ORA000002 CDMA Communication Flow(NSS)ISSUE1.3.ppt

7/27/2019 ORA000002 CDMA Communication Flow(NSS)ISSUE1.3.ppt

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HUAWEI TECHNOLOGIES CO., LTD. All rights reserved

www.huawei.com

Internal

ORA000002 CDMA

Communication

flows( NSS)

ISSUE 1.3


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HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 2

Upon completion of this course, you will be able to:

Understand the basic flows of CDMA

Understand the information name

Understand the meaning of important parameters

Improve the capabilities of problem analysis and fault

location according to the flows

Memorize the abbreviation of messages .


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Chapter 1 Brief introduction of CDMA Flows

Chapter 2 Communication flows of CDMA


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Brief introduction of CDMA flows

Registration flows

Authentication flows

Calling flows

Handoff flows

Supplementary service flows

Short message flows

Basic CDMA flows


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Brief introduction of CDMA flows

Mobile phone power on/off: location updating flows and authentication flows

Mobile phone calling: calling flows and authentication flows

Migration in the conversation: handoff flows and authentication flows

Mobile phone hooks up : calling flows

Short message: short message flows and authentication flows

Supplementary service: supplementary service flows and authentication

flows

The flows that the main services may involved in are as follows:


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Chapter 1 Brief introduction of CDMA Flows



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2.1 Location registration flows

2.2 Authentication flows

2.3 Calling flows

2.4 Handoff flows

2.5 Supplementary service flows

2.6 Short message flows


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Location Registration flow( involve VLR and HLR)

LOCATION UPDATE REQ: Location Update Request

REGNOT : Register Notification

LOCATION UPDATE ACCEPT: Location update Accept


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Location Registration flow ( Cross VLR)


REGNOT : Register Notification

REGCANC: Register Cancellation

LOC ACP: Location update Accept


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Location Registration flow for Switch off


MSINACT: MS inactive

LOCATION UPDATE ACCETP: location update accept


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Questions

Why not all the location registrations are sent to

HLR?

What is the meaning of MSCID in the location

registration message, and what is the function ?

Why does the switch off message need to beregistered ?


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Answers Question 1: Not all the requests of location registrations are sent to HLR.

If the subscribers data has already existed in VLR and the subscriber is

activated, the registration is processed by VLR. Otherwise the

registration requests are sent to HLR, and processed by HLR.

Question 2: MSCID is the identification of MSC mainly including

SID( System Identification) and SWNO( Switch No.). It uniquely

identifies one switch entity, and is used to determine whether the MS isroaming.

Question 3: Switch off registration are mainly used to inform HLR that

the subscriber has already powered off. If other subscribers call it,

system can send the access refuse directly to the calling party according

to the subscribers status in HLR.


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2.3 Calling flows

2.4 Handoff flows




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The Parameters in Authentication

Parameters involved in authentication: RAND, RANDC, ESN, MIN,

SSD

Parameters involved in SSD updating: A_KEY, RANDSSD, ESN,

RANDBS, RANDU

Random number involved in authentication: RAND, RANDC,

RANDSSD, RANDBS, RANDU

Authentication results in authentication: AUTHR, AUTHBS,

AUTHU


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Generation of Authentication Parameters

Authentication Parameters generated by HLRRANDSSD

RANDU (When SSD is not shared )

Authentication Parameters generated by MSC/VLRRAND

RANDU (When SSD is shared )

Authentication Parameters generated by BSCRAND

Authentication Parameters generated by MSRANDBSRANDC


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SSD Algorism:

RNADSSD

56bits

ESN

32bits

SSD Algorism

SSD_A SSD_B

64 bits 64 bits

A_Key

64bits


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CAVE (Cellular Authentication and Voice Encryption)

RNAD_CHALLENGE

32 bits

ESN

32 bits

CAVE

AUTHR/AUTHU/AUTHBS

18 bits

AUTH_DATA

24 bits

SSD

64 bits


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Authentication flow when SSD is not shared


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Authentication flow when SSD is shared


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SSD Update when SSD is not shared


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SSD Update when SSD is shared


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Questions

What is the meaning of SSD_sharing?

How does the SSD_sharing influence the authentication flows?

Why is the SSD update flow introduced?

Describe the SSD update flow when SSD is not shared.


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Answers

Question 1: SSD_sharing means that the SSD is stored in VLR.

Question 2 : whether the SSD is shared determines where the

authentication is done. If SSD is shared, authentication is able to be

done at the VLR, else this work is done at the AC.

Question 3: The introduction of SSD update flows is mainly for theprotection of invalid authentication when SSD is stolen.

Question 4: Please refers to slide introduced before.


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2.3 Calling flows

2.4 Handoff flows




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MS calls MS ( in local MSC)


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MS calls MS ( cross MSC)


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MS calls PSTN


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PSTN calls MS


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Questions

What is the difference between the local call and

inter-office call?

Please describe the flows triggered when the MSregistered in Beijing makes a call in Shenzheng.


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Answers Question 1: There are two essential differences between

Intra-office mobile calling and Inter-office mobile calling: one is

that whether the location request message carry the TLDN or

not, local office assigns the TLDN in intra-office calling flows,

the called office assigns the TLDN in inter-office calling flows;

the other is that whether the signals route outgoing according

as the TLDN.

Question 2: Location Register flow, Authentication flow,

Calling flow


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2.3 Calling flows

2.4 Handoff flows

2.5 Supplementary service flows2.6 Short message flows


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HandOff flow on A interface in one BSC


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HandOff flow on A interface between BSCs


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Forward HandOff


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Backward HandOff


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HandOff to Third Party


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Questions

What is the difference between Forward HandOff

and Backward HandOff?

When does the third parties handoff happen?

What is the main function of FACDIR


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Answers Question 1: the Forward Handoff is that MS handoff from the serving

MSC to a new target MSC; and the Backward HandOff is that MShandoff from the serving MSC to the primary controlling MSC.

Question 2: Whether HandOff to Third Party happens depends on the

startup standard value of Third Party HandOff and handoff depth

together, when the current handoff times, viz. the handoff depth equal to

the startup standard value of Third Party Handoff, the MS will handoff to

the third party.

Question 3: FACDIR is used to set up inter_office handoff circuits,

which is MAP circuit.


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2.3 Calling flows

2.4 Handoff flows

2.5 Supplementary service flows2.6 Short message flows


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FEATURE SERVICE


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Call Forwarding Unconditional( CFU)


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Call Forwarding Busy( CFB)


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Call Forwarding No Answer ( CFNA)


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Call Forwarding Default( CFD)

Note:

In the following cases, the call does not be connected to the serving MSC when the CFD

is subscribed.

1. Do-not-Disturb Service has been activated

2. MS has not registered

3. MS has been deactivated

4. Dont activate calling transfer


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Conference Call(CC)


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Message Waiting Notification(MWN)


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Questions

What is the priority of 4 types of call forwarding?

What is the difference between CFNA and CFB ?

In Conference Call flow, if a user exits, will the

conference call terminated?


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Answers Question 1: CFU>CFB>CFNA>CFD

Question 2: There are two differences between CFNA and CFB :

CFNA has gotten a TLDN and set up a call to the

called office, while CFB dose not get any TLDN from

the HLR to which the called MS belongs;Forwarded-to number of CFNA is retrieved by the

calling MSC from the HLR to which the called MS

belongs, while in CFB, it is sent by the HLR to which

the called MS belongs directly.

Question 3: In CC, if the main controlling user exits, theconference call terminates; but if a common user exits, other

users continue the conference call.


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2.3 Calling flows

2.4 Handoff flows




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MS Sends Short Message in Access Channel

BSS MSC

ADDS Transfer

SMSDPP

smsdpp(ack)

ADDS Page


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MS Sends Short Message in Service Channel

BSS MSC

ADDSDeliver

SMSDPP

smsdpp(ack)

ADDSDeliver Ack


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MS Receives Short Message in Paging Channel

BSS HLRMSC

SMSRE

smsreq

SMSDPP

ADDSPage

ADDSPageAck

smsdpp


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MS Receives Short Message in Service Channel

BSS HLR MCMSC

SMSREQ

smsreq

SMSDPP

ADDS Deliver

ADDS Deliver Ack

smsdpp


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Questions

1. If the subscriber receives an extremely short

message during conversation, which channel is

used to deliver the Short message?

2. What is the influence of the length of the short

message when a MS originates a short message?


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Answers Question 1: ADDS Deliver Message.

Question 2: The length of the short message mayaffect the A_interface message . If the length of the

short message is less than a certain threshold, it is

sent from the access channel using the ADDS

transfermessage; if the length is more than a

certain threshold, it is sent from the service channel,

using the ADDS delivermessage.


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Review

This section mainly describes common flows of

CDMA including: location registration,

authentication, calling, handoff, supplementary

services and short message.

Describing the important messages and

parameters in each flow.


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References

IOS40Interface A Specifications

ANSI41DInterface C/D

Specifications

ANSI-664 Supplementary Service


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Documents

ORA000002 CDMA Communication Flow(NSS)ISSUE1.3.ppt