Hi Ronni,
Thanks very much for that it may take me a little while to process it all. Option click on Wireless Menu for me does not show Noise (presumably because i¹m still on 10.6.8) but with your tip, I can now find it in System Profiler. Looking at your figures you obviously have a better network connection than me but maybe less intervening internal brick walls than my 120 yr old Albany cottage ;o) Also, from the comparison, I take it that for the MSC Index that higher numbers are better? At the moment, I am back to my old modem/network setup whilst I get a UPS to cover my new modem and phone but then, when I get a chance, I will take the laptop around a few different spots and compare the figure on each nettwork to get an idea how the walls attenuate the signals. Cheers Neil -- Neil R. Houghton Albany, Western Australia Tel: +61 8 9841 6063 Email: n...@possumology.com on 9/2/17 13:33, Ronni Brown at ro...@mac.com wrote: > Hi Neil, > > I wasn¹t going to attempt a reply as it involves a fairly complex reply. Not > knowing what Modem or how it displays its settings/readings. I mainly deal > with Apple Wi-Fi Networks this might helpful explanation to you or not ;-) > --- > RSSI (Receive Signal Strength Indication), is the relative signal strength in > a wireless environment in arbitrary units. > RSSI or received signal strength indication can go from 0 to -100 (for Apple - > other vendors can measure it differently as RSSI has no stated units) > > Apple appears to have decided to use a less negative number (closer to zero) > to mean a stronger signal. > > Signal-to-Noise Ratio (SNR) > > One option in determining where to best place your AirPort base station is to > measure its signal quality from a wireless client. In theory, where the signal > quality is best would make for ideal candidates for placement. This would hold > true for a single or multiple base stations in an extended wireless network. > > > One method to calculate signal quality is to compute the Signal-to-Noise Ratio > (SNR). > SNR is the signal level (in dBm) minus the noise level (in dBm). Both of these > values are typically represented as negative numbers. For example, a signal > level of -53dBm and a noise value of -90dBm would yield an SNR of 37dB (i.e., > SNR = Signal - Noise = -53 -(-90) = 37) > > > The calculated SNR value, as measured from a wireless client, would decrease > as the range to the base station increases due to applicable free space loss. > Also an increase in RF interference from microwave ovens, cordless phones, > walls, ceilings, etc, which would increase the noise level, would also > decrease the overall SNR value. > > > SNR Guideline > * 40+dB = Excellent signal > * 25dB to 40dB = Very good signal > * 15dB to 25dB = Low signal > * 10dB to 15dB = Very low signal > * 5dB to 10dB = Little or no signal > > > The following are two methods to take signal & noise level readings: > > > Method 1 - Using iStumbler > Download and install a copy of iStumbler <http://istumbler.net/> . Use > iStumbler's Inspector feature (select Edit > Inspector from the iStumbler's > menu) to take the signal and noise level readings. > > > Method 2 - Using OS X System Profiler / System Report > Click on the Apple icon on the menu bar > About This Mac > More Info >System > Report > Network > Wi-Fi - Interfaces > > Current Network Information > Find > your wireless network > Signal / Noise > > Jot down the numbers that you see here, for example > > -50 dBm / -90 dBm > > SNR = Signal minus Noise, so using the example below: > > -50 dBm - (-90 dBm) = 40 dB SNR > > Regardless of which method you use to gather the reading, you would plug them > into the SNR formula. The desired goal value is an SNR of 25+dB. At this SNR > value, wireless clients should be getting reasonable throughput performance > with the base station. This is also the value you would want at the location > where you would want to place a second base station to extend the first if you > are planning on extending the wireless range. > > > Then use the familiar chart to evaluate your signal quality. > > 40dB+ SNR = Excellent signal > 25dB to 40dB SNR = Very good signal > 15dB to 25dB SNR = Low signal > 10dB to 15dB SNR = Very low signal > 5dB to 10dB SNR = No signal > > As you might imagine, the SNR will change in relation to the location of your > Mac laptop to the router > > If you are getting SNR values of less than 25+dB at the client, either try to > locate the source of the Wi-Fi interference or try relocating the base station > until they are within a 25+dB range. > > My Airport ¹Simultaneous Dual-Band 802.11n Wi-Fi 5GHz /2.5GHz¹ Network. > Option click on Wireless Menu shows my 5GHz RSSI: -55 dBM Noise: -95 dBM Tx > Rate: 300 Mbps MSC Index: 15 > > Transmit Rate: This is the max network speed available with the current > signal strength. The data rate is measured in Mbps. > MCS Index: Short for Modulation and Coding Scheme, MCS is only associated > with 802.11n networks. > > Hope this makes sense to you and helps to answer your questions some what. > > Regards, > Ronni > > 13-inch MacBook Air (April 2014) > 1.7GHz Dual-Core Intel Core i7, Turbo Boost to 3.3GHz > 8GB 1600MHz LPDDR3 SDRAM > 512GB PCIe-based Flash Storage > > macOS Sierra 10.12.3 > >> On 8 Feb 2017, at 3:11 pm, Neil Houghton <n...@possumology.com> wrote: >> >> Hi all, >> >> As a result of changing internet plan, I scored a new modem. It creates 2 >> wireless networks - one on 2.4GHz and one on 5GHz. >> >> >> Both appear to work just fine so I used the option click on the wireless >> menu-bar icon to see what differences were apparent. Report as follows: >> >> 2.4GHz network: >> RSSI: -68 >> Transmit rate: 117 >> MCS Index: 14 >> >> >> 5GHz network: >> RSSI: -70 >> Transmit rate: 162 >> MCS Index: 12 >> >> >> I'm not sure what that all means ;o) >> >> I understand transmit rate - which would seem to suggest that the 5GHZ at >> 162 is performing slightly better than the 2.4GHz at 117 ?? >> >> >> Are the other figure significant? >> Are there other factors to consider when choosing which network to use? >> >> >> >> TIA >> >> >> >> Cheers >> >> >> >> Neil
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