Future-Proof, Mesh Networking
Mesh network requirements have evolved from their military origins as
requirements have moved from the battlefield to the service provider, and
residential networking environments. Today, to cover large areas with a single
wired Internet link, more cost effective and efficient means of bandwidth
distribution are needed. This implies more relay nodes (hops) than were needed
before. Further, growing demands for Video and Voice-over-IP require packets to
be moved over the mesh at high speeds with both low latency and low jitter.
These requirements (more hops to cover large areas, more efficient bandwidth
distribution and better latency and jitter for Video and VOIP) has given rise to
the newer mesh architectures.
Three Generations of Mesh Architectures
1: First, Second and Third Generation Mesh Network Topologies
Three generations of mesh architectures are shown above. Note
: First and
Second, both use a single radio as backhaul:
• First Generation
: 1-Radio Ad Hoc Mesh (left). This network uses one radio channel
to service clients and backhaul. This architecture provides the worst of all the options, as expected, since both backhaul and service compete for bandwidth.
• Second Generation
: Dual-Radio with Single Radio Ad-Hoc meshed backhaul (center).
A single radio
ad hoc mesh is still servicing the backhaul, packets traveling
toward the Internet share bandwidth at each hop along the backhaul path with
other interfering mesh backhaul nodes - all-operating on the same channel.
• Third Generation
: 3-Radio Meshdynamics Mesh (right). Provides separate backhaul and service functionality
dynamically manages channels of all uplink and downlink radios so that
each backhaul (hop) is on
Meshdynamics Structured MeshTM
multi-radio backhauls. They are the wireless equivalent of (scalable)
Single Channel Backhauls
With one backhaul radio available for relaying packets, all nodes communicate
with each other on one radio channel. For data to be relayed from mesh node to
mesh node, that node must repeat it in a store-and-forward manner. A node first
receives the data and then retransmits it. These 2 operations cannot occur
simultaneously because, with only a single radio channel, simultaneous
transmission and reception would interfere with each other.
This inability - to simultaneously transmit and receive - is a serious
disadvantage. If a node cannot send and receive at the same time, it loses ½ of
its bandwidth as it attempts to relay packets up and down the backhaul path. A
loss of ½ with each hop implies that after 4 hops, a user would be left with
(½*½*½*½) = 1/16 of the bandwidth available at the Ethernet link. This is 1/(2N)
relationship defines the fraction of the bandwidth available to a user after N
hops, see Figure 2. .
Fig.2: (left) Competing mesh products suffer from ½ Bandwidth loss with each hop.
Click to Enlarge.
Fig 3: (right): Meshdynamics MeshControlTM
Software engenders Frequency Agility. Click to
Third generation mesh products eliminate bandwidth degradation with a dual channel backhaul. There is been no measurable bandwidth degradation and this is the significant departure from both first and second-generation mesh architectures. A single channel backhaul would be incapable of delivering video feeds beyond 1-2 hops: typical video bandwidth requirements would cripple the system. Latency and jitter would be unacceptable.
Switching to another channel contains local interference at one section of the network. With one radio backhauls, this is not possible: the
entire network is on the same channel and switching to another channel is simply not practical.
The performance of single channel backhauls is thus heavily compromised in RF polluted environments or under malicious attacks. Military field trials with dual channel backhaul have demonstrated frequency agility,
ensuring that the network is active - even with malicious RF interference.
Backhaul radios (blue, Fig. 3) simply switch to non-interfering channels. More
Radio Hardware and Protocol Abstraction Layer is Future-Proof
Meshdynamics' dual channel implementation is not limited to any particular number or type
of physical radios, or indeed to the concept of separate physical radios at all.
Instead, the Meshdynamics
mesh networking algorithms ("MeshControlTM
") treat multiple physical and/or logical radios as a pool of
available connections- e,g, Satellite, Cellular, Wi-Fi etc.
Each connections is to be dynamically managed for optimum performance
for stationary, mobile or
The software is uniquely
, allowing rapid addition of new radio
frequencies, radio suppliers and new technologies. The MeshControlTM
software is therefore future-proof: it may be rapidly extended to
support new RF standards, as they become proven and commercially
Decoupling the logical
topology-definition processes from the specific physical
radio in this fashion delivers distributed dynamic radio
intelligence benefits for current as well as emerging radio
software -- which controls channel selection and network topology configurations
-- is abstracted from specific radio hardware and protocols, by design.
This substantially decreases time to market and better manufacturing
scale, reducing both development- and unit cost over custom hardware
Bridging Across Multiple Networks
Extends Networks Seamlessly.
products take our radio agnostic, Radio Frequency (RF) Agility one step
further. The "RF robot" software runs
at a radio-abstracted layer: the same
mesh control software supports
radios operating on different frequency bands and protocols.
Fig 4: Configurable Board supports up to 4
Fig 5: Interoperability between 5 GHz and 2.4 GHz sub trees
Fig. 4 shows how this level of flexibility is leveraged in the MD4000 Modular
Mesh Products. There are 4 mini-PCI slots on the board, two on the bottom and two on top. Each of the four slots can house a different frequency radio. This opens up some interesting possibilities including 2.4 GHz backhaul systems being part of a mesh with 5.8 GHz backhauls.
Since the service and backhaul radios are distinct, it is possible to use a service radio to bridge over from a 5.8 GHz backhaul to 2.4 GHz backhaul – as shown in Fig.
5. The 4325 Mobility Relay node on the bottom left has joined the mesh – even though the upper links are 5.8 GHz (blue
) – through the service radio (pink
(Click on Figure to Enlarge).
New mesh requirements (more hops to cover larger areas, more efficient bandwidth distribution, better latency and jitter for Video and VOIP) have given rise to the Third Generation of mesh architectures. Third Generation multi-radio backhaul architectures deliver the higher bandwidth and more-deterministic performance necessary to meet these new requirements.
Software-oriented approaches based on distributed dynamic radio intelligence support frequency agility, automated channel selection, dynamic topology configuration, and radio agnostic meshes, provide more effective single framework solutions for larger scale and diverse application environments.
This combination of features delivers higher performance but is also opening
many new applications for wireless mesh, see:
The Abstracted Network for Enterprises and the Internet of Things