C-CF CDMA1X System Messages and Call Flow-20071031-A-3.0

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HUAWEI TECHNOLOGIES CO., LTD.

www.huawei.com

HUAWEI Confidential

Security Level:

C-CF CDMA1X System Messages

and Call Flow

ISSUE 3.0



HUAWEI TECHNOLOGIES CO., LTD. HUAWEI Confidential Page 2

System messages refer to some specific network system

messages. The function of system messages is to implement

the message interaction between the MS and network system.

In order to perform information interaction between one

subscriber and another, an MS should be provided with the

related network/system information, For example, the function

of system messages is just like the message interaction

between the airport and airplane. The information such as the

take-off time, flight course, flight height, and landing time is

obtained through the interaction between the airport and

airplane to ensure the normal running of the airport and

airplane.

Introduction




References

Is20005a Protocol

RF150




Objective

By studying this lesson, you will understand:

Overview and category of system messages

Common system messages

Contents of system messages

System messages in the call flow




Chapter 1 Classification of System Messages

Chapter 2 Common System Messages

Chapter 3 Call Flow

Content




Messages in CDMA




Classification of system message

In the CDMA system, almost all the call flows are started by system messages.

Some CDMA channels are only used for carrying messages, not carrying service

Sync Channel

Paging Channel

Access Channel

Only

message

while other CDMA channels carry service,signaling, and messages as well.

Forward Traffic Channel

Reverse Traffic Channel

Service and information




System Messages Structure

The methods for sending messages

are as follows:

1. Confirmation method

2. Multiple resending method

The messages can be decoded by

the drive test device




Acquisition & Idle States System Messages




Acquisition & Idle States System Messages

The cdma2000 protocol stipulates

thirteen kinds of system messages, of

which six are required system

messages:

Sync Channel Message SCHM

Access Parameters Message APM

System Parameters Message SPM

Neighbor List Message NLM

CDMA Channel List Message CCLM

Extended System Parameters Message




Optional System Messages

The following seven messages are optional in the protocol:

Global Service Redirection Message GSRDM

Extended Neighbor List Message ENLM

Extended CDMA Channel List Message ECCLM

Private Neighbor List Message PNLM

General Neighbor List Message GNLM

User Zone Identification Message UZIM

Extended Global Service Redirection Message EGSRDM




Conversation State System Messages

The following system messages are

sent through the Traffic Channel:

In-traffic System Parameters Message

Neighbor List Update Message

Extended Neighbor List Update

Message




Question

Which messages are required in the CDMA protocol? In which state can an MS receive system messages?

I’ve been calling for quite a while with the drive testing equipment,

yet only seen a few system messages. Why ?






Chapter 3 Call Flow

Content




MS State Change Flow

After power up, the MS will captures the system

System Determination Substate :

obtain and select the system

Pilot Channel Acquisition Substate:

obtain a available pilot channel

Sync Channel Acquisition Substate:

obtain the system configuration and time of the CDMA system

Timing Change Substate:

keep time synchronized with the CDMA system.

Mobile Station Idle State:

Ready for a outgoing call or incoming call in the idle state




Basic Acquisition – On the Right System




The System Determination Algorithm




Synchronization Channel Message

Send broadcast in the sync channel

(Sync)

The important parameters in the

message are as follows:

MIN_P_REV

SID,NID,PILOT_PN

LC_STATE

SYS_TIME

PRAT

CDMA_FREQ and EXT_CDMA_FREQ

When capturing the sync channel,

the MS starts to continually listen

on the paging channel.

MS reads synchronization channel




MS Monitor Paging Channel for configuration Msg

Sufficient configuration messages must be collected before the MS do any operations.

Six possible configuration messages are

specified in the protocol and some of them are

optional.

Every configuration message contains a

sequence number. In this case, the MS can

differentiate the message based on the

updated number.

The MS reads all the desired configuration

messages again when it is over 600 seconds

after the configuration messages are read last

time or the sequence number of the read

messages is changed.

The following analyzes these six

configuration messages.




Access Parameters Message

The access parameter message controls the

operations performed by the MS in the access

process.

The important parameters in the message are

as follows:

NOM-PWR,INIT-PWR,PWR-STEP

NUM-STEP

PAM_SZ

PSIST

MSG_PSIST

MAX-REQ-SEQ

MAX-RSP-SEQ

…




Access Case: MS access slow

Trouble description: The customer was very unsatisfied with the slow system access in a certain

place. It took an average of 9 seconds.

Trouble analysis :

The first cause that should be considered is improper setting of access parameter. The main

access parameters of the network obtained by drive test software are as follows: INIT_PWR =

0, NOM_PWR= -6, PWR_STEP = 4, ACC_TMO = 3, PROBE_BKOFF = 0, BKOFF =

0,SLOT= 160ms.It is found that the setting of NOM_PWR are faulty. NOM_PWR is the assigned transmit

power offset and is set by BTS as the correcting factor for MS calculating transmit power open

loop evaluation. If the value set is too small, the close loop correction measured through the

reverse power control may fail to calibrate the incorrect offset of open loop evaluation

Trouble shooting:

1, Change NOM_PWR to 3dB2, Tests show the connection time is 3 or 4 seconds less.

Conclusion:

the connection time can be efficiently reduced by optimising the access parameters

NOM_PWR or INIT_PWR.




System Parameters Message

Indicates whether other system messages on the

paging channel are available.

Notifies the MS of the changes of the pagingchannel, instructs to search again, informs of the

roaming state of the MS, and provides the

registration parameter.

The important parameters in the message :

REG-ZONE, ZONE-TIMER

MAX_SLOT_CYCLE_INDEX

T-ADD, T-DROP, T-COMP,

T-TDROP

Width of pilot frequency searching window

Flag of whether the optional system messages are sent

…




Extended System Parameters Message




(Extended) CDMA Channel List Message

The important parameters in the message :

NUM_FREQ / CDMA_FREQ

RC_QPCH_SEL_INCL

…

The MS hashes to that channel based on the IMSI.

The MS and system will both obtain the result.




Neighbor List Message

The important parameters in the message:

NGHBR_PNOffset

…

NLM inform the NGHBR_PNOffset to MS




Global Service Redirection Message

Seldom use global service redirection Msg now!




Question

In the CDMA protocol, which configuration messages are sent by pagingchannel?

According to cdma2000 protocol, six of the thirteen kinds of system

messages are mandatory? Seven kinds of optional messages are?






Chapter 3 Call Flow

Content




MS Registration Flow




An actual Registration Flow




Receive an Incoming Call




Receive an Incoming Call

It marks here that

the call has been

set up.




An Actual Page and Page Response




Channel Assignment and Traffic Channel Confirmation




Service Negotiation and Mobile Alert




The Human Answers! Connect Order




Placing an Outgoing Call




Mobile-Originated Call Scenario




Origination

T ffi Ch l A i t




Traffic Channel Assignment

T ffi Ch l C fi ti




Traffic Channel Confirmation

St t R t/R




Status Request/Response

St t R M




Status Response Message

S i R t




Service Request

S i C t/S i C t C l t




Service Connect/Service Connect Complete

E di A C ll




Ending A Call

A B tif l E d t N l C ll




A Beautiful End to a Normal Call

A ft H d ff




A soft Handoff

M bil R t th H d ff!




Mobile Requests the Handoff!

S t A th i th H d ff




System Authorizes the Handoff

M bil I l t th H d ff




Mobile Implements the Handoff

Neighbor List Updated Handoff is Complete




Neighbor List Updated, Handoff is Complete




Question

What are the important messages when the MS is called?




Summary

Structure and categories of the CDMA system messages

Six mandatory system messages

State transition procedure of capturing the system after the

MS is switch-on

Common call flow

Key messages in the flow



谢谢 www.huawei.com

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C-CF CDMA1X System Messages and Call Flow-20071031-A-3.0