Band usage for feed via wireless internet

Status
Not open for further replies.

KMD877-KMG983

Member
Joined
Mar 22, 2012
Messages
16
Location
Stagecoach, NV
If there's already a thread, WIKI or FAQ on this topic, please forgive me and point me to the documents.

The feed in my county has become inactive. I've sent an old file server in for rehab to use to provide feed for at minimum fire-rescue channels. This is a rural, extremely high fire danger area and the feed could be beneficial not only to citizens concerned about a working incident, but also for scanner buffs who might be out and about and want to follow an incident on their smart phones when they are in locations where they can't take a scanner or out of range for portable scanning.

We're on wireless internet out here and the amount of usage is is measured. I'm allowed 16 gb total usage per month (inclusive of all internet uses.) I haven't done these kinds of calcs in over a decade but at constant 32 kbs I come up with usage greater than 16 gb/month. Am I missing something here or is this not doable over wireless internet with these limitations?

Thanks.
 

mikev

Member
Joined
Dec 19, 2002
Messages
218
Location
Northern VA
You should only be using 32Kbit/sec if you're running a stereo feed with two different scanners. Mono feeds are only running at 16Kbit/sec. But even still, I don't think you're doing your math right.

8 bits = 1 Byte
1024 Bytes = 1 KB
1024 KB = 1 MB
1024 MB = 1 GB

So... 16Kbit/sec / 8 bits/byte = 2000 bytes/sec / 1024 bytes/KB = 1.95KB/sec * 60 sec/min * 60 min/hr * 24 hr/day * 30 day/mo = 5062500 KBytes/mo... divide by 1024 twice and you end up with 4.83 GB for a 16Kbps mono stream running 24/7 for 30 days. In theory, a 32Kbit/sec audio stream should be double that.

Something you might want to clarify with your carrier... if they are doing 1024 or 1000.... For example, hard disk manufacturers claim that 1GB = 1,000,000,000 (1000 * 1000 * 1000) bytes, not 1,073,741,824 (1024 * 1024 * 1024)... hence the loss of significant quantities of disk space when formatting (i.e. a 250 GB drive becomes 232 GB to the operating system). Some carriers use 1024 (I know for certain that Verizon does)... others may be going the same route as hard drive manufacturers.

But even with 1000 instead of 1024, you're still well under 16 GB/mo (5.18 GB/mo).
 
Last edited:

KMD877-KMG983

Member
Joined
Mar 22, 2012
Messages
16
Location
Stagecoach, NV
Thanks for the math lesson!

Mike,

Thanks. Where I kept screwing up was I forgot to convert bits to bytes - what a basic foolish mistake! I know better but I just got caught in that loop and couldn't see where I went wrong. Plus it makes sense to run 16 kbs since this would be a relatively simple feed if I get this going.

I will definitely find out from the wireless carrier whether they calculate based on 1000 or 1024. Not a huge difference but given that I also work on web projects that involve transfer of large files, I sure want to make sure that there is "room" for everything.

I really appreciate the "tech support" that this forum offers.

Best regards from Stagecoach, NV.
 

mikev

Member
Joined
Dec 19, 2002
Messages
218
Location
Northern VA
Or alternately... they could be saying that you get 16,384 MB/mo, which is still slightly different (take out one 1024 division)... So when they say 16 GB/mo, get a real and true number of how they figure when you hit that limit. It may be in the fine print on their website... or you may need to check your account on their site, if you're already a customer of theirs... might be able to figure it out from looking at your bill.
 

KMD877-KMG983

Member
Joined
Mar 22, 2012
Messages
16
Location
Stagecoach, NV
Thanks. The bill just shows round numbers.... xx.x gb used. However I know the guy who owns the service (not personally but professionally) so I think the idea of asking how they base their usage calculations is the way to go. Also there is someone I know who lives in an area that just got equipped with U-verse who would likely agree to support the feed, however I'd feel more confident if I had personal control of the scanner - to be able to mute a channel that goes noisy, etc.

"Back in the day" we actually used to provide scan feeds to the fire stations by having a Motorola Mitrek radio located at the station with the highest elevation. Using tone remote desk sets anyone could change the priority channel or mute a channel (e.g., if department X was conducting an overly chatty drill on a tactical channel that was becoming annoying.) The setup was unbelievably functional but then we had some serious money that we could use to put this together. Us "retired folk" don't quite have those resources. Come to think of it, with the budget crises going on everywhere, the FD probably wouldn't have those resources any more either!

Thanks again for the useful ideas.
 

talkpair

Member
Joined
Apr 27, 2009
Messages
957
Location
Clinton County, MO
I recently set up a very minimal Linux box using a discarded IBM Aptiva 233 MHz computer.
It's only function is to stream audio to RadioReference. This allows me to take my more valuable machines off the grid during electrical storms, allowing the dinosaur to take the sacrificial hit. I run no other applications on it, and there is no graphical user interface.

In two experiments, I sent instructions on the command line to show the network card's statistics, wait 3600 seconds (one hour), then show the network card's statistics again.

Experiment 1:
With one 16 KB mono stream connected, 536,592 RX bytes, and 7,565,144 TX bytes passed through the network card in a one hour period.
If you add the RX and TX bytes, multiply by 24 (hours), then by 30.4375 (days in a month).....it works out to about 5.92 GB per month.

Experiment 2:
With two 16 KB mono streams connected, 887,921 RX bytes, and 15,110,292 TX bytes passed through the network card in a one hour period.
If you add the RX and TX bytes, multiply by 24 (hours), then by 30.4375 (days in a month)....it works out to about 11.7 GB per month for two streams, or 5.84 GB for one stream.

As you can see, there is some discrepancy between the 5.84 GB figure and 5.92 GB figure in the two experiments.

Keep in mind that there is some other network activity probably going on here, such as IP lease renewals, which contribute to the network card's statics, but may not contribute to internet usage.

Although my estimates are higher than mikev's, I think we all can agree that my worst case figure of 5.92 GB per month is still way below the monthly bandwith allowance.
 

travisd

Member
Joined
May 6, 2010
Messages
20
Since you know the folks that run the ISP, see if they'll "sponsor" the fee in return for extra bandwidth. AFAIK, RadioReference allows for that in some fashion. They get some publicity out of it, and you don't eat into your bandwidth.

Heck, you never know - since they're wireless, perhaps they would let you put the system at one of their tower sites for better coverage?
 

KMD877-KMG983

Member
Joined
Mar 22, 2012
Messages
16
Location
Stagecoach, NV
Thanks for the ideas.

Interesting concepts. Thanks. I'll investigate all of them, especially placing the receiver up at the radio tower. Maybe Highlands Wireless would provide a feed for the good PR that it produces.
 
Status
Not open for further replies.
Top