70.6 E-OTD Timing Measurement Accuracy

3GPP51.010-1Mobile Station (MS) conformance specificationPart 1: Conformance specificationTS

Scope of Tests

This test procedure plan is intended verify the operation of Enhanced Observed Timing Difference (E-OTD) measurement functionality from an E-OTD capable GSM Mobile Station (MS).

The scope of this test plan is limited to verification of the MS physical layer against 3GPP TS 05.05, Release 1999, version 8.7.1, annex I. Specifically, this includes validation of MS observed timing measurement accuracy only.

The recommended measurement test environment is shown in the present document annex 6.

70.6.1 E-OTD Accuracy, Sensitivity Performance Tests using GMSK Signals

70.6.1.1 Definition

Enhanced Observed Timing Difference is a mechanism intended to provide location information from an MS within a GSM network. E-OTD measures the burst timing alignment between the serving cell for the MS and a minimum of two neighbor cells. The observed timing difference, along with the BSIC or Cell ID of each neighbor cell that can be received and measured by the MS, is reported to the network. Using this information, an E-OTD capable network can calculate the location of the MS using triangulation techniques.

Although an E-OTD capable MS must receive a minimum of two neighbors in order to provide the network with useable data for E-OTD positioning, only one neighbor is required for the timing measurement tests described in this procedure.

70.6.1.2 Conformance requirement

The RMS90 measurement error of an E-OTD capable MS receiving a neighbor shall not exceed 100 nanoseconds and 300 nanoseconds at a minimum neighbor carrier signal strength relative to relative sensitivity levels of 12 dB and –8 dB respectively, as specified in 3GPP TS 05.05, annex I, sub clause I.2.1, table I.2.1

70.6.1.3 Test purpose

E-OTD measurement accuracy is heavily influenced by the type of RF environment available to the MS at the time a Measure Position Request is received from the network. Nearby neighbor stations that provide a relatively high C/N to the MS receiver should result in greater measurement accuracy than those further away with a low C/N.

The purpose of this test case is to verify that an E-OTD capable MS can provide an observed timing difference (OTD) measurement of sufficient accuracy when measuring against a GMSK neighbor. During this test, there shall be no co-, adjacent-, or alternate-channel interference.

Specific PICS statements

PIXIT statements

70.6.1.4 Method of Test

Initial Configuration

Neighbor Cell: One neighbor cells with a minimum configuration of a BCCH in order to allow the MS to perform the required measurements. The neighbor BCCH shall be included in the serving BCCH System Information Neighbor List.

Assistance Data: The assistance data listed in Table 70.6.1-1 and Table 70.6.1-2 shall be provided by the serving base station simulator. Without assistance data, successful validation of the MS physical layer may be impossible due to limitations imposed by the device’s upper protocol layers.

Table 70.6.1-4: RRLP Measure Position Request Field Values,
E-OTD Reference BTS for Assistance Data Element

Field Name

Value

Comments

BCCH Carrier

Range 0-1023

ARFCN of Serving BCCH

BSIC

Range 0 to 65

BSIC of Serving BCCH

Time Slot Scheme

Either 0 or 1, as applicable

0=All time slots 156.25 bits long
1=Time slots 0 and 4 are 157 bits long, all other time slots are 156 bits long.

BTS Position

None

Not applicable for timing accuracy measurements

Table 70.6.1-2: RRLP Measure Position Request Field Values,
E-OTD Measurement Assistance Data for System Information List Element

Field Name

Value

Comments

Number of Neighbors

1

E-OTD Neighbor Present

1

BSIC

Range 0 to 63

BSIC of neighbor BCCH

Multiframe Offset

Range 0-51

The value of this field is specific to the test configuration, and shall be calculated according to 3GPP TS 04.31, Annex A, Section A.2.2.3.

Time Slot Scheme

Either 0 or 1, as applicable

0=All time slots 156.25 bits long
1=Time slots 0 and 4 are 157 bits long, all other time slots are 156 bits long.

Rough RTD

Range 0-1250

Set to rough RTD value for the specific test configuration

Expected OTD

None

Not Applicable

Uncertainty of Expected OTD

None

Not Applicable

Fine RTD

None

Not Applicable

Relative North

None

Not Applicable

Relative East

None

Not Applicable

70.6.1.5 Test procedure

a) Configure serving base station simulator to transmit GMSK dummy bursts in time slots 1 through 7.

b) Establish RF connectivity between the E-OTD compatible MS and its serving base station simulator, verify RSSI of -80 dB.

c) Disable the interfering signal generator.

d) Configure the neighbor base station simulator such that its power (as measured at the antenna terminal of the E‑OTD MS under test) is -90 dBm, and that it is transmitting GMSK dummy bursts in time slots 1 through 7.

e) The serving base station SS initiates a Measure Position Request RRLP message. Begin logging E-OTD Measure Position Response RRLP message from the MS under test. The Measure Position Request is repeated a minimum of 250 times at 5 s intervals and the response RRLP messages are logged.

f) The SS calculates each trial’s error relative to the known RTD, sort the data in ascending order, develop the 90 % subset M and calculate the RMS90 error.

g) Disable the interfering signal generator.

h) Configure the neighbor base station simulator such that its power (as measured at the antenna terminal of the E‑OTD MS under test) is -110 dBm, and that it is transmitting GMSK dummy bursts in time slots 1 through 7.

i) The serving base station SS initiates a Measure Position Request RRLP message. Begin logging E-OTD Measure Position Response RRLP message from the MS under test. The Measure Position Request is repeated a minimum of 250 times at 5 second intervals and the response RRLP messages are logged.

j) After transmitting 250 Measure Position Request RRLP messages to the MS under test, calculate each trial’s error relative to the known RTD, sort the data in ascending order, develop the 90 % subset M and calculate the RMS90 error.

70.6.1.6 Test Requirements

Verify that the RMS90 error calculated for each procedure in 70.6.1.5 is within the test conformance requirements listed in Table 70.6.1-3

Table 70.6.1-3, Test Conformance Requirements

Procedure

RMS90 error, 3GPP TS 05.05,
Annex I, Minimum Performance Requirement

RMS90 error, 3GPP TS 51.010, 70.6.1, Test Conformance Requirement

Step f

 100 nanoseconds

110 nanoseconds

Step j

 300 nanoseconds

310 nanoseconds

70.6.2 E-OTD Accuracy, Interference Performance Tests

70.6.2.1 Definition

Enhanced Observed Timing Difference is a mechanism intended to provide location information from an MS within a GSM network. E-OTD measures the burst timing alignment between the serving cell for the MS and a minimum of two neighbor cells. The observed timing difference, along with the BSIC or Cell ID of each neighbor cell that can be received and measured by the MS, is reported to the network. Using this information, an E-OTD capable network can calculate the location of the MS using triangulation techniques.

Although an E-OTD capable MS must receive a minimum of two neighbors in order to provide the network with useable data for E-OTD positioning, only one neighbor is required for the timing measurement tests described in this procedure.

70.6.2.2 Conformance requirement

The RMS90 measurement error of an E-OTD capable MS receiving a neighbor with a co-channel interference ratio of 0 dB shall not exceed 300 nanoseconds, 10dB not exceeding 100 nanoseconds, adjacent channel interference ratio of –18dB not exceeding 500 nanoseconds, -8 dB not exceeding 200 nanoseconds, as well as an adjacent channel (400 kHz ) interference ratio of –41dB not exceeding 100 nanoseconds, as specified in 3GPP TS 05.05, Release 99, Annex I, Section I.2.1, Table I.2.2

70.6.2.3 Test purpose

E-OTD measurement accuracy is heavily influenced by the type of RF environment available to the MS at the time a Measure Position Request is received from the network. As the C/I ratio due to neighbor cell co-channel interference is reduced, E-OTD measurement accuracy may be reduced as well.

The purpose of this test case is to verify that an E-OTD capable MS can provide an observed timing difference (OTD) measurement of sufficient accuracy when measuring against a GMSK neighbor in the presence of a channel interference with a 0 dB, 10dB, -18dB, -8dB, and –41dB C/I.

Specific PICS statements

PIXIT statements

70.6.2.4 Method of Test

Initial Configuration

Neighbor Cells: at least two neighbor cells with a minimum configuration of a BCCH in order to allow the mobile to perform the required accuracy measurements. The neighbor BCCH shall be included in the serving BCCH System Information Neighbor List.

70.6.2.5 Test procedure

Co-Channel test procedure at 0dB C/I:

a) Configure serving base station simulator to transmit GMSK dummy bursts in time slots 1 through 7

b) Establish RF connectivity between the E-OTD compatible MS and its serving base station simulator, verify RSSI of -80 dBm

c) Enable the interfering signal generator on the frequency of the neighbor cell at a power (at the antenna connection of the EOTD-capable MS) of -80 dBm

d) Configure the neighbor base station simulator such that its power (as measured at the antenna terminal of the E-OTD MS under test) is -80 dBm, and that it is transmitting GMSK dummy bursts in time slots 1 through 7.

e) The SS initiates a Measure Position Request RRLP messages and begins logging E-OTD Response messages from the MS under test. The Measure Position Request message is repeated 250 times at 5-second intervals and the response RRLP messages are recorded.

f) After transmitting 250 Measure Position Request RRLP messages to the MS under test, calculate each trial’s error relative to the known RTD, sort the data in ascending order, develop the 90% subset M and calculate the RMS90 error.

Co-Channel test procedure at 10dB C/I:

g) Establish RF connectivity between the E-OTD compatible MS and its serving base station simulator, verify RSSI of -80 dBm

h) Enable the interfering signal generator on the frequency of the neighbor cell at a power (at the antenna connection of the EOTD-capable MS) of -90 dBm

i) Configure the neighbor base station simulator such that its power (as measured at the antenna terminal of the E-OTD MS under test) is -80 dBm, and that it is transmitting GMSK dummy bursts in time slots 1 through 7.

j) The SS initiates a Measure Position Request RRLP messages and begins logging E-OTD Response messages from the MS under test. The Measure Position Request message is repeated 250 times at 5-second intervals and the response RRLP messages are recorded.

k) Repeat Step f) and calculate the results.

Adjacent channel test procedure at -18dB C/I:

l) Establish RF connectivity between the E-OTD compatible MS and its serving base station simulator, verify RSSI of -70 dBm

m) Enable the interfering signal generator on either of the channels adjacent to the frequency of the neighbor cell at a power (at the antenna connection of the EOTD-capable MS) of -62 dBm. The RF channel used by the interfering signal generator during this test must not be the same as that used by the serving base station simulator.

n) Configure the neighbor base station simulator such that its power (as measured at the antenna terminal of the E-OTD MS under test) is -80 dBm, and that it is transmitting GMSK dummy bursts in time slots 1 through 7.

o) The SS initiates a Measure Position Request RRLP messages and begins logging E-OTD Response messages from the MS under test. The Measure Position Request message is repeated 250 times at 5-second intervals and the response RRLP messages are recorded.

p) Repeat Step f) and calculate the results.

Adjacent channel test procedure at – 8dB C/I:

q) Establish RF connectivity between the E-OTD compatible MS and its serving base station simulator, verify RSSI of -70 dBm

r) Enable the interfering signal generator on either of the channels adjacent to the frequency of the neighbor cell at a power (at the antenna connection of the EOTD-capable MS) of -72 dBm. The RF channel used by the interfering signal generator during this test must not be the same as that used by the serving base station simulator.

s) Configure the neighbor base station simulator such that its power (as measured at the antenna terminal of the E-OTD MS under test) is -80 dBm, and that it is transmitting GMSK dummy bursts in time slots 1 through 7.

t) The SS initiates a Measure Position Request RRLP messages and begins logging E-OTD Response messages from the MS under test. The Measure Position Request message is repeated 250 times at 5-second intervals and the response RRLP messages are recorded.

u) Repeat Step f) and calculate the results.

Adjacent channel (400kHz) test procedure at -41dB C/I:

v) Establish RF connectivity between the E-OTD compatible MS and its serving base station simulator, verify RSSI of -70 dBm

w) Enable the interfering signal generator on either of the channels alternate (400 kHz offset) to the frequency of the neighbor cell at a power (at the antenna connection of the EOTD-capable MS) of -39 dBm. The RF channel used by the interfering signal generator during this test must not be the same as that used by the serving base station simulator.

x) Configure the neighbor base station simulator such that its power (as measured at the antenna terminal of the E-OTD MS under test) is -80 dBm, and that it is transmitting GMSK dummy bursts in time slots 1 through 7.

y) The SS initiates a Measure Position Request RRLP messages and begins logging E-OTD Response messages from the MS under test. The Measure Position Request message is repeated 250 times at 5-second intervals and the response RRLP messages are recorded.

z) Repeat Step f) and calculate the results.

70.6.2.6 Test Requirements

Verify that the RMS90 error calculated for each procedure in 70.6.2.5 is within the test conformance requirements listed in Table 70.6.2-1.

Table 70.6.2-1, Test Conformance Requirements

Procedure

RMS90 error, 3GPP TS 05.05,
Annex I, Minimum Performance Requirement

RMS90 error, 3GPP TS 51.010, 70.6.2, Test Conformance Requirement

Step f

 300 nanoseconds

310 nanoseconds

Step k

 100 nanoseconds

110 nanoseconds

Step p

 500 nanoseconds

510 nanoseconds

Step u

 200 nanoseconds

210 nanoseconds

Step z

 100 nanoseconds

110 nanoseconds

70.6.3 E-OTD Accuracy, Multipath Performance Test using GMSK Modulated Signals.

70.6.3.1 Definition

Enhanced Observed Timing Difference is a mechanism intended to provide location information from an MS within a GSM network. E-OTD measures the burst timing alignment between the serving cell for the MS and a minimum of two neighbor cells. The observed timing difference, along with the BSIC or Cell ID of each neighbor cell that can be received and measured by the MS, is reported to the network. Using this information, an E-OTD capable network can calculate the location of the MS using triangulation techniques.

Although an E-OTD capable MS must receive a minimum of two neighbors in order to provide the network with useable data for E-OTD positioning, only one neighbor is required for the timing measurement tests described in this procedure.

70.6.3.2 Conformance requirement

The RMS90 measurement error of an E-OTD capable MS receiving a TU3 Rayleigh-faded neighbor shall not exceed 1.5 microseconds, as specified in 3GPP TS 05.05, Release 99, Version 8.7.1, Annex I, Clause I.2.3, Table I.2.3

70.6.3.3 Test purpose

E-OTD measurement accuracy is heavily influenced by the type of RF environment available to the MS at the time a Measure Position Request is received from the network. Rayleigh fading to the neighbor cell will reduce E-OTD measurement accuracy.

The purpose of this test case is to verify that an E-OTD capable MS can provide an observed timing difference (OTD) measurement of sufficient accuracy when measuring against a TU3 Rayleigh fading GMSK distant neighbor. During this test, there shall be no co-, adjacent-, or alternate-channel interference.

Specific PICS statements

PIXIT statements

70.6.3.4 Method of Test

Initial Configuration

Neighbor Cell: at least one neighbor cell with a minimum configuration of a BCCH in order to allow the mobile to perform the required accuracy measurements. The neighbor BCCH shall be included in the serving BCCH System Information Neighbor List.

Assistance Data: The assistance data listed in Table 70.6.3-1 and Table 70.6.3-2 shall be provided by the serving base station simulator. Without assistance data, successful validation of the MS physical layer may be impossible due to limitations imposed by the device’s upper protocol layers.

Table 70.6.3-5: RRLP Measure Position Request Field Values,
E-OTD Reference BTS for Assistance Data Element

Field Name

Value

Comments

BCCH Carrier

Range 0-1023

ARFCN of Serving BCCH

BSIC

Range 0 to 65

BSIC of Serving BCCH

Time Slot Scheme

Either 0 or 1, as applicable

0=All time slots 156.25 bits long
1=Time slots 0 and 4 are 157 bits long, all other time slots are 156 bits long.

BTS Position

None

Not applicable for timing accuracy measurements

Table 70.6.3-2: RRLP Measure Position Request Field Values,
E-OTD Measurement Assistance Data for System Information List Element

Field Name

Value

Comments

Number of Neighbors

1

E-OTD Neighbor Present

1

BSIC

Range 0 to 63

BSIC of neighbor BCCH

Multiframe Offset

Range 0-51

The value of this field is specific to the test configuration, and shall be calculated according to 3GPP TS 04.31, Annex A, Section A.2.2.3.

Time Slot Scheme

Either 0 or 1, as applicable

0=All time slots 156.25 bits long
1=Time slots 0 and 4 are 157 bits long, all other time slots are 156 bits long.

Rough RTD

Range 0-1250

Set to rough RTD value for the specific test configuration

Expected OTD

None

Not Applicable

Uncertainty of Expected OTD

None

Not Applicable

Fine RTD

None

Not Applicable

Relative North

None

Not Applicable

Relative East

None

Not Applicable

70.6.3.5 Test procedure

a) Configure serving base station simulator to transmit GMSK dummy bursts in time slots 1 through 7

b) Establish RF connectivity between the E-OTD compatible MS and its serving base station simulator, verify RSSI of -80 dBm

c) Disable the interfering signal generator

d) Configure the neighbor base station simulator such that its power (as measured at the antenna terminal of the EOTD MS under test) is -110 dBm with Rayleigh fading disabled. The neighbor shall be transmitting GMSK dummy bursts in time slots 1 through 7

e) Configure the fading simulator for Rayleigh fading corresponding to a velocity of 3 kph, with a 12-tap delay and amplitude spread in accordance with 3GPP TS 05.05, Release 99, Rev. 8.7.1, Annex C, Section C.3.3.

f) With the carrier from the serving base station simulator disabled, enable TU3 Rayleigh fading on the neighbor cell, and verify an average RSSI (at the antenna connection of the MS) of -110 dBm

g) Re-enable the serving base station simulator carrier, verify an RSSI (at the antenna connection of the MS) of -80 dBm

h) The SS initiates a Measure Position Request RRLP messages and begins logging E-OTD Response messages from the MS under test. The Measure Position Request message is repeated 250 times at 5-second intervals and the response RRLP messages are recorded.

i) After transmitting 250 Measure Position Request RRLP messages to the MS under test, calculate each trial’s error relative to the known RTD, sort the data in ascending order, develop the 90% subset M and calculate the RMS90 error.

70.6.3.6 Test Requirements

Verify that the RMS90 error calculated in Step i) is < 1.5 microseconds

70.6.4 E-OTD Accuracy, Interference Performance Tests, 8PSK BCCH

70.6.4.1 Definition

Enhanced Observed Timing Difference is a mechanism intended to provide location information from an MS within a GSM network. E-OTD measures the burst timing alignment between the serving cell for the MS and a minimum of two neighbor cells. The observed timing difference, along with the BSIC or Cell ID of each neighbor cell that can be received and measured by the MS, is reported to the network. Using this information, an E-OTD capable network can calculate the location of the MS using triangulation techniques.

Although an E-OTD capable MS must receive a minimum of two neighbors in order to provide the network with useable data for E-OTD positioning, only one neighbor is required for the timing measurement tests described in this procedure.

70.6.2.2 Conformance requirement

The RMS90 measurement error of an E-OTD capable MS receiving an 8PSK neighbor with a co-channel interference ratio of 0 dB shall not exceed 300 nanoseconds, 10dB not exceeding 300 nanoseconds, adjacent channel interference ratio of –18dB not exceeding 500 nanoseconds, -8 dB not exceeding 200 nanoseconds, as well as an adjacent channel (400 kHz ) interference ratio of
–41dB not exceeding 100 nanoseconds, as specified in 3GPP TS 05.05, Release 99, Annex I, Section I.2.1, Table I.2.2

70.6.2.3 Test purpose

E-OTD measurement accuracy is heavily influenced by the type of RF environment available to the MS at the time a Measure Position Request is received from the network. As the C/I ratio due to neighbor cell co-channel interference is reduced, E-OTD measurement accuracy may be reduced as well.

The purpose of this test case is to verify that an E-OTD capable MS can provide an observed timing difference (OTD) measurement of sufficient accuracy when measuring against a neighbor modulated with 8PSK in time slots 1-7, in the presence of a channel interference with a 0 dB, 10dB, -18dB, -8dB, and –41dB C/I.

Specific PICS statements

PIXIT statements

70.6.4.4 Method of Test

Initial Configuration

Neighbor Cells: at least one neighbor cell with a minimum configuration of a BCCH in order to allow the mobile to perform the required accuracy measurements. The neighbor BCCH shall be included in the serving BCCH System Information Neighbor List.

70.6.4.5 Test procedure

Co-Channel 8PSK test procedure at 0dB C/I:

a) Configure serving base station simulator to transmit in time slots 1 through 7

b) Establish RF connectivity between the E-OTD compatible MS and its serving base station simulator, verify RSSI of -80 dBm

c) Enable the interfering signal generator on the frequency of the neighbor cell at a power (at the antenna connection of the EOTD-capable MS) of -80 dBm

d) Configure the neighbor base station simulator such that its power (as measured at the antenna terminal of the E-OTD MS under test) is -80 dBm, and that it is transmitting 8PSK bursts modulated with pseudo-random data in time slots 1 through 7.

e) The SS initiates a Measure Position Request RRLP messages and begins logging E-OTD Response messages from the MS under test. The Measure Position Request message is repeated 250 times at 5-second intervals and the response RRLP messages are recorded.

f) After transmitting 250 Measure Position Request RRLP messages to the MS under test, calculate each trial’s error relative to the known RTD, sort the data in ascending order, develop the 90% subset M and calculate the RMS90 error.

Co-Channel 8PSK test procedure at 10dB C/I:

g) Establish RF connectivity between the E-OTD compatible MS and its serving base station simulator, verify RSSI of -80 dBm

h) Enable the interfering signal generator on the frequency of the neighbor cell at a power (at the antenna connection of the EOTD-capable MS) of -90 dBm

i) Configure the neighbor base station simulator such that its power (as measured at the antenna terminal of the E-OTD MS under test) is -80 dBm, and that it is transmitting 8PSK bursts modulated with pseudo-random data in time slots 1 through 7.

j) The SS initiates a Measure Position Request RRLP messages and begins logging E-OTD Response messages from the MS under test. The Measure Position Request message is repeated 250 times at 5-second intervals and the response RRLP messages are recorded.

k) Repeat Step f) and calculate the results.

Adjacent channel 8PSK test procedure at -18dB C/I:

l) Establish RF connectivity between the E-OTD compatible MS and its serving base station simulator, verify RSSI of -70 dBm

m) Enable the interfering signal generator on either of the channels adjacent to the frequency of the neighbor cell at a power (at the antenna connection of the EOTD-capable MS) of -62 dBm. The RF channel used by the interfering signal generator during this test must not be the same as that used by the serving base station simulator.

n) Configure the neighbor base station simulator such that its power (as measured at the antenna terminal of the E-OTD MS under test) is -80 dBm, and that it is transmitting 8PSK bursts modulated with pseudo-random data in time slots 1 through 7.

o) The SS initiates a Measure Position Request RRLP messages and begins logging E-OTD Response messages from the MS under test. The Measure Position Request message is repeated 250 times at 5-second intervals and the response RRLP messages are recorded.

p) Repeat Step f) and calculate the results.

Adjacent channel 8PSK test procedure at – 8dB C/I:

q) Establish RF connectivity between the E-OTD compatible MS and its serving base station simulator, verify RSSI of -70 dBm

r) Enable the interfering signal generator on either of the channels adjacent to the frequency of the neighbor cell at a power (at the antenna connection of the EOTD-capable MS) of -72 dBm. The RF channel used by the interfering signal generator during this test must not be the same as that used by the serving base station simulator.

s) Configure the neighbor base station simulator such that its power (as measured at the antenna terminal of the E-OTD MS under test) is -80 dBm, and that it is transmitting 8PSK bursts modulated with pseudo-random data in time slots 1 through 7.

t) The SS initiates a Measure Position Request RRLP messages and begins logging E-OTD Response messages from the MS under test. The Measure Position Request message is repeated 250 times at 5-second intervals and the response RRLP messages are recorded.

u) Repeat Step f) and calculate the results.

Adjacent channel (400kHz) 8PSK test procedure at -41dB C/I:

v) Establish RF connectivity between the E-OTD compatible MS and its serving base station simulator, verify RSSI of -70 dBm

w) Enable the interfering signal generator on either of the channels alternate (400 kHz offset) to the frequency of the neighbor cell at a power (at the antenna connection of the EOTD-capable MS) of -39 dBm. The RF channel used by the interfering signal generator during this test must not be the same as that used by the serving base station simulator.

x) Configure the neighbor base station simulator such that its power (as measured at the antenna terminal of the E-OTD MS under test) is -80 dBm, and that it is transmitting 8PSK bursts modulated with pseudo-random data in time slots 1 through 7.

y) The SS initiates a Measure Position Request RRLP messages and begins logging E-OTD Response messages from the MS under test. The Measure Position Request message is repeated 250 times at 5-second intervals and the response RRLP messages are recorded.

z) Repeat Step f) and calculate the results.

70.6.4.6 Test Requirements

Verify that the RMS90 error calculated for each procedure in 70.6.4.5 is within the test conformance requirements listed in Table 70.6.4-1

Table 70.6.4-1, Test Conformance Requirements

Procedure

RMS90 error, 3GPP TS 05.05,
Annex I, Minimum Performance Requirement

RMS90 error, 3GPP TS 51.010, 70.6.4, Test Conformance Requirement

Step f

 300 nanoseconds

310 nanoseconds

Step k

 100 nanoseconds

110 nanoseconds

Step p

 500 nanoseconds

510 nanoseconds

Step u

 200 nanoseconds

210 nanoseconds

Step z

 100 nanoseconds

110 nanoseconds

70.6.5 E-OTD Accuracy, Multipath Performance Test, 8PSK BCCH

70.6.5.1 Definition

Enhanced Observed Timing Difference is a mechanism intended to provide location information from an MS within a GSM network. E-OTD measures the burst timing alignment between the serving cell for the MS and a minimum of two neighbor cells. The observed timing difference, along with the BSIC or Cell ID of each neighbor cell that can be received and measured by the MS, is reported to the network. Using this information, an E-OTD capable network can calculate the location of the MS using triangulation techniques.

Although an E-OTD capable MS must receive a minimum of two neighbors in order to provide the network with useable data for E-OTD positioning, only one neighbor is required for the timing measurement tests described in this procedure.

70.6.5.2 Conformance requirement

The RMS90 measurement error of an E-OTD capable MS receiving a TU3 Rayleigh-faded 8PSK-modulated neighbor shall not exceed 1.5 microseconds, as specified in 3GPP TS 05.05, Release 99, Annex I, Clause I.2.3, Table I.2.3

70.6.5.3 Test purpose

E-OTD measurement accuracy is heavily influenced by the type of RF environment available to the MS at the time a Measure Position Request is received from the network. Rayleigh fading to the neighbor cell will reduce E-OTD measurement accuracy.

The purpose of this test case is to verify that an E-OTD capable MS can provide an observed timing difference (OTD) measurement of sufficient accuracy when measuring against a TU3 Rayleigh fading distant neighbor modulated with 8PSK in time slots 1-7. During this test, there shall be no co-, adjacent-, or alternate-channel interference.

Specific PICS statements

PIXIT statements

70.6.5.4 Method of Test

Initial Configuration

Neighbor Cells: At least one neighbor cell with a minimum configuration of a BCCH in order to allow the mobile to perform the required accuracy measurements. The neighbor BCCH shall be included in the serving BCCH System Information Neighbor List.

Assistance Data: The assistance data listed in Table 70.6.5-1 and Table 70.6.5-2 shall be provided by the serving base station simulator. Without assistance data, successful validation of the MS physical layer may be impossible due to limitations imposed by the device’s upper protocol layers.

Table 70.6.5-6: RRLP Measure Position Request Field Values,
E-OTD Reference BTS for Assistance Data Element

Field Name

Value

Comments

BCCH Carrier

Range 0-1023

ARFCN of Serving BCCH

BSIC

Range 0 to 65

BSIC of Serving BCCH

Time Slot Scheme

Either 0 or 1, as applicable

0=All time slots 156.25 bits long
1=Time slots 0 and 4 are 157 bits long, all other time slots are 156 bits long.

BTS Position

None

Not applicable for timing accuracy measurements

Table 70.6.5-2: RRLP Measure Position Request Field Values,
E-OTD Measurement Assistance Data for System Information List Element

Field Name

Value

Comments

Number of Neighbors

1

E-OTD Neighbor Present

1

BSIC

Range 0 to 63

BSIC of neighbor BCCH

Multiframe Offset

Range 0-51

The value of this field is specific to the test configuration, and shall be calculated according to 3GPP TS 04.31, Annex A, Section A.2.2.3.

Time Slot Scheme

Either 0 or 1, as applicable

0=All time slots 156.25 bits long
1=Time slots 0 and 4 are 157 bits long, all other time slots are 156 bits long.

Rough RTD

Range 0-1250

Set to rough RTD value for the specific test configuration

Expected OTD

None

Not Applicable

Uncertainty of Expected OTD

None

Not Applicable

Fine RTD

None

Not Applicable

Relative North

None

Not Applicable

Relative East

None

Not Applicable

70.6.5.5 Test procedure

a) Configure serving base station simulator to transmit 8PSK bursts modulated with pseudo-random data in time slots 1 through 7

b) Establish RF connectivity between the E-OTD compatible MS and its serving base station simulator, verify RSSI of -80 dBm

c) Disable the interfering signal generator

d) Configure the neighbor base station simulator such that its power (as measured at the antenna terminal of the EOTD MS under test) is -110 dBm with Rayleigh fading disabled. The neighbor shall be transmitting 8PSK bursts modulated with pseudo-random data in time slots 1 through 7

e) Configure the fading simulator for Rayleigh fading corresponding to a velocity of 3 kph, with a 12-tap delay and amplitude spread in accordance with 3GPP TS 05.05, Release 99, Rev. 8.7.1, Annex C, Section C.3.3.

f) With the carrier from the serving base station simulator disabled, enable TU3 Rayleigh fading on the neighbor cell, and verify an average RSSI (at the antenna connection of the MS) of -110 dBm

g) Re-enable the serving base station simulator carrier, verify an RSSI (at the antenna connection of the MS) of -80 dBm

h) The SS initiates a Measure Position Request RRLP messages and begins logging E-OTD Response messages from the MS under test. The Measure Position Request message is repeated 250 times at 5-second intervals and the response RRLP messages are recorded.

i) After transmitting 250 Measure Position Request RRLP messages to the MS under test, calculate each trial’s error relative to the known RTD, sort the data in ascending order, develop the 90% subset M and calculate the RMS90 error.

70.6.5.6 Test Requirements

Verify that the RMS90 error calculated in Step i) is < 1.5 microseconds

70.6.6 E-OTD Accuracy, Sensitivity Performance Tests for 8PSK Modulated signals

70.6.6.1 Definition

Enhanced Observed Timing Difference is a mechanism intended to provide location information from an MS within a GSM network. E-OTD measures the burst timing alignment between the serving cell for the MS and a minimum of two neighbor cells. The observed timing difference, along with the BSIC or Cell ID of each neighbor cell that can be received and measured by the MS, is reported to the network. Using this information, an E-OTD capable network can calculate the location of the MS using triangulation techniques.

Although an E-OTD capable MS must receive a minimum of two neighbors in order to provide the network with useable data for E-OTD positioning, only one neighbor is required for the timing measurement tests described in this procedure.

70.6.6.2 Conformance requirement

The RMS90 measurement error of an E-OTD capable MS receiving a neighbor shall not exceed 100 nanoseconds and 300 nanoseconds at a minimum neighbor carrier signal strength relative to relative sensitivity levels of 12 dB and –8 dB respectively, as specified in 3GPP TS 05.05, annex I, sub clause I.2.1, table I.2.1

70.6.6.3 Test purpose

E-OTD measurement accuracy is heavily influenced by the type of RF environment available to the MS at the time a Measure Position Request is received from the network. Nearby neighbor stations that provide a relatively high C/N to the MS receiver should result in greater measurement accuracy than those further away with a low C/N.

The purpose of this test case is to verify that an E-OTD capable MS can provide an observed timing difference (OTD) measurement of sufficient accuracy when measuring against an 8PSK neighbor. During this test, there shall be no co-, adjacent-, or alternate-channel interference.

Specific PICS statements

PIXIT statements

70.6.6.4 Method of Test

Initial Configuration

Neighbor Cell: One-neighbor cells with a minimum configuration of a BCCH in order to allow the MS to perform the required measurements. The neighbor BCCH shall be included in the serving BCCH System Information Neighbor List.

Assistance Data: The assistance data listed in Table 70.6.6-1 and Table 70.6.6-2 shall be provided by the serving base station simulator. Without assistance data, successful validation of the MS physical layer may be impossible due to limitations imposed by the device’s upper protocol layers.

Table 70.6.6-7: RRLP Measure Position Request Field Values,
E-OTD Reference BTS for Assistance Data Element

Field Name

Value

Comments

BCCH Carrier

Range 0-1023

ARFCN of Serving BCCH

BSIC

Range 0 to 65

BSIC of Serving BCCH

Time Slot Scheme

Either 0 or 1, as applicable

0=All time slots 156.25 bits long
1=Time slots 0 and 4 are 157 bits long, all other time slots are 156 bits long.

BTS Position

None

Not applicable for timing accuracy measurements

Table 70.6.6-2: RRLP Measure Position Request Field Values,
E-OTD Measurement Assistance Data for System Information List Element

Field Name

Value

Comments

Number of Neighbors

1

E-OTD Neighbor Present

1

BSIC

Range 0 to 63

BSIC of neighbor BCCH

Multiframe Offset

Range 0-51

The value of this field is specific to the test configuration, and shall be calculated according to 3GPP TS 04.31, Annex A, Section A.2.2.3.

Time Slot Scheme

Either 0 or 1, as applicable

0=All time slots 156.25 bits long
1=Time slots 0 and 4 are 157 bits long, all other time slots are 156 bits long.

Rough RTD

Range 0-1250

Set to rough RTD value for the specific test configuration

Expected OTD

None

Not Applicable

Uncertainty of Expected OTD

None

Not Applicable

Fine RTD

None

Not Applicable

Relative North

None

Not Applicable

Relative East

None

Not Applicable

70.6.6.5 Test procedure

a) Configure serving base station simulator to transmit 8PSK bursts in time slots 1 through 7.

b) Establish RF connectivity between the E-OTD compatible MS and its serving base station simulator, verify RSSI of -80 dBm.

c) Disable the interfering signal generator.

d) Configure the neighbor base station simulator such that its power (as measured at the antenna terminal of the E‑OTD MS under test) is -90 dBm, and that it is transmitting 8PSK bursts in time slots 1-7.

e) The serving base station SS initiates a Measure Position Request RRLP message. Begin logging E-OTD Measure Position Response RRLP messages from the MS under test. The Measure Position Request is repeated a minimum of 250 times at 5-second intervals and the response RRLP messages are logged.

f) The SS calculates each trial’s error relative to the known RTD, sort the data in ascending order, develop the 90 % subset M and calculate the RMS90 error.

g) Disable the interfering signal generator.

h) Configure the neighbor base station simulator such that its power (as measured at the antenna terminal of the E‑OTD MS under test) is -110 dBm, and that it is transmitting 8PSK bursts in time slots 1-7.

i) The serving base station SS initiates a Measure Position Request RRLP message. Begin logging E-OTD Measure Position Response RRLP messages from the MS under test. The Measure Position Request is repeated a minimum of 250 times at 5 s intervals and the response RRLP messages are logged.

j) After transmitting 250 Measure Position Request RRLP messages to the MS under test, calculate each trial’s error relative to the known RTD, sort the data in ascending order, develop the 90 % subset M and calculate the RMS90 error.

70.6.6.6 Test Requirements

Verify that the RMS90 error calculated for each procedure in 70.6.6.5 is within the test conformance requirements listed in Table 70.6.6-3

Table 70.6.6-3, Test Conformance Requirements

Procedure

RMS90 error, 3GPP TS 05.05,
Annex I, Minimum Performance Requirement

RMS90 error, 3GPP TS 51.010, 70.6.6, Test Conformance Requirement

Step f

 100 nanoseconds

110 nanoseconds

Step j

 300 nanoseconds

310 nanoseconds