Mesh applications often require a string-of-pearls formation where the end-to-end path is non line-of-site (NLOS). Additionally, there may be points along the path where
only backhaul is needed - no client Access Point. The
baseline two radio MD4250-AAxx
supports this requirement.
If wireless client
access is needed, the MD4350-AAIx
has one 2.4GHz Access
Point (AP) as the third radio in slot 2, in addition to the
5.8GHz wireless backhaul up link and downlink radios is
slots 0,1 respectively (see above). The third radio is also
used to bridge networks. In the figure below, a 5GHz
based backhaul is bridged to a 2.4GHz based sub tree.
density or congested areas require more focused
reception. MD4458-AAII houses
two access points to provide twice the client access
radio power. The two AP radios may be on the same
channel and not interfere, using sectored antennas. The
4458-AIII may also serve as
an edge node: with one uplink and three AP radios
radio uplink-downlink backhaul comes in two flavors. 4250-AAxx
uses radios configured to operate in the 5GHz spectrum. 4220-IIxx
uses radios configured to operate in the 2.4 GHz spectrum.
When deciding whether to use 2.4GHz based products (4220) vs.
the 5.8GHz (4250) product, RF pollution must be considered.
Wi-Fi 802.11b/g clients are 2.4GHz and will interfere with a
2.4GHz node-to-node (backhaul) link. In addition,
802.11b clients - if attached to the 2.4GHz backhaul
downlink will slow the performance of of the
node-to-node link. 4220 mesh nodes thus should be
limited in servicing few child nodes. On the positive
side, 2.4 GHZ has about twice the range at 5GHz, so
4220 are preferable where range supersedes backhaul
In all other situations, 5GHz mesh nodes (4455-AAIA,
4454-AAAA, 4250-AAxx) are suggested.