802.11r Channels ====================== .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11r define specific channels?** No, 802.11r works over existing Wi-Fi channels in 2.4 GHz or 5 GHz bands; it doesn’t define new channels. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11r improve roaming across different channels?** It speeds up key negotiation and authentication, allowing faster handoff even when moving between APs on different channels. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Can 802.11r handle roaming between 2.4 GHz and 5 GHz channels?** Yes, 802.11r supports fast transitions even when roaming between different frequency bands. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does channel switching during roaming affect 802.11r performance?** Minimal impact, since 802.11r reduces handoff time significantly regardless of channel changes. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What role do channels play in 802.11r Fast Transition?** Channels determine where the client associates next, but 802.11r optimizes security and authentication during the switch. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Is the client aware of channel changes during 802.11r roaming?** Yes, the client scans and switches channels as needed; 802.11r ensures the transition is quick and seamless. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11r support roaming on overlapping channels?** Yes, but overlapping channels can cause interference, so proper channel planning is still essential. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does channel width affect 802.11r roaming?** Roaming works similarly on 20 MHz or wider channels; channel width doesn’t impact the fast transition process directly. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Can 802.11r reduce roaming delays caused by channel changes?** Yes, by pre-authenticating and caching keys, it minimizes delays when clients switch channels. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11r require APs on the same channel for fast roaming?** No, APs can be on different channels; 802.11r manages roaming across channels efficiently. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11r interact with DFS channels during roaming?** It supports roaming onto DFS channels but must comply with DFS regulations and radar detection requirements. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Can 802.11r improve roaming in environments with many channel options?** Yes, it makes transitions between APs on different channels smoother and faster. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Is there any difference in 802.11r roaming on 2.4 GHz vs 5 GHz channels?** 802.11r speeds roaming equally on both bands, but 5 GHz often offers more channels and less interference. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does channel interference impact 802.11r fast roaming?** Indirectly — interference affects signal quality, but 802.11r reduces authentication delays regardless. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What happens if an AP moves to a new channel in an 802.11r network?** Clients using 802.11r will re-associate quickly on the new channel due to fast transition capabilities. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11r require special channel coordination among APs?** No special coordination is required, but good channel planning still improves overall network performance. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Can 802.11r support roaming between APs on different regulatory channels?** Only if allowed by the regulatory domain; otherwise, roaming between disallowed channels is not possible. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11r handle roaming when channel availability is limited?** It still reduces handoff times, but limited channel options may increase contention and interference. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11r impact how clients scan channels during roaming?** It reduces the need for full re-authentication, but clients still scan channels to find the best AP. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow Topics in this section, * :ref:`List of channels ` * :ref:`List of channel widths ` * :ref:`List of Bands ` * :ref:`Reference links ` .. _channels_80211r_step4: .. tab-set:: .. tab-item:: 2.4 GHz Channels for 802.11r ===================== ======================= ====================== ============== Channel Number (MHz) Center Frequency (MHz) Frequency Range DFS Required ===================== ======================= ====================== ============== 1 2412 2401 – 2423 No 2 2417 2406 – 2428 No 3 2422 2411 – 2433 No 4 2427 2416 – 2438 No 5 2432 2421 – 2443 No 6 2437 2426 – 2448 No 7 2442 2431 – 2453 No 8 2447 2436 – 2458 No 9 2452 2441 – 2463 No 10 2457 2446 – 2468 No 11 2462 2451 – 2473 No 12 2467 2456 – 2478 No (region dependent) 13 2472 2461 – 2483 No (region dependent) 14 2484 2473 – 2495 No (Japan only) ===================== ======================= ====================== ============== .. tab-item:: 5 GHz Channels for 802.11r ===================== ======================= ====================== ============== Channel Number (MHz) Center Frequency (MHz) Frequency Range DFS Required ===================== ======================= ====================== ============== 36 5180 5170 – 5190 No 40 5200 5190 – 5210 No 44 5220 5210 – 5230 No 48 5240 5230 – 5250 No 52 5260 5250 – 5270 Yes 56 5280 5270 – 5290 Yes 60 5300 5290 – 5310 Yes 64 5320 5310 – 5330 Yes 100 5500 5490 – 5510 Yes 104 5520 5510 – 5530 Yes 108 5540 5530 – 5550 Yes 112 5560 5550 – 5570 Yes 116 5580 5570 – 5590 Yes 120 5600 5590 – 5610 Yes 124 5620 5610 – 5630 Yes 128 5640 5630 – 5650 Yes 132 5660 5650 – 5670 Yes 136 5680 5670 – 5690 Yes 140 5700 5690 – 5710 Yes 144 5720 5710 – 5730 Yes 149 5745 5735 – 5755 No 153 5765 5755 – 5775 No 157 5785 5775 – 5795 No 161 5805 5795 – 5815 No 165 5825 5815 – 5835 No ===================== ======================= ====================== ============== .. _channels_80211r_step5: .. tab-set:: .. tab-item:: List of channel widths * channel widths .. _channels_80211r_step6: .. tab-set:: .. tab-item:: List of Bands ======================= ====================== ====================== ============================================================ Band Name Frequency Range (GHz) Frequency Range (MHz) Channels ======================= ====================== ====================== ============================================================ 2.4 GHz Band 2.400 – 2.485 2400 – 2485 1 – 14 (region dependent) UNII-1 5.150 – 5.250 5150 – 5250 36, 40, 44, 48 UNII-2 (DFS) 5.250 – 5.350 5250 – 5350 52, 56, 60, 64 UNII-2 Extended (DFS) 5.470 – 5.725 5470 – 5725 100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140, 144 UNII-3 5.725 – 5.825 5725 – 5825 149, 153, 157, 161, 165 ======================= ====================== ====================== ============================================================ .. _channels_80211r_step17: .. tab-set:: .. tab-item:: Reference links * Reference links