Where aren't RF used for internet coms

[alhaji_aminu]

Salam

I am an awful  electrical engineering student-well I take solace in the fact that I am switching to Medicine soon.  I mean that by the way I am paying little of not attention to the networking and information technology aspects of it. I do love signal processing though.

My question is simple.

Why can't engineers figure out a way of moving data through radio waves? my understanding is that most of the internet networks are terrestrial and satelite based.
I actually heard a company here in the US that is trying to use power lines for internet connectivity. so if that is possible why not RF waves?

[dfynest]

...and here I was thinking wireless was a means of transferring data via RF

[zezezee]

Salam mallam Aminu,

Any form of communications that is not thru the conventional wired medium, is through Rf waves. Satellitle and terrestial based communications deploy Rf waves as transport medium as well. But the diffirence is the frequencies employed in the actual communication.

With regards to the company trying to use power lines for internet, I say its because with wireless(RF) networks, u have limitation in the amount of data that can be pushed, and u have so many other considerations to make: interference, power levels, frequency allocations, to name a few. But with power lines, u have less considerations to make, and more bandwidth(amount of data) to push. Needless to mention that powergrid for internet is still in its R&D stages, its not been fully researched.

Please feel free for any questions...I love digital signal and image processing as well man!

A huta lafiya.

[gogannaka]

Salaam,
I was wondering if any of you guys has any idea what kind of thing is contained(i mean cct diagram) in those d#@$n expensive broadband/wi-fi antennas?
If not for the very expensive antennas wireless internet would have been very cheap.

And isnt it possible for one to capture the broadband/wi-fi signals using the ordinary yagi uda antenna or better still cable t.v antenna?......help out pls.

[zezezee]

Mr G-naka,

Malam kwana biyu, hope all is well.

With regards antennas, im not too sure how expensive they are would affect the price of internet services around. It is basic business attribute  that fixed costs dont affect how expensive services can b predominantly, but running costs r those that determine that.

With respect to yagi antennas, it is possible to capture any type of signal using any type of antenna, but only if the antenna is operating under the same technology as the transmitting antenna. By that, i am referring to frequency band, access technology (TDMA, FDMA, OFDMA, CDMA etc), power levels, etc.

lastly, the the type of circuit u have over the network has to be the same on both ends as well. wether it wld b packet or circuit switched network.

I think these with a few other considerations wld answer ur questions....

im sure there wld b other stuff that some ppl might want to add to these ones here...

[gogannaka]

Thank u zzz.
Lets talk about the common 2.4ghz and 5.2ghz wifi.
The frequency of transmission is 2.4ghz and 5.2ghz ko? and usually they employ the line of sight technology(l.o.s).
So now i'm saying, isn't there a way i can decrypt the data from the tx side.
I'd give u an example.Take cable t.v for instance,they operate in UHF and the pictures are sent encrypted or encoded then at the recieving end they get decoded by a preset decoder.You see this signals come in binary and one could use a smart i.c (P.I.C for instance) to actually simulate the binary codes sent from the tx side and prodeuce a simple decoder that will decode the signals.That is what the local decoder freaks do in nija here.
I think this technology could be used same for data. We just need an idea on the encryption method used by the transmission side of data transmission.I guess the 2.4 and 5.2ghz wifi can be easier to BREAK.....What do u see?

[zezezee]

mallam g-naka,

to start with, line of sigh technology as u referred to it, does not play much significance in wireless communication, well to my knowledge so far de sha. for any communication to take place, there has to be a tx and an rx, thats the most basic. LOS depends on how powerful ur signal is and the property of the antennas themselves, well, lets not dwell in that for far too long.

secondly, when u talk about decrypting RF signals over 2.4/5.2Ghz (ISM) bands, u have a big work to do man! think about these points here:u knw the ISM bands are unlicenced bands all across the world. which means in any country u go to, u have uncountable no of networks found on the frequency band. this means that there will obviously b high interference there, and since ppl still use those bands for communication, despite these bands being congested and over occupied. this in turn means their equipment must have a way of overcoming these bottlenecks. the answer here lies in how good their access technology is (FHSS (frequency hopping spread spectrum) or DSSS(direct sequence spread spectrum)) and their encryption/decryption. and by this, we all know they wld spend all they can to make this the state-of-the-art technology man!

now, for this encryption/decryption thing, we r talking about a dynamic encryption here...where the ciphering changes with very transmission and doesnt last the whole transmission period, if its for quite a long time...the key keeps changing, needless to mention that it is most prob 128-bit encrption, which wld take ur program (developed by an expert in the field) quite some time to decrypt. by this, we r talking about hours (if not days). and mark u, the key changes so fast, prob a thousand or more times in a second. so tell me, how u can ever decrypt this kinda information.

the only way is to lias with an insider, from the company to give u their decryption sequence and then u can work with it....and even at that, u r gonna have to need an expert in the field to be able to do that for u.

but there r known methods of gaining access to wireless networks if u want..... for those that a lazy enough to keep their settings on the default settings...hehe

that one is easy!

[gogannaka]

WOW...Thats a great challenge.
I was thinking maybe one could  develop something like a radio communication reciever whereby by tuning you could actually tune the data signals.......But the facts u mentioned above make it quite impossible.

One would have to study D.S.P kenan.... :roll:

[ikoro]

I KNOW THAT THE RF SIGNALS CAN NOT BE ABLE TO TAKR CARE OF TODAYS FAST RATE OF DATA TRANSFER BECUASE OF ITS  BANDWDITH AND FREQUENCY LEVEL.

POWER LINE TECHNOLOGY IS THE EASILY USED HERE IN KOREA AND IT CAN SUPPORT SO MANY LARGE AMOUNT.

WE SHOULD THINK OF ABOUT A WAY OUT FOR US.