Saturday, November 21, 2009

Error Rate | QoS

Error rate is a ratio between an amount of information that is received in error as compared to the total amount of information that is received over a period of time. Error rate may be expressed in the number of bits that are received in error on the number of blocks of data (packets) that are lost over a period of time. WiMAX error rates can be affected by a number of factors including signal quality and system configuration. Some of the common error rate measures for WiMAX include bit error rate (BER) and packet loss rate (PLR).

Bit Error Rate (BER)

BER is calculated by dividing the number of bits received in error by the total number of bits transmitted. It is generally used to denote the quality of a digital transmission channel. Bit errors can occur randomly over time (random errors) or in group (burst errors).

Random errors are bits in a received digital signal that are received in error that occur in such a way that each error can be considered statistically independent from any other error. Burst errors are the distortion or failure of a digital receiver to correctly decode groups of digital bits. Burst errors typically have a high bit error ratio (BER) compared to the overall BER of a communication link or channel.

Packet Loss Rate (PLR)

Packet loss rate is a ratio of the number of data packets that have been lost in transmission compared to the total number of packets that have been transmitted. Some applications (such as digital television) are more sensitive to packet loss rate than bit error rates.

Related Posts with Thumbnails