Distributed Averaging With Short Node Memory

This paper is explain about important process before consensus process between node sensor.

DISTRIBUTED algorithms for solving the average consensus problem have received considerable attention in the distributed signal processing and control communities recently.

This paper can explain more detail. File Size: 812 KB.

Optimization and Analysis of Distributed Averaging With Short Node Memory Click Here

Found on IEEE explore website

So, Information about this paper according my understanding is

1) Author Name : 

Boris N. Oreshkin, Mark J. Coates, and Michael G. Rabbat

2) Title Of Paper : 

Optimization and Analysis of Distributed Averaging With Short Node Memory

3) Source : 

IEEE TRANSACTIONS ON SIGNAL PROCESSING, VOL. 58, NO. 5, MAY 2010

4) Summary Of Reported Research :

This paper proposes on average consensus algorithm, each sensor nodes not only consider the data information from neighbors but also the data previously obtained. This is very important to obtained faster convergence time and acurate data information. 

This result applies to the general class of distributed averaging algorithms using node state prediction, and shows that, even in its simplified form and even at the theoretical level, accelerated consensus may provide considerable processing gain. 

5) Strength Of Invention:

This paper provides theoretical performance guarantees for accelerated distributed averaging algorithms using node memory. 

An important contribution of this paper is the derivation of upper bounds on the spectral radius of the accelerated consensus matrix. 

6) Weakness :

In this paper Initialization scheme of problem is complicated. Therefore Need simpler initialization schemes are the focus of ongoing investigation.

7) Limitation:

In this paper, focus on a linear predictor and derive a closed-form expression for the optimal mixing parameter one should use to combine the local prediction with the neighborhood averaging. 

Indoor High-Bandwidth Optical Wireless

This paper explain to me more about technology LASER in implementation on WSN Communication.

This paper can explain more detail. File Size: 1.02 MB.

Indoor High-Bandwidth Optical Wireless Links for Sensor Networks Click Here

Found on IEEE explore website

So, Information about this paper according my understanding is

1) Author Name : 

Jarir Fadlullah, and Mohsen Kavehrad

2) Title Of Paper : 

Indoor High-Bandwidth Optical Wireless Links for Sensor Networks

3) Source : 

IEEE Journals And Magazines, JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 28, NO. 21, NOVEMBER 1, 2010

4) Summary Of Reported Research :

In this paper, focus to measurement of Indoor optical wireless communication.

At present, there are high-bandwidth laser transmitters available in the market. This can be built with separated components. For receiver there are high sensitivity component such as Photo Multiplier Tube (PMT) and Avalanche Photo Dioda (APD). But in this paper using  LASER diode as the transmitter and APD as the receiver, and obtain frequency domain responses.

Important Result is about data rate aspect

On data rate aspect, data rate performance is measured in terms of delay spread values and eye diagrams. The eye diagrams show that there is minimal inter-symbol interference for data links operating at 800 Mbps and 1 Gbps. This is an amazing result considering the components used are not specifically optimized for communication.

5) Strength Of Invention:

This paper is the first to demonstrate that laser -based FSO capable of handling data rates up to 1Gbps in indoor optical wireless link. Although using component that not specifically optimized for communication purposes. 

6) Weakness :

At this trial has not considered factors interference between nighbour sensors. Placement sensor important to avoid this problem.

Another problem of laser is shadowing, But solution for this problem is using multispot difuse configuration.

LASER shadowing problem

this picture taken from This Link

7) Limitation:

In this paper, focus to measurement of Indoor optical wireless communication based on LASER technology. Several parameter that observed is Frequency respon vs Size lense with different position, delay spread, and data rate.

Low Power Free Space Optical Communication

This paper is the first to introduce me to a simple physical design of FSO. Describe design and implementation of optical comercial component electronics. The design based on the problems that arise in the use of FSO .

This paper can explain more detail. File Size: 388 KB.

Low Power Free Space Optical Communication in Wireless Sensor Networks Click Here

Found on IEEE explore website

So, Information about this paper according my understanding is

1) Author Name : 

James Mathews, Matthew Barnes and D. K. Arvind

2) Title Of Paper : 

Low Power Free Space Optical Communication in Wireless Sensor Networks

3) Source : 

2009 12th Euromicro Conference on Digital System Design / Architectures, Methods and Tools

4) Summary Of Reported Research :

In this paper, explain about how to design FSO transceiver ( Transmitter and Receiver ).

In Transmitter side,  link using an optical emittier to produce the transmission at a carrier

frequency and a controller to modulate the baseband data for transmission.

In Receiver side an optical detector use to receive the carrier signal, analog circuit use to

recover modulated data from the received signal 

and then digital signal processor to demodulate the received data and perform packet recovery.

The importan result from this paper is

>> Both of receiver and transmitter design with commercial available component. But coverage distance only 10 - 15 meter. Is to short than RF communication.

>> In case of power consumption, in 3 Volt supply and 2 KHz frequency carrier, Idle current around 30.1μA, and active receive current arround  42.2μA . In transmiter side, transmit current arround 100 μA. This is explain that FSO more eficient energy than RF communication. 

As shown in the table below

>> In case of data rate, The maximum data rate of the optical link is limited by the response of the optical components. The data rate of the transceiver implementation was limited by the components selected to maintain current consumption below the 100μA budget, it is not possible to work with high data rate.

>> In case of beam divergence, FSO should guarantee LOS communication. LASER have low beam difergence. The solution of this problem is to expand the surface of the detector receiver. It bad idea because physical size of receiver become larger. Best solution is using transmitter with wider beam divergence. It gave new parameters namely axial and lateral coverage. Placement of node sensor which using FSO communication should consider this aspect.

5) Strength Of Invention:

FSO more eficient energy than RF communication.

6) Weakness :

Design Transceiver is using analog design wich more complex and difficult to analyze. coverage distance only 10 - 15 meter. Is to short than RF communication.

7) Limitation:

This paper propose physical design of FSO communication consider comercial component availability. With several parameter to observed. That is Data Rate, Sensitivity, Power Consumption, Coverage distance ( axial and lateral coverage ).

Optical Wireless Communication for Underwater

This paper is very interesting for me. Tell me about WSN applications in the under water field. In this paper show compare about performance LED wavelength take on water attenuation. This is inspiring me about wavelength that more survive if used for FSO communication between Sensor.

Underwater wireless optical communication has been used for application between mobile vehicles or fixed node. It because Green or Blue light more carry data higher than acoustical andmegnetic.

This paper can explain more detail. File Size: 2.97 MB

Optical Wireless Communication for Underwater Wireless Sensor Networks: Hardware Modules and Circuits Design and Implementation Click Here

Found on IEEE explore website

So, Information about this paper according my understanding is

1) Author Name : 

Davide Anguita, Davide Brizzolara And Giancarlo Parodi

2) Title Of Paper : 

Optical Wireless Communication for Underwater Wireless Sensor Networks: Hardware Modules and Circuits Design and Implementation.

3) Source : 

OCEANS 2010, IEEE Conference Publication.

4) Summary Of Reported Research :

In this paper, An experimental purpose to simulating water attenuation from different wave length. 

First step, for simulating water, used water pipe with length 2 meter. Pipe built from high density polyethylene.

Step two, simulating point to point communication with measuring photodiode sensitivity to Wavelength light that produce from LED. And the result is Infra Red become the best in sensitivity of photodiode. With smallest absorbsion coeficient 6.0 x 10^-2  Cm^-1

For detail look at this table

but when the light was tested in muddy water, Infra Red is more bad performance than Red Light, Blue Light and Green Light. The output current for infrared is less than  blue/green light at 10m, even if the sensitivity of the photodiode is higher for infrared.

5) Strength Of Invention:

Optical Underwater Communication has advantage

>> The high data-rate, which can range from Mb/s to Gb/s, if using LASER.

>> Possibility of using relatively low-power components and circuits equipped with

     LEDs and photodiodes;

>> Possibility of targeting relatively small dimensions and low costs for the

     communication system

6) Weakness :

in addition to the discussion about the influence of water turbidity , this paper does not include light interferen parameters that might increase the BER.

7) Limitation:

Simulation and Testing was limited to solving the problems of communication point to point.

RF/FSO with LEACH

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This paper is a development of the previous paper. By the same author name. With a discussion of the same topology. But in this paper, the authors add the implementation of LEACH algorithm purpose to comparison algorithm.

File size: 604 KB

RF/FSO and LEACH Wireless Sensor Networks: A case study comparing network performance Click Here

Found on IEEE explore website 

So, Information about this paper according my understanding is

1) Author Name : 

Sashigaran Sivathasan

2) Title Of Paper : 

RF/FSO and LEACH Wireless Sensor Networks: A case study comparing network performance

3) Source : 

Wireless And Optical Communication Network, 2009. IEEE Conference Publication

4) Summary Of Reported Research :

With the same topology ( Figure 1 ) from Previous Paper

This paper compare RF/FSO performance with RF-based LEACH ( Low Energy Adapting Clustering Hierarchy ) proposed in the literature.

First to compare that. Author using two main parameter to observed:

network lifetime and network area coverage.

From Author and references, Network Life time means "Time from when the network begins sensing and transmitting data, until time when network coverage falls to 0% of the total deployment area".

Authors means that The percentage of coverage area refers to the percentage of the network deployment area still within sensing range of the deployed sensors.

On RF LEACH session simulation, For the LEACH network, five nodes are selected to become candidate cluster heads during each round. Each round may have fewer than five cluster heads functioning, because some nodes have run out of energy.

when many sensors are dead , the base station will be increasingly isolated.And network coverage become zero in the second to 232. but in the second to 300, few nodes are still active and working very briefly and then die.

On RF/FSO session simulation, From graph show better result. Maximum Lifetime in the second to 293.

From both of graph, RF/FSO network better 26 % more longer life time with higher coverage area then RF LEACH.

RF/FSO network can survive until second to 293. While RF LEACH only second to 232.

5) Strength Of Invention:

From Result of simulation aproach, RF/FSO WSN has a longer lifetime and larger average network coverage when compared to the RF LEACH WSN.

6) Weakness :

In this paper, energy per bit of RF LEACH set in nominal 20 nJ,30 nJ up to 50 nJ. But on RF/FSO, energy per bit arround 19 pJ. Although FSO more efficient in energy, I think this is not fair to compare.

7) Limitation:

This paper discusses the parameters used to simulate both of the RF/FSO and LEACH WSNs. Simulations in this paper using MATLAB.

Two parameters were observed: network lifetime and network area coverage.

Paper About RF/FSO Transmision Media Hybrid

Power consumption is an important design consideration for wireless sensor networks (WSNs).  Hybrid radio frequency/free space optical (RF/FSO) WSNs have the potential to reduce this power consumption substantially. 

This paper studies the performance of the RF/FSO WSN by comparing its network lifetime against the lifetime of a traditional RF-only WSN.

File Size: 156 KB

RF/FSO Wireless Sensor Networks: A performance study Click Here

Another Version File Size: 630 KB

Lifetime Comparison of RF only and hybrid RF or FSO Wireless Sensor Networks Clic Here

So, Information about this paper according my understanding is

1) Author Name : 

Sashigaran Sivathasan And Dominic C. O’Brien

2) Title Of Paper : 

RF/FSO Wireless Sensor Networks: A performance study

3) Source : 

IEEE Communications Society subject matter experts for publication in the IEEE "GLOBECOM" 2008 proceedings.

4) Summary Of Reported Research :

Sensing, communication and data processing contribute to the power consumption of a sensor node, with most power being consumed for communications.

Therefore, the lifetime of the network might be extended by employing more energy-efficient communications.

On WSN transmission media usually using RF transmission. But this way is not efficient in energy. This paper propose RF/FSO hybrid for better performance and life time. Important report from this paper are.  

First this paper explain about alocation of transmission type. (Figure 1). Node sensor which Line Of Sight (LOS) with base station using transmission FSO. But node sensor which not LOS using transmission RF. This figure explain about topology which will be simulated.

This topologi made by considering Block Factor. Block Factor means everythings that make communication between each sensor become not LOS.

From this topology, known two point. Non Reconfiguring Network and Reconfiguring Network. Non Reconfiguring Network means that e.g if node 2 ( Clusster Head ) dead, node 4,5,and node 6 considered dead. Reconfiguring Network means that node 4,5 and 6 capable to searching new Cluster Head if node 6 dead.

Simulation from this paper show that better lifetime get from Reconfiguring Network. Reconfiguring Network become not benefit if blocking factor is low. In this case network does not require communication multihop. Node can comunicated with base station directly.

Another result from simulation are 

Best RF/FSO network coverage is when the blocking factor is low. Blocking factor make node sensor force increasing coverage area. This make increasing energy consumption. To avoid that, important to increasing node density. High node density means position each other of nodes isn't too far. This will guarantee each node sensor communication become more successfully.

5) Strength Of Invention:

From Simulation aproach, this paper show that Hybrid RF/FSO at least twice more longer liftime than only RF. Hybrid RF/FSO is better alternative for designing WSN on future work.

6) Weakness :

RF, FSO and Hybrid RF/FSO must Line Of Sight. Network Reconfiguration still important if Blocking factor is high.

7) Limitation:

This paper just simulating performance of RF/FSO in one topology as shown as figure 1.

Analizing relationship between lifetime, blocking factor, coverage area and node density.
Analyzing comparison between Non Reconfiguration Network and Configuration Network.