* radio fréquences: transmissions radio numériques simultanément double fréquence et bi-bande
* radio fréquences: transmissions radio numériques double fréquence et bi-bande simultanée

DualBand = en français c'est "bi-bande" (ou "double bande")

Point d'accès Prog Mosaic pour Wi-Fi - dual band
www.legrand.fr/.../077913-point-d-accn-s-pro...
Bi-bande et bi-radio. Conformes aux normes 802.11a et 802.11b/g; Débit brut : 54 Mbits/s maxi sur chaque fréquence (802.11a et 802.11g) simultanément ...

http://www.google.fr/search?complete/search?client=serp&hl=i...

http://www.google.fr/#hl=it&tbo=d&sclient=psy-ab&q=simultané...

http://www.google.fr/#q=simultanément double fréquence et d...

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http://www.wi-fi.org/files/11nbasics_glossary.pdf
Dual-band:
Designates a product that can communicate on a wireless network in either the 2.4MHz or 5MHz frequency bands. Dual-band Wi-Fi devices can offer either "selectable" or "concurrent" operation. For selectable dual-band devices, the user must select one of the frequency bands. Concurrent devices operate in both 2.4 and 5 GHz at the same time.

Dual-band concurrent:
Only APs designated as "dual-band concurrent" can support both 2.4GHz and 5.0 GHz clients simultaneously

Frequency band:
Wi-Fi 802.11n operates at two frequencies: 5 GHz and 2.4 GHz. Only devices which operate in the same frequency band can communicate with one another. Wi-Fi CERTIFIED n devices may support one or both of these frequency bands.

Concurrent operation:
Wi-Fi Access Points with concurrent operation can transmit on both 5 GHz and 2.4 GHz frequency bands at the same time. Sometimes referred to as "simultaneous dual-band"

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Dual-band router Definition from PC Magazine Encyclopedia
www.pcmag.com › Solutions › Encyclopedia
A wireless router that supports both 2.4 and 5 GHz frequency bands of the ... Buffalo Technology's Nfinity Dual Band router simultaneously runs 11n and 11a at 5 ...