Subject: [104attendees] Thanks and a question about Freedom Square ptp relay - for traffic lights or just for camera?

From: Alexandre PETRESCU <[email-masked]>
Date: Sat, 30 Mar 2019 21:23:28 +0100

Hello IETFers attendees of Prague 2019,

I was very happy to come back to Prague; I thank the organisers.  My 
meeting was very effective.

One of the reasons I came to Prague is because of my interest in 
vehicular communications.

As far as I know, Prague is probably the only city I could visit 
recently with IETF cities (e.g. Hawaii, Singapore), and among other 
smartcities (e.g. NYC), that uses point-ot-point relays for 
communication between lamp posts.  The point to point way of extending 
range is interesting compared to putting an IoT SIM device in each 
object talking to a single central server, in a hub-and-spoke manner.  
Such ptp manner is used usually along railways and highways in many 
places in Europe, but rarely if ever in cities.

The data of a lamp post is not huge, other than maybe the data generated 
by the camera sitting on it.  But this ptp system is also near traffic 
lights.

I wanted to ask somebody from Prague whether these ptp links are for 
traffic lights data, or just for the cameras?

Thank you in advance.

I could take this photo of this ptp antenna system, illustrated below.

It is situated at Freedom Square (namesty Svobody) in Prague. 
https://www.google.fr/maps/place/n%C3%A1m.+Svobody,+160+00+Praha+6-Dejvice,+Tch%C3%A9quie/@50.1007249,14.4003959,3a,75y,25.24h,99.08t/data=!3m6!1e1!3m4!1sBEh0g9MTUk85pUbJIrEAFg!2e0!7i13312!8i6656!4m5!3m4!1s0x470b95243c98dcfb:0x697ce639304df973!8m2!3d50.1010657!4d14.3997911

-- 
--
Alexandre Petrescu NYC,
[email-masked], tél 0169089223

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From: Ondřej Caletka <[email-masked]>
Date: Sat, 30 Mar 2019 22:59:18 +0100

> places in Europe, but rarely if ever in cities.

Traffic lights controllers are certainly connected by underground
cables, unless it's a temporary installation. And in the case of
temporary installation, it's rarely controlled remotely.

This looks like backhaul for the CCTV system, probably operated by
municipal police. Certainly no commercial subject would be allowed to
put such devices into the public space. There are strict rules – no
overhead cables, carefully placed technology, etc., which can be only
broken by the city itself "for better good". So I'm not so excited about
seeing such wireless links on every other post.

We also have lots of IoT SIM cards everywhere, like in Wi-Fi-enabled
tram/bus stop shelters, Wi-Fi-enabled trams, parking meters or "smart"
benches. There is also some kind of traffic telemetry system with small
cameras on lamp posts measuring traffic intensity by picture analysis. I
guess the capacity of LTE network is not sufficient for CCTV operation.

Anyway, I'm glad you liked the city. See you again in two years ;)

--
Ondřej Caletka