ERAN3.0 LCS Feature Introduction

HUAWEI TECHNOLOGIES CO., LTD.

www.huawei.com

Huawei Confidential

Security Level: internal

47pt

30pt

:

FrutigerNext LT Medium

: Arial

47pt

28pt

Huawei eRAN3.0 LCS

Feature Introduction

HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential

35pt

32pt

) :18pt

The Overview of LCS

Page 2

LCS Network Elements

E-SMLC :Location center that calculates the network-based locations of UEs.

GMLC :Handles UE location request from LCS clients;

Obtains the latitude and longitude of UE, and then returns the information to the LCS client;

Serves as a LCS operation platform to manage the related data of users, services, service subscription, Service Providers (SPs), and accounting.

eNodeB : Performs location-related measurements, and reports measurement results.

MME :Transparently transmits positioning-related messages between the E-SMLC and other NEs .

UEs :Perform positioning measurements specific to positioning methods upon receiving an LCS request from the E-SMLC.

LCS client: Requests location information about one or multiple UEs by initiating a location service request .

E-SMLC and GMLC is LCS new introduced

MME

UE

eNB

GW

LCS Client

GMLC

eNB

LPPa

LPP

S1-MME SLs

SLg

Le

S1-US11

HSS

S6a

SLh

E-SMLC


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Typical LCS Procedure

Page 3

Step 3:The UE reports its own positioning

capability to the E-SMLC.

Step 4:The E-SMLC selects one or a combination of

positioning methods based on the UE's positioning

capabilities.

Step 5:The E-SMLC exchanges location procedures

with the serving eNodeB or UE to obtain a

location estimate, positioning measurements or

assistance data.

Scenario of 1a and 7a: MO-LR, allows an UE to

request either, its own location and optionally,

velocity or location assistance data.

Scenario of 1b and 7b: MT-LR, An external LCS

client requests the current location and optionally,

velocity of a target UE from a GMLC.

Scenario of 1c and 7c: NI-LR, At any time after

detecting an emergency situation (i.e. after

emergency Attach, UE requested emergency PDN

Connectivity), the MME may initiate the EPC NI-LR

procedure.


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) :18pt

LCS Classification

Page 4

LCS

CP-LCS UP-LCS

E-CID (UE assisted only)

OTDOA (UE assisted only)

A-GPS (UE assisted/UE

based)

LCS type:

CP-LCS : Control Plane LCS

UP-LCS: User Plane LCS(transparent to E-UTRAN)

LCS mode:

UE based: UE calculates the location

UE assisted: E-SMLC calculates the locationCommon LCS mode LCS method:

E-CID,OTDOA,A-GPS

Huawei LCS


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32pt

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LCS Type

User Plane Position type

Pro:

Just the UE support required, No change on the

Network Device

Con:

1) Few UE support this positioning method

2) It would occupy a bearer, and the Positioning Signal

would be charged

3) The Positioning Services cant be controlled by

the Operator.

Page 5

Two Positioning type: User-plane

positioning type and E-UTRAN control-

plane positioning type.

SLP is the SUPL entity responsible for

positioning over the user plane. UE eNode B MME

E-SMLC

LTE-Uu S1

SLs

SLP

SUPL

beare

r

Proprietary

interface

possible

SET

Control Plane Position type

Pro:

1) Operator can well control the Positioning Services

2) Most UE would support it

3) Positioning signal would not be charged

Con:

Need the Network device to support

Huaweis viewpoint: Positioning Service selecting depends on the UE, because just few UE support the User plane position, but Most of UE support Control Plane Position we recommend the later method.


35pt

32pt

) :18pt

Positioning Principles for E-CID

Page 6

When a UE performs registration, location

update, or call setup, it reports the RRC

Connection Request message with the cell ID

of the serving cell included.

The eNodeB calculates TA and AOA .

TA: Type 1 TA

A UE complying with 3GPP Release 9 can report

the difference between the UE RX time and TX

time using RRC signaling messages.

Type 2 TA

Obtaining this type of TADV requires UEs to

initiate random access.

Type 1 TA is more accurate than type 2 TA.

AOA: An eNodeB can obtain AOA only after it is configured with the smart antenna.

In E-CID, the eNodeB calculates the Timing Advance (TA) between the

antennas of the serving eNodeB and the UE to be located, and measures the

Angle of Arrival (AoA) of the received signal. The E-SMLC then determines

the geographical location of the UE based on the TA and the AoA.

The E-CID positioning range is about hundreds of meters.


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) :18pt

E-Cell ID positioning Procedure

Page 7

Step 1,E-SMLC get the Location Request

from the MME.

Step 2 and Step 3, E-SMLC Request the

UEs Position Capability .

Step 4 and Step 5,E-SMLC Request

Measure Information from the eNB.

Step 6,E-SMLC provide the Assistance Data

to the UE.


UEs Measure information ,E-SMLC use it

together with the Measure Information

from the eNB to calculates the final

location.

Step 9, E-SMLC Return the Position to the

MME.


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) :18pt

Positioning Principles for OTDOA

Page 8

Two hyperbola branches are derived

when the difference of distances from

the UE to eNodeB 0 and eNodeB 1is a

constant (d1- d0) and that from the UE

to eNodeB 1 and eNodeB 2 is a

constant (d2 - d1).

The UE location is determined as the

crossing point of the two hyperbola

branches.

Time synchronous: To OTODA eNBs

need to using the GPS receiver to

obtain each eNBs system time. And a GPS receiver card should be deployed

on the eNBs side.

In OTDOA, the UE measures the arrival time of the positioning reference

signals (PRS) transmitted from multiple eNodeBs, and reports the time to

the E-SMLC. The E-SMLC then determines the geographical location of

the UE based on hyperbola principles.

The OTDOA positioning range is from tens of meters to hundreds of

meters.


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O-TDOA positioning Procedure


from the MME.



Step 4 and Step 5,E-SMLC Request O-TDOA

Assistance Data from the eNB.


to the UE.


UEs Measure information and using it to

calculates the final location.


MME.

Page 9


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32pt

) :18pt

Positioning Principles for A-GPS

Page 10

The E-SMLC collects the

information about GPS satellites

( the reference location,

reference time, and the

ionosphere model ),

and then sends the assistance

data to the target UE.

The E-SMLC sends the assistance data to the target UE. Though the

assistance data, the UE can acquire the GPS satellite signals more efficiently,

which will shorten the time of measuring the pseudo-ranges, reduce the

power consumption, and improve the receiving sensitivity.

The A-GPS positioning range is about tens of meters.


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A-GPS positioning Procedure

Page 11


from the MME.



Step 4 ,E-SMLC get the A-GPS Assistance

Data.


to the UE.


UEs Measure information and using it to

calculates the final location.


MME.


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32pt

) :18pt

Key Parameter Introduction(OTDOA)

Page 12

MO

Parameter ID

Default Value

Actual

Unit

MML Command

ENodeBAlgoSwitch

LcsSwitch

OTDOA switch: Off

OtdoaSwitch(OTDOA switch)

OtdoaSwitch

None

MOD ENODEBALGOSWITCH

LST ENODEBALGOSWITCH

CellChPwrCfg

PrsPwr

0

-3175~3175

-15.875~15.875

0.005 dB

MOD CELLCHPWRCFG

LST CELLCHPWRCFG

MO

Parameter ID

Description

ENodeBAlgoSwitch

LcsSwitch

Location Services (LCS) switch, containing a sub-switch used to enable or disable the Observed Time Difference of Arrival (OTDOA)-based positioning method. If the sub-switch is turned on, OTDOA-based positioning is enabled.

CellChPwrCfg

PrsPwr

Specifies the offset of the pilot power relative to the reference signal power.

There was no parameter of A-GPS and ECID.


35pt

32pt

) :18pt

Performance & Scenarios of LCS

First method selected

Positioning method differs with the requirement of wireless environment :

Second method selected

Method not recommended

Method Precision Handset Participation Environment

A-GPS

10~50m

Yes Outdoors

O-TODA

50~100m Yes Indoors, Outdoors

E-CID 100~1000m

No No Limit Position

Positioning method is selected based on factors that may include the LCS Client type, the

required QoS, wireless environment ,UE positioning capabilities and eNodeB positioning

capabilities.

Scenario Positioning Methods

A-GPS OTDOA E-CID

Urban

Rural

far Rural


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Maintenance of LCS

Page 14

Counter Name Description

L.LCS.EcidMeas.Req Number of E-CID measurement requests in a cell

L.LCS.EcidMeas.Succ Number of successful E-CID measurement requests

in a cell

L.LCS.OtdoaMeas.Req Number of OTDOA measurement attempts received

by an eNodeB

L.LCS.OtdoaMeas.Succ Number of successful OTDOA measurement

requests sent by an eNodeB

Thank you www.huawei.com

Documents

ERAN3.0 LCS Feature Introduction