Using STL dish to share Lan link connection

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fmrfman
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Using STL dish to share Lan link connection

Post by fmrfman » Thu Oct 09, 2014 1:18 pm

We have a licensed 950 MHZ STL link and was wandering if anyone has tried "piggybacking" a LAN link(i.e. WiFi link) across their STL link on the same antenna?

TPT
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Re: Using STL dish to share Lan link connection

Post by TPT » Thu Oct 09, 2014 1:36 pm

Don't think it would work very well. Typical WiFi links are up 2 or 5 GHZ, the STL operates around 950 MHZ. Even to use two STL transmitters into one dish, some kind of combining network is required, so that the two transmitter don't burn up each other. Then remember that an STL path is one way, while the WIFi link has transmitters and receivers on both ends--so even on the STL receive end, the WiFi transmitter might not be too happy into a mismatched antenna --plus the receiver front end of the STL.

fmrfman
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Re: Using STL dish to share Lan link connection

Post by fmrfman » Thu Oct 09, 2014 1:42 pm

Good thoughts TPT. Besides the fact that a PR-950 is tuned for 950 MHZ it didn't make much sense to me. Trying to find a way to experiment with something until the management made up there minds to spend some real money. We are a non-profit non-comm with limited resources.

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Re: Using STL dish to share Lan link connection

Post by Deep Thought » Thu Oct 09, 2014 4:09 pm

If the antenna locations are easily accessible you might want to try a Ubiquity Nanobridge-class 5 GHz link. They're pretty cheap (under $200 for both ends) and if you have a clear line of sight can span a fairly decent distance.

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TPT
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Re: Using STL dish to share Lan link connection

Post by TPT » Thu Oct 09, 2014 4:19 pm

Well, may need to spend some $$ for a tower climber, but if you hang the small dishes just under the existing STL dishes, the link will probably work. Unless it is a long hop, path loss is somewhat similar.

Typical configuration for these links put the transceivers just behind or below the dish, with a short coax jumper. The units are then powered by a length of CAT-5 to a supply/pass-through device at the bottom of the tower. Which makes the system vulnerable to lightning, if they are mounted very high.

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Re: Using STL dish to share Lan link connection

Post by KPJL FM » Mon Oct 13, 2014 8:01 am

Check out Moseley solution:
http://moseleysb.com/mb/lanlink_900D.html
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fmrfman
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Re: Using STL dish to share Lan link connection

Post by fmrfman » Thu Oct 16, 2014 12:44 pm

I've ordered the NanoBridge M5 400s. One thing that concerns me is that we have a wireless internet provider on our tower. I noticed he has one of M5 dishes on an offset pole mount that puts the dish about 2 feet out from the tower. We are FM broadcasting through a 10 bay at the top of a 400 ft tower and he is probably at like 200 ft. so I don't understand why he would have used that mount.

It's 11 miles line of site to the tower. I hope the 30km+ claim is even close to true!

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Re: Using STL dish to share Lan link connection

Post by Deep Thought » Fri Oct 17, 2014 12:05 am

I know someone using these for a 19 mile hop that is more reliable than his 950 MHz digital STL...
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stephend2
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Re: Using STL dish to share Lan link connection

Post by stephend2 » Sat Oct 18, 2014 9:26 pm

11 miles is a little much IMO for nanobridge units.

at 10-16 miles, I'm using 30dbi dual pol dishes and mikrotik radios. 15-16+ miles, I'm using 34dbi dual pol dishes and the same mikrotik radios. Once configured properly, this is getting me well north of 100 mbps. While you may not need that throughput, I typically engineer links for high reliability, if properly done, you have plenty of fade margin and no packet loss, important for any real time applications. Some of the links I've built out are carrying traffic for > 100 internet customers and I transport IP audio as primary STL for 4 radio stations in the area. We are also deploying VoIP over the network with great results.

If you are only trying to get an internet connection to the site and only for non realtime data such as remote control and monitoring, you'll most likely be just fine with the nanobridge/nanobeam line.

Actually, today, I had to setup for a remote broadcast in a pinch, I used a nanobeam m5-400 connected to a rocket m5 on a 19dbi 120 degree sector 10 miles away, with the nanobeam about 12 feet above ground. It works great for the application, however, I would not trust it permanently. Signal was in the -80dbm range on that. 18.7 mile link we deployed a couple weeks ago with 34dbi dishes has received signal at each end of -47dbm and is very steady with no packet loss. We have been thoroughly testing and about to turn it over to a customer with 20x20mbps dedicated internet and 10+ lines of VoIP running over it. With that, we were able to deploy dedicated carrier class internet access to a business in a remote area that had no other options. They currently are on a bundle of t1s that go down every time it looks like rain.

fmrfman
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Re: Using STL dish to share Lan link connection

Post by fmrfman » Sat Oct 18, 2014 9:55 pm

stephend2 thanks for the thorough feedback. To correct my previous post I actually ordered Nanobeam m5--400s. I found the microtik stuff in my web searching today. Looks like their equipment may be better suited for what I want to do.

If I put the ubiquiti m5s up and get 20 MBPS at 11 miles in a hard rain that would be enough. Heck I would settle for 5 MBPS. I am hoping to take the output of our Axia system and feed it over the link in addition to providing IP access to our XMTR remote control box. In other words a digital "STL".

If you are only going 2 to 5 miles you might be able to create a link with the "cheap stuff" that you can rely on 24/7 365. In my research it seems that commercial broadcast outfits that want to go outside of the old school licensed STL stuff should look beyond the "cheap" WiFi equipment and look in the $2000 range.

Hopefully I will prove myself wrong. I'll be updating this post with statistics as the link goes "live".

Tower crew scheduled for this coming week.

Mark

fmrfman
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Re: Using STL dish to share Lan link connection

Post by fmrfman » Sat Oct 25, 2014 8:16 pm

Project on hold. Tower climber delayed and Ubiquiti supplier messed up the order twice.

Anyone else out there using a WiFi ethernet link to replace your STL?

I am planning on feeding the AES/EBU output of our Orban 8500 into a D/A and then into our BE 25T transmitter. Orban is on the studio side at this point.

Any suggestions/advice?

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Re: Using STL dish to share Lan link connection

Post by Baylink » Sun Oct 26, 2014 4:46 pm

My inclination would be to say that you want some device between the radios and the transmitter that is going to do an audio sanity check on the signal going through, whether that's your Orban or some other device. If your DA converter itself will not produce insane audio, then more power to it.
Last edited by Baylink on Sun Oct 26, 2014 6:43 pm, edited 1 time in total.

fmrfman
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Re: Using STL dish to share Lan link connection

Post by fmrfman » Sun Oct 26, 2014 5:25 pm

For whatever reason our processor is at the studio. I plan to move it out to the transmitter site and use the analog output from the processor to feed the transmitter. Seems to be the easiest way without spending any unnecessary additional money. Orban recommends putting the processor at the transmitter site.

fmrfman
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Re: Using STL dish to share Lan link connection

Post by fmrfman » Mon Nov 10, 2014 11:51 am

O.K. the link is up. I went with Rocket M5s. At 11 miles my speed test is coming in at 40MBPS both ways. Soon to begin long term reliability/audio transport testing. Here is a picture of the link status.

Click on the picture to see it better:
KMST Wireless Link Quality.jpg

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Re: Using STL dish to share Lan link connection

Post by kcbooboo » Tue Nov 11, 2014 6:07 am

I'm helping someone with a pair of M5-300 units. We managed to talk to each one with a laptop and network cable. Each is still set at the default IP address of 192.168.1.20.

Without changing anything, should the two units communicate and show real good signal when placed 20 ft apart, or must the IP address of one unit be changed before the two will recognize each other?

Eventually these will be used as an STL. I'm not an IT guy so all of the settings are completely foreign to me. I'm not at all sure how we want to set these units up: as a "Station", as an "Access Point", or as an "AP Repeater". Do I need to specify the various MAC addresses to make the units lock up? I just need enough info to get the units chatting with each other for now.

= = = = =

Also, to the original poster, the Moseley StarLink 950 MHz STL system uses a splitter/duplexer to allow their LanLink (902-928 MHz frequency-hopping, spread-spectrum) to utilize the same antenna. The combination works great. The STL is unidirectional while the LanLink is bidirectional. One thing to remember is that these devices tend to operate in half duplex mode, i.e. they can either transmit or receive, but not do both simultaneously. Some network equipment may be quite unhappy with that. They're also easily overloaded with heavy network traffic, so use an intelligent switch or router to keep routine traffic off the wireless link.

Bob M.

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