Wireless Mesh Networks
Why Mesh?
Solves the Range vs. Data Rate Dilemma
The physics of broadband
wireless communications stipulates that trade-offs between data rate and radio
range for any given transmitter power output have to be made. That is, for a
specified transmit power, the data rate available (i.e. throughput) will
decrease as range from the transmitter increases. This is true for any radio
modulation or protocol. Once a radio reaches the maximum allowed power level, it
must start dropping data rates to increase transmit distance.
Transmit power is typically limited by regulation or available battery power on the end users device. This is why cellular (centralized) networks offer high data rates close to the cell or access point, but much lower rates as you move even a short distance away. The same physics explains why the downlink data rates (from the high power cell to the mobile user) are much higher that the uplink (from the low power mobile user to the cell) in cellular systems.
Meshing, on the other hand, offers both long end-to-end range and high data rates by hopping through a series of intermediate nodes. Since the distances between each node (i.e. hop) is relatively short compared to the distance between the end transmitter and receiver, each hop can be completed at much higher data rates than is possible with a direct connection. This creates an end-to-end connection that supports high downlink and uplink data rates over very long distances. In other words, meshing lets you have both higher data rates and longer range by making radio physics work for you, not against you. This phenomenon can used to enhance any personal area, local area and wide area radio technologies.
Improved Spectral Reuse
Since nodes in a mesh network transmit
over much shorter distances (via hopping through intermediate nodes) than is
typical in cellular or centralized networks, they also transmit at much lower
power levels. This reduces system wide interference and enables spectrum to be
reused with greater density.
Non-Line of Sight and Congestion Mitigation
Hopping through
intermediate nodes allows mesh networks to route around obstacles and local
network congestion.
Technology Overview
MeshNetworks' technology is the most widely deployed and powers the largest mobile mesh networks in the world.
MeshNetworks Enabled Architecture (MEA™) technology leverages patented and proven routing techniques originally developed for battlefield communications. By pushing intelligence and decision making to the edge of the network, high performance and scalable broadband networks can be built at very low cost.
Mesh Networking 101
Mesh networking is typically implemented in
two basic modes: infrastructure and/or client meshing. To gain the maximum
benefit that meshing can offer, both modes need to be supported simultaneously
and seamlessly in a single network.
Infrastructure meshing creates wireless backhaul mesh among wired Access Points and Wireless Routers. This reduces system backhaul costs while increasing network coverage and reliability.
Client meshing enables wireless peer-to-peer networks to form between and among client devices (i.e., end users) and does not require any network infrastructure to be present. In this case, clients can hop through each other to reach other clients in the network.
MeshNetworks Offers a Complete Solution
MEA technology supports
both infrastructure and client meshing. MEA’s infrastructure meshing creates a
robust and scalable network, while client meshing enables end users to instantly
form a broadband wireless network among themselves – with or without the
inclusion of network infrastructure. In fact, MeshNetworks Multi-Hopping™
technology can turn every client device into a router/repeater. As users join
the network they improve network coverage and increase network throughput. MEA
networking is unique in that it supports Continuous Mesh™ routing. That is, it
supports simultaneous operation of infrastructure and client meshing while it
also allows clients to move seamlessly between infrastructure-based and
client-based peer-to-peer networks.
Self-forming, self-healing routing intelligence distributes clients between Access Points, eliminating bottlenecks and improving overall network performance. MEA technology also improves network robustness, as clients can hop to alternate Access Points if their current Access Point is congested or fails. It also lets clients form large, ad hoc peer-to-peer networks anywhere, anytime. Peer-to-peer networking reduces the demand on network Access Points, freeing up capacity for other users. All these capabilities create low-cost, seamless and simple to deploy wireless PAN, LAN or WAN solutions.
MeshNetworks’ Ad Hoc Networking Technologies
MeshNetworks Scalable Routing (MSR™)
The first core technology powering MEA solutions is MeshNetworks Scalable
Routing (MSR™) protocol. The MSR protocol is more than a routing algorithm, it
is a complete mobile ad hoc networking solution that can mesh enable any 802.xx
radio platform.
MSR technology utilizes an optimized and proven hybrid ad hoc routing algorithm that combines both proactive and reactive routing techniques. This enables support for high speed mobility, unmatched scalability and low messaging overhead. The result is a high performance solution that automatically adapts to varying network conditions, degree of client mobility and relevant RF environmental conditions on a packet by packet basis. Initially designed using high fidelity modeling, MSR has been optimized on large scale real world deployments.
Adaptive Transmission Protocol (ATP™) Service
The second core
technology leveraged by all MEA products is Adaptive Transmission Protocol
(ATP™) service. ATP services tightly bind the MSR protocol to the underlying
radio platform. It interprets platform specific RF parameters and provides a
radio agonistic, yet radio aware view of current RF conditions. It also works
with the MSR protocol to adapt and optimize route selection, data rate
modulation, and power output based on capabilities available on each specific
radio platform MAC and Phy implementation. ATP also detects and deals with
asymmetric RF links between nodes, a frequent occurrence in real world wireless
networks.
In short, MSR and ATP technology work together to create a cross-layer optimized mesh solution for high performance and self-configuring wireless networks. The intellectual property and techniques employed in these core technologies are protected by an extensive portfolio of patents.
For more information about MSR & ATP click here
Other Patented MeshNetworks’ Technologies
Quadarature Division Multiple Access (QDMA®) Radio Platform
As
part of its exclusive license to the ITT/DARPA mobile ad hoc networking
Intellectual Property and patent portfolio, MeshNetworks received the rights to
the Quadarature Division Multiple Access (QDMA™) mobile radio platform. The QDMA
radio is designed and optimized for mobile ad hoc broadband networking. Its
multi-channel MAC and Phy are optimized to meet the scalability and reliability
required in mission critical mesh networks. RF challenges encountered in wide
area mobile networks such as Doppler shifting, rapid Raleigh fading and
Multipath are handled efficiently by the QDMA radio. QDMA solutions have been
successfully deployed in Public Safety, transportation and Homeland Security
mobile data networks.
For more information about QDMA radio technology click here
MeshNetworks Positioning System (MPS™)
Some of the world’s largest Public Safety agencies are trialing
MeshNetworks Positioning System (MPS™) products as part of their MEA/QDMA mobile
broadband network solutions. MPS technology provides high precision position
location for outdoor and indoor applications – something GPS can’t match. And
unlike GPS, MPS software can be configured to provide position information to
the end user being located, as well as to neighboring users and/or central
network monitoring points. MPS is ideal for Search & Rescue, Asset
Management and Automatic Vehicle Location (AVL) applications.
For more information about MPS click here
MeshNetworks Technology Can Be Found in the Following Products:
MeshConnex Software Suite - High
performance embedded meshing networking software
MeshNetworks Digital ASIC - MEA routing
engine and QDMA baseband modem
MEA/QDMA product line - Turnkey
mobile broadband networking and location solutions
Info provided by;
http://www.meshnetworks.com/pages/technology/intro_technology.htm