[Commotion-discuss] Router brand/model suggestions?

Sun Jun 7 18:28:01 EDT 2015

Sorry for jumping on an older thread, but I'm going to offer some sharply
contrasting opinions to Andy's recommendations from a week ago.  These come
from putting up lots of 5.8GHz wireless backhaul links for WasabiNet.

"Generally, for outdoor service you want more centrally located
omnidirectional equipment, but you can also use wall-mounted omni or
directional access points for coverage."

Omni antennas are only going to be useful when you want to provide
360degree coverage over the immediate vicinity (e.g. w/in 30-50meters), and
directly to wifi clients like laptops or mobile devices.  Long distance
links effectively require the use of some sort of directional antennae, not
just to focus transmitted energy over a narrower area (aka longer range),
but also to reduce the of interfering noise received.  Also, as Andy
mentioned, you lose MIMO functionality using omnis, which can be become
critical if you need to use the noise-canceling features for long-distance
links to work in noisy environments.

360 degree coverage for long-distance links is achieved by putting up
multiple directional antennas on the same mast, rotated 120degrees from
each other (assuming antennas with 120degree beam width), and tuned to
non-overlapping channels.  This is actually why you see the antenna arrays
on mobile phone towers arranged so.

Since outdoor APs like the Nanostations from Ubiquiti are reasonably cheap
and easy to cable up, you get more effective use of the radios by hanging
multiple units in parallel and tuned to different channels.  For meshing
operations, this would mean having your mesh partitioned across multiple
channels.  But, that can actually be preferred in most circumstance, since
crowding a single channel with too many radios will mean crappy bandwidth
for all of them.

Here is a WasabiNet mast I recently had to redo.  There are two Nanostation
M5's that act as nodes on two 5.8GHz backhaul meshes, each on a different
channel and pointed opposite directions (i.e. bridging one mesh to the
other).  Also, there is a Nanostation M2 and an Nanostation M2 loco, both
also on different 2.4GHz channels, whose connectivity is provided by the
backhaul mesh.  Finally, I hung an additional Nanostation M5 Loco as a
spare, with its radio disabled.
https://plus.google.com/photos/+WasabinetGogogo/albums/5452670245024802561/6157749241444058114?banner=pwa&pid=6157749241444058114&oid=111527167238510651213

So, 5 radios total, and all are wearing shielding to reduce
self-interference (pre-fab RF Armor shields on the Nanostations, homemade
shields on the Locos).  This is actually pretty critical, since
self-interference can render co-located radios almost completely deaf.

Finally, as to using indoor gear like TP-Link products with DIY antennas,
do some research ahead of time on the cost of the pigtails and cable
fittings you'll need for whatever aerials you have.  These parts
unavoidably impart substantial dB loss on your signal, especially long
pigtails, and they can end up costing enough to make the total assembly
more expensive than a pre-fab equivalent.  Plus, you lose the convenience
of powering radios via POE, making the requirement of keeping pigtails as
short as possible very awkward if the antenna has to be mounted outdoors
somehow.

The integrated patch antennae on outdoor gear like UBNT Nanostation,
Nanobeam, etc, are extremely sensitive, since they forgo cable fittings and
use very short pigtails.  It can be quite difficult to replicate this
sensitivity with discrete, non-integrated antennae.  Indeed, I gave up on
crimping my own pigtails years ago since they were so lossy.

On Mon, Jun 1, 2015 at 9:44 AM, Andy Gunn <andygunn at opentechinstitute.org>
wrote:

> Great, more thoughts on this below.
>
> On 05/30/2015 09:55 PM, Jared Hoy wrote:
> > Thanks for the reply Andy. Good questions!
> >
> > The intent was an outdoor network with point to point and omni
> > directional or multi directional down tilt antennas. Though I
> > suppose indoor expandability would be a future consideration. So
> > the focus would be outdoor at this time, with indoor later on.
>
> Great - there are lots of options for equipment with that. Generally,
> for outdoor service you want more centrally located omnidirectional
> equipment, but you can also use wall-mounted omni or directional
> access points for coverage.
>
> > I would like to have the option of buying antennas or experimenting
> > with my own. For point to point it seems easier, cheaper, and
> > better to just purchase a small dish. I would like to use an omni
> > or patch on one connector with a dish on the other (any thoughts?)
>
> Building antennas can be a lot of fun, but can also be pretty fiddly -
> there are lots of resources, especially from amateur (Ham) radio
> operators. Search for resources on biquad and amos/quados antennas,
> such as:
> http://www.qsl.net/yu1aw/ANT_VHF/Amos_Ant/amos_antennas.htm
>
> http://www.scribd.com/doc/121631287/AMOS-Antenna-With-Semicircular-Radiation-Diagram-For-2-4-GHz
>
> I also wrote a blog post about AlterMundi's work using 2x2 MIMO
> equipment to provide a directional signal, coupled with an omni signal
> out of a single router:
>
> https://commotionwireless.net/blog/2014/11/05/do-it-yourself-antennas-for-community-networks/
> There original documentation is here, and is great:
> http://docs.altermundi.net/RedesMiniMaxi/MontajeDeUnNodo
>
> > The initial intent of the network will be multipurpose, but my
> > thoughts are this:
> >
> > * redundant point to point connection between campus locations.
> >
> > * Wireless community backup communications network for emergency
> > situations, community based information for a decentralized
> > internet style network. Similar to the Red Hook project and
> > others.
> >
> > * Other than that, it would serve as an experimental platform for
> > leaning and local communication for those who are in range and
> > wish to cooperate.
>
> Sounds good - wireless is a great platform for those things. Think
> about how / where you can provide wired connections as well - either
> Ethernet or fiber - the performance and reliability can't be beat!
>
> > I understand the basic limitations of wireless communications such
> > as channel capacity and interference, but I would really like to
> > see this system implemented on a large scale.   If only we had
> > larger frequency bands to work with. I would really like to see a
> > community supported mesh with backhauls which approach the scale of
> > the cellular network. Maybe that's going way to far, but that's my
> > dream! I really like the idea of the ubiquiti air fiber for long
> > distance backhauls. Gotta start somewhere.
>
> I highly recommend using 5GHz for backhaul and point-to-point in this
> day and age - 2.4GHz is pretty crowded. It can be used for small mesh
> networks and Access Points, but you can definitely take 5GHz backhauls
> to a large scale - the very big Wireless Internet Service Providers
> (WISPs) use it pretty extensively.
>
> Point-to-point links provide great performance, and can bridge
> different types of networks at each end (point-to-multipoint or mesh).
> For this, I would look at something like the Ubiquiti NanoBeam series:
> https://www.ubnt.com/airmax/nanobeam-ac/
> The lower-gain (shorter range) models are fairly affordable:
> http://streakwave.com/Itemdesc.asp?ic=NBE-M5-16-US&o1=0
>
> For Do-It-Yourself point-to-point links, the AlterMundi method works,
> and you could use two dishes to provide the full MIMO capacity through
> (just orient the antennas in front of the dishes at 90 degrees from
> each other - i.e. one vertically polarized and the other horizontally
> polarized). The TP-Link routers work well for this - the WDR3600 would
> be my first choice, as it is fairly affordable ($50 or so). You can
> also re-flash the firmware to use just about anything else - Commotion
> / LibreMesh / qMp or whatever else for meshing.
>
> For omni-directional mesh routers, I recommend the Rocket M2 or M5
> (depending on which band you want to use), or TP-Link WDR3600 (or
> WDR4300) routers. For the TP-Links, you will need to find an outdoor
> enclosure to weatherproof them. The antenna you use can be anything
> you want - the high-performance Ubiquiti AirMax omnis:
> https://www.ubnt.com/airmax/airmax-omni-antenna/
> More reasonably priced but shorter range omnis:
> http://streakwave.com/itemdesc.asp?ic=OARDSBX244&eq=&Tp=&o1=0
> http://streakwave.com/itemdesc.asp?ic=OARDSBX55&eq=&Tp=&o1=0
> (Note, with these you don't gain the benefits of dual-polarity, but
> there will still be a 2x2 MIMO signal)
>
> Streakwave and other distributors have just about every type of
> antenna you could dream of, but you can also play with making your own!
>
> For directional mesh routers, you can't beat the Ubiquiti NanoStation
> M2 or M5, or the TP-Link routers with custom antennas.
>
> > Thanks, Jared
>
> Sure thing - I recommend going through some of our group activities
> that are focused on wireless planning as well, to think and work out
> router type and placement:
>
> https://commotionwireless.net/docs/cck/planning/design-your-network-every-network-tells-story/
> https://commotionwireless.net/docs/cck/networking/wireless-challenges/
>
> https://commotionwireless.net/docs/cck/networking/types-of-wireless-networks/
> https://commotionwireless.net/docs/cck/networking/guidelines-for-mesh/
>
> Good luck!
> -A
>
>
> > On Wed, May 27, 2015 at 11:39 AM, Andy Gunn
> > <andygunn at opentechinstitute.org
> > <mailto:andygunn at opentechinstitute.org>> wrote:
> >
> > Hi Jared - I'm hoping a lot of people chime in on this one, as
> > there are lots of possibilities!
> >
> > Are you planning an indoor network, an outdoor
> > (building-to-building) network, or both?
> >
> > Are you planning on building your own antennas, or purchasing
> > pre-made antennas?
> >
> > What will the network be used for?
> >
> >
> >
> > On 05/26/2015 11:19 PM, Jared Hoy wrote:
> >> I've been interested in Commotion and meshing for a while, but
> >> until now haven't really had time to pursue it. Recently I've
> >> been discussing it with fellow students and teachers at my school
> >> and it seems many are interested in putting up some nodes. Also
> >> sounds like my school may be interested in hosting some nodes on
> >> top of the campuses as well.
> >
> >> I told them I'd like to get 3 or 4 routers on my own so we can
> >> experiment before promoting it formally. That being the case, I
> >> need to determine the best brand and model. I see Ubiquity,
> >> Mikrotik, and TP-Link brands listed on commotion along with the
> >> many models. I was leaning toward the Ubiquiti Rocket M2 as it
> >> seems to be quite reliable and I like having the two external
> >> coax connections.
> >
> >> Is the Rocket my best option at this time? I'd like something
> >> that offers reliability and has external antenna connections
> >> (hopefully more than one) while still being relatively
> >> inexpensive. I'd rather spend a little more to get something that
> >> offers expandability in the future though.
> >
> >> Most people don't want to contribute unless they see what it
> >> offers and how it works, so I figure I'll purchase the first
> >> batch to kick things off.
> >
> >> Any suggestions? Any thoughts on the other brands and models?
> >
> >> Thanks, Jared
> >
> >
> >
>
> --
> Andy Gunn, Field Engineer
> Open Technology Institute, New America
> andygunn at opentechinstitute.org | 202-596-3484
> PGP: F1D2 CD5E 9F15 EEB0 232A 1EFA EEDC DC5C F1D5 653C
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-- 
Ben West
me at benwest.name
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