I bought 4 Microchip's Picdem Z, but I can create only a tree network with the Miwi stack provided. If I use the Zigbee 2006 Stack I have to spend 3500$ O_O
So is there a constructor that provide a stack which works with big mesh topology ?
I can't develop my own stack, it represents too much work. That's why I'd want to know if a constructor proposes a free stack which support big mesh networks design.
I don't have a nodes limitation, so I'm opened to any suggestion.
If you intent to sell the product $3500 for the software is a bargain. You could not hire one decent software developer for a month for that and there are months if not years of work here.
I can understand why people want and think all software should be free. Open source software can only happen when there are enough interested and talented people to make it happen. (or some company willing to underwrite the developent cost)
Not that it will ever really come up but it is illegal and worse morally reprehensible to use an opensource code project like that for a commercial product without observing the terms of the GPL it's likely placed under.
I think it was Cisco, or maybe some Linksys routers that a lawsuit was going on about because it used busybox but violated the GPL licenses doing it.
It looks like you will not easily (if at all) find a Beacon Mesh network. If you do it may not be free.
The problem with using Zigbee in beacon mode is that you're limited to tree routing only. However tree routing is inherently unreliable because if you lose a router, you also lose all of the devices on the branches underneath the router.
On the other hand, if you use mesh routing, if one router goes down, you can do a route discovery and find an alternate path. This is (in marketing terms) called "self healing".
In fact, the current IEEE 802.15.4 and ZigBee specifications restrict the synchronization in the beacon-enabled mode to star-based networks, while it supports multi-hop networking using the peer-to-peer mesh topology, but with no synchronization.