Packet Error Rate Measurement
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C.S0033 Tests Performed Using PER How is a PER Measurement Made? Packet Error Rate (PER) is used to test the performance of an access terminal's receiver. PER is the ratio, in percent,
Packet Error Rate Formula
of the number of FTAP or FETAP Test Packets not successfully received by packet error rate to bit error rate the access terminal (AT) to the number of FTAP or FETAP Test Packets sent to the AT by the test packet error rate wifi set. See Forward Test Application Protocol (FTAP) , Multi-carrier Test Application Protocol and Forward Enhanced Test Application Protocol (FETAP) . To perform a packet error rate measurement, the test set sends an
Bit Error Rate Calculation
FTAP (when current physical layer subtype is subtype 0) or FETAP Test Packet (when current physical layer subtype is subtype 2) or FMCTAP Test Packet (when current physical layer subtype is subtype 3) to the access terminal. See Release A Physical Layer Subtype or Release B Physical Layer Subtype to configure the physical layer subtype. Each packet contains 16 FCS (Frame Check Sequence) bit, which
Bit Error Rate Example
provide information about the packet. If the AT is able to decode the packet and the FCS checks (the information relayed by the FCS matches the packet characteristics), then the packet is successfully received. The AT sends one or more FTAP/FETAP/FMCTAP Loop Back Packets to the test set to indicate how many FTAP/FETAP/FMCTAP Test Packets were successfully received for each 16-slot "observation interval" (frame). The AT sends one Loop Back Packet (or more, if needed to convey all of the records) containing a record for each FTAP/FETAP/FMCTAP Test Packet in the observation interval. The Loop Back Packets are queued for transmission on the Reverse Traffic Channel, and the AT must provide buffering for at least 8 FTAP/FETAP/FMCTAP Loop Back Packets. An FTAP/FETAP/FMCTAP Loop Back Packet is generated even if no FTAP/FETAP/FMCTAP Test Packets were received during the 16-slot observation interval. In performing the PER measurement, the test set: always operates with 100% packet activity (see Fixed Settings ). 100% packet activity means that all slots contain Forward Traffic Channel or Control Channel packets (data). The test set fills any empty slots with filler data directed to a random AT other than the AT
be challenged and removed. (March 2013) (Learn how and when to remove this template message) In digital transmission, the number of bit errors is the number of received bits of a data stream over acceptable bit error rate a communication channel that have been altered due to noise, interference, distortion or
Packet Loss Rate Definition
bit synchronization errors. The bit error rate (BER) is the number of bit errors per unit time. The bit error packet error rate calculator ratio (also BER) is the number of bit errors divided by the total number of transferred bits during a studied time interval. BER is a unitless performance measure, often expressed as a percentage.[1] http://rfmw.em.keysight.com/rfcomms/refdocs/1xevdo/1xevdo_meas_cperror_desc.html The bit error probability pe is the expectation value of the bit error ratio. The bit error ratio can be considered as an approximate estimate of the bit error probability. This estimate is accurate for a long time interval and a high number of bit errors. Contents 1 Example 2 Packet error ratio 3 Factors affecting the BER 4 Analysis of the BER 5 Mathematical draft https://en.wikipedia.org/wiki/Bit_error_rate 6 Bit error rate test 6.1 Common types of BERT stress patterns 7 Bit error rate tester 8 See also 9 References 10 External links Example[edit] As an example, assume this transmitted bit sequence: 0 1 1 0 0 0 1 0 1 1 and the following received bit sequence: 0 0 1 0 1 0 1 0 0 1, The number of bit errors (the underlined bits) is, in this case, 3. The BER is 3 incorrect bits divided by 10 transferred bits, resulting in a BER of 0.3 or 30%. Packet error ratio[edit] The packet error ratio (PER) is the number of incorrectly received data packets divided by the total number of received packets. A packet is declared incorrect if at least one bit is erroneous. The expectation value of the PER is denoted packet error probability pp, which for a data packet length of N bits can be expressed as p p = 1 − ( 1 − p e ) N {\displaystyle p_{p}=1-(1-p_{e})^{N}} , assuming that the bit errors are independent of each other. For small bit error probabilities, this is approximately p p ≈ p e N . {\displaystyle p_{p}\approx p_{e}N.}
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