binary1000
Premium
join:2005-10-04
White Lake, MI | reply to whoever
Re: Lowest cost 900Mhz gear
Besides the WaveIp stuff that uses 5Mhz channels on 900MHz is there anyone else doing the narrow channel thing so it would be possible to mount a few 900Mhz APs on one tower with antennas that have good side attenuation? |
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Stealthwave
join:2005-07-03
Alvin, TX | The SR9 is going to be able to run at 5, 10, or 20ghz like the SR2 & SR5 cards from what I was told.
If even says it from the website.
»www.ubnt.com/supper_range9.php4 |
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lutful
Premium
join:2005-06-16
Ottawa, ON
 ·TekSavvy Solutions..
2 edits | reply to binary1000
said by Stealthwave  :The SR9 is going to be able to run at 5, 10, or 20ghz like the SR2 & SR5 cards from what I was told. Just noticed your post. Yes, the SR cards all have same Atheros MAC/BB chip so software should be able to narrow down channel size to 10Mhz or 5Mhz.
But FCC rules for 902Mhz-928Mhz ISM and SR9 RF design may limit the choice of channel center frequencies. At 20Mhz it seems to be just 915Mhz but maybe 910Mhz and 920Mhz is possible at 10Mhz and 5Mhz channel widths.
said by binary1000 :5Mhz channels on 900MHz is there anyone else doing the narrow channel thing so it would be possible to mount a few 900Mhz APs on one tower An alternate approach will be to use a single SuperAP that directly controls multiple sector antennas on the tower.
I am thinking the single SuperAP could use BPSK or Canopy-style BFSK modulation with fewer sub-carrier OFDM (maybe 8-FFT instead of 64-FFT of WiFi and 256-FFT of WiMax) for both carrier/interference robustness and better throughput.
It would have been very expensive with FPGA or DSP technology of past years, but Lattice Semiconductor just released the very low-cost ECP2 FPGA with DSP blocks.
Amazingly, the FPGA intellectual property (developed for Canopy-style FPGA) is up for sale for a few hundred bucks from this US R&D company: »www.comblock.com/com1028.htm
A few FPGA-DSP geniuses (and lots of cash) could give us a $299 Super-AP and $99 CPE for both 900Mhz and upcoming 600-800Mhz UHF bands but my past work experience is that established companies (like Motorola, Nortel, Cisco) get comfortable with what they have already designed and do not rock their own boats too much.  |
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