![](/images/backgrounds/165623/165623-6855x1.png)
Appendix A: About the Technology
The values in the table below show the minimum xDSL transmission time in milliseconds (ms).
Frame Size |
|
|
| xDSL Data Rate |
|
|
| ||
(da:sa:lt:data:crc) |
|
|
|
|
|
|
|
| |
7040 | 6400 | 3200 | 1536 |
|
|
|
| ||
[bytes] | 896 kbps | 768 kbps | 384 kbps | 64 kbps | |||||
kbps | kbps | kbps | kbps | ||||||
|
|
|
|
| |||||
|
|
|
|
|
|
|
|
| |
64 | 0.088 | 0.097 | 0.194 | 0.405 | 0.694 | 0.810 | 1.620 | 9.719 | |
128 | 0.176 | 0.193 | 0.386 | 0.805 | 1.379 | 1.609 | 3.219 | 19.313 | |
512 | 0.699 | 0.769 | 1.538 | 3.205 | 5.494 | 6.410 | 12.820 | 76.922 | |
1024 | 1.397 | 1.537 | 3.074 | 6.405 | 10.980 | 12.810 | 25.620 | 153.719 | |
1518 | 2.071 | 2.278 | 4.556 | 9.492 | 16.272 | 18.984 | 37.969 | 227.813 | |
|
|
|
|
|
|
|
|
|
RATE ADAPTIVE TRANSMISSION
The following definitions are useful for understanding the operation of the Megabit Modem:
•Bit Error Rate (BER) is the ratio of received bits that are in error relative to the total number of bits received, measured over time. For example,
•Signal to Noise Ratio (SNR) is the ratio (typically expressed in dB) of the received signal power to the received noise power. It is a measure of the quality of the transmission.
•Margin (SNR margin) is the amount of degradation in SNR that the system can tolerate under the current conditions and still achieve a
•Reach is the longest loop length that the system can support with a given margin and a BER of less than
Megabit Modem 310F and 320F User Manual | 47 |