OpenHardware

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abstract

On, July 10th, 2007, we had a fantastic 3 hour workshop at the SAX event (WSFII guifi.net Catalunya), with more than 20 participants from different european and us projects on open wireless hardware. The task was to distinguish how "Open Hardware" could be defined and to describe two kinds of accesspoints, a very simple one - a simple node - and a more complex one, which people in Catalunia call a super node.

aim

The aim of these definitions shall be, that they can be given to various hardware manufacturers in the world, hoping that one or more of them are going to build these devices and for Do-it-yourself (DIY) building (in a similar way to other hobbyist fields, as robotics) . We are all very positive that the various free wireless communities around the globe will make extensive use of these devices.

definition

The definition of Open Hardware was defined to be a system that runs a free open source software (FOSS) based operating system with full FOSS driver support for all included components, plus a freely available complete documentation on the entire hardware and its design.

The device should be shipped with a FOSS operating system. Amongst the attendees of the workshop the most preferred OS would be OpenWrt plus a nice and well designed webGUI on top of it.

Regarding the prices, these systems should be as inexpensive as possible at the places they are used, which might also be achieved by special distributions in bigger charges with less packaging (10,50,100 boards in one box) for communities.

Simple Node

  • single wireless a/b/g radio device with support for virtual access points
  • single Ethernet port with high tolerance PoE support (4-30V)
  • power system must resist reverse polarity
  • 4 Mbyte Flash
  • 16 Mbyte RAM
  • 200 MHz CPU
  • serial port
  • JTAG interface
  • one Antenna plug (reverse SMA) and no explicit need for diversity
  • for outdoor usage (which is regarded to be a standard scenario) the board does not need a box and does not need to be shipped with antenna and power supply
  • power consumption should be as low as possible (solar systems!)

Comment: Finding the consensus on the design for the simple node was quite easy and did not take very long. It seems that the needs and wishes of the different groups represented by the attendees are very similar.


Additional note: An outdoor metal box with an integrated 1/4 lambda lightning protection element would be perfect. Kinda like this, but with a cheaper 1/4 lambda element integred instead of the extra gas element. http://www.tenda.cn/upfiles/2007526105643.jpg

Super Node

  • two embedded wireless a/b/g radio devices with support for virtual access points
  • two Ethernet ports with standard 802.3af PoE support
  • power system must resist reverse polarity
  • 8 Mbyte Flash
  • 32 Mbyte RAM
  • 500 MHz CPU
  • two USB 2.0 ports
  • two miniPCI slots (both stackable up to 8 cards)
  • serial port
  • JTAG interface
  • two Antenna plugs (reverse SMA) and no explicit need for diversity
  • for outdoor usage (which is regarded to be a standard scenario) the board does not need a box and does not need to be shipped with antennas and power supply
  • power consumption should be as low as possible (solar systems!)

Comment: Finding a compromise on the super node really was a hard time, because there can be different ways to achieve the same goals. For example, if wireless USB devices had a better FOSS support, many of the super nodes could just easily be built without the need for miniPCI. Also super nodes can be built with simple wireless bridges connected over ethernet (high power consumption?). But anyway, after many looong discussions the group had a consensus on the points listed above.

Wireless USB devices

As already mentioned, super nodes could well be build using wireless USB devices instead of mini PCI cards (less expensive cabling, less interference between the devices). But to be able to use them, people need FOSS drivers for them, which support all wireless modes (managed, ad-hoc, AccessPoint), and the USB devices should have a reverse SMC antenna connector.

- JuergeN -

This include USB modems (see Huawei E220).

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