. 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.

15. 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.

16. 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

17. 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.

18. Questions ?

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