10Base-T RD Receiver Circuit Signal Acceptance Test (BER)
1000BASE-T/100BASE-TX/10BASE-T Physical Layer Compliance Tests Manual
90
Intel Confidential
23.4
Test Fixtures
Various lengths of Category 5 and/or Category 3 cable between 1 and 100 spec. meters.
23.5
Test Procedure
1. Connect the UUT and the link partner using the desired Category 5 cable length and verify that
a gigabit link has been established.
2. On the receiving system, go to the Transmit and Receive menu, and select the Receive option.
3. On the UUT, go to the Transmit and Receive menu, and select the Transmit option.
4. Allow the proper number of frames to be sent (see
).
5. After transmissions is complete, press the <Esc> key on the receiver first and then the
transmitter to stop the test and record the following results:
a. Link partner: Transmit Good Packets and Transmit Total Packets
Both of these statistics should equal each other.
b. UUT: Receive Good Packets and Missed Packets.
6. Calculate the bit error rate (BER).
7. Repeat steps 1 through 7 for each cable length.
8. Verify the measurements meet specifications.
23.6
Calculating Bit Error Rate (BER)
The basic BER equation is as follows:
,
where:
•
TGP = number of good frames transmitted (#_Transmit_Good_Packets)
•
MP = number of missed packets (#_Missed_Packets)
•
RGP = number of good frames received (#_Receive_Good_Packets)
•
BF = number of bytes/frame
•
BB = 8 (number of bits/byte)
Note:
Conditions where the transmit link partner overwhelms the receive unit should be avoided. When
this happens, the receive statistics counters may show "RX No Resources", "RX No Buffers", or a
large number of missed packets. This complicates the BER calculation and the equations for the
calculations will not yield accurate BER numbers. The TX transmit speed (frames per second) can
BER
TGP MP
–
RGP
–
TGP BF
×
BB
×
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