Sensor Network MAC protocol & Applications

KIRAN KUMAR REDDY V LENIN THUMMALAPALLI

802.11Network Delay

Power Used

802.11

Sensor Application

time

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

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

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

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

802.11

Sensor Application

S-MAC T-MAC

time

B-MAC TRAMA

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 Delay

Power Used

802.11

Sensor Application

S-MAC T-MAC

time

B-MAC TRAMA

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.

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 ApplicationAcoustic signals, such as muzzle blasts and shockwaves provide the easiest and most accurate wayto detect shot.

Applicable MAC : S-MAC, T-MAC, B-MAC, and TRAMA.

TRAMA is best suitable.

Marine Microorganism DetectionRegions of sharp temperature change in oceans(thermoclines) are a breeding ground for certainmarine microorganisms.

Applicable MAC S-MAC, T-MAC, B-MAC.

B-MAC is best suitable.

Volcanic Eruption Detection

Volcanic Earthquake radiates acoustic wavesinto atmosphere and seismic waves into theground.

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.

Questions ?

THANK YOU