Re: [ipwave] draft-ietf-ipwave-ipv6-over-80211ocb-00 RSU term

[Jérôme Härri <[e-mail]>]

Following your feedback,

Whereas a full MIMO remains arguable at this stage (my personal view I have
to admit), as one would need to orient the beams and learn the channel state
which is constantly moving (basically tracking a vehicle), a key benefit of
having two antennas on a RSU (and actually on a OBU) could be antenna
diversity with space-time coding (e.g. 2x1). Unfortunately, OCB does not
allow this (and neither MIMO). So, multi-antennas so far can only be used
for multi-transceivers as far as I know. 

But as we aim at beyond DAY 2, we never know what the future holds...so,
having multiple antennas, with different patterns might be expected in the
future. We should leave it open. 

BR,

Jérôme
_____________________________________________
From: its [mailto:[e-mail]] On Behalf Of François Simon
Sent: Monday 13 February 2017 16:33
To: 'Alexandre Petrescu'
Cc: [e-mail]; [e-mail]
Subject: Re: [ipwave] draft-ietf-ipwave-ipv6-over-80211ocb-00 RSU term


Two Antennae: Multiple Input Multiple Output (MIMO) technology - The
antennas at each end of the communications circuit are combined to minimize
errors and optimize data speed.

Non-intersection RSUs:

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-----Original Message-----
From: Alexandre Petrescu [mailto:[e-mail]] 
Sent: Saturday, February 11, 2017 3:42 AM
To: François Simon <[e-mail]>
Subject: Re: [ipwave] draft-ietf-ipwave-ipv6-over-80211ocb-00 RSU term



Le 11/02/2017 à 01:30, François Simon a écrit :
> Both are arguable.
>
> a) Antennas:  Depend on applications.  In the picture, this is mostly 
> for intersections where OBE's transmissions comes from all directions.  
> An omni-directional is more appropriate for tolling applications.

If this is for intersection, then why are there _two_ antennas, each omni?
IT should be 180deg for each.  It makes no sense to put 2 omnis. 
One omni would be sufficient.

And do they have a figure which is _not_ for intersection? (i.e. for along
the road?)

Alex

> b) boosters on surge-suppressor......; I do not see the point.  I miss 
> the point.
> Fygs
>
> -----Original Message-----
> From: Alexandre Petrescu [mailto:[e-mail]]
> Sent: Friday, February 10, 2017 11:28 AM
> To: François Simon <[e-mail]>
> Subject: Re: [ipwave] draft-ietf-ipwave-ipv6-over-80211ocb-00 RSU term
>
> Thanks for the note.
>
> As a side note, note that omni antennas dont make much sense on pole 
> along roads - should be sector antennas.  This is a common mistake at many
sites.
>
> In addition to surge-suppressors one should use boosters too, to 
> extend reach.
>
> Le 10/02/2017 à 17:12, François Simon a écrit :
>> I would be very careful to replace RSU with RSR systematically 
>> (global change).  The figure below shows how, in the US, FHWA sees 
>> the implementation (one of several):
>>
>>
>> In this figure, the RSR is in the left hand bottom corner.
>>
>> Fygs
>>
>>
>>
>> -----Original Message-----
>> From: its [mailto:[e-mail]] On Behalf Of Alexandre 
>> Petrescu
>> Sent: Friday, February 10, 2017 5:34 AM
>> To: [e-mail]
>> Subject: [ipwave] draft-ietf-ipwave-ipv6-over-80211ocb-00 RSU term
>>
>> draft-ietf-ipwave-ipv6-over-80211ocb-00
>> RSU term
>>
>> Hello IPWAVErs,
>>
>> We received multiple comments about the RSU term.  The strongest 
>> issue is that apparently there are conflicts between our assumption 
>> of RSU to be a router and FHWA(?) thinking RSU is more like an 
>> interface to a router, or something like a master-RSU controlling
(slave?) RSUs.
>> Unless FHWA tells us they agree RSU is a router, I will modify the
>> following:
>>
>> Old:
>>> 2.  Terminology
>> [...]
>>> RSU: Road Side Unit.
>>
>> New:
>>> RSR: Road Side Router; an IP router equipped with, or connected to, 
>>> at least one interface that is 802.11 and that is an interface that 
>>> operates in OCB mode.
>>
>> and substitute RSR for RSU throughout.
>>
>> This old 'RSU' term, now RSR, is absolutely needed in the draft when 
>> discussing IP handovers and Mobile IP.
>>
>> Alex
>>
>>
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