B.1 General
25.1723GPPRelease 17Requirements for support of Assisted Galileo and Additional Navigation Satellite Systems (A-GANSS) Frequency Division Duplex (FDD)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.1.1-1: 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 |
51.2 m |
7.7 m |
24.5 m |
|
Vertical accuracy |
102 m |
102 m |
102 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.1.1-2: Parameters for fine time assistance test
|
Information element |
Value |
|---|---|
|
TUTRAN-GPS drift rate |
0 |
|
TUTRAN-GANSS drift rate |
0 |
|
UE Positioning GPS Reference Time Uncertainty |
10.2 s |
|
GANSS TOD Uncertainty |
10.2 s |
B.1.2 Time assistance
For every Test Instance in each TTFF test case, the GANSS/GPS Reference Time shall have a random offset, relative to GANSS/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/GANSS 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 GANSS/GPS Reference Time shall be set to the nominal value.
B.1.3 GANSS reference time
For every Test Instance in each TTFF test case, the GANSS reference time (and GPS reference time, if applicable) 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.
For test cases which include satellites from regional systems, such as QZSS and SBAS, the reference location shall be selected within the defined coverage area of the systems.
B.1.5 Satellite constellation and assistance data
The satellite constellation shall consist of 24 satellites for GLONASS; 27 satellites for GPS, Modernized GPS and Galileo; 3 satellites for QZSS; 2 satellites for SBAS and 35 satellites for BDS (5 GEO, 27 MEO, 3 IGSO). Almanac assistance data shall be available for all these satellites. At least 7 of the satellites per GPS, Modernized GPS, Galileo, GLONASS and BDS constellation shall be visible to the UE (that is, above 15 degrees elevation with respect to the UE). At least 1 of the satellites for QZSS shall be within 15 degrees of zenith; and at least 1 of the satellites for SBAS shall be visible to the UE. For BDS with reference location in Asia, at least 1 of the visible satellites shall be a GEO (above 15 degrees elevation with respect to the UE). All other satellite specific assistance data shall be available for all visible satellites. In each test, signals are generated for only 6 satellites (or 7 if SBAS is included). The HDOP for the test shall be calculated using these satellites. The simulated satellites for GPS, Modernized GPS, Galileo, GLONASS and BDS shall be selected from the visible satellites for each constellation consistent with achieving the required HDOP for the test. For BDS with reference location in Asia, 1 of the simulated satellites shall be a GEO.
NOTE: Currently up to 30 BDS satellites (maximum 22 MEO) can be supported.
B.1.6 Atmospheric delay
Typical Ionospheric and Tropospheric delays shall be simulated and the corresponding values inserted into the Ionospheric Model IEs.
B.1.7 Sensors
The minimum performance requirements shall be met without the use of any data coming from sensors that can aid the positioning.
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 GNSS signals
The GNSS signal is defined at the A-GNSS 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 [13] 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 AGNSS it shall:
– discard any internally stored GPS and GANSS 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 GNSS measurements using the ‘new’ reference time or reference location or other information.
B.1.11 GNSS system time offsets
If more than one GNSS is used in a test, the accuracy of the GNSS-GNSS Time Offsets used at the system simulator shall be better than 3 ns.
Annex C (normative):
Propagation conditions