Bob Metcalfe, the inventor of Ethernet, breezed into Barcelona last week, to deliver the keynote at NetEvents, a speed dating conference for networking vendors and computer journalists.

Metcalfe was the founder of 3Com; these days he is general partner a Polaris Venture Partners and a big fan of Zigbee, or 802.15.4, the upcoming cheap-as-chips wireless networking standard. Indeed he's such a big fan that his VC outfit has invested in some Zigbee start-ups and he is now chairing Ember Networks, a Zigbee mesh networking firm, which recently raised $25m. And of course, Metcalfe is a big enough fan to spend his NetEvents keynote spreading the word about the next wireless networking revolution.

Zigbee has the potential to connect up almost all electronic devices in common usage, Metcalfe told the conference.

The short-range networking system enables devices equipped with cheap and low-power Zigbee-compliant chips to seamlessly create ad hoc networks linking a wide range of devices.

"With Zigbee networked microprocessors you can link your lights with your cellphone. It is being promoted like Ethernet and applications include sensors monitoring power or lighting, medical devices and asset management like RFID," Metcalfe said.

"We are looking to get sub-$5 chips with a five-year battery life and a 50m range."

Zigbee devices can form star topology or even peer-to-peer local area networks, offering data rates of up to 250 kbps. The fully handshaked protocol technology supports up to 255 devices per network and operates using CSMA-CA channel access across 2.4GHz and 868/915 MHz frequency bands.

According to Metcalfe, around 500,000 Zigbee chips will ship this year, after the standard is ratified. Next year, the dams will open, flooding millions of chips onto the market. But how many? That's difficult to work out exactly, he says: "There are between five and 50 million devices estimated to ship next year. We just don't know how many and there are several reasons for this. There will be different market reactions and adoption rates are chaotic."

Zigbee devices will slot in to a wide variety of markets and this will create challenges for vendors, according to Metcalfe. "There is a big discussion with Zigbee on how to manage and configure it. If you have a switch to turn off nine lights at home how do you do this? Crank up the Cisco command line interface in your home to do this? Probably no."

The answer is different for different environments, he says. In the home, developing for consumers creates an "endless series of interface problems", because these users are not IT literate.

At the other end of the user spectrum, enterprises will face difficulties due to a lack of middleware which will be necessary for the complex management of Zigbee infrastructures, Metcalfe forecasts.

He acknowledges that there is confusion in the market over the potential impact of Zigbee technology: "We choose Zigbee because the domain name was available. There is confusion with Zigbee, Bluetooth and 802.11. A lot of potential adaptors are confused."

Security concerns have never been far away from Zigbee, Metcalfe said. "There are security concerns, both real and imaged. Security is a concern and designers of systems will put security in, and maybe it will work."

He is sceptical about the value of 3G. "The only g that matters is 802.11.g. There is Zigbee and they are putting 802.11 into cellphones coming out this year. This will create a real clash of cultures and be very disruptive. WiMAX is a further disruption running down the road.

Lastly, Metcalfe predicts that open source software will not displace Microsoft and traditional vendors, though he accepts that the distributed development model is spurring on established players. "I am not sure that open source is the model we are going to adopt, but it is very disruptive and pushing the established vendors." ®

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