When there are multiple transmitter antennas in a single cell, and they are operating on the same carrier frequency interference may occur. As the frequency is been reused, the transmitted data may overlap each other transmission and thus reduces the data throughput. If the transmitted stream share the same channel, data outrage occurs on the cell edge. By underutilization of the provided bandwidth, collision of data packet can be prevented but causing loss of the bandwidth. Since mesh network development is very easy and cost effective related to ad-hoc communication but in dense mobile nodes, they may share same frequency and time resources. To analysis this phenomena technically, a term interference channel is introduced, which is shared by all the transmitting resources. Every transmitter is paired with its receiver, and if they share same frequency they all lie in the same interference channel. Some interferences are self generated, such as for security reasons jamming is required and for non-linear components in radio transmissions. If the overlapping is in simultaneous mode, all together interference is regarded as noise.
Types of Interference
Hampering of communication in mesh nodes are caused by interference and interference can be classifieded into two types.
a) Radio Interference
The interference that acts the radio spectrum, it is also termed as physical interference. This type of interference can be of destructive nature and also can be implied as constructive nature.
b) Contention Interference
Contention interference is mostly caused by CSMA/CD (carrier sense multiple access/collision detection) protocol, according to this protocol in large vicinity like city where wireless nodes are many in number have to compete with neighboring nodes. With this regards two terms are considered for estimating the interference caused, those are
1) Transmission Range
2) Interference Range
The transmission range provides with the probability of the correct transmitted message between sender and receiver. Interference range is the information or an estimate that can denie the range beyond which the transmitted data can be interfered and messages received are incorrect.