TIS Measurement — CTIA OTA Test Plan / 3GPP OTA Methods

What Is TIS?

TIS (total isotropic sensitivity) measurement is the measurement in which the receiver sensitivity, including the antenna, is determined by measuring and integrating the lowest field level at which the device provides the defined error rate in defined directions on the sphere.

Purpose of TIS

The purpose is to determine receiver performance in the device's actual use configuration and verify that it meets operator requirements.

Which Products Is TIS Applied To?

Cellular devices and modules
CPE and routers
In-vehicle connection units
Wearable devices

In Which Sectors Is TIS Used?

TelecommunicationsElectronicsSoftwareCyber Security

Standards Related to TIS

CTIA OTA Test Plan
3GPP TS 38.521-2
3GPP TR 37.977
ETSI OTA measurement methods

TIS Conditions

Screening: Spherical; with standard defined angle steps
criterion: Lowest field level providing defined block/bit error rate
Kutuplanma: Her noktada iki dik kutuplanma
Integration: Integration of direction-based sensitivities on the sphere

Equipment for TIS

Antiglare chamber and spherical positioner
network emulator
Calibrated measuring antenna and reference dipoles
Error rate measurement and integration software

Sample Requirements for TIS

The device must support error rate reporting
The connection must be stable
Chamber calibration must be up to date
The device must be in final configuration

Duration of TIS

Weeks depending on scan resolution and number of bands; TIS measurement is significantly longer than TRP.

TIS Procedure

1The room path loss is calibrated.
2The device is installed on the locator and connected to the network.
3The level corresponding to the error rate threshold is sought in each direction.
4Scanning is completed at two polarizations.
5TIS is calculated by integrating the values.
6The result is reported on a band-by-band basis.

TIS Acceptance Criteria

The acceptance criterion is given as the maximum TIS value in the operator acceptance plans or in the specification.

Evaluation of Results

TIS measurement takes a long time because it requires threshold searching in all directions; Reducing the scan resolution shortens the time but increases the uncertainty. Internal device interference (self-interference) may distort the TIS result and should be examined separately.

TIS Report

Implemented test plan
Device and software description
Calibration and angle step
TIS results by band
Measurement uncertainty

Accreditation

EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.

Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.

Scope and authorisations

Related Regulations

Operator acceptance programs

RF and Wireless Testing — What Does This Testing Field Cover?

The section below describes the field that the TIS test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.

RF and wireless testing shows that a device containing a radio uses the spectrum correctly and operates within the limits the relevant legislation allows. This family is a separate body of work from EMC: EMC addresses unwanted interference, whereas here INTENTIONAL emission is assessed.

Spectrum is a public and limited resource, and this determines the legal character of the field. A device spilling outside its permitted band or emitting excess power is not merely a technical defect but a violation that disrupts someone else's service. Radio conformity is therefore policed more strictly than other test fields and markets maintain their own national regimes.

Measurements run separately on the transmitter and receiver sides. On the transmitter side, output power, occupied bandwidth, frequency error, unwanted emissions, adjacent channel power and the power envelope are measured. On the receiver side, sensitivity, selectivity, blocking and spurious response rejection are assessed. The receiver side is often neglected, but in some bands it is a regulatory requirement.

Access protocol specific behaviours are a third axis: listen before talk (LBT), duty cycle, dynamic frequency selection (DFS) and transmit power control (TPC). These mechanisms enable spectrum sharing and it must be shown that they work correctly.

HUMAN EXPOSURE is the fourth axis and one of the most commercially critical. For devices used close to the body, SAR (specific absorption rate) is measured; for devices used at a distance, a field strength assessment is made. Limits and measurement methods vary by market; the same device is assessed separately for Europe and the United States.

Market regimes are decisive in this family and do not substitute for one another: the Radio Equipment Directive and ETSI harmonised standards in Europe, FCC authorisation in the United States (through a TCB for intentional radiators), ISED in Canada, MIC in Japan, KC in South Korea and SRRC in China each carry their own set of requirements. The same device requires a separate file for each market, and some markets impose a local representative or local testing requirement.

Module integration is the subject that raises the most questions in the field. Using a certified radio module does not automatically make the device compliant. A module certificate is valid for a defined antenna, a defined supply and defined conditions of use; if the antenna changes, the layout changes or the module is operated at a different power level, reassessment is required.

The presence of several radios in the same device (Wi-Fi + Bluetooth + cellular + NFC) gives rise to a simultaneous transmission assessment: SAR and unwanted emission measurements are made for the worst case in which the radios operate together.

Method groups in this field

Transmitter measurements
Output power, occupied bandwidth, frequency error, unwanted emissions, adjacent channel power, power spectral density.
Receiver measurements
Sensitivity, selectivity, blocking, spurious response rejection.
Spectrum sharing mechanisms
Verification of listen before talk, duty cycle, dynamic frequency selection and transmit power control.
Human exposure
SAR measurement (handheld and body-worn devices), field strength assessment, multi-radio scenarios.
Protocol conformity
Cellular network conformity testing, Bluetooth and Wi-Fi certification testing, GNSS performance.
Antenna measurements
Gain, radiation pattern, efficiency and total radiated power (TRP) measurements.

Commonly confused in this field

Using a certified module does not automatically make the device compliant; if the antenna, layout or power level changes, reassessment is required.
An FCC file does not replace a CE file; each market operates its own regime.
Receiver side measurements are a regulatory requirement in some bands; measuring only the transmitter produces an incomplete file.
SAR limits and measurement methods differ by market; a result in one market does not carry over to another.
For devices carrying several radios the simultaneous transmission scenario must be assessed; measuring them individually is not sufficient.
Some markets impose local testing or a local representative requirement; technical conformity alone does not secure market access.

Which decisions these results support

Market access under radio equipment legislation
Verification of the antenna and RF front end design
SAR and RF exposure conformity
Verification of module integration and the scope of reassessment
Determining the worst case in multi-radio scenarios

Related Tests

Frequently Asked Questions About TIS

According to which standard is TIS made?

TIS is executed in scope CTIA OTA Test Plan, 3GPP TS 38.521-2, 3GPP TR 37.977 and ETSI OTA measurement methods. The limit values and acceptance criteria to be applied are defined in the product standard; The version valid for your product is confirmed in writing at the offer stage.

Which products does TIS apply to?

Mainly applied to Cellular devices and modules, CPE and routers, In-vehicle connection units and Wearable devices. Whether your product is included in the scope is determined by examining its technical specifications and intended use.

Under what conditions is TIS done?

The determining parameters are: Screening — Spherical; with standard defined angle steps, criterion — Lowest field level providing defined block/bit error rate and Kutuplanma — Her noktada iki dik kutuplanma. The full terms are in the "Test Conditions" section on the page and vary depending on the product standard.

What kind of sample is needed for TIS?

The device must support error rate reporting, The connection must be stable and Chamber calibration must be up to date. The number of samples is determined according to the product standard and the scope to be reported.

How long does TIS take?

Weeks depending on scan resolution and number of bands; TIS measurement is significantly longer than TRP. This duration belongs to the experiment itself; sample preparation, queuing and reporting are also evaluated. A realistic schedule for your product is given in the offer.

What is the TIS result called "appropriate"?

The acceptance criterion is given as the maximum TIS value in the operator acceptance plans or in the specification.