Connect802 can help with the selection and system design for many manufacturer's Wi-Fi Wireless Mesh Router and Bridging equipment. We understand Mesh Router technology, point-to-point and point-to-multipoint wireless bridging and we know how to build a system that will meet your requirements.
If you have questions, please don't hesitate to call us today! We'll be happy to provide you with any technical explanation that you need to help you assure a successful wireless networking deployment.
Typical 802.11 wireless mesh router and wireless bridging applications relate to the support for distributed devices or applications such as video surveillance or building-to-building (wireless) Ethernet connectivity.
Instead of using Ethernet cables to create an infrastructure framework into which the various computers, printers, and other devices attach in a network, Wi-Fi can be used to build the infrastructure. Mesh routing provides a mechanism by which a wireless alternative to Ethernet cabling is deployed. Connect802 offers a variety of options for Wi-Fi infrastructure, from our turnkey Connect EZ Infrastructure Turnkey Wireless LAN Bundle, to custom-designed RF repeater clouds and mesh routers, bringing fault-tolerant wireless Ethernet connectivity to places that were previously thought of as unreachable. Questions? We've got you covered.
Wi-Fi connectivity is most often though of as being a way for a client computer, like a notebook computer, to communicate back to a wired Ethernet network (and the Internet) through an 802.11 access point device. Wi-Fi radio links can also be used to take the place of traditional Ethernet cabling when pulling a cable just isn't practical. Consider these situations where it would be prohibitively expensive, or simply impossible to install Ethernet wiring:
Historic buildings where walls and floors can't be drilled or defaced
Airports and other large venues where the nature of the building prevents pulling cables
Hotels and other commercial buildings where installing cables would be tremendously complicated and could be disturbing to the people in the building
Linking buildings where trenching cabling underground or stringing cable overhead is not an option
Any outdoor installation where it would be unreasonable to use 100-meter lengths of Ethernet cable and intervening repeaters to stretch across a wide area
Any outdoor installation where it would be impossible to run cables, for example: across an interstate highway, a river, or (as was encountered by the engineering team at Connect802) up the side of a mountain to a ski cabin in the woods!
Why Are Four (and Sometimes Three) Mesh Routers Required?
If you needed to connect two buildings across the street from each other you could use two Access Points with WDS or you could use two Mesh Routers. There is no advantage to using Mesh Routers in this scenario. They're more expensive than Access Points (because they're more sophisticated). The only exception might be if the Mesh Router choice operated at a higher power level than you could obtain with an Access Point. This is only an issue at distances greater than 2000-feet Line-of-Sight and that's what the Connect802 Connect EZ Predictive RF CAD Design can ascertain.
Creating a link with two Mesh Routers offers no fault-tolerance or redundancy, the single-most fundamental differentiator for Mesh Routing over WDS. That's because (of course) if one of the two Mesh Routers fails then the link fails. One could consider using a third Mesh Router, but that only provides redundancy for ONE of the two other Mesh Routers. If the building on the North side of the street has one Mesh Router and the building on the South side of the street has two then you've still go a single point of failure (if the North Mesh Router fails the link fails).
In this scenario you would need two Mesh Routers on each building for redundancy and fault-tolerance
Mesh may use the protocol called AODV ( Ad-hoc On-demand Distance Vector) to build routes using a broadcast "route request" packet that attempts to locate the best path to a particular destination. In large networks the impact of this broadcast traffic can be significant. An alternative mesh routing protocol known as DSDV (Highly Dynamic Destination-Sequenced Distance-Vector Routing) in which nodes (mesh routers) intermittently send routing information updates to their peers.
When considering an outdoor, point-to-point or point-to-multipoint mesh router configuration you must take into consideration the required height above the ground at which you'll need to mount your antennas. It's a wonderful thing that wireless network sales and marketing folks talk about how their product has a range of "40 miles" (and many of the outdoor Wi-Fi LAN bridge, mesh router, and wireless network equipment vendors do make those valid claims). No matter what kind of antenna you use, and no matter what the power output of a device may be, if you're antenna is only 10-feet above the ground then you're just not going to reach out more than 7 or 8 miles, and that's assuming a clear line of sight (LOS). This is because the earth curves away from you, and the microwave radio signals don't curve with it. Calculating earth curvature is a key element of outdoor wireless networking.
In a radio mesh network , each wireless device is capable of acting as a router as well as an end station; it not only transmits and receives data for itself but passes on data for others as well. As long as you are in range of another device you have coverage. The more devices the better the coverage. Mesh networks may involve either fixed or mobile devices.
The principle is similar to the way packets go around the Internet , data will hop from one device to another until it reaches destination. Dynamic routing capabilities included in each device allow this to happen. To implement such dynamic routing capabilities, each device needs to communicate its routing information to every device it connects with, "almost in real time". Each device determines what to do with the data it receives. Either pass on to the next device or keep it. The algorithm used should ensure that the data takes the "most appropriate route".
The choice of radio technology for mobile mesh networks is crucial. In a traditional wireless network where laptops connect to a single access point such as in WiFi , the more laptops connected the less bandwidth available. This is because the devices share a fixed bandwidth amount. With mesh technology and adaptive radio, devices in a mesh network will only connect with other devices that are in a set range. Like a natural load balancing system the more devices the more bandwidth available, provided that not too many hops are taken in the average communications path. However, in many naive wireless mesh implementations, the hop count increases as the number of nodes increases, leading to severe scalability problems.
To prevent increased hop count from canceling out the advantages of multiple transceivers, one common type of architecture for a mobile mesh network includes multiple fixed base stations with "cut through" high-bandwidth terrestrial links that will provide gateways to services and the Internet and mobile devices that relay data between each other and to the fixed base stations. An operator deploying a mobile mesh network will only need to deploy a minimal base station infrastructure and will rely mostly on the devices to extend coverage. However, the "cut through" bandwidth of the base station infrastructure must be substantial.
