3385940
| Frage | Antworten |
| 2.4 GHz ISM Band | 100 MHz wide 2.4 - 2.5 GHz |
| UNII-1 Band | 5.15 - 5.25 GHz 100 MHz wide Four 20 MHz channels |
| UNII-2 Band | 5.25 - 5.35 GHz 100 MHz wide Four 20 MHz channels |
| UNII-2 Extended | 5.470 - 5.725 GHz 255 MHz wide 12 channels |
| UNII-3 Band | 5.725 - 5.850 GHz 125 MHz wide Five 20 MHz channels |
| Narrowband | Uses little bandwidth to transmit data |
| Spread spectrum | Uses more bandwidth to carry data Spreads data across frequencies |
| Delay spread | Delay between main signal and reflected signal |
| Intersymbol interference (ISI) | Delay spread too great |
| Dwell time | Specific amount of time FHSS system transmits on specific frequency before switching to next frequency |
| Hop Time | Amount of time to change from one frequency to another |
| Direct Sequence Spread Spectrum | 1 and 2 Mbps |
| High-Rate DSSS | 5.5 and 11 Mbps |
| Baker code | Use of a pseudorandom number DSSS data encoding |
| Complementary Code Keying (CCK) | DSSS data encoding Provides faster speeds for HR-DSSS |
| Differential binary phase shift keying (DBPSK) | Modulation of signal to carrier signal Uses two phase shifts |
| Differential quadrature phase shift keying (DQPSK) | Modulation Four phase shifts Faster throughput |
| PBCC | Packet Binary Convolutional Code Modulation technique 5.5, 11, 22, and 33 Mbps |
| OFDM | Orthogonal Frequency Division Multiplexing Used at 5 GHz and ERP-OFDM at 2.4 GHz |
| How many subcarriers in OFDM | 52 subcarriers per channel Each subcarrier is a separate channel Subcarrier width is 312.5 KHz |
| Error correction used in OFDM | Convolutional Coding |
| Modulation used in OFDM | Binary Phase Shift Keying (BPSK) Quadrature Phase Shift Keying (QPSK) for lower data rates |
| Higher OFDM data rates modulation method | 16-QAM 64-QAM |
| QAM | Quadrature Amplitude Modulation Hybrid of phase and amplitude modulation |
| How many channels in 2.4 GHz | 14 |
| 2.4 GHz Channels | 1 - 2.412 2 - 2.417 3 - 2.422 4 - 2.427 5 - 2.432 6 - 2.437 7 - 2.442 8 - 2.447 9 - 2.452 10 - 2.457 11 - 2.462 12 - 2.467 13 - 2.472 14 - 2.484 |
| DSSS / HR-DSSS channel width | 22 MHz |
| Number of 20 MHz channels in 5 GHz for usage | 25 |
| Usable 40 MHz channels in 5 GHz | 12 |
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