Fixed
mesh networks are generally built with the expectation that many nodes have no
direct backhaul, network, or Internet access. In fact, if each location had some
kind of enterprise or Internet access, distributing service by wireless would be
almost unnecessary.
In
a fixed installation, locations for nodes are chosen with an eye for providing
the right overall level of bandwidth with the fewest points. Fixed mesh networks
also can effectively offer non-line-of-sight service by ringing an obstacle -- a
tall building, a hill, a cluster of trees, an area of known interference -- with
enough nodes to bypass it. These fixed networks are typically directional enough
over each link to avoid major security risks.
In
contrast, peer-to-peer mobile mesh networks -- which are a long way from actual
deployment -- rely on individual devices connecting to each other through
devices within radio range. Scalability can be an issue because each device has
to manage known optimal paths, which can change from millisecond to millisecond.
When an uplink of some kind is added via cell, satellite, or wire, the network
becomes dynamically aware and can handle queued interactions.
Node-to-node
network utilizes a fixed mesh network with mobile mesh network in an
infrastructure mode. Node-to-node connects each node using infrastructure mode
and it provides a network cloud that none-nodes or clients using 802.11b or g
can roam in the network. It is has
the benefits of both mobile mesh and fixed installations. Clients have the
ability to roam the network similar to roaming a cellular network.
There
are two methods of roaming in a node-to-node configuration: Patchwork roaming
and Mobile Mesh roaming.
Nodes
in a mobile mesh by their very nature roam in and out of coverage and between
networks.
With
Patchwork roaming, wireless connection between client’s hardware and mesh
network, a wireless data networks, public Wi-Fi hotspots, and enterprise
WLAN’s, are difficult to operate at best.
The clients using Ipv4 that do not automatically change the IP address
when moving between mesh nodes and wireless nodes. Manual intervention may be required. With Patchwork seamless roaming can be achieve; however, it
requires DHCP to set every few seconds. The
solution will be wait until Ipv6.
Mobile
meshes implements self-contained dynamic addressing and rendezvous technologies
to simplify address management and enable true nomadic operation without
reliance on external clients hardware. Mobile devices can join and leave a
mobile mesh and/or connect to public or private fixed infrastructure, all while
retaining connectivity to critical services.
Wireless
Mesh topology every node has a connection to every other node in the network
realm. There is two types of mesh topologies: full mesh and partial mesh.
Full
wireless mesh topology occurs when every node
in a realm is connected to every
other node in a network. Full mesh is yields the greatest amount of redundancy,
so in the event that one of those nodes fails, network traffic can be directed
to any of the other nodes. Full wireless mesh is difficult to achieve on a large
scale using MeshAP; however, small-scale area like offices or small campus may
be ideal. One should note that it is difficult to deploy a full mesh topology.
Partial
mesh topology yields less redundancy than full
mesh topology. With partial mesh, some nodes are organized in a full mesh scheme
but others are only connected to one or more nodes in the network realm. Partial
mesh topology is commonly found in either small or large networks or fulfilling
the last mile connection to a full meshed backbone.
There
are 4 main types of partial wireless mesh nodes topologies:
- Point-to-point
- Point-to-multipoint or Multipoint-to-point, and
- Multipoint-to-multipoint,
- Metropolitan
Point-to-point and point-to-multipoint networks have long been the standard
for fixed wireless deployments and some 802.11 based networks.
In testing of mesh networks have proven to be most versatile, overcoming
a number of disadvantages in traditional wireless topologies.
This section will detail the fundamentals of MeshAP and its inherent
advantages.
A
point-to-point network is the simplest form of wireless network, composed of
two radio and two high gain antennas in direct communication with each other.
Point to point links are often used to provide high-performance,
dedicated connections or high-speed interconnect links.
These links are quick to deploy individually, but do not easily scale to
create a large network. Client used these nodes in a site-to-site configuration.
A
point-to multipoint or a Multipoint to point nodes share link between an uplink node
with omni directional
antenna and repeater nodes or downlink nodes with high gain directional
antennas. This
type of
network is easier to deploy than Point to point network because adding a new
subscriber only requires equipment deployment at
the subscriber site, not at the uplink node; however, each remote site must be
within range and clear line of sight of the base station.
Trees, hills and other line of sight obstruction make point to multipoint
nods impractical for residential and home office coverage.
A Point to Multipoint network is suited for either backhaul operations or
customers that need reliable, high-speed connections, but are not willing to pay
for dedicated capacity that may go unused.
The nodes performed as a bridge to the uplink network and are generally
in wired configuration for the clients. The problem with point to Multipoint
node topology is that they are not design to mesh with other nodes due to the
directional antenna.
Multipoint
to multipoint networks creates a routed mesh topology that mirrors the structure
of a wired Internet. To build a
mesh network, indoor or outdoor
Internet access is first established with the deployment of an access switch connected to a wired ISP.
Additional access routers are then deployed throughout the coverage area
until a maximum density is achieved. Each
access router not only provides access for attached users, but also become part
of the network infrastructure by routing traffic through the network over
multiple hops. This allows any
client to join the network at any point of the mesh, even if the clients are not
using a node. Client can access the entire mesh wireless or wired making this
the best choice to deploy for areas that require larger coverage MeshAP.
Metropolitan
node topology uses the two
mesh type networks. They
are Backhaul and Last Mile.
Backhaul are either a Point-to-Point or Point-to-Multipoint topology.
It design is to provide a backbone to the uplink nodes (see MeshAP configuration.)
The nodes use dual antennas one being directional to the uplink the other
providing connection to the last mile. The
last mile antenna tends to be omni directional. Backhaul
Wiana configuration uses two different realms, channels, and ESSID.
Clients do not use the backhaul as an access point.
The prime mission is to bring bandwidth to different part of the last
mile. The uplink nodes in backhaul provide multi redundant connections to the
wired Internet and have more capacity than 11 MBPS.
Depending on the size of the area cover numerous backhaul points maybe
required to cover a large city.
Last
Mile is a Multipoint-to-Multipoint topology is nodes that have single radio cards with omni antennas and are linked to the backhauls omni antenna.
The difference between Last Mile and Multipoint-to-Multipoint topology is
that Internet connection does not come from a wired router but through the
backhaul mesh via a central point.
These
are just a few examples of the type of topology that a LocustWorld MeshAP can configure.
The complexity increases when adding a second wireless radio card to a
node and adding different types of antennas.

A
mixed node network is the complex form of wireless network, composed of two
radio and two high gain antennas in direct communication with each other and a
third party wireless bridge/repeater. Mixed
Nodes are often used to provide high-performance, dedicated connections or
high-speed interconnect links. These
links are quick to deploy individually, but do not easily scale to create a
large network. Client used these bridge/repeater nodes in an indoor environment.
The main benefit is that the indoor unit is a low cost commercial
product.
Similar
to a mixed node network is the complex form of wireless network, composed of two
radio and two high gain antennas in direct communication with each other and a
series of third party wireless bridge/repeater.
Mixed Nodes are often used to provide high-performance, dedicated
connections or high-speed interconnect links.
These links are quick to deploy individually, although they do not easily
scale to create a large outdoor network they do scale to become a large indoor
network. Client used these bridge/repeater nodes in an indoor environment.
The main benefit is that the indoor unit is a low cost commercial
product.
Mesh
Structure
Rectangular
Mesh Structure
The
rectangular mesh structure, is the original topology proposed for a digital wave
guide mesh. The main problem with this structure is the direction-dependent
dispersion, which increases with frequency.
Triangle
Mesh
Alternative sampling lattices have been studied to
obtain more uniform wave propagation characteristics in all directions. When the
sampling of the surface is hexagonal, the triangular digital wave guide mesh is
obtained. This structure has better dispersion characteristics than the
rectangular mesh. The same dispersion analysis as presented for the rectangular
mesh is valid for the triangular mesh.