First Generation Mesh
: A single
radio provides both service (connection to individual user devices) and backhaul (links across the mesh to the wired or fiber connection), so wireless congestion and contention takes place at every node. Users soon discovered that only two-three radio "hops" were possible between connections to the wired or fiber Ethernet. Support was also poor for Video and Voice applications because of varying delay across the network.
Most industrial mesh network providers have "upgraded" to the
dual radio described below.
RF Interference: This architecture is the
worst of all possible worlds. Client and backhaul
share the same radio, subject to RF interference from other
radios operating on the same or adjacent frequencies.
Second Generation Mesh: a.k.a
1+1, Dual-Radio, Multi-Radio : To solve these contention and congestion issues, second generation mesh was developed by placing two radios in each node, combining an 802.11b/g service radio with an 802.11a backhaul radio. While this offered a performance improvement over first-generation mesh, problems remain. With heavy user demand, there is still significant contention and congestion on the backhaul links. This limits the number of radio hops - typically three or less - before
a wired Ethernet feed is needed.
RF Interference: This architecture segments
interference from client radios and the backhaul. But note
all backhaul radios share the same frequency, subject to RF
interference from others operating on the same or adjacent
frequencies. Worse, RF interference from other radios also operating on the
common backhaul frequency cannot be avoided - the entire
mesh network would need to switch all backhauls to
another common channel. This is both unrealistic and unstable
in practice. A comparative
Performance Analysis explains why "dual radio" mesh
network products runs out of steam after a few hops, see
Generation MeshTM Meshdynamics' solutions
begin by adding additional logical- or physical radios to each
mesh node. One radio is used to create the uplink - the link
to its upstream (nearer the wired source or "root") node.
Another radio creates the down link - a link downstream to the
next neighbor node. Both up link and downlink radios are
active at the same time (see animation above) and together
form the patented Structured MeshTM Backhaul.
RF Interference: Meshdynamics patented multi-radio multi-channel backhaul ensures deterministic latency and jitter by eliminating
both the bandwidth degradation effects of single radio backhauls and
involuntary contention in multi-hop networks.