A Review Paper on Performance Analysis of Improved Mobility Adaptive Slotted CSMA/CA MAC Protocol with Adaptive Backoff Exponent Algorithm for Mobile IEEE 802.15.4 Wireless Sensor Networks

A Review Paper on Performance Analysis of Improved Mobility Adaptive Slotted CSMA/CA MAC Protocol with Adaptive Backoff Exponent Algorithm for Mobile IEEE 802.15.4 Wireless Sensor Networks

Vaibhav Choudhary1

Scholar

Vivekananda Institute of Technology Jaipur (RAJ.), India

Neeraj Sharma2

Assistant Professor Vivekananda Institute of Technology

Jaipur (RAJ.), India

Abstract The IEEE 802.15.4 standard MAC protocol for WSNs is design mainly for static sensor networks and its capability to support the networks of mobile sensor has not yet been established. Integrating node mobility features in WSNs raises many new challenges to the research association. In WSN, node mobility is expected to facilitate many applications, from home healthcare and medical monitoring to detect the target and monitoring animals. Mobility in WSN raises new challenges and problems that occur at MAC layer due to the existing link failure and new link formation. To overcome these limitation of mobile nodes we have proposed mobility adaptive (MA)- CSMA/CA with adaptive BE for mobile WSNs in this paper. The proposed MAC is energy efficient while maintaining high throughput and low latency compared to the existing standard CSMA/CA MAC protocol of IEEE 802.15.4. The proposed work is implemented on Qualnet 5.0.2 Network Simulator and the performance of CSMA/CA and MA-CSMA/CA MAC protocol is evaluated for mobile WSNs.

Keywords- Wireless Sensor Network (WSN), carrier sense multiple access with sollision avoidance (CSMA/CA), Mobility Adaptive (MA)- CSMA/CA, Adaptive Backoff Exponent (ABE).

1. INTRODUCTION

   Wireless sensor networks can provide a better solution of real-world problems. Recently there has been major improvement in WSN due to the growth in technologies like MEMS & NEMS and low power electronics. WSN can connect the physical world with the virtual world by formation of a network of sensor nodes. WSNs are suitable for many applications which are security, monitoring the environment, precision agriculture, surveillance, smart homes, automation, vehicular traffic management, creative industries, habitat monitoring, monitoring health of structures and disaster detection etc. Now the node mobility in WSNs gives many other applications.

   The working of the MAC protocol is to manage the data transmission efficiently among nodes. Mobility in WSN raises new challenges and problems that occur at MAC layer due to the existing link failure and new link formation. Designing MAC protocol for mobile scenario is a difficult task, especially in case of WSN which are inherent resource constrained.

   The rest of the paper is prepared as follows. In Section II, we present the overview of WSNs. Section III presents key problems and challenges in designing an efficient MAC protocol for mobile WSNs. In section IV we present mobility adaptive CSMA/CA MAC protocol with ABE algorithm for mobile WSNs to overcome the key problems addressed by mobility. Section V present simulation and analysis of MA- CSMA/CA MAC protocol and finally section VI concludes the paper and gives some directions for future work.

2. OVERVIEW OF 802.15.4 WSNS

   1. WSN Technology

      WSN is a wireless network that consists of spatially distributed autonomous device by using sensor to monitor physical or environmental conditions such as temperature, sound, vibrations, pressure, motions or pollutants at different locations. It appeared as an important area for research and development. The Sensor Node, a basic factor of WSN, is composed of Sensing, Computation and wireless Communication unit. WSNs are very much suitable for applications such as security, surveillance, environmental monitoring , smart homes, automation, vehicular traffic management, habitat monitoring etc.

      A block diagram of WSN system architecture and a sensor node is as shown in Fig. 1 and Fig. 2.

      Fig. 1 System architecture of Wireless Sensor Network

      Fig. 2 Block diagram of a sensor node

   2. MOPEA System Architecture

   MOPEA system is a step towards next generation quality farming. It involves the conceptualization, design, development, evaluating it and application of different ways to use information and communication technologies (ICTs) in the rural domain, with a primary focus on agriculture. It is an initiative focusing on the application of WSN to different areas of the agricultural sector. It seeks to enhance existing methodologies of agriculture through the use of low cost sensor networks which spreading the farm environment and to give macro and micro climate information specific to the crop being cultivated. This information, in conjunction with crop specific decision rules, aids the development of Decision Support Systems (DSS) which provide timely advisories and farm status to farmers through established communication networks like Internet, SMS, Radio etc. The development of WSN applications in precision agriculture makes it possible to increase efficiencies, production and profit in many agricultural production systems.

   It is generally based on organic farming as organic farming have some advantages over chemical farming. Organic agricultural methods are internationally regulated and legally made compulsory by various nations, based on standards set by the (IFOAM) International Federation of Organic Agriculture Movements, an international organization for organic farming organizations established in 1972. IFOAM defines the motive of organic farming that reflects the health of soil, ecosystems and people. It depend on ecological process, biodiversity and cycles adapted for local conditions, rather than using of input with adverse effects. Organic agriculture joins tradition, innovation and science to benefit the environment and promoting fair relations and a good quality life for all is involved" .

   Fig.3 Overall architecture of WSN based Modern

   Organic Precision E- agriculture.

   Fig. 4 MOPEA System Architecture

   The system architecture of MOPEA is as shown in the Fig.

   1. There are basically 3 subsystems in system architecture, Gateway Subsystem and Remote Administration System as shown in Fig. 4. The motes internetwork among themselves and pass their data to the Gateway Subsystem which is present on the field. The Gateway Subsystem is mainly responsible for changing the sensor data from Farm Site motes in their engineering units. A process on the Gateway Subsystem brings the locally stored WSN data and stores it on the Remote Administration System database on an active internet connection. The Remote Administration System applies mechanisms to view, analyse and plotting the data. Required Decision Support Systems (DSS) is also available on the Remote Administration System.

      III ENERGY SAVING MECHANISMS FOR MAC

      PROTOCOL IN WSN

      Energy efficiency is a basic requirement in a WSN. This is a design parameter in MAC (Medium Access Control) protocols for WSN due to the limited resources in sensor nodes that include lower battery power. For avoiding the waste of limited energy, many energy saving mechanisms are proposed for MAC protocols. This section provides a survey on various energy saving mechanisms which can be proposed for MAC protocols in WSN.

      1. EnergyManagement in Sensor Networks

         The Sensor nodes normally have very limited amount of energy and hence the nodes need to save energy to maximize their lifetime. In a typical Wireless Sensor Network, the waste of energy occurs due to idle listening, Overhearing, collisions, Over emitting, overheads and presence of many control packets etc. A WSN is diffrent from networks based on infrastructure. The awareness of application is one of the major criteria for WSN. Hence the MAC protocols should be capable enough to provide the need of specific application area while being energy efficient. The Energy saving mechanisms depends on many other design and factors such as network topology, deployment strategy, antenna mode, controlling mechanisms, delaying, throughput, Quality of Service (QoS) requirements and number of channels to be used in communication etc.

      2. Energy SavingMechanisms in WSN

         In literatures, there are many energy saving mechanisms which have been used and explored for the MAC protocol in WSN. The energy saving mechanisms which are directly used for the MAC layers are as follows: 1. duty cycling, 2. energy-efficient scheduling, 3. scheduled rendezvous, on-

         demand wake-up scheme, energy efficiency by the directional antennae and clustering etc. Other than these mechanisms, there are many other methods that works as supports for energy efficiency in WSN for MAC layers. Bothe of them help to improve the performance of MAC protocol in general even they do not belong to the MAC layer. These mechanisms are named as follows: energy-efficient routing mechanism, energy efficiency through topology control and data aggregation etc. We use a brief discussion of these mechanisms and discuss their strengths and weaknesses.

         There are two major categories of Energy Efficient scheduling mechanisms: distributed scheduling mechanisms (non-hierarchical and hierarchical networks). First one, Distributed scheduling mechanisms in non-hierarchical networks which include sponsored sectors, random independent scheduling (RIS), lightweight deployment-aware scheduling (LDAS), maximization of sensor network life (MSNL), probing environment and adaptive sensing (PEAS), probing environment and collaborating adaptive sleeping (PECAS), and last one is optimal geographic density control (OGDC). The DS mechanisms in hierarchical networks include low-energy adaptive clustering hierarchy known as LEACH, enhanced low energy adaptive clustering hierarchy known as E-LEACH, linear distance-based scheduling (LDS), and balanced-energy sleep scheduling (BESS).

         Scheduled Rendezvous type of MAC protocol needs a prescheduled rendezvous time at which all neighbouring nodes are waked up together. Here in this method, a node wakes up periodically and sleeps until it is the next rendezvous time. The prime advantage of such a scheme is that when a node is awake it is sure for all its neighbours to awake as well. Hence it is easier to send or receive packets. A message to neighbours can also be send easily.

         Directional antennas are receiving increasing interest and research to reduce delay and interference, while requiring lower transmission power. Omni directional antennae have a uniform gain in each direction, while directional antennae have a different antenna gain in each direction. So the signal level at a receiver can be increased or decreased by rotating the orientation of the transmitting antenna. Some designers use directional antenna in their MAC design of sensor networks. There are many advantages of using a directional antenna, but it is found that signal interference is an issue to resolve. The other disadvantage is that they may require adjustments. This can happen in case of a mobile node or multichannel environment.

         In any multi hop sensor network energy efficient routing is an essential feature. In this case a node acts as a router to release packets from one to another neighbour. This causes consumption of extra energy. Efficient routing algorithm can save a significant amount of energy in a network. As per the Friis transmission equation, transmission power of network is dependent on distance or range. Hence multi hopping can save a significant amount of energy than that of single-hop networks. In the same manner, if the network is dense having multi hop topology, efficient routing can save a good amount of energy.

         Energy saving in media access communication is an active research area. In this paper, we have surveyed the existing energy saving mechanisms for MAC protocols. Energy

         saving mechanisms are different in MAC protocols. Due to a wide range of sensor network applications, it is impossible for one particular type of mechanism to be used universally. Energy efficiency depends on a particular network and application area. In our opinion, a mixed approach would be a necessary development path for energy-efficient MAC protocols.

         1. RELATED WORK

            Above content discusses some of the on-going and past agricultural projects in India using WSN technology which such as Agrisens, mKRISHI, Geosense and many more. Many of the farming activities can be precisely done resulting in providing optimized and minimized cost incurred in farming.

            We have also surveyed the importance of organic farming over chemical farming. We have visited many farmers, NGOs and other organizations which are working in the field of organic farming and after our survey we concluded that organic farming can sustain the health of soils, ecosystems and people.

         2. SIMULATION AND RESULT

            In simulation studies, version 5.0.2 of the QualNet network simulator is used here and the IEEE 802.15.4 physical layer and MAC protocol parameters distributed with the QualNet-5.0.2 package. This section provides a comparative analysis of MICA Motes & MICAZ energy models. In Wireless Sensor Networks both the types of hardware like MICA and MICAZ mote are implemented. The energy consumed in all modes such as transmit mode, sleep mode, receive mode and idle mode are taken for both motes at same transmission power level and is shown in Fig.5 and compared. Finally Mica-Z seems to be more promising energy model as compared to Mica Mote, practically in sensor nodes transmitting at higher power level.

            TABLE -I. SIMULATION PARAMETERS

            Parameter Name	Parameter Value
            Simulation Tool	Qualnet 5.0.2
            Simulation Time	60 Seconds
            Channel frequency	2.4GHz
            Path loss model	Two Ray
            Radio type	802.15.4 Radio
            Transmission power	3 dbm
            Modulation Scheme	OQPSK
            MAC Protocol	802.15.4
            Routing Protocol	Bellman ford
            Traffic	CBR

            0.15

            0.1

            0.05

            0

            MicaZ

            MicaMote

            Fig.5 Energy consumed by MicaZ and Mica mote energy model in mili-joule

         3. CONCLUSIONS

The study area of WSN is increasing and day by day new ideas are emerging. This paper presents MOPEA system architecture using energy efficient technology with the importance of organic agriculture. Thus, it is envisaged that WSN could become a major driver for Green Growth. In this paper, we have examined the existing energy saving mechanisms for MAC protocols. This article can be used as a rule towards the design and development of eco environmental friendly agriculture system using WSN technology. This will happen if we develop novel, energy efficient and cost effective technology for WSN chipsets.

REFERENCES

1. Uday B. Desai. B. N. Jain. S. N. Merchant Wireless Sensor Networks:TechnologyRoadmap. www.iith.ac.in/~ubdesai/WSN_Roadmap_Final_%20Report.pdf.

2. J.Zheng and M.J.Lee, Will IEEE 802.15.4 Make Ubiquitous Networking a Reality?: A Discussion on a Potential Low Power, Low Bit Rate Standard, IEEE Communications Magazine, June 2004

3. B. Yahya and J. Ben-Othman, Towards a classification of energy aware MAC protocols for wireless sensor networks, Wireless Communications andMobile Computing, vol. 9, no. 12, pp.15721607, 2009.