Northpoint technology new wireless DSL/Tv ?

[Tisual]

I have been following the story on northpoint tech. who want to reuse the existing DBS spectrum from ground based antenna to transmit digital tv and provide broadband access.

The company url is Northpoint Technology , the compass link.

I was wondering based on the info they provide what speeds is it possible for them to provide in upload/download before they would saturate the bandwidth they are wanting to claim ?

This would be great for alot of people who can't get DSL can someone who is more technical than I read through it and tell me if its feasible and what is your opinion on it ?

 

[Howard]

Something about using the roughly the same spectrum as satellite frequencies but just low enough to keep from interfering with them. It's based on the same idea as cellular phones (areas known as cells, etc.), I think, and uses directional broadcasting.

I just skimmed through it, I'm not sure.

 

[Tisual]

I'm not technical enough to figure out the frequencies and bandwidth, but does anyone have any idea as to what capacity they would have in regards to broadband ?

Would they be able to provide higher than DSL/cable rates ?

 

[blahblah99]

Their wireless broadband satellites only use up a small chunk of the RF spectrum (12.2Ghz -12.7Ghz), a mere 500Mhz. It may not seem like a lot of megahertz, but there are modulation techniques that can squeeze a lot of data into that box. I'm no expert in this area, but I am sure it can provide bandwidths greater than multiple T3s.

In comparison, if you consider the way cell phones work, a voice signal only needs a bandwidth of around 6-8Khz. Add 1000 users and you will need a bandwidth of 6-8Mhz. 100,000 users = bandwidth of 600-800Mhz. Etc, Etc.

Using modulation techniques such as time division multiple access (or TDMA for short), more users can be squeezed on a smaller bandwidth slot. Each user is allocated a limited time on a frequency slot, ie, the slots are shared in time over multiple users - hence the name time division multiple access.

Another technique used is CDMA - code division multiple access in which each user is given his/her own PIN number to decrypt the digitized data. Using this technique, digitized data can be "added" and sent along a single frequency slot, and only the user with the EXACT PIN number can extract his/her voice data.

There are other techniques that exists to overcome this bandwidth problem. The CDMA technique was orginally developed for US army use back in the 60's or 70's. Interestingly, that technique was only declassified for civilian use around the 80's.