What is Wireless RSSI level ?

Tags: RSSI

RSSI (Recieved Signal Strength Indicator) is a common name for the signal strength in a wireless network environment. It is a measure of the power level that a RF client device is receiving from an access point, for example. RSSI is the relative signal strength in a wireless environment and can be measured in any unit of power. It is often expressed in decibels (db), or as percentage values between 1-100, and can be either a negative, or a positive value.

The closer the figure is to zero, the better. For example, RSSI of -65 is better than -85. As a general example, a good signal would be -50, a reasonable would be -75, and a bad one would be -90, while -100 would provide no service at all.

To get a meaniful measurement of a good quality signal, you would have to subtract the noise on the line from that signal power level and consider the difference. A higher difference of signal to noise indicates better signal.

Notes:
Look at the RSSI only on an associated client
Some older chipsets used RSSI from 0 to 256, or 0 to 127. Most newer chipsets use 0 to 100.

User Reviews/Comments:

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by Sabbir - 2015-09-16 01:55

Thank you . but can you explain the relation what is the relation between RSCP and RSSI

by Philip - 2015-09-16 07:47

Here is the relation between RSSI and RSCP.

RSSI is the Rx level without considering and before descrambling / dispreading / noise on the line.
RSSI (dBm) = RSCP (dBm) - Ec/Io (dB)

RSCP = Received Signal code power. It is the collected RF energy after the correlation / descrambling process.
RSCP (dBm) = RSSI (dBm) + Ec/No (dB)

Ec: scrambling code energy per chip
No: Total energy per chip (as measured by a UE).
Io: Total energy per chip (as measured by a scanning device).

Ec/No: signal-to-noise ratio (as measured by a client). Energy per chip over the noise, a measure of the quality of the signal.

Ec/Io: signal-to-noise ratio (as measured by a scanning device). It is the ratio of the received energy per chip (code bit) and the interference level, usually in dB. If there is no interference present, the interference level is equal to the noise level.

by anonymous - 2016-09-28 02:58

does all the devices has inbuilt rssi

by calamares - 2016-12-08 08:51

It is possible if the signal in your location is not good then their have a solution to make the RSSI or dbm it can make it a good signal?

by wizbang_fl - 2017-01-03 00:43

From my experience signal strength is reduced because of barriers between the transmission point and receiving point. Examples: Heavy Walls, Vertical Differential (transmitter upstairs and downstairs low signal or vise versa) Noise is caused because of other equipment generating competing RF signal (AC or Furnace, Microwaves, larger powered electrical motor, or poorly shielded one) Most of which can be solved by relocating the transmission point or adding a WIRED secondary transmission point (effectively creating a second route that doesn't need to travel through the point creating the RF noise) My experience if the 2nd transmission point isn't wired it will be a dismal disappointment. If you do the work and wire the 2nd transmission point you will be much more satisfied with the end result.

Perhaps my favorite and CHEAP way of increasing power on a router is by adding some pieces of tin foil to the bottom of the router (especially if there is bare metal to attach it to (I just use duct tape) this will almost always increase the signal by 4 to 5, without added noise. Example I was just barely getting a signal on the opposite end of our condo. by adding 4 strips of crumpled up tin foil I improve the signal from -60 to -55 that allowed the wireless device on the other end to catch and keep the signal. But I've had to relocate a router due to line of sight to a device was passing through a large amount of AC duct work.

Think in terms of a straight line from your router to whatever wireless device you are trying to get a signal to keep in mind that routers don't generally transmit vertically beyond 5* and electronics etc will add noise to the signal.

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