IoT M2M blog

The home of free hints and tips about wireless IoT / M2M

PTRCB Over-the-Air Test

PTRCB Over-the-Air Test ( TRP, TIS and RSE )

For cellular applications such as 2G or 3G basic RF performance is measured in terms of the product being able to transmit and receive reliably on a network. The scientific way to measure performance is in an anechoic chamber.  The measurements numbers used are outlined here;

TRP – Total Radiated Power

This defines how much power is being radiated from the device and is measured in dBm. The higher this number, the better the device is able to transmit.

TIS – Total Isotropic Sensitivity

This defines how low a signal the device can receive and demodulate. The lower this number (with a minus figure) the better the device can operate in weak signal environments.

RSE – Radiated Spurious emissions

In practice this is the most difficult test for cellular products to pass. These are radio waves output by the device which are above the power limit set by regulatory authorities to avoid interference. When a test confirms a radiated spurious emission over the limit either the device or the antenna must be modified to get it below the limit and thus pass certification. Otherwise the device cannot be sold in that country.

Different operators, especially in the USA (such as AT&T, Sprint etc) have specific numbers for TRP and TIS that the device must reach to be accepted on their networks. Other operators do not specifically set any requirements. No matter if it is mandatory or not, it is our experience that the wireless products with the best TRP and TIS values succeed in the market. Passing RSE is mandatory for any operator whom requires PTCRB or type approvals. A design that has optimized TRP/TIS will usually pass RSE on the first attempt.

Wireless products are regulated in each country by slightly different standards.

Credit: Taoglas

2. Performance

The Basic concepts – TRP, TIS and RSE

For cellular applications such as GSM or CDMA basic RF performance is measured in terms of the product being able to transmit and receive reliably on a network. The scientific way to measure performance is in an anechoic chamber.

The measurements numbers used are outlined here;

TRP – Total Radiated Power

This defines how much power is being radiated from the device and is measured in dBm. The higher this number, the better the device is able to transmit.

TIS – Total Isotropic Sensitivity

This defines how low a signal the device can receive and demodulate. The lower this number (with a minus figure) the better the device can operate in weak signal environments.

RSE – Radiated Spurious emissions.

In practice this is the most difficult test for cellular products to pass from Taoglas’ experience. These are radio waves output by the device which are above the power limit set by regulatory authorities to avoid interference. When a test confirms a radiated spurious emission over the limit either the device or the antenna must be modified to get it below the limit and thus pass certification. Otherwise the device cannot be sold in that country.

Different operators, especially in the USA (such as AT&T, Sprint etc) have specific numbers for TRP and TIS that the device must reach to be accepted on their networks. Other operators do not specifically set any requirements. No matter if it is mandatory or not, it is our experience that the wireless products with the best TRP and TIS values succeed in the market. Passing RSE is mandatory for any operator whom requires PTCRB or type approvals. A design that has optimized TRP/TIS will usually pass RSE on the first attempt.

Wireless products are regulated in each country by slightly different standards.

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