Need help on selecting a point-to-Point reliable Wireless Communication Module

I've to implement a wireless communication system. Details are as follows.

• Range is about 600m
• Point-to-point communication
• No LoS is available. (but not highly obstructed)
• Won't need much higher data rates.
• Should be reliable.
• No constraints with supply power, size etc...
• Intended to handle with PICs of Arduinos.
• Price is not a major issue (but prefer a reasonable price..)

Please point me to a proper transceiver module that can be used for the purpose.

Don't have prior experience with wireless modules (so, you can assume fine details and then let me know of them). A straight answer is much appreciated..

Thanks !

Without a clear line of sight, you're pretty much screwed.

From your specifications, it appears your project is way over your head. I would suggest you work with a professional consultant that will go down your list of requirements and point out the failure points. This will save you a lot of money on failed attempts to learn wireless on your own.

Hi anubis_sc

Have you looked into Ubiquiti Wireless solutions, they have a good range, they have a new product out call airfiber which looks pretty amazing. Also SAF Tehnika have a good product.

I found this info on the Ubiquiti airfiber -

Ubiquiti airFiber 24 GHz Point-to-Point radio

Ubiquiti airFiber 24 GHz Point-to-Point radio Advanced Antenna System - YouTube

Well, thanks for your advice @WHT. But I wont be able to go for that option. I'll have to do this somehow. Yeah, I don't have any practical experience in using wireless modules. But I'm well experienced in using microcontrollers. Also I have sound theoretical knowledge on wireless communication.

I'm a electronic and telecom engineering undergrad, I'm having my 6 months training (which is part of the curriculum). That's why this is so important to me.

So please give some guidance. Actually I cant get an idea on which module I should buy. I've found various modules. But I'm not sure whether they are capable of giving me the expected results under given conditions. Just help me with that (at least)..

PS:
I've fount this module. What's your idea about it..

Xbee Pro 900

Will this suit for my need ??
(I've found Xbee modules comes handy in those apps, don't they??)

Any thought, guidance... is highly appreciated!!!

Thanks @backtothefuture but the cost is way to high for this kind of requirement, don't you think. Also, can you be a bit specific, as the divece you showed is much advanced it's be a waste if I use it for this kind of app. I hope there may be a module for me, for an amount less than $200 ??

What's your opinion about this (above mentioned) Xbee module?

XBee Pro 900

Hope I'll get a positive feedback.. I'm badly in need of help...

https://www.sparkfun.com/products/9099
XBee Pro 900 RPSMA


50 mW (17 dBm) HAHAHHA....That's a freakin' *toy* radio. You be lucky to get it to talk back to an AP more than a few hundred feet *with* a clear line of sight.


/edit to add
TwoXBee units can indeed work 6 miles *WITH*:
12 dBi very directional Yagi antennas.
75 foot masts at both ends.

Then what are you suggesting. Continue with this or any other (better) alternatives??

Let's look at your requirements. and the limitations and expectations.

* Range is about 600m
Low power (50 mW) devices begin to get unreliable past 100 meters.

* Point-to-point communication
PtP is very different usually describes fixed radios with directional and roof top antennas. What you are describing it more like PtM with omni antennas.

* No LoS is available. (but not highly obstructed)
"Not highly obstructed" is relative. To a wireless profession, that might mean one shrub; to an unexperienced person that might mean a light forest. A single building usually completely blocks a signal, a few trees might add 10 to 20 dB loss (cutting the signal by 10 to 100 times less).

* Won't need much higher data rates.
Need and technology are two different things. While you may only need to pass a few hundred bytes of data per second, the wireless technology still sees the wireless propagation at much higher rate. If you can't meet that, then you end up with lots of retries that drag things down.

* Should be reliable.
That's relative. Snow pack reporting data with only a few bytes per week is reliable (lots of retries).

* No constraints with supply power, size etc...
That's relative. If you don't have electric utility power, then solar can get very expensive.

* Intended to handle with PICs of Arduinos.
Programming hardware is not relevant. Teh only thing relevant is if you can hop onto an ethernet connection.

* Price is not a major issue (but prefer a reasonable price..)
Again...that's relative. $50,000 or $5,000,000 is certainly reasonable for some people, but not for others.

With all that said...Without paying for a professional consultant with wireless experience, I'd abandon your project until you spend a year learning wireless on your own.

Thanks @WHT for your detailed explanation. I won't be able to disagree with your arguments. But please note that this is not a professional kind of project which needs 100% guaranty for success. This is a training project, they gave us this knowing the possibilities. Also, there is no wireless pro here (actually, that's why I'm referring to this forum as there are enough pros).

I really know, I might fail. How can I be experienced without giving a first try? this is a valuable opportunity for me to get hands on experience on related area. On the other hand, I'll do my best to make this a success.

The major issue I'm facing here is that I can't decide on a suitable wireless module under absence of LoS.

(Following post is connected to this. I'm starting another post as then I'll get privilege to post URLs )

It's true the Xbee pro 900's Tx power is 50 mW. But in the manual it says that the range can be extended using a high gain antenna.

What manual say can't be wrong, eh?

I know the absence of LoS is a (the) major issue. So if this failed, in any case, then cant I use an intermediate repeater or something?
(Of course, another similar Xbee pro module can be used, but it'll increase the cost.. )

I'll examine more on this LoS issue. (May be we'll be able to chop down some trees )
(The LoS issue is caused by some coconut trees planted in the intermediate estate)

Please give some positive answer.. I know this can fail, I'm ready for that. But I need your help to minimize that probability..

Ahhh...A training project. That's different. The whole point is you learned something, even if it doesn't work very well.

Any wireless devise can have a greater range with an higher gain antenna. A dinky 6 dBi gain rubber duck omni directional antenna can be replaced with an 18 dBi very directional antenna (a 12 dB increase) and it will get four times the range. So if your Arduino was at a fixed location that didn't need to have the antenna re-aimed all the time, that would work.

The Xbee is around $50. Why not spend $80 for a Ubiquiti Picostation (it has an included 6 dBi antenna - though I honestly think it's closer to 4 dBi). By using a more standard wireless solution, your opportunities for repeaters and other solutions expand. You can drop in low cost repeating access points to minimize a non-LOS path problem.

I've posted a reply, it said that a moderator will have to approve that, but it's still not there (how many moderators are there BTW??). Can't wait until that appear. I'll post again.

Thanks @WHT for your reply. Will you provide me with details about that "Ubiquiti Picostation" thing (If possible please put relevant links. I'm not really sure whether the "Ubiquiti Picostation" I found by Googling is the one you meant). Can you explain why you prefer it over "Xbee pr 900"?
I found Xbee module much easy to use (through manuals and other readable materials, of course). I found tutorials on using them with Arduinos, which I'm also hoping to use.
Xbee module operates in ISM band. So, no issue on getting specific permissions etc...
Yes, as you thought, two end stations are fixed. No issue with that. As I'm going to practically implement this, your guidance much expected and highly appreciated..Thanks in advance..

If you're going between buildings, I would recommend using phone lines instead since it will be much cheaper and more reliable. Panoptic Technology makes some great P2P solutions using existing phone infrastructure. Panoptic Technology