[Tinyos-devel] two zigbee implementations

Thu Jul 24 14:20:04 PDT 2008

Although we are not SC, net2 discussed the current proposals for 15.4
and Zigbee WGs, and our recommendation is to form two WGs.

Our concern is 15.4 WG, as it is proposed, would have people
exclusively from Berlin. Zigbee WG, as it is proposed, would have
people exclusively from Porto.

An excerpt from the page on working groups
(http://tinyos.net/scoop/special/working_groups) states:

"While not a requirement, the SC strongly encourages that the initial
member list include multiple perspectives. Working groups bring people
together to work on a topic collaboratively; ideologically exclusive
groups are contrary to this goal."

We think there are good reasons why we want people from different
perspectives to be in a WGs and we would like to see this tradition
given a continuity. Or we should discuss why these proposed WGs should
be exceptions.

- om_p

On Thu, Jul 24, 2008 at 8:15 AM, Mário Alves <mjf at isep.ipp.pt> wrote:
> Dear all,
>
> As an additional input to your decision, I had contacted Gianluca Dini (U.
> Pisa, gianluca.dini at ing.unipi.it) and he just confirmed their interest in
> contributing to the security and application layers.
>
> Looking forward to read from you,
>
>   Mário
>
> Mário Alves wrote:
>
>> Hello again,
>>
>> Porto's research activities that might become interesting contributions to
>> the TinyOS community (i.e. involving implementations/validations over
>> TinyOS) go much in the direction of:
>> - MACs: namely IEEE 802.15.4-based and dominance-based
>> - network level architectures/topologies/protocols: namely ZigBee-based
>> (Mesh, Cluster-Tree and variants) and Hexagonal
>>
>> Inherent to all these research efforts, issues such as energy/timing
>> efficiency, reliability and mobility are of primary importance for us.
>>
>> Application (AL) and Security (SL) Layers (in ZigBee or any other
>> protocol) are not considered in our research agenda at this point.
>> Therefore, we keep our availability to join the WGs you decide, even as
>> leaders/chairs, but if the ZigBee AL and SL are to be addressed, additional
>> human resources and skills would be required.
>>
>> Cheers,
>>
>>   Mário
>>
>>
>> David E. Culler wrote:
>>
>>> My theory is that if the working group has a focus and direction that
>>> people are enthusiastic about critical mass will form around it.  If it is
>>> buried in existing groups that already have a lot to do, it will bump along
>>> sub-critical.  The primary determiner is some people to step forward to
>>> chair or co-chair.
>>>
>>> Assuming that happens, there will be some interesting points of
>>> intersection.  Specifically,
>>>
>>> 1. If an 15.4 LP MAC group forms and produces a high quality MAC it would
>>> be natural for NET to put its protocols on top of it.  Thus, it would make a
>>> lot of sense to get buy in on the proposed MAC design before a huge amount
>>> of work goes into implementing it.  If, in addition, a Zigbee group forms
>>> and if that group is implementing the Zigbee mesh protocol, it would have a
>>> similar interest.
>>>
>>> 2. If a Zigbee group forms, it will need to make some decisions about how
>>> it utilizes the work of other working groups.  Does it utilize NET protocols
>>> or implement an additional one.  If a new mesh protocol is done, perhaps
>>> that would best be done jointly with NET, so it can leverage a lot of the
>>> same substructure.
>>>
>>> Even with joint activity on the mesh protocol, there is plenty of other
>>> stuff for the zigbee working group, as most of the implementation goes into
>>> the ZAPS and ZCL upper layers.  Indeed, these layers could be hosted over a
>>> variety of transports.
>>> Most of these issues would naturally be clarified in the working group
>>> charter and membership documents - assuming folks step forward to kick off
>>> the groups.
>>>
>>> D.
>>>
>>> Mário Alves wrote:
>>>
>>>>
>>>>
>>>> Philip Levis wrote:
>>>>
>>>>>
>>>>> On Jul 11, 2008, at 9:44 AM, David E. Culler wrote:
>>>>>
>>>>>> So, volunteers permitting, I would most like to see option 1.  Core
>>>>>> should remain Core.  These other WGs should push Core to enable them.
>>>>>>
>>>>>>
>>>>>> Omprakash Gnawali wrote:
>>>>>>
>>>>>>> Enumerating the options:
>>>>>>>
>>>>>>> 1. 15.4 WG. Zigbee WG.
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>> I agree in theory -- the only drawback to this breakdown is whether
>>>>>  there's enough critical mass for working groups to form around the  topics.
>>>>> This historically is why tasks like 15.4 and zigbee have  fallen under
>>>>> existing WGs (core and net2, respectively); doing so gave  the developer
>>>>> (each had a single developer) a group of other folks  working on somewhat
>>>>> similar problems with whom they could talk and  collaborate. That being
>>>>> said, now that WGs have moved their  discussions to -devel, this might be
>>>>> much less of an issue than it  once was.
>>>>>
>>>>> Phil
>>>>>
>>>> Honestly, I see relevant points in both David's and Philip's comments.
>>>>
>>>> Note that our (Porto) work goes far beyond the default IEEE
>>>> 802.15.4/ZigBee protocols as defined in their standard specifications. We
>>>> have been proposing, implementing and validating new mechanisms to enhance
>>>> their behaviour and that are backward compatible with their standard
>>>> specifications.  So, not only the "default" protocols will be available
>>>> within the TinyOS community, but also these add-ons.
>>>>
>>>> Surely there is no sense of forming WGs with only one
>>>> contributor/institution each. Thus, if there are neither enough momentum nor
>>>> critical mass (at least 3-4 contributors/institutions), there is no
>>>> motivation for the (new) 15.4 and ZigBee WGs to see the light. Even if such
>>>> a critical mass exists, I wonder if a separate ZigBee Working Group should
>>>> be formed. Then why not creating separate WGs dedicated to ISA SP100,
>>>> WirelessHART or 6LoWPAN? Moreover, looking at the other existing TinyOS WGs,
>>>> they all (unless eventually 8051) seem quite broad (core, net2, sim,
>>>> testbed,...). Thus, if keeping ZigBee within the Net2 WG is not an option, I
>>>> would go for just one new 15.4/ZigBee WG (Option 3 of Omprakash).
>>>>
>>>> Ultimately, the final decision should be taken by TinyOS management
>>>> people, who have a more integrative view of what is being done by what WG
>>>> and also about future directions that should be followed.
>>>>
>>>> Cheers,
>>>>
>>>>   Mário
>>>>
>>>>
>>>
>>>
>>>
>>
>
> --
> ==========================================
> Mario Ferreira Alves
> e-Mail: mjf at isep.ipp.pt
> Polytechnic Institute of Porto (IPP)
> School of Engineering (ISEP)
> Rua Dr. Antonio Bernardino de Almeida, 431
> 4200-072 Porto, Portugal
> ------------------------------------------
> IPP-HURRAY! Research Group/CISTER Research Unit
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> Fax: +351 22 8340509
> ------------------------------------------
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