[OLPC-AU] XO 1.5 and Mesh networks

[James Cameron]

On 07/10/2010, at 9:14 PM, Peter Williams wrote:
> Just a short question.  Am I correct in saying in a course we are
> developing for OLPC that mesh networks in the XO 1.5s need an access
> point and that meshing between 1.5s without an access point   Is not
> possible as it was with XO 1.0s.?

No, this is not correct.  It is however a common understanding.  Please take care not to conflate the concepts in your training material, and be specific.  Identify what works now.

"mesh" technically means a laptop that is routing packets for other laptops.  But the term has ended up meaning peer to peer collaboration without infrastructure.  These are different functions.

On XO-1 in the stable release os802 8.2.1, and os852 10.1.2, we provided an IEEE 802.11s style of implementation for peer to peer without infrastructure, which also did routing of packets for other laptops.  (Implemented in the wireless device firmware).

On XO-1.5 and XO-1 in the stable release os852 10.1.2, we provided an IEEE 802.11g ad-hoc implementation for peer to peer without infrastructure, which did not provide routing of packets for other laptops.

On XO-1 in the stable release os802 8.2.1, and os852 10.1.2, the IEEE 802.11s style of implementation was initiated by clicking on one of the concentric circle icons in the neighbourhood view.

On XO-1.5 in the stable release os852 10.1.2, the IEEE 802.11g ad-hoc is initiated by right-click on the frame device icon for network, and choosing "Create new wireless network".  See http://wiki.laptop.org/go/Ad_hoc_networking

The XO-1 and XO-1.5 will easily collaborate provided the XO-1 is upgraded to os852 as well, and the XO-1 user avoids the concentric circle icons.  This is briefly covered in the release notes: http://wiki.laptop.org/go/Release_notes/10.1.2#Under_the_tree_is_not_automatic_when_mixing_laptop_models

Now, an especially important reason to separate the concepts is that on XO-1.5 the situation may be about to change:

1.  The IEEE 802.11s style implementation which is missing on the XO-1.5 might be completed ... our Wiki shows that there is activity towards this <http://wiki.laptop.org/go/Thinfirm_1.5> but it is not yet available in a stable build.  If and when it is, the XO-1.5 will have the same or similar capability to route packets on behalf of other laptops.

2.  The user interface for starting Ad-hoc mode might be completed ... our bug tracker contains http://dev.laptop.org/ticket/9845 "Alternative to Create a new wireless network." which has reached a point where icons have been placed in the neighbourhood view for starting ad-hoc network mode rapidly.

(Combining these two suggests that on XO-1 you'll have a set of concentric circle icons for XO-1 under a tree collaboration, and that on XO-1 and XO-1.5 you'll have a set of mayan numeric icons for the same thing.)

--
James Cameron
System Test Coordinator
One Laptop per Child