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for the usual 2g and 3g networks, the received signal levels at the mobile handsets are around -80dbm. any signal weaker than -80dbm is considerd to be less than minimum required.

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Posted by chandra

Meaning of RSSI - "Receive Signal Strength
Indicator", is a circuit to measure the strength of
an incoming signal. The basic circuit is designed
to pick RF signals and generate an output
equivalent to the signal strength. The ability of
the receiver to pick the weakest of signals is
referred to as receiver sensitivity. Higher the
receiver sensitivity, the better. There are
circuits which measure the signal strength based
on the output voltage. If the signal strength is
good the output voltage is higher and the output
voltage is poor if the signal strength is low.
Some indicators are designed to flash one of
their lights indicating the signal strength.
Depending on the received signal power, an
amplifier can be used to boost the signal.

Common devices with inbuilt RSSI are cell
phones, wireless network adapters and even
remote control. Antennas contain a RSSI Circuit
that can help us align the antenna for maximum
signal reception. In Windows XP, a software is
preinstalled to indicate signal strength and data
rate. There are many other tools to measure
signal strength. Ranging from software
preinstalled on your computer to freewares and
sharewares are available for measuring signal
strength. Some tools are only capable of basic
signal power indication while some can even
analyze data and suggest improvements and
solutions. RSSI is also used while implementing
Bluetooth Solutions.

Other Related Definitions:

“…RSSI is an indication of the power level being
received by the antenna. Generally, the higher
the RSSI level is the stronger the signal. Overall,
a level of 700 or more is considered adequate”
[Motorola.com]

“…a mechanism by which RF energy is to be
measured by the circuitry on a wireless NIC. This
numeric value is an integer with an allowable
range of 0-255 (a 1-byte value) called the
Receive Signal Strength Indicator (RSSI)" [IEEE
802.11 standard ]

“…Received Signal Strength Indicator (or
Indication): A signal or circuit that indicates the
strength of the incoming (received) signal in a
receiver. (The signal strength indicator on a cell
phone display is a common example). RSSI is
often done in the IF stage before the IF
amplifier. In zero-IF systems, it is done in the
baseband signal chain, before the baseband
amplifier.
RSSI output is often a DC analog level. It can
also be sampled by an internal ADC and the
resulting codes available directly or via peripheral
or internal processor bus. " [Dallas
Semiconductor ]

“…RSSI eliminates the need for additional
hardware in small wireless devices, and exhibits
favorable properties with respect to power
consumption size and cost. Because of its
attractiveness the research community has
extensively considered the use of radio signal
strength." [Yale University]

“… Use the Rx Signal Strength indicator as a
visual medium to know if you are nearer to the
device. Stronger signal strength will indicate you
are nearer to the device. " [Cognio Corporation]

“…To implement a power control link the remote
device must implement a Receive Signal Strength
Indicator (RSSI). For a transceiver wishing to
take part in a power controlled link it must be
able to measure its own receiver signal strength
and determine if the transmitter on the other
side of the link should increase or decrease its
output power level. The RSSI makes this
possible." [Antenna Systems & Technology]

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Posted by ravitheleo

The signal level at a receiver input and it is expressed in decibel.

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Posted by sagitraz