802.11g AP/Bridge Collocation
802.11g AP/Bridge Collocation
(OP)
I'm working on linking four offshore oil platforms with bridged point-to-point 802.11g links. 802.11g says radios must have at least 4 dB adjacent channel rejection (ACJ) for not more than 10% packet error rate (@36 Mbps data rate). I have measured an ACJ of 11 dB. System gain is 99 dB so I figured I need 88 dB of antenna isolation. When explaining this to client, he said overlaying the three available channels with collocated APs is common practice. In a typical indoor installation with collocated APs, isolation between antennas is likely to be only 40-50 dB. How can this work without greatly compromising range?
Talk To Other Members
RE: 802.11g AP/Bridge Collocation
You can dig into the public domain 802.11 specs, or here is what wikipedia says "Although the statement that channels 1, 6, and 11 are "non-overlapping" is incomplete, the 1, 6, 11 guideline has merit. If transmitters are closer together than channels 1, 6, and 11 (e.g. 1, 4, 7, and 10), overlap between the channels will probably cause unacceptable degradation of signal quality and throughput."
RE: 802.11g AP/Bridge Collocation
The specs are not in the public domain. I do have access to draft copies of 802.11a, b, & g.
I've requested customer referrals from the vendor but have received nothing yet. I am really hoping to contact someone who has done this or at least tried.
RE: 802.11g AP/Bridge Collocation
(802.11 a, b , g are there)
RE: 802.11g AP/Bridge Collocation
RE: 802.11g AP/Bridge Collocation
Thanks for the link to the standards. Will check it out.
zappedagain
re: 802.11 channelization
See table 105, table 111, & fig 141 in 802.11b.
802.11g references the channelization defined in 802.11b.