Ben WPAN

Ben WPAN is a project to create an innovative patent-free wireless personal area network (WPAN) that is copyleft hardware. The primary protocol is 6LoWPAN, pronounced "SLoWPAN". The project lead is Werner Almesberger and it involves using the UBB, new testing software, and the Ben Nanonote to produce a next generation wireless personal area network.

Goals

• Ben Nanonote Connectivity
• Internet Connectivity
• Patent-Free Wireless Playground
• Use in Sensor Networks
• Use in Factory Automation

Reason

When you get wireless connectivity in a piece of copyleft hardware, we can expect it to:

• be able to incrementally improve or modify many more things than you typically could without the need of a large investment or a large team.
• be able to manufacture the same or an improved solution, because not only the result is published, but also the entire process. See for example the extensive test tools Werner created as part of the ben-wpan development, for antenna performance testing as an example.
• be able to verify whether the communication protocols embody principles you find valuable, to avoid interested parties twisting the behavior of the network in their favor (net-neutrality, Quality of Service, lawful interception).

These are the core things that you will uniquely and typically find in copyleft hardware wireless solutions. On top of that of course we still have to implement useful applications. At the application layer, to the user it often does not matter whether they use a proprietary or a free network. The user rightfully only judges whether stuff works or not.

We are quite optimistic though that once we unleash the Ben WPAN, we will in fact see the most spectactular new wireless applications on copyleft hardware for the very reasons listed above.

FAQ and Innovation

What applications are possible from the creation of Ben WPAN? What does the future look like?

The 6LoWPAN protocol (IPv6 over Low power Wireless Personal Area Networks) used in Ben WPAN is designed for industrial control and monitoring applications where very low cost and power consumption are important. The future of computing is already towards lowering power consumption with an explosion of growth in mobile computing. The future is bright for Ben WPAN.

To call this Zigbee, do we have to pay a fee? Is the situation similar to the distinction between MESA and OpenGL?

If we called it ZigBee, maybe. But we shouldn't call it ZigBee, because it isn't ZigBee, not even ZigBee in disguise :-)

IEEE 802.15.4 is an open standard (specifications can be accessed without royalties, implementations are free from royalties (*)) for PHY and (bits of) MAC. Then you put the rest of your stack on top. This could be ZigBee, 6LoWPAN, or something else.

(*) Of course, with patents, there could always be issues. The standard explicitly warns that:

Attention is called to the possibility that implementation of this
standard may require use of subject matter covered by patent rights.
By publication of this standard, no position is taken with respect
to the existence or validity of any patent rights in connection
therewith. The IEEE shall not be responsible for identifying
patents or patent applications for which a license may be required
to implement an IEEE standard or for conducting inquiries into the
legal validity or scope of those patents that are brought to its
attention.

We don't know if contributors were asked to disclose any patent claims.

ZigBee is only royalty-free if not used for commercial purposes which makes it incompatible with the GPL and licenses with similar intent.

The good news about ZigBee is, as various sources assure me, that it is gradually being replaced by 6LoWPAN. From the original ZigBee stack, only the top is preserved, and 6LoWPAN (and IEEE 802.15.4) is used underneath. This basically means that ZigBee is becoming or has already become irrelevant except for those who specifically seek ZigBee compatibility.

6LoWPAN is an open standard, specified in RFC4944 and other documents. Standardization work is still on-going (IETF's process regarding IPR claims is interesting) IETF has many claims disclosed with regard to RFC4944 .

To the final question, no, Ben WPAN and Zigbee are not the same as the distinction between MESA and OpenGL.

Is freedom really innovation? As in we have the freedom to make our own WPAN?

Freedom is an enabler for innovation. Remember the dark ages , when all the best universities involved in kernel-level research could do was to obtain a SunOS academic source license, and distribute their work in the form of precompiled object files?

Is Ben WPAN ONLY innovative in Free Software circles?

IEEE 802.15.4 and 6LoWPAN are also used outside Free Software circles.

There's the Contiki project (still under an Open license, i.e., 3-clause BSD) that can provide a code base for 6LoWPAN and maybe some bits of IEEE 802.15.4 too.

And then there are many vendor-specific stacks. You just don't hear so much about 6LoWPAN because it mainly targets industrial systems and integrated solutions and is not advertised as a standard for consumer products.

Is there an innovation in the software development connected to the linux kernel, mesh networking or some other non-process-based innovation?

At the moment, no. We don't even have proper support for the stack in Linux yet, let alone in mainline. So there's still a bit of work left to be done.

Or, are we caught just doing the same thing that is happening in industry, but without any money?

Before you can overtake the herd, you have to catch up with it.

Not having to start from zero should be a great benefit for any research/innovation project.

That is an unfortunate property of the current situation. Luckily, it's neither a prerequisite, nor has anyone here taken a vow of poverty. (Let's hope some sponsor reads this :-)

Is the Ben WPAN technology slow or slowfi?

ATBEN/ATUSB are not "slow." Slow is a cute term that makes better sense applied to radio technology such as HopeRF that works in lower frequency bands such as 800/900 MHz and indeed has low throughput, maybe 50-100 Kbps, while the basic radios Werner has made can deliver a megabit or better per second.

What would be the dream that can sell someone who is not a freedom advocate and is just interested in having connectivity? Is it simply so one can gain network connectivity to a hub, aka, get internet?

Connecting to the Internet is one application, although wifi to most people would make a LOT more sense. A more sensible use case is wireless connection between Ben (or any Linux computer) and one or many small. cheap sensor pods, such as Arduinos or similar cheap, low power intelligent units.

Ben has a display and keyboard, and Linux. It can operate as a "super node" talking to some number of dedicated sensor systems. The advantage of Ben is it requires very little power (easily fed by a small solar panel).

Connecting to the Internet is the primary use we have in mind. People who are building devices that need low-power and short-range communication may also find this technology interesting and may find a role for ATBEN/ATUSB.

Likewise, those who already have IEEE 802.15.4 devices may find a role for ATBEN/ATUSB.

We don't know enough about the industrial/sensor sector to venture a guess on whether ATBEN/ATUSB could be popular. There is a fair amount of activity in this area also in the Free Software community, e.g., with the Contiki OS. They also have a list of hardware they support or are at least aware of.

What range can we expect?

With my ATBEN/ATUSB prototypes, I've obtained good to acceptable BER for a distance between stations of 4-7 meters indoors in a residential area with relatively few interferences.

WPAN is designed for a radius of about 10 m. Some manufacturers of similar chips boast outdoors distances of > 100 m, but I'm not sure how reproducible such experiments are.

How many nanonotes could talk to each other at the same time?

This would mainly depend on the duty cycle of their application. If all they do is send a few bytes of sensor data every few hours, there could be tens of thousands nodes in a PAN. (PAN = Personal Area Network, the equivalent to a single LAN in WiFi terminology.)

Progress

Ben and Ben talking. [3:30 min, 14.9 MB]
(background info: the video was cut using the command-line melt utility from the MTL framework, sound track P97 made with Korg Kaossilator, scripts)

As of mid-April 2011, the hardware design is complete, and several hand-made prototypes of the two boards exist and have been shipped to people who may be willing to test the design. The two board are:

~~ ATBen: plugs into Ben's 8:10 port

~~ ATUsb plugs into a USB port on a Linux computer

Testing by the designer (Werner Almesberger, wpwrak on IRC) has succeeded.

http://Tuxbrain.net in Spain is getting price and delivery quotes for fabrication and assembly. If all goes well, early assembled units could be available during early Summer, 2011.

Note that things can and do go wrong. It's not over until it's over.

Also, a lot of software work still needs to be done. The driver level code for 802.15.4 has been demo'd. A production test program is working which verifies that a board is not severly compromised.

There are a small number of programs to send and receive data. However, there's still a lot to do in order to have a useable 6LoWpan stack.

Production Notes

PCB

As mentioned above Tuxbrain is leading the production of the first batch assessed by the project leader Werner. PCBs are already done and sent to SMT vendor to perform the integration of components; here are some pics of the PCBs.

• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 

Depanelization and Grinding

• 
• 

Production Test

The full production test process is described here: http://downloads.qi-hardware.com/people/werner/wpan/prod/

First Batch

• 
• 
• 
• 
• 
• 
• 
• 
• 
• 

Outcomes

This section is incomplete. You can help by expanding it {{{1}}}.