Wireless sensor networks

Zigbee networks have this wonderful capability to self-heal, which means they can reorder connections between them if one of them is inoperable. This works our of the box when you deploy them. But you have to have in mind that achieving this is not as easy as you would think. None of it is plug&play. So to make your life a bit easier, here are some pointers which, I hope, will help you.

• Be careful when you are ordering your equipment abroad. There are many rules and regulations you need to comply before you get your Xbee radios. What they do is they wait until you prove that you won’t use the technology for some kind of evil take over control of the world project :). For this, they have EAR (Export Administration Regulations) which basically means “This product may require a license to export from the United States.”.
• I don’t know if this applies for every country, but when we purchased our Xbee radios from Mouser, this was mandatory! What we needed to do was to print out a form and write information about our company and send them a copy via email. With this document, we proved that we are a legitimate company.
• When you complete your purchase and send all the documentation, you are not clear yet. Then customs will take it from there :). There will be some additional costs. Before purchasing, make sure you have as much information about costs as possible. Because it can get costly in the end.
• I suggest you use companies from your country. You can seriously cut your costs. Here in Slovenia, the best option so far as I know is Farnell. And based on my personal experience, they rock! All I need to say!
• Make plans when ordering larger quantities. Do not, I say, do not make your orders in December! :) Believe me! You will have problems with stock they can provide for you. So, we were forced to buy some things from Mouser, which was extremely painful because of all the regulations you need to obey when importing goods from the USA.
• Make sure that firmware version on your Xbee radios is exactly the same! Do not get creative!!! I propose using templates. You can get template by exporting settings/profile in X-CTU application. Make sure you have enabled “Upgrade firmware” so you can be sure each radio has the same firmware.
• And again: make plans! Plan everything! In months advanced! You will thank me later :)
• Test, test, test. Wireless networks can be tricky.

If you are serious, I suggest you buy this book, Building Wireless Sensor Networks. You will get a glimpse of how networks work in lumens terms. It is a good starting point for everybody who wants to build wireless networks.

Additional resources:

• http://www.digi.com/aboutus/export/generalexportinfo
• http://doresearch.stanford.edu/research-scholarship/export-controls/export-controlled-or-embargoed-countries-entities-and-persons
• http://www.bis.doc.gov/licensing/exportingbasics.htm