Multi-channel Wireless Sensor Network MACprotocol based on dynamic route

PREPARATION:

Ameera Saad Al-harthi 43580054

SUPERVISOR:

Dr. Abdulteef semia

Out Line

Introduction of multi WSN and MAC protocol

Dynamic route multi-channel MAC protocol.

Step to apply Step to apply Dynamic McMAC protocol.

Simulation Result.

Introduction

Wireless sensor network (WSN): define as a group of spatially dispersed and dedicated sensors for monitoring and capturing information from an environment, processing data and transmitting them via radio signals.

usually work together to achieve specific task.

Application examples: Disaster relief applications, Environment control, Medicine and health care,….

Introduction (cont..)

MAC protocol : media access control

is a sublayer of the data link layer (layer 2). The MAC sublayer provides addressing and channel access control mechanisms that make it possible for several terminals or network nodes to communicate within a multiple access network.

It is the key and basic protocol to ensure the effective communication of WSN

MAC protocol has many problems such as

Highly dependent on time synchronization.

Low throughputs.

Data delay.

Introduction (cont..)

In WSN, the multi-channel MAC protocol is available to provide a better communication service as the bandwidth is limited and capacity improvement.

MCMAC protocols can be generally classified into two categories :

1. Single rendezvous SR-MCMAC protocols:

one agreement made between a transmitter and a receiver occurs over only one channel at any time.

2. multiple (parallel) rendezvous (MR) protocols:

multiple agreements made between different transmitter-receiver pairs occur over multiple channels at the same time.

Dynamic route multi-channel MAC protocol

Dynamic route allocation algorithm which reduced data delay and increased the throughputs.

Deboned on the neighbor table, it put probability for different relationship neighbors to avoid ( collision )

a large number of nodes sent the data to the same parent node.

Before sending data, the node will determine the type of receiver randomly according to the probability.

Then it chooses a node of this type which is on the control channel from the local neighbor table, and transfer data through an idle data channel chosen from the channel tables.

Step to apply Dynamic McMAC protocol

1. Establish node hierarchical model.

2. Dynamic route selection.

3. The Analysis of algorithm.

1. Establish node hierarchical model

1. The sink node sends broadcast message before data transmission.

Broadcast message includes hops (the initial value is 0) which used for setting the hierarchy of node.

2. node receives message and updates local hops, that the current hierarchy.

If the node receives several messages, it sets the minimal hops as its hierarchy.

3. At the end of broadcast, the hierarchy of the whole network established.

4. After the establishment of hierarchy, each node establishes a path to the sink node by themselves’ and the neighbors’ hops.

Suppose node a’s hierarchy is la, and the signal cover is w. -node b is in the signal cover of a, the hierarchy of b is .

• Definition 1 neighbor node: When |-|=1, node b is a’s neighbor node.• Definition 2 parent node: When -=1, node b is a's parent node.• Definition 3 brother node: When =, node b is a’s brother node.• Definition 4 child node: When -=1, node b is a's child node.In figure

2. Dynamic route seletion

We divide the whole network into one control channel (CC) and data channels (DC).

The CC is used for controlling message, channel reservation and message broadcast

DC is for data transmission.

Each node maintains two tables in local:

1. The neighbor node table (NT, Neighbor Table)

2. The channel table (CT, Channel Table).

NODE E LOCAL NEIGHBOR TABLE

NODE E CHANNEL MAINTAIN TABLE

3. The Analysis of algorithm

Suppose node R is in the level i (1 < i < n).

The probabilities of node R selecting parent node, brother node and child node as its target node are, , .

The three probabilities meet the following conditions.

0<P<1 .

++=1.

.

All Equation shows that when selecting target node, it will consider the parent node firstly, the brother node secondly and the child node finally.

With the decreasing value of i, the hierarchy of the node is closer to sink node, and the number of its parent nodes become less and less.

Also, the value of should become smaller, while the value of and should be increased.

SIMULATION RESULTS

Use NS2 tool.

The experiment compared the throughputs and data delay with the multi-channel protocol and analyzed them.

The result of the simulation is

1. Throughputs of network

2. Average delay analysis

CONCLUSION

WSN: group of sensor capturing information from an environment, processing data and transmitting them and send it to sink.

To solve data collision, delay and throughputs in MAC protocol, use multi-channel protocol based on dynamic route selection.