RSSI stands for signal strength in a WiFi network. It’s an important part of a healthy Internet network to reap the best benefits out of your WiFi systems. Staying dependent on the dotted signal indicators as we find in our phones and routers are useful only for general purpose, but they do not show us the exact measures in numbers to get to the task of some calculation and find out what works best of our WiFi. And it often gets us in confusion in case we have no wit to set up the networks for their best performance. This is where RSSI comes as handy.
RSSI is a hidden format behind your everyday dotted or bar-based WiFi indicators. In most cases, the chief culprit of low performance is either varying signals or hindrance coming through a wall, a moving object, other routers, radio waves or some electromagnetic fields. In short, you can’t know it by yourself unless a check is done. You may be sitting nearer to the antenna yet an unknown field may be cutting your WiFi. This could be a big issue with different types of servers. So to get a right tweak for wireless networking, IEEE 802.11 networks that we commonly use we have to get to RSSI.
- Understanding RSSI
RSSI is a measure of signal strength, to be as straightforward as it can be. However, the measure can be done in different ways, and RSSI does it by checking the power level received by antenna and cable exactly before any kind of signal loss occurs due to any reasons.
Its measurement is a bit different than normal counting of numbers. Better RSSI, means better signals, are also measured in minus. Hence an RSSI nearer to zero is indicating better signal.
| – 25 is very good|| – 50 is good|| – 75 is low signal|| – 100 is no signal|
Now coming to technicals, RSSI level is a count taken of intermediate frequency (IF) just before amplification for most cases, and for zero-IF systems, the measure comes from the baseband signal. RSSI output is an analog level output and can be sampled by internal ADC.
To check RSSI, one may recite to geeky calculations if he wishes or can use a handy app like Netspotapp.com, that we will come later too.
I.I. RSSI, dBm and Noise
Though RSSI can be used at a place of dBm while in deeper terms both are very different. The dBm is a power ratio of references to one mW. So dBm is a direct index, the RSSI is a relative index.
For better signal management and good quality signal measurement one may subtract the noise directly from the signal power. Signal to noise differences are as better as they get for ultimately they show better signal against the noise.
I.II. Calculative Approach to RSSI
At an absolute level, it’s hard to conclude because of the nature of WiFi and different layers of calculations to get the right intermediate position, yet as RSSI is useful, we may try to find out the best ways to get to a meaningful calculation that gives us our results.
As we mentioned, Quality varying from 0% to 100% is normally the case when higher the number the better the link quality. So apart from the technical case, the purpose is to find the conditions of domestic noise. That can vary devices and its systems so we get SNR margin and check if the signal is usable as the quality should be above 30%.
SNR margin = signal(dBm) – noise(dBm)
E.g. if signal (RSSI) = -55db, and noise = -85db, then:
(-55db signal) – (-85db noise) = 30 SNR margin
Here better SNR margin indicates good and consistent signals. In a sample case, 54 Mbps data rate will require at least 25 dB of SNR margin.
The case becomes
db >= -50 db = 100% quality
db <= -100 db = 0% quality
For RSSI signal between -50db and -100db,
quality ~= 2 * (db + 100)
RSSI ~= (quality / 2) – 100
Now as we look at other examples.
High quality: 90% ~= -55db
Medium quality: 50% ~= -75db
Low quality: 30% ~= -85db
Unusable quality: 8% ~= -96db
As shows the above calculations, one can get a fairly decent observation of his signal case.
RSSI and NetSpot
As given at the beginning, the overall calculation goes a bit nerdy when it comes to regular users and those with novice understanding.
Therefore using an application gives you a fare chance to get an X-ray of your Wi-Fi connection and its performance.
RSSI is too low, and you can be sure of a troubled Network card and jump to a recheck through replacement of its hardware or driver. Same goes it’s too high. However, if it’s at right bar, your network card is clear to send (indicating as CTS).
A network monitoring tool as is NetSpot will bring you ease that the regular newbie or a user would expect in finding the right RSSI levels of their system and get an idea of tweaking it to the best performance. The major reason to go for the app are as follows
- Different systems have different maximum RSSI so one can be pretty confused in case data calculations isn’t operating in an Internet connection based app to sync with a higher server.
- 11 is standard technology for its independent nature. So by the sane token it has no specific preset of RSSI value and so of power levels. They are measured in mW or dBm but the measure you relate to depends totally on the systems used.
- Chipset makers and vendors give their individuals setups and measures. The range of RSSI values can vary anywhere , from 0 to RSSI_Max that’s your systems value. And RSSI is found in early stage getting an 802.11.
- To check and make use of the signal strength measurements, NetSpot is updated and keeps keen on Untitled channel by channel.
- NetSpot also does the calculations in two side checkups to find strength in twofold dimensions.
- RSSI Network Chart: he Networks Chart bases on 2.4 or 5 GHz bands that are commonly used. It compares it to other networks and shows the signal strengths for each.
- Wireless Network Detector: Other is Signal Strength visual indicator that appears like a graph and prepares the network’s signal strengths. You can move and find the best place to get the signals.
So those checks and builds are the basic functions to give you an appropriate way to find performance of your system and WiFi in your surroundings.
You can go by the calculations if you are nerdy or can use the Netspotapp.com for appropriate measures but once you are apt at knowing of RSSI levels, you can certainly be far better in using your home or office network for all purposes.