AREDN Mesh Data Network
In late 2019, RATS installed a 3-sector, 5 GHz AREDN mesh node at our repeater site in Chesterfield County. At the time, several other AREDN nodes were operating from sites in downtown Richmond, northwestern Hanover, and eastern Henrico County. This network made possible, for the first time in our area, the long-distance transport of data over amateur frequencies at broadband speeds with low latency. Testing from a privately-owned AREDN node south of Manchester, ping latency to the node in Beaverdam was frequently under 10 milliseconds round-trip.
For a variety of reasons, the RATS AREDN project stalled between 2020 and 2022. Many of the previous nodes are now offline, but the main 3-sector site in Chesterfield County remains on the air and ready for other nodes to link up. We're in the early stages of restoring service from a previous AREDN site in downtown Richmond, and additional privately-owned and operated nodes are planned.
The current Chesterfield node is situated 200 feet up the tower and represents a tremendous asset to the amateur community, as the starting point for a modern, high-speed data backbone dedicated to amateur radio communications.
What is AREDN?
From the AREDN project web site:
In today’s high-tech society people have become accustomed to different ways of handling their communication needs. The preferred methods involve short messaging and keyboard-to-keyboard communication, along with audio-video communication using Voice over IP (VoIP) and streaming technologies.
The amateur radio community is able to meet these high-bandwidth digital communication requirements by using FCC Part 97 amateur radio frequency bands to send digital data between devices which are linked with each other to form a self-healing, fault-tolerant data network. Some have described this as an amateur radio version of the Internet. Although it is not intended for connecting people to the Internet, an AREDN® mesh network will provide typical Internet or intranet-type applications to people who need to communicate across a wide area during an emergency or community event.
To connect to the AREDN network, a supported WiFi router or access point is reflashed with custom AREDN firmware and then aimed at another nearby node. AREDN nodes will automagically recognize each other and link up when in range. The AREDN firmware handles the routing of traffic to other nodes and services within the accessible portion of the network.
Since it uses Internet-standard protocols, a wide variety of familiar applications and services can be provided within the mesh.
Until AREDN came along, "data" over ham radio meant the sluggish transport of short messages and sometimes very small files using technologies such as packet radio or any number of sound card digital modes. With AREDN, broadband speeds enable real-time video conferencing, VoIP telephony, web and e-mail services, file sharing, video streaming, and much more.
AREDN is the next generation of amateur radio data services. It is the (literal) broadband replacement for dial-up-like protocols of yesteryear. It offers a familiar user interface -- web browser, common "Internet" applications, simple Ethernet hook-ups -- using hardware that is often less expensive and uses far less power than conventional packet, sound card digital modes, and similar technologies. AREDN enables the rapid transmission of images, videos, and other files, as well as real-time video streaming.
What AREDN is NOT
AREDN is not a replacement for commercial Internet services, nor does it (normally) provide general Internet access. It's not a way to check your GMail or Yahoo mail, watch YouTube, browse CNN, stream SiriusXM, update Microsoft Windows, or post to your Facebook, Twitter, Mastodon, or OnlyHams feed. You may recognize many of the applications and web-based services that do work and might be hosted within the AREDN network, but they're (generally) not communicating with the public Internet. Only users within the mesh can access these services.
The AREDN network does not have the capacity to handle general-purpose, unrestricted Internet access, much of which would likely occur over encrypted protocols which are not permitted on a Part 97 network anyway. General-purpose Internet access is outside the scope and spirit of the AREDN network and the amateur service, and RATS WAN gateways will not normally provide this functionality. RATS, or any user on the mesh network, may provide restricted connectivity for access to certain services like Winlink e-mail, network time synchronization, and outbound VoIP calling.
RATS Role in AREDN and our AREDN Roadmap
The role of the club generally, and the Technical Committee's AREDN team specifically, will be to facilitate the sustained operation of a reliable, quality, regional AREDN network backbone focused on central Virginia, and to offer the basic user instruction and support necessary to facilitate its continued growth. The club served a similar role with its build-out of regional APRS services in the mid 2000's.
The RATS Technical Committee is currently operating with a very conservative approach to spending, limiting spend to emergency repairs and critical system upgrades only. RATS will continue to maintain the club-owned Chesterfield node. A planned re-activation of a site in downtown Richmond will be 100% privately funded, as will any further build-out of the AREDN backbone through at least 2024.
The RATS Technical Committee's AREDN team serves as a volunteer coordinating entity for this regional mesh system. We encourage anyone considering construction of a high-visibility backbone site to coordinate with us on frequency selection and placement to ensure optimal network performance.
The build-out of AREDN is a multi-phase process. We are currently in Phase 1.
If you are within range of our Chesterfield site, all you need to do is install the AREDN firmware on some supported hardware and then aim it at our tower behind Chesterfield Town Center. There is plenty of great documentation on the AREDN web site and the RATS Technical Committee may also be able to assist.
At minimum, you'll need:
If your budget allows, we strongly encourage the addition of either a high-gain omnidirectional antenna, or one or more high-gain sector antennas, to provide fill-in service as a neighborhood node.
The Ubiquiti ISP Design Center is a great tool for modeling projected node coverage and checking for an unobstructed path to the AREDN backbone. You can get a general idea of expected coverage regardless of brand, make, or model of data radio and antenna you select, but you may need to experiment a bit if you're not using Ubiquiti equipment. The Technical Committee can assist with performing a link calculation given some parameters for your station. If you'd like to run your own, use these values for our Chesterfield node. This tool will help you determine how high you need to place your antenna to establish a reliable link to Chesterfield.
Grow the Mesh
If you are able to contribute vertical resources to the mesh backbone, we want to talk to you! We're looking for locations to install 5.8/2.4 GHz AREDN equipment to expand the backbone and local service footprint throughout the metro Richmond area. If you've got a tower at home or have a good lead on a facility that may be able to provide some rooftop or tower space for a 501c(3), please contact the Technical Committee.
Tunnel Access Available
You can extend the RATS AREDN system even if you don't have a direct line-of-sight to an existing node. AREDN tunnel access is available. Additional VPN connectivity options are also available. Contact us to make arrangements.
Join the AREDN Team
If you are a RATS member with an interest in IP networking, wireless mesh technologies generally or AREDN specifically, and especially if you have experience in these fields, the Technical Committee Chairman would like to talk to you.
About the RATS Chesterfield Node
The RATS Chesterfield AREDN node consists of three Ubiquiti Rocket M5 data radios, each connected to Airmax 120-degree sector antennas. The data radios and antennas are 200 feet up the WCVE-TV tower and are connected to the RATS repeater rack via Ubiquiti ToughCableCARRIER CAT6. Like the RATS repeaters, the mesh equipment is served by UPS battery and diesel generator power.
Above: Coverage projection for the W4RAT Chesterfield AREDN node, produced using the Ubiquiti ISP Design Center. Note that connectivity at 5.8 GHz is highly dependent on unobstructed line-of-sight and will require use of towers or other tall structures in the orange and yellow areas. [Zoom to City view]
Proposed - RATS Downtown Node (Service Restoration)
The RATS Downtown node will be a restoration of previous AREDN offerings, with 360 degrees of coverage from three 5.8 GHz sector radios. This node will have direct line-of-sight back to Chesterfield and will considerably expand the availability of AREDN services. Outlying communities benefiting from new or enhanced coverage will include Mechanicsville, Ashland, Varina, Chester, and Short Pump. This node will also fill in a coverage hole along the Rt 1/301/I-95 corridor in south Richmond.
The construction and maintenance of this node will be privately financed with no club expenses incurred. It will operate under the W4RAT call sign as a key part of the AREDN backbone in central Virginia. It will be equipped with emergency backup power.
Parameters for link calculations in the Ubiquiti ISP Design Center:
Above: Coverage projection for the proposed W4RAT Downtown AREDN node, produced using the Ubiquiti ISP Design Center.
Club Member Node - Manchester - Construction Pending
This privately owned and operated node will provide service on 5.8 GHz with a single omnidirectional antenna at a height of around 20 feet. It will provide fill-in service within a portion of a coverage hole in the Manchester area of south Richmond. This node will extend coverage of the Chesterfield node via VPN link to RATS equipment. Stations wishing to reach this node should consider a high-gain directional antenna at a height of at least 20 feet.
If/when the proposed RATS Downtown node is constructed, the Manchester node may be outfitted with a directional antenna pointed at Downtown. Once an RF path exists between Manchester and Downtown, Manchester will begin providing a redundant path between Downtown and Chesterfield for scenarios where there is path loss or congestion between those two sites.
Construction is expected to begin this summer (2023). This node will be equipped with battery and generator backup power.
Above: Coverage projection for the proposed KG4PEQ Manchester AREDN node produced using the Ubiquiti ISP Design Center.