IEEE 802.11j
Encyclopedia
802.11j-2004 or 802.11j is an amendment to the IEEE 802.11
standard designed specially for Japan
ese market. It allows Wireless LAN
operation in the 4.9 to 5 GHz band to conform to the Japanese rules for radio operation for indoor, outdoor and mobile applications. The amendment has been incorporated into the published IEEE 802.11-2007 standard.
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.
) and Physical Layer (PHY
) Specifications: 4.9 to 5 GHz Operation in Japan
" is designed specially for Japan
ese 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.
IEEE 802.11
IEEE 802.11 is a set of standards for implementing wireless local area network computer communication in the 2.4, 3.6 and 5 GHz frequency bands. They are created and maintained by the IEEE LAN/MAN Standards Committee . The base version of the standard IEEE 802.11-2007 has had subsequent...
standard designed specially for Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
ese market. It allows Wireless LAN
Wireless LAN
A wireless local area network links two or more devices using some wireless distribution method , and usually providing a connection through an access point to the wider internet. This gives users the mobility to move around within a local coverage area and still be connected to the network...
operation in the 4.9 to 5 GHz band to conform to the Japanese rules for radio operation for indoor, outdoor and mobile applications. The amendment has been incorporated into the published IEEE 802.11-2007 standard.
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.
4.9 - 5 GHz operation in Japan
The 802.11j standard "Wireless LAN Medium Access Control (MACMedia Access Control
The media access control data communication protocol sub-layer, also known as the medium access control, is a sublayer of the data link layer specified in the seven-layer OSI model , and in the four-layer TCP/IP model...
) and Physical Layer (PHY
PHY
PHY is an abbreviation for the physical layer of the OSI model.An instantiation of PHY connects a link layer device to a physical medium such as an optical fiber or copper cable. A PHY device typically includes a Physical Coding Sublayer and a Physical Medium Dependent layer. The PCS encodes and...
) Specifications: 4.9 to 5 GHz Operation in Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
" is designed specially for Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
ese 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.http://www.apco911.org/frequency/4-9GHz/4-9GHz.htmExternal links
- 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