mhammett

Yes Likely, but not guaranteed. That server may very well be directly on Sprint's network. That server may also reside on Company A's network. Company A may connect to Companies B, C and D, but neither Level 3 or Sprint. They may connect to Company E, F and G where Company G has a connection to Level 3. Not the case in real life, but Level 3's 2,700 network peers may have zero overlap with Sprint's 1,300 peers. You would then rely on the intermediary networks to connect. Each network that originates the communication (whether the request from the client or the reply from the server) has complete discretion over the direction of the first hop of their outgoing traffic. The network the server is on may have 15 peers, but only send data out of two of them. When determining what network path to take, the major factor is network hops (as opposed to router hops). There is additional tuning that each network can do to affect the flow of traffic into and out of their network. Few networks actually determine on a path-by-path basis what way is best. Companies that do this are InterNAP (hardware and network), ArbiNet (network) and Route Science (since deceased and was a hardware product). Whatever address block you want to see how it is connected to the Internet. It won't graphically depict all connections they have, but it will show how that address block is viewed by the Internet in terms of what network path to take to get there. These changes happen administratively for whatever reason and a failure of a circuit\device\provider.

Well correct, satellite radio is there as is GPS (the most widely used GPS), but I'd reckon that most forms of satellite communications are above 5 GHz. That said, that wasn't one of my main points.

*blush* Thanks. ;-) BGP is a protocol. More appropriate words in your depiction would be <Internet>. I'll spin this off to a new thread as to not clutter the Chicago thread with how the Internet works. ;-) http://s4gru.com/index.php?/topic/2710-how-the-internet-works-haha/

I spun this out of the Chicago thread as it was OT. It started with me saying that the physically closest speed test site isn't always your best site. Well, BGP is just a protocol. More appropriate there would be "Internet". Latency is from you to the server you're talking to, then back to yourself. It is called the Round Trip Time (RTT). Each device along the line adds a bit of latency. These devices include amplifiers, routers, switches, radios, xWDM gear, etc. Everything that touches the signal adds latency. Actually, even the fiber itself adds latency compared to microwave. This is assuming everything is running smoothly. Congestion can add tremendous latency. It can also add jitter. It obviously reduces throughput. Not all carriers connect to all other carriers. http://fixedorbit.com/stats.htm shows how many peers the top ten networks have. A peer is another provider running BGP (the protocol of how providers talk to each other). Sometimes carrier A has to go through B, C and D to get to E. I will post some traceroutes from my border router to different Chicago area SpeedTest.net sites. That goes my network, (well, another one not named), then AboveNet, then NTT, then Steadfast, then the SilverIP server. That goes my network, (well, another one not named), then AboveNet, then Verizon, then InterNAP, then Blast. That goes my network, (well, another one not named), then AboveNet, then Level 3, then GigENet. To make it more interesting... Just because that's the path my data takes to get there, it may take a completely different path on the way back. Blast's Aurora server is physically closest to me. It's actually only about 3.1 miles away from me at one point. However, my best performance latency wise is to SilverIP. However, my best performance throughput wise was GigENet. Take a look at http://bgplay.routeviews.org/ and plug in an address block advertised on the Internet to see how connections between carriers change.

*nods* I know those guys well. They received funding from the ARRA. Their project was known as IBOP-South. Other projects in Illinois that received funding are DATA (connected to my network), IBOP-EC (soon connecting to my network), IBOP-NW (will connect to my network later) and UC2B. I believe they have 100x100 EoC deployed. Not that 100x100 is a lot, but there's a lot more copper in the ground than fiber and pretty quick\easy to turn up.

I wonder if anyone is using any EoC in backhaul. A few companies (XO and Megapath come to mind) are putting a lot of stock in it.

http://www.telecomramblings.com/2012/11/counting-the-on-net-towers/

BTW: AAV isn't really a technology. It just means someone other than Sprint.

The FCC's ULS has all information about all licenses. It's up to you to find the magic needed in their search page to get what you want. I used a 100 mile radius of CH01XC181 in my search.

Can anyone tell me what modulations Sprint's LTE deployment supports? What are the receive sensitivities for those modulations? What is the required SNR for those modulations?

For the betterment of mankind, always offload.

Yeah, one of the WISPs is leaving the site and I think is less than inspired to maintain organization. I'll be installing my dishes with care. ;-) *nods* I'll take better pictures when I'm back. I wasn't worried about the Sprint stuff when I was there.

Which set of pictures? :-p In the first set, all microwave backhaul would be for the Fixed Wireless Broadband providers on the tower. In the second set, yes, there are two backhauls. Here is an album of the microwave backhaul licenses Sprint has in the Chicago metro area: https://plus.google.com/photos/113290727794626880879/albums/5815581425345592769

I saw some partial corrections, but let me go over it, since none were fully laid out. Throughput is almost solely determined by channel size and modulation used (assuming there is sufficient SNR). Larger channel sizes and more complex modulations result in better throughput. Attenuation is almost solely determined by the inverse of the frequency. If all else is the same, 800 MHz will penetrate better than 5800 MHz. 5800 MHz can be made to penetrate better than 800 MHz, but it would take extraordinary power on 5800 and little power on 800 to accomplish this. Not always true, however, as 80 GHz has lower free space loss (attenuation in the air) than 60 GHz because 60 GHz is an oxygen absorption layer. The more oxygen you're going through, the more signal you lose. Technologies such as diversity and MIMO can accomplish more penetration or more throughput compared to a standard setup. Traditionally, less attenuation is desired for maximum coverage. As cells become smaller to support higher throughput, attenuation becomes your friend to prevent self-interference. You don't want one tower interfering with the next tower's ability to provide service. This is an advantage of the MMDS\ITFS (I forget their new names... EBS and something?) band that Clear uses is that they are good for small cell deployments. Traditionally, bands are larger the higher you go in frequency because the frequencies are more similar. 1900 MHz is more than double 800 MHz and they both act very differently. 60 GHz is more than double 24 GHz and they both act very differently. The 80 GHz band is actually a pairing of 5 GHz chunks at 80 GHz and 90 GHz. That's 5 GHz in one band for one purpose. At the lower end of the spectrum, the first 5 GHz contains almost every form of wireless communication you experience other than satellite. It is easier to provide 100 MHz wide channels at 24 GHz than 20 MHz wide channels at 1900 MHz or 10 MHz wide channels at 800 MHz simply because there is more room to work.

Thanks. *nods* If I was interested in the Sprint gear at the time, I would have grabbed more detailed pictures. I was just after an overview of the site including what types of antennas were pointing what directions, what poles were available, did those poles have LOS to the intended sites, etc.