B.1 General

25.1713GPPFrequency Division Duplex (FDD)Release 17Requirements for support of Assisted Global Positioning System (A-GPS)TS

This annex specifies the additional parameters that are needed for the test cases specified in clause 5 and applies to all tests unless otherwise stated.

B.1.1 Parameter values

Additionally, amongst all the listed parameters (see annex E), the following values for some important parameters are to be used in the measurement control message.

Table B.1: Parameter values

Information element	Value – TTFF tests (except nominal accuracy test)	Value – TTFF tests (nominal accuracy test)	Value – Periodic tests
Measurement Reporting Mode	Periodical reporting	Periodical reporting	Periodical reporting
Amount of reporting	1	1	Infinite (see note)
Reporting interval	20 000 ms	20 000 ms	2 000 ms
Horizontal accuracy	50 m	15 m	50 m
Vertical accuracy	100 m	100 m	100 m
NOTE: Infinite means during the complete test time.

In the Sensitivity test case with Fine Time Assistance, the following parameter values are used.

Table B.2: Parameters for Fine Time Assistance test

Information element	Value
TUTRAN-GPS drift rate	0
SFN-TOW Uncertainty	lessThan10

B.1.2 Time assistance

For every Test Instance in each TTFF test case, the IE GPS TOW msec shall have a random offset, relative to GPS system time, within the error range of Coarse Time Assistance defined in the test case. This offset value shall have a uniform random distribution.

In addition, for every Fine Time Assistance Test Instance the IE UTRAN GPS timing of cell frames shall have a random offset, relative to the true value of the relationship between the two time references, within the error range of Fine Time Assistance defined in the test case. This offset value shall have a uniform random distribution.

For the Moving Scenario and Periodic Update Test Case the IE GPS TOW msec shall be set to the nominal value.

B.1.3 GPS Reference Time

For every Test Instance in each TTFF test case, the GPS reference time shall be advanced so that, at the time the fix is made, it is at least 2 minutes later than the previous fix.

B.1.4 Reference and UE locations

There is no limitation on the selection of the reference location, consistent with achieving the required HDOP for the Test Case. For each test instance the reference location shall change sufficiently such that the UE shall have to use the new assistance data. The uncertainty of the semi-major axis is 3 km. The uncertainty of the semi-minor axis is 3 km. The orientation of major axis is 0 degrees. The uncertainty of the altitude information is 500 m. The confidence factor is 68 %.

For every Test Instance in each TTFF test case, the UE location shall be randomly selected to be within 3 km of the Reference Location. The Altitude of the UE shall be randomly selected between 0 m to 500 m above WGS‑84 reference ellipsoid. These values shall have uniform random distributions.

B.1.5 Satellite constellation and assistance data

The satellite constellation shall consist of 24 satellites. Almanac assistance data shall be available for all these 24 satellites. At least 9 of the satellites shall be visible to the UE (that is above 5 degrees elevation with respect to the UE). Other assistance data shall be available for 9 of these visible satellites. In each test, signals are generated for only a sub-set of these satellites for which other assistance data is available. The number of satellites in this sub-set is specified in the test. The satellites in this sub-set shall all be above 15 degrees elevation with respect to the UE. The HDOP for the test shall be calculated using this sub-set of satellites. The selection of satellites for this sub-set shall be random and consistent with achieving the required HDOP for the test.

B.1.6 Atmospheric delays

Typical Ionospheric and Tropospheric delays shall be simulated and the corresponding values inserted into the Ionospheric Model IEs.

B.1.7 UTRA Frequency and frequency error

In all test cases the UTRA frequency used shall be the mid range for the UTRA operating band. The UTRA frequency with respect to the GPS carrier frequency shall be offset by +0.025 PPM.

B.1.8 Information elements

The information elements that are available to the UE in all the test cases are listed in annex E.

B.1.9 GPS signals

The GPS signal is defined at the A-GPS antenna connector of the UE. For UE with integral antenna only, a reference antenna with a gain of 0 dBi is assumed.

B.1.10 RESET UE POSITIONING STORED INFORMATION Message

In order to ensure each Test Instance in each TTFF test is performed under Time to First Fix (TTFF) conditions, a dedicated test signal (RESET UE POSITIONING STORED INFORMATION) defined in TS 34.109 [11] clause 5.4 shall be used.

When the UE receives the ‘RESET UE POSITIONING STORED INFORMATION‘ signal, with the IE UE POSITIONING TECHNOLOGY set to AGPS it shall:

– discard any internally stored GPS reference time, reference location, and any other aiding data obtained or derived during the previous test instance (e.g. expected ranges and Doppler);

– accept or request a new set of reference time or reference location or other required information, as in a TTFF condition;

– calculate the position or perform GPS measurements using the ‘new’ reference time or reference location or other information.

Annex C (normative):
Propagation conditions