BLER，是Block Error Rate的简称，中文习惯成为误块率，或块差错率，英文解释是：Block error rate (BLER) measurements are made on a mobile telephone handset without imposing an undesirable processing burden on the handset. An information block flow is maintained by sending repeated message blocks from a test set which are defined at a selected layer in the protocol stack below the topmost layer. Ack/nack messages sent by the handset in response to the message blocks are monitored to determine whether the message blocks have been correctly transported, and thus derive the BLER. The message blocks sent by the test set can either be empty GMM_INFORMATION messages, or LLC frames with invalid frame check sequences.  

简单的讲，误块率(BLER)在通信系统中是指传输块经过CRC校验后的错误概率，是有差错的块与所接收的总块数之比。误块率（BLER）用于W-CDMA/LTE的性能测试（在多径条件下的解调测试等）。

在用途上，误码率（BER，bit error rate）是用来衡量接收机特性的指标，而BLER是用来衡量系统性能测试的。在实现上，两者的测量都要经过解交织、速率匹配和维特比译码等一系列的信道解码过程，但是BLER是在CRC之后测量，每发生一个需要丢掉的误码块就记一个错误，而BER是在CRC之前测量，每发生一个比特错误就记一个错误。由此可见，BLER不但测量信道解码后的数据块的错误，而且还检查CRC的错误。