8. Ora000002 Cdma Communication Flow(Nss)Issue1.1

8/6/2019 8. Ora000002 Cdma Communication Flow(Nss)Issue1.1

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Wireless Curriculum Development SectionWireless Curriculum Development SectionWireless Curriculum Development SectionWireless Curriculum Development Section

ISSUEISSUE

ORA000002 CDMAORA000002 CDMA

Communication flows (NSS)Communication flows (NSS)

ORA000002 CDMAORA000002 CDMA

Communication flows (NSS)Communication flows (NSS)

1.01.0


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Confidential Information of

Huawei. Security Level: Internal

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ContentContent

Chapter 1 Brief introduction of CDMA Flows

Chapter 2 Communication flows of CDMA


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Brief introduction of CDMA flowsBrief 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 flowsBrief 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 authenticationflows

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


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ContentContent

Chapter 1 Brief introduction of CDMA Flows

Chapter 2 Communication flows of CDMA


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Chapter 2 Communication flows of CDMAChapter 2 Communication flows of CDMA

2.1 Location registration flows2.1 Location registration flows

2.2 Authenticationflows

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( in local VLR)Location Registration flow( in local VLR)


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Location Registration flow( involve VLR and

HLR)

Location Registration flow( involve VLR and

HLR)

LOCATION UPDATE REQ: Location Update Request

REGNOT : Register NotificationLOCATION UPDATE ACCEPT: Location update Accept


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Location Registration flow ( Cross VLR)Location Registration flow ( Cross VLR)


REGNOT : Register Notification

REGCANC: Register Cancellation

LOC ACP: Location update Accept


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Huawei. Security Level: Internal11

Location Registration flow for Switch offLocation Registration flow for Switch off


MSINACT: MS inactive

LOCATION UPDATE ACCETP: location update accept


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QuestionsQuestions

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 be

registered ?


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AnswersAnswers

Question 1: Not all the requests of location registrations are

sent to HLR. If the subscribers data has already existed inVLR 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 mainlyincluding SID( System Identification) and SWNO( Switch No.).

It uniquely identifies one switch entity, and is used to

determine whether the MS is roaming.

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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2.1 Location registration flows

2.2 Authentication flows2.2 Authentication flows2.3 Calling flows

2.4 Handoff flows




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The Parameters in AuthenticationThe Parameters in Authentication

Parameters involved in authentication: RAND, RANDC, ESN,

MIN, SSD

Parameters involved in SSD updating: A_KEY, RANDSSD,

ESN, RANDBS, RANDURandom number involved in authentication: RAND, RANDC,

RANDSSD, RANDBS, RANDU

Authentication results in authentication: AUTHR, AUTHBS,

AUTHU


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SSD Algorithm:

RANDSSD

56bits

ESN

32bits

SSD Algorithm

SSD_A SSD_B

64 bits 64 bits

A_Key

64bits


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CAVE (Cellular Authentication and Voice Encryption)

RAND_CHALLENGE

32 bits

ESN

32 bits

CAVE

AUTHR / AUTHU / AUTHBS

18 bits

MIN

24 bits

SSD

64 bits


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Authentication flow when SSD is not sharedAuthentication flow when SSD is not shared


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Authentication flow when SSD is sharedAuthentication flow when SSD is shared


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SSD Update when SSD is not sharedSSD Update when SSD is not shared


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SSD Update when SSD is sharedSSD Update when SSD is shared


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QuestionsQuestions

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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AnswersAnswers

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 isable 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 the protection of invalid authentication when SSD is

stolen.

Question 4: Please refers to slide introduced before.


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2.2 Authentication flows

2.3 Calling flows2.3 Calling flows

2.4 Handoff flows




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MS calls MS ( in local MSC)MS calls MS ( in local MSC)


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MS calls MS ( cross MSC)MS calls MS ( cross MSC)


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MS calls PSTNMS calls PSTN


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PSTN calls MSPSTN calls MS


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QuestionsQuestions

What is the difference between the local call

and inter-office call?

Please describe the flows triggered when the

MS registered in Beijing makes a call in

Shenzheng.


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AnswersAnswers

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 flows2.4 Handoff flows




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HandOff flow on A interface in one BSCHandOff flow on A interface in one BSC


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HandOff flow on A interface between BSCsHandOff flow on A interface between BSCs

Source BSC


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Forward HandOffForward HandOff

Target MSCAnchor/Serving MSC


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Backward HandOffBackward HandOff

Target MSC Anchor/Serving MSC


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HandOff to Third PartyHandOff to Third Party

Target MSC


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QuestionsQuestions

What is the difference between ForwardHandOff and Backward HandOff?

When does the third parties handoff happen?

What is the main function of FACDIR


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AnswersAnswers

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

serving MSC to a new target MSC; and the Backward HandOff is

that MS handoff 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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2.2 Authentication flows

2.3 Calling flows

2.4 Handoff flows

2.5 Supplementary service flows2.5 Supplementary service flows



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FEATURE SERVICEFEATURE SERVICE


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Call Forwarding Unconditional (CFU)Call Forwarding Unconditional (CFU)


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Call Forwarding Busy (CFB)Call Forwarding Busy (CFB)


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Call Forwarding No Answer (CFNA)Call Forwarding No Answer (CFNA)


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Call Forwarding Default (CFD)Call Forwarding Default (CFD)

llowing cases, the call does not be connected to the serving MSC when the CFDribed.

ot-Disturb Service has been activated

as not registered

as been deactivated


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Message Waiting Notification (MWN)Message Waiting Notification (MWN)


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QuestionsQuestions

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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AnswersAnswers

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, the

conference call terminates; but if a common user exits,

other users continue the conference call.


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Confidential Information ofHuawei. Security Level: Internal

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2.3 Calling flows

2.4 Handoff flows


2.6 Short message flows2.6 Short message flows


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MS Sends Short Message in Access ChannelMS Sends Short Message in Access Channel

BSS MSCMC

ADDS Transfer

SMSDPP

smsdpp(ack)

ADDS Page


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MS Sends Short Message in Service ChannelMS Sends Short Message in Service Channel

BSS MSC MC

ADDS Deliver

SMSDPP

smsdpp(ack)

ADDS Deliver Ack


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MS Receives Short Message in Paging ChannelMS Receives Short Message in Paging Channel

BSS HLR MCMSC

SMSREQ

smsreq

SMSDPP

ADDS Page

ADDS Page Ack

smsdpp


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MS Receives Short Message in Service ChannelMS Receives Short Message in Service Channel

BSS HLR MC MSC

SMSREQ

smsreq

SMSDPP

ADDS Deliver

ADDS Deliver Ack

smsdpp


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QuestionsQuestions

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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AnswersAnswers

Question 1: ADDS Deliver Message.

Question 2: The length of the short message

may affect 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 transfer message; if

the length is more than a certain threshold, it is

sent from the service channel, using the ADDS

delivermessage.


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ReviewReview

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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ReferenceReference

IOS40 Interface A Specifications

ANSI41D Interface C/D Specifications

ANSI-664 Supplementary Service


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Documents

8. Ora000002 Cdma Communication Flow(Nss)Issue1.1