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= Slow Hopping Approach =

Among many other enhancements, the [https://en.wikipedia.org/wiki/IEEE_802.11h-2003 2003 802.11h] amendment added the "Channel Switch Announcement" as an optional tagged parameter in management frames (e.g. beacons). Section 8.4.2.21 of 802.11-2012 describes the element. It contains a "New Channel Number" field that describes, as you might expect, the new channel that associated stations should tune to. Additionally, it contains a "Channel Switch Count" which tells STAs when they should tune to the new channel. A value of {{{0}}} informs them that they should tune immediately while any value {{{N}}} for {{{N > 0}}} informs them they should tune immediately before the beacon {{{N}}}th [https://en.wikipedia.org/wiki/Beacon_frame Target Beacon Transmission Time (TBTT)]. Since beacons are multicast and have no error recovery, a large value of {{{N}}} increases the reliability of client stations tuning to the new channel since they only need to overhear one of the {{{N}}} beacons to properly schedule the retuning event.

== Changes to the 802.11 Reference Design ==

== Characterization ==

||  [[Image(wiki:802.11/wlan_exp/app_notes/tutorial_hop_mac/figs:standard_80211.jpg, width=800)]]  ||
||  ''Standard 802.11'''  ||
||  [[Image(wiki:802.11/wlan_exp/app_notes/tutorial_hop_mac/figs:slow_hop_80211.jpg, width=800)]]  ||
||  ''Slow Frequency Hopping 802.11'''  ||