Free Software defined radio cannot pass FCC regulations by nature

Posted Jul 9, 2007 10:34 UTC (Mon) by tialaramex (subscriber, #21167)
In reply to: Free Software defined radio cannot pass FCC regulations by nature by pascal.martin
Parent article: A green light for free-software defined radio?

That's not true, the only thing you could do if you obeyed "the most strict regulation" is remove all radio transceivers from your design. Several small, uninteresting countries have an almost total ban on civlian radio equipment.

What actually seems to happen is that vendors try to ensure that they can meet the letter of the law for a few major markets, such as the US, UK and Western Europe and Japan. Other countries will either certify or not, and if necessary the product won't be officially available in those countries, though if it's popular of course it will enter on the grey market.

They can meet the letter of the law by for example including a different driver CD with a different uploadable firmware for US vs European markets, in the US the driver sets a register to say 0x01, while the European driver asks during installation what country it is in, and chooses one of 0x02, 0x03 or 0x04 according to local regulations. Different radio frequencies are "not available" in software depending on which value is set.

In my country some of the 802.11 frequencies are "not available". Most wireless devices bought here can detect networks on these frequencies but will refuse to connect to them, inevitably some people (the same sort who think NAT is a security feature) see this as a way to control access to their network, they modify a wireless hub by overwriting the firmware to think its in Japan, and then make a registry change or similar small alteration to the software on PCs that connect to the network. Perhaps it may cause interference with safety-of-life critical radio systems here, but no-one cares about that.