Page 39 May June 2014 TCA

THE BROADBAND HIGHSPEED AMATEUR [RADIO]
MULTIMEDIA NETWORK (BBHN HAMNET)—PART 1

Special thanks to Dana Shtun, VE3UK, node and vice versa; plus you don’t have wireless blind spots, or when paired with
Steven Kavanagh, VE3SMA, Barry Malowanchuk, to worry about nodes affecting things as another node, provide a wireless Access
VE4MA and Industry Canada for their help. they come and go. However, and this is Point (AP) (see Figure 2 on the next page).
What do hydro smart-meters, cellular phone the 800 pound gorilla in the room, if the A Mesh network is self-organizing and
systems, and the BBHN have in common? spoke between you and the ISP fails, self-healing. If a node leaves or joins the
They are all examples of wireless mesh you’re cut off from cyberspace. Even network, the Mesh automatically
(like fshing nets or gauze bandages) worse, if the hub fails, everything, reorganizes the OSPF routing, and a node
networks, very intelligent and autonomous, everywhere stops, and all nodes are only needs to “see” its next node
but not quite self-aware like “Skynet” cut off! (see Figure 1 below) neighbour to have access to the entire
(from the Terminator movies) – yet! On the other hand, a Mesh network has Mesh. As long as you don’t overload it
Mesh networks are used anywhere you no central hub or specifc routing to/from (multiple nodes streaming HDTV video
need to provide wireless fdelity (Wi-Fi) nodes and is very portable and malleable. isn’t a good idea), a Mesh network can
or wireless local area network (WLAN) A commercial version was brought in after move large amounts of high-speed data,
digital communications. the 2010 Haitian earthquake to re-establish but it has one major weakness because
NETWORKS: INTERNET VS MESH digital communications in the Port-au-Prince you need several nodes to establish it
area. and more to expand it. However, it is
The Internet is a “hub-and- spoke” or “star” well-suited for specifc and/or essential
network. There’s a central hub (server) A Mesh network uses Open Shortest Path tasks such as public service events or
with “spokes” (like a wheel) that radiate First (OSPF) routing whereby all nodes are emergency communications (EmComm)
out (like a star) to individual users (clients). in constant communication with each covering a local area when/where
The spokes are combinations of transceivers, other to move data (video, audio, commercial systems are not available.
landlines and other “black box” technology pictures, text, email, fles, etc.) effciently
connecting an Internet Service Provider and expeditiously. More importantly, any Note: A node can also act as an Internet
Gateway for the entire Mesh, but providing
(ISP) to your router (node). Star networks node can act as an ad hoc server – for Internet connectivity is not the primary
are fxed in place and are not very easy to example, a webmail server with Winlink purpose of the BBHN since it’s usually
move, but they can exchange huge amounts 2000 (WL2K) radio email connectivity – deployed when you don’t have Internet
of high-speed digital data between any or act as a stand-alone digipeater to fll in access.

Figure 1: Mesh & Hub-and-Spoke (Star) Networks
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