Will it work?

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by clivedoubell</i>
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http://www.winncom.com/moreinfo/item/WRSP6-2.4%20%20%20%20%20%20/index.html
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That's a nice dish. We did a 5.8GHz link between JHB and PTA with 2x 40dbi radiowaves dishes like that but using highend radios (tsunami)
Sandton City roof to the Voortrekker monument, if I remember correctly that's about 40kms [:D]

At those distances the curvature of the earth is your biggest enemy though. Elevation is essential.

clivedoubell, I think your problem will be the signal back from the sentech towers, since they don't use directional equipment you might not get enough signal without a receiving amp.

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Guys,

I don't think Clive will need a signal amplifier. The antenna works both ways. It effectively "boosts" your transmit signal due to its directivity (gain).

Clive will probably have more signal than the average Joe. For example, if he was 5km from the tower he would have had an ok signal. Now if he is 25km from the tower the signal loss due to the extra distance is 10x log10 of ((5/25)*(5/25)) or 14 dB. If he puts up the dish (and aims it correctly) with its 30 dB gain, he will "score" about 15dB (transmit and receive).

Ajax
 
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">yeah two words NO & VSAT<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

dont do the vsat thing!! im about to rip the dish off the wall, wack a burner under it and use it as a skottel braai.
 
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by ajax</i>
<br /> If he puts up the dish (and aims it correctly) with its 30 dB gain, he will "score" about 15dB (transmit and receive).<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Assuming he has LOS.
 
Hi Guys

TheRoDent - I've been thinking exactly that. I have a friend that lives in Randburg and I think a 802.11 between him and me will do the trick nicely. I have this as my PLan B. Thanks for the links - I'll investigate.

ajax - I agree with you 100%. It is known as the Antenna Reciprocity Theorem in the clever books. I like your sums. I will lose a few more db's due to cable and connector loss, maybe another +/-5dB if I use N or TNC Connectors and low loss RG312 (I think). Or is it RG213 - I forget.

nroets - Yes I have LOS. There is a big valley between me and Randburg. I can see the Mintek tower clearly (through binoculars after the rain when the smog has cleared).

One small problem however. I just found out the price of the 30dB antenna. $1250.00!!!. Probably R10,000+ when I get it here. Maybe they misunderstood me and thought I wanted a quote on their whole company:-) Anyway I think I must look for cheaper solutions. I wonder where I can pick up a 2 meter dish (even secondhand) locally. Any ideas?

I got a patch antenna today. It's really a pisswilly little thing. Ideal for placing at the focal point of a 2 meter dish maybe?

I also now have a problem with Sentech. I don't have a personal bank account as I do everything through my company's bank account. This is much too much for them to understand (I think their brains were about to melt when I explained that). Now they want payslips. I work as a contractor/consultant so I don't get payslips. This is also way beyond their level of comprehension. Then they wanted IRP5's. I don't work as an employee so I don't have IRP5's. Now they want to see my company's books for the last two years. This is where I draw the line. My company's books have absolutely stuffall to do with them. So it seems that I have a little problem.

Cheers
Clive
 
Yea dude, 2 years worth of company records is a bit personal, especially for some internet connection

sheesh

I would want to see those books if I was interested in buying your company... are they perhaps considering buying your company? [:o)] [:D]
 
Clive, just double check with Fastcomm first if the Tower you have in question has the 29 km software enabled else you will be wasting time and good money.


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<font size="1"><font color="black">The opinions expressed here are mine alone and do not necessarily reflect the opinions of my employer</font id="size1"></font id="black"></center>
 
Clive: I can get a dish Ant 27Dbi for around R540+vat. 99cm Let me know if u interested, I can also quote on a 30Dbi if u want
 
ProAsm - No all towers are set for 5.7 km. A guy at FastComm told me so. He also said that with 29 km there is a 8% loss of something. I didn't understand what he was talking about and I didn't want to show him (and the woman there) my ignorance. Can you perhaps explain the difference between 29 km and 5 km settings. Do they supply more power to the tx/amplifiers or do some tweaking with antenna directivity?

Cheers
Clive
 
Basically with the 29km software you can expect logging on a little difficult (depending on the distance), also your packetloss and pings will increase by approx 10% (again distance depending).
Places with the distance software is currently under Beta so to speak and anyone using it at a great distance must realise they are taking a chance.
For instance I am doing experiments atm in Durban with 2 of my outlying Nodes on the 29 km software.
One is at Tower 60 which basically points at the highway (no one close by) but 14 km away is Westville and Pinetown who will only get Towers in Phase II.
I already have several clients there logging onto this tower and they know that once a Tower goes up in Westvile and Pinetown this Tower 60 will be set back to 5.7 ks.
The same at the Bluff (Tower 90), the node facing South/West is set on 29 km which feeds a large population of people in the Mobeni/Montclair and Woodlands area's 6+ ks away.
The chances are it will reach much further afield also and I will be doing tests there.
Again, once a Tower goes up in that area, Tower 90 will be switched back to 5.7
Now lets say I get a guy at Athlone Park (20ks) or Isipingo (15ks) who decides to logon to this signal, he will be warned in advance that the moment a tower goes up in the Montclaire/Woodlands area, he is gonna run out of signal, although the chances are that the new Tower at Woodlands will have its South/West node set to 29 ks.

In Gauteng this kinda of experimentation is very difficult due to the vast size and desity of places everywhere but it could happen [:)]


<hr noshade size="1"><center><font color="blue">MyWireless Stuff</font id="blue">
<font size="1"><font color="black">The opinions expressed here are mine alone and do not necessarily reflect the opinions of my employer</font id="size1"></font id="black"></center>
 
Thanks ProAsm

I'm not relying on the 29km option being available at the Mintek tower. I'm thinking of a high gain link (+30dB) at my end. My understanding of RF propagation and antenna theory says this must work, unless there is something about the protocol and signal timing that will cause a problem.

If I knew the following:

1) The tower's output power.
2) The tower's receiver tangential sensitivity.
3) The tower's antenna gain.
4) The tower's tx and rx feeder losses
5) The tower's antenna VSWR

and the same for the modem side.

I could estimate quite accurately whether the RF link would make sense. If I further would to know the CDMA timing specs I could figure out if the timing would make sense.

Anybody have any ideas?

Clive
 
Clive to put it in a nutshell.
If the node has been set to 5.7 ks and you live say 20 km away.
You can put up a 100 foot dish with 100 dB gain and get a signal of 50% etc etc - you will NOT log into the system.
You cannot compare IPWireless technology with normal Wireless RF technology as it is vastly different.
So unless the node has been set for extended range (29 km) you will not logon regardless of what you do.


<hr noshade size="1"><center><font color="blue">MyWireless Stuff</font id="blue">
<font size="1"><font color="black">The opinions expressed here are mine alone and do not necessarily reflect the opinions of my employer</font id="size1"></font id="black"></center>
 
Clive, ask/bribe TheRodent to hack into Sentech's tower and set it for 29km [:p]

Ajax
 
ProAsm - I believe you.

Is it possible for you to explain WHY this is so - I would like to understand.

Thanks
Clive
 
Clive, the whole reason behind this is all towers are situated in a grid where one does not overlap the other with regarding the same frequency as what was happening is many users were getting stronger signal strengths from a distance tower than the closest tower then they could not logon because of the distance then phone the Help Desk and complain and the poor Help Desk guys did not have a clue whats going on.


<hr noshade size="1"><center><font color="blue">MyWireless Stuff</font id="blue">
<font size="1"><font color="black">The opinions expressed here are mine alone and do not necessarily reflect the opinions of my employer</font id="size1"></font id="black"></center>
 
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