IEEE 802.11j
802.11 is a set of
IEEE standards that govern wireless networking transmission methods. They are commonly used today in their
802.11a,
802.11b, and
802.11g versions to provide wireless connectivity in the home, office and some commercial establishments.
The
802.11j standard "Wireless LAN Medium Access Control (
MAC) and Physical Layer (
PHY) Specifications: 4.9 to 5 GHz Operation in
Japan" is designed specially for
Japanese market. Finalized in
2004, the standard works in the 4.9 GHz to 5 GHz band to conform to the Japanese rules for radio operation for indoor, outdoor and mobile applications.
802.11j defines uniform methods that let APs move to new frequencies or change channel width for better performance or capacity -- for example, to avoid interference with other wireless applications.
Public Safety
In the
USA, the 4.9 GHz band is reserved for use by public safety wireless applications. The transmission mask is narrower for the public safety band than for consumer part 15 applications. Thus one cannot simply operate 802.11j equipment in the public safety band and be FCC compliant. Public safety agencies are working with manufacturers and the FCC in order to leverage Commercial Off The Shelf (COTS) equipment. There are public safety groups working closely with the manufacturing community, federal interests, and standards bodies to create an 802.11 series standard for public safety.[
1]
See also
*
IEEE 802.11a*
IEEE 802.11h*
IEEE 802.11p*
The 802.11j-2004 standard*
Status of Project IEEE 802.11j IEEE Task Group TGj
*
802.11 Standard Modified For Japan Information Week November 29, 2004
*
Wi-Fi extensions should breathe new life into 802.11a Wireless Watch
The Guardian December 13, 2004
*
Wi-Fi Goes International Ed Sutherland
Wi-Fi Planet December 6, 2004
*
4.9GHz Cisco wireless aids police Enterprise Networks and Servers August 2005
