IEEE Consumer Electronics Magazine - July 2017 - 45

deployment of nodes and the CH selection by using the fuzzylogic technique, the lifetime of the network increases as compared to other existing protocols.

Using fuzzy-based clustering
techniques for transmitting sensed
data to the BS helps minimize
the energy consumption of
sensor nodes and improve the
network lifetime.

PROPOSED PROTOCOL
The proposed model uses a periodic threshold sensitive
RBHR scheme to measure two environment parameters. One is
the soil temperature, and the other is the soil-moisture
content of the agricultural field. The decision regarding when irrigation needs to be started in the field can be based on the temperature and moisture-threshold values. Before going into the
details of the proposed protocol, some assumptions regarding
the network are as follows: all sensor nodes and the BS are stationary after deployment, sensor nodes are aware of their own
locations by any localization methods proposed for WSNs [5],
and the BS is located at the center position of the sensing field.

REGION-BASED NODE DEPLOYMENT

tion occurs only when there is an intense requirement of
water in the field. The proposed protocol is the threshold-sensitive protocol where nodes sense the environment parameters continuously, but data transmission to the BS occurs only
when the sensed value is in the range specified by the users.
This helps the farmer make decisions regarding irrigation.
However, there is a limitation of threshold sensitivity; if the
sensed value never reaches the set thresholds, nodes never
communicate to the BS, and the farmer does not know about
the field conditions.
We propose a new routing protocol that transmits the data
after a fixed time interval. Hence, the data transmission to the
BS does not only depend on the rigid or mild thresholds but
also on the PT. By using a PT, the farmer/user obtains information related to temperature and moisture content after
every fixed time interval. For transmitting data to the BS,
hybrid routing is used where all the type-1 nodes deployed in
REG-9 transmit their data directly to the BS. Type-3 and
type-2 nodes deployed in middle and outermost regions,

Three types of heterogeneous sensor nodes (type-1, type-2,
and type-3 nodes) are deployed in a (A × A) unit2 network
area for sensing and transmitting information regarding the
agricultural field. To provide efficient coverage over the
entire field, the total agricultural area is divided among nine
fixed regions, as shown in Figure 1. Since we are considering
specific land areas, the division of all the regions can be easily specified through field measurement. The region division
can be done based on the availability of the different types of
heterogeneous nodes in the network and their range of sensing, because the further a node is from the BS, the more energy it consumes in data transmission. Thus, the outermost
region's (REG-1, REG-2, REG-3, and REG-4) nodes that are
very far from the BS require more energy to transmit data to the BS compared
with the middle region's (REG-5, REG-6,
REG-7, and REG-8) nodes and the
(0, 100)
(20, 100)
(100, 100)
innermost region's (REG-9) node.
Therefore, type-3 nodes having more
REG-1
energy than type-1 and type-2 nodes
(40, 80) Type-2 Nodes (80, 80)
(20, 80)
(100, 80)
should be placed in outermost regions,
REG-5
type-2 nodes having energy less than
Type-3 Nodes
(60, 60)
type-3 nodes but greater than type-1
(40, 60)
(80, 60)
nodes should be placed in middle
REG-9
Type-1 Nodes
regions, and finally, type-1 nodes having
REG-3 REG-7
REG-8 REG-4
much less energy should be deployed in
BS
Type-2 Type-3
Type-3 Type-2
the innermost region. However, in the
(50, 50)
Nodes Nodes
Nodes Nodes
proposed network model, we have
deployed type-3 nodes in the middle
(20, 40)
(60, 40)
regions, type-2 nodes in the outermost
(40, 40)
REG-6
regions, and type-1 nodes in the innerType-3 Nodes
most region.
(80, 20)
(0, 20)
(20, 20)

PERIODIC THRESHOLD SENSITIVE
HYBRID ROUTING PROTOCOL
For irrigation, continuous data (contains field information) transmission to
the BS is not required, because irriga-

REG-2
Type-2 Nodes

(60, 20)

(80, 0) (100, 0)

(0, 0)

FiGURE 1. The network architecture.

july 2017

IEEE Consumer Electronics Magazine

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