RE: [WISPA] Licensed Backhaul options

[Dustin Jurman]

Title: Message

Charles you make a good point, but I’m going to throw a “but” in here:    but the Orthogon / Canopy 300 radio’s will run also run at:   64 QAM .92 dual          -62 receive sensitivity              +18 output     (252.9 throughput) 64 QAM .75 dual          -68 receive sensitivity              +18 output    (206.7 throughput) 16 QAM .87 dual          -71 receive sensitivity              +20 output    (160.8 throughput)     Full list can be found in the release notes and if you do the math on those modulations you can get some very good performance.  I do agree with you that the licensed links would make more sense, but hanging 4 foot dishes on towers becomes a very expensive task or if you have to do a non-penetrating roof mount skid, the cost difference between the sleds is big.  So we have to take in more than the cost of the radio’s, licenses, leases and dishes but put together the total cost because if you are hanging BIG dishes you’re going to dig deeper into your pocket.   Sorry I missed you at the show, I’m on baby watch so when she saw wireless beer and gear she called foul and took away my kitchen pass L.   Dustin Jurman     From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Charles Wu Sent: Saturday, March 18, 2006 5:26 PM To: 'WISPA General List' Subject: RE: [WISPA] Licensed Backhaul options   >The Spectra would be around $20k with external antennas. A licensed product is going to be at least that, and probably $5k more. Sit back and actually think for a second about this comparison, and you'll realize that a similarly performing "unlicensed" solution will cost MUCH MORE (and be much riskier) relative to the licensed solution   The main difference is that the spectra requires 30 Mhz of ABSOLUTELY CLEAN SPECTRUM in both the vertical and horizontal polarities (150 Mb "Air Rate" transmits on V-pol & 150 Mb "Air Rate" transmits on H-pol -- cut off 1 polarity, you halve throughput)   In addition, the Rx sensitivity of the Spectra at the 300 Mb data rate (256 QAM) is -59 dB with an output power of +18 (so you'll need HUGE dishes to guarantee the link budget)   So, lets do a "theoretical" path calc / comparison (15 miles)   11 Ghz Licensed Link (100 Mb Full Duplex) Rx Sensitivity: -76 dBm Tx Power: +21 dBm 4' Dish: +39 dBi   Expected RSSI: -42.9 (>30 dB of fade margin = ROCK SOLID LINK =)   5 GHz Spectra Rx Sensitivity: -59 dB Tx Power: +18 6' Dish: +34 dBi   Expected RSSI: -49.4 (~10 dB of fade margin w/ 2' more of each dish)   Then there's all sort of "real-world" performance issues that occur with higher-order modulation schemes and license-exempt operation   -Charles   ------------------------------------------- WiNOG Austin, TX March 13-15, 2006 http://www.winog.com -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Travis Johnson Sent: Friday, March 17, 2006 10:03 PM To: WISPA General List Subject: Re: [WISPA] Licensed Backhaul options Travis Microserv Charles Wu wrote: You don't need licensed to high throughput backhaul. For example, Orthogon's Spectra provides 300Mbps aggregate at a price point generally Less than 45Mbps licensed.       Hi Matt,   I am curious to see where / what you got those numbers for the Orthogon Spectra?   -Charles   ------------------------------------------- WiNOG Austin, TX March 13-15, 2006 http://www.winog.com       -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Matt Liotta Sent: Thursday, March 16, 2006 1:28 PM To: WISPA General List Subject: Re: [WISPA] Licensed Backhaul options       -Matt   Bobby Burrow wrote:     I'm looking at moving to a licensed solution to increase throughput across one of out backhaul links that spans 5 hops. Distances between hops range anywhere from 7 to 19 miles.   We are currently using the dual nstreme Mikrotik solution and it is working very well, however the WRAP/RB532 solutions are only yielding ~25Mb per hop.   Can anyone recommend a licensed radio manufacturer that should net us 50Mb-100Mb per hop?   Thanks,   Bobby Burrow East Texas Rural Net www.etxrn.com

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