nandish
07-30-2003, 05:35 PM
I would like to introduce myself as Nandish Chalishazar from the
University of kansas. I am involved in a research project where we established a 802.11b wireless link over 8 Km in the north grip region of Greenland which does not require us to comply with the FCC regulations. We had used the hyperlink HA2401-AGC1000 amplifier and HG2415U-PRO 15 dBi omnidirectional antenna in conjuction with the orinoco 802.11b cards to establish a 8 Kmwireless link in Greenland. The hyperlink amplifier had a fixed transmit power of 1 W and a receive gain of 17 dB. This was part of a research project that we took to greenland. We tested these equipment on the ice sheet and went around different tracks of 8 Km in Greenland. A lot of measurements of the signal power, noise power and SNR were made using the orinoco client manager software.
I came back to kansas and started analyzing the data. I am currently
trying to see how close the theoretical model that I developed matches
the measurements that I made in Greenland. I noticed a problem on these
lines and I have been desperately trying to find an answer to that. In my measurements, I had the card, amp and antenna combination at both my base station as well as the mobile station. One of the weird things that I noticed was that the signal power measurements that I made matched the theoretical model when I did not include the 17 dB of receive gain while doing a link budget calculation. Also, the interesting thing that I noted was the following. The 802.11b card by itself was seeing a noise power of around -88 dBm. Now, when I connected the amplifier (supposed to have a receive gain of 17 dB and transmit power of 1 W) and the external antenna, I still saw the noise power levels of -87 dBm. The amp had a noise figure of 3.5 dB and receive gain of 17 dB. so, theoretically, I should be seeing
a bump in the noise power and the signal power. Noise power measurements by the software showed the same value. Also, my signal power measurements matched the theoretical model when I ignored the receive gain of 17 dB. However, I am aware that the amplifier was working fine and the link would not have worked over 8 Km without that. Also, I tested the amps in the lab with the network analyzer and it did show a receive gain of 17 dB and a transmit power of 1 W. Thus, I am confused about the measurements that I am seeing.
I am not sure if there is something wrong with my understanding of the way in which the client manager software makes the measurements or if the amplifier had an AGC in the receive direction. It was a lot of hard work on the ice sheets for these measurements and I find myself stuck with this problem. I would like to thank you in advance for all the help that you may provide. Looking forward to your reply.
Thanks
Nandish
University of kansas. I am involved in a research project where we established a 802.11b wireless link over 8 Km in the north grip region of Greenland which does not require us to comply with the FCC regulations. We had used the hyperlink HA2401-AGC1000 amplifier and HG2415U-PRO 15 dBi omnidirectional antenna in conjuction with the orinoco 802.11b cards to establish a 8 Kmwireless link in Greenland. The hyperlink amplifier had a fixed transmit power of 1 W and a receive gain of 17 dB. This was part of a research project that we took to greenland. We tested these equipment on the ice sheet and went around different tracks of 8 Km in Greenland. A lot of measurements of the signal power, noise power and SNR were made using the orinoco client manager software.
I came back to kansas and started analyzing the data. I am currently
trying to see how close the theoretical model that I developed matches
the measurements that I made in Greenland. I noticed a problem on these
lines and I have been desperately trying to find an answer to that. In my measurements, I had the card, amp and antenna combination at both my base station as well as the mobile station. One of the weird things that I noticed was that the signal power measurements that I made matched the theoretical model when I did not include the 17 dB of receive gain while doing a link budget calculation. Also, the interesting thing that I noted was the following. The 802.11b card by itself was seeing a noise power of around -88 dBm. Now, when I connected the amplifier (supposed to have a receive gain of 17 dB and transmit power of 1 W) and the external antenna, I still saw the noise power levels of -87 dBm. The amp had a noise figure of 3.5 dB and receive gain of 17 dB. so, theoretically, I should be seeing
a bump in the noise power and the signal power. Noise power measurements by the software showed the same value. Also, my signal power measurements matched the theoretical model when I ignored the receive gain of 17 dB. However, I am aware that the amplifier was working fine and the link would not have worked over 8 Km without that. Also, I tested the amps in the lab with the network analyzer and it did show a receive gain of 17 dB and a transmit power of 1 W. Thus, I am confused about the measurements that I am seeing.
I am not sure if there is something wrong with my understanding of the way in which the client manager software makes the measurements or if the amplifier had an AGC in the receive direction. It was a lot of hard work on the ice sheets for these measurements and I find myself stuck with this problem. I would like to thank you in advance for all the help that you may provide. Looking forward to your reply.
Thanks
Nandish