cd ma final
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CALL PROCESSING IN CDMA
MOBILE INITIALIZATION
INITIALISATION
IDLE
ACCESS
TRAFFIC
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MOBILE TRANSITION INTO DIFFERENT STATES
POWER-UP
Mobile
Initialization
State
Mobile
Idle
State
Mobile
System Access
State
Mobile
Traffic Channel
State
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PILOT & SYNCH
PAGING
ACCESS
TRAFFIC
INITIALIZATION
IDLE
SYSTEM ACCESS
TRAFFIC CHANNEL
INITIALIZATION
COMPLETE
BASE STATION
ACCESS
CALL SETUP
PILOT:
Power,phase,timing
Overhead info
Mobile Direct
Messages
Access messages
Messages
Voice
SERVICE SIGNALLING LAYER
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MOBILE INITIALIZATION TO IDLE STATE
MOBILE SWITCHED ON
SCAN PN OFFSET 1-512
& MEASURE PILOT SIGNAL
STREGTH
SELECT BEST SIGNAL
PN OFF SET PILOT
READ SYNCH
CHANNEL
READ PAGINGCHANNEL
SID/NID
YES
NO
MOBILE IS NOWIN IDLE MODE
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MOBILE- PILOT CHANNEL ACQUISTION SUBSTATE
SCAN ALL PILOTS
F1 PN168 W32
F2 PN168 W32
F3 PN168 W32
Srch PN?? W0
PILOT SEARCHER SCANS THE ENTIRE RANGE OF PNs
LO
RF
Handset RAKE RECEIVER
Chips 0
PN 0
32 K
512
-20
0
Ec/Io
1
2
3
Rake Fingers
Reference PN
All PN Offsets
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Go to Paging Channel, Get Configured
Access Parameters Msg
System parameters Msg
CDMA Channel List Msg
Extended System Parameters Msg
Neighbor List Msg
Global Service Redirection Msg
Read the Configuration Messages
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MOBILE IDLE STATE
Page ChannelMonitor & Pilot
Search
Sub state
Idle Handoff
Mobile System
Access State
Mobile Initialization
State
Mobile has fully
acquired system
timing
Idle Handoffcomplete
Mobile unable to
Receive Paging
Channel
Call Termination
Call Origination
Registration
Mobile receives
Acknowledgement to an
Access transmission
Other than origination or
Page response
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Slotted Mode & Quick Paging Channel
ObjectiveTo extend the battery life of a mobile in slotted mode by reducing
the time the mobile spends monitoring paging channels.
Slotted ModePaging channel divided into slots and slot cycles. Mobile monitors
specific slot in a slot cycle.
F-QPCH Functionality
Paging or configuration change indicators is sent out on theF-QPCH 100ms prior to the message on the F-PCH.
If the mobile cannot detect an indicator to be off, the mobile will
read the F-PCH slot immediately following the F-QPCH slot.
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SEQUENCE 1 2 Ns
Probe1 2 3 Np 1 2 3 Np Time
tg
Persistence
Test
PowerStep
tgIP
IP= -Mean Rx Power(dbm) +
OpenloopAdjust + ProbeInitialAdjust
ACCESS PROCEDURE
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ACCESS HANDOFF FEATURES
Access
Handoff
Mobile Traffic
Channel State
Access Entry
Handoff
Origination
Mobile (MS) searching for pilots Active-
Neighbors-Remaining State
No
Yes
BS sends general
Page to MS
MS performs access attempt. Up to
6 strongest pilots ind.
Active pilot in msg capsule
Channel Assignment into
Soft Handoff (CAMSHO)
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The Traffic Channel State
From Mobile System
Access State
To Mobile
Initialization State
Traffic
Channel
Initialization
State
Conversation
Sub State
Release
Sub State
Waiting for
Mobile
Answer
Sub state
Waiting for
Order
Sub state
MS call termination MS receives
An Acknowledge order on
Forward traffic channelMS cell origination
MS receives an
Acknowledge order
On forward Traffic
Channel
MS userDisconnects or MS
Receives Release
Order
MS receives an
Alert order
MS user
Answers
call
MS receives
Release Order
MS receives
Release order
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CONVERSATION SUBSTATE
Messages being sent on the traffic channel
Continuous confirmation of the traffic channel
Locating handoff candidates
Performing handoffs
Power control
Overload control
Other call activities
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NAME
MIN
ESN
Location
Desired Slot Cycle
Station Class Mark Billing Information
BSC
HLR
REGISTRATION
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TYPES OF REGISTRATION
AUTONOMOUS
Power up
Power down
Timer based
Distance based
Zone based
NON-AUTONOMOUS
Parameter Change
Ordered
Implicit
Traffic Channel
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HANDOFFS
Idle Handoff when the mobile is in Idle state, the mobile may move from one cell to
another
HandoffDuring Access
Access Entry Handoff
Access Probe Handoff
Access Handoff
Channel Assignment into Soft Handoff
Soft Handoff make-before-break type of handoff
Inter Frequency handoff when the mobile has to retune to a different CDMA frequency
Traffic Channel HandoffsSoft Handoff
Soft-Softer Handoff
Softer Handoff
Hard Handoff
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CDMA Soft Handoff Mechanics
F1 PN168 W32
F2 PN168 W32
F3 PN168 W32
Srch PN?? W0
RAKE RECEIVER
LO
RFMSCBase Station A
Base Station B
Handset
Pilot
Ec/Io
Voice,Data,
Messages
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The Pilot Searching Process
Mobile reports
Results of search to
Base Station
Base Station
Alters Pilot SetsIf necessary
Mobile Searches
for strong
pilot signals
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The Pilot Searching Process
ACTIVE SET
CANDIDATE SET
NEIGHBOR SET
REMAINING SET
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Neighbor Set Candidate
setActive Set Neighbor
Set
PilotStrength
T_ADD
T_DROP
(!) (2) (3) (4) (5) (6) (7) Time
Handoff Signalling
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Why Power Control
ObjectivesMaximum QOS
Maximum capacity
Minimize interference
Power Control Algorithm
Forward Link Power Control(FLPC, FPC)Reverse Link Power Control(RLPC, RPC)
Power Control is required
Near-far Problems
Path loss Fading
Performance Objectives
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Power Control
Mobile Tx Power (dBm) =
OPEN LOOP
k Mobile Receive Power(dBm)+ Parameters
+ Access Probe Corrections
+ CLOSED LOOP Corrections (dB)
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Reverse Link Power Control
Two separate algorithms
Reverse Open Loop (Autonomous Control)
Performed in the mobile
Adjust for path loss
Output Power based on received signal strength
Tx power = - [Mean Received Signal Strength] + correction_factors
Reverse Closed Loop (Base Station Directed Control)
Base Station directs mobile to adjust power
Controls frame error rate of signal received at the serving base station
Consists of an inner loop and an outer loop
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Reverse Link Closed Loop Power Control
Base Station sends power control bits
800 controls per second (800 Hz)
Closed Outer Loop (at base station)
Calculates Ec/Io set point
Based on R-FCH frame error rates
Closed Inner Loop (at base station)Compare Ec/Io set point with measured Ec/Io
Send power control bits(up/down) to mobile
Mobile Adjust its power
Based on power control bits from base station
Step size of its adjustable
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Forward Link Power Control
Reverse Link Closed Loop process is adopted
Mobile sends power control bits on R-PICH
800 control per second (800 Hz)
Based on Eb/Nt and FER objectives
Base station received power control bits
Variable power step size controlled by the base station
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VOCODERS
Vocoders compress speech, reduce bit rates
CDMA uses a superior Variable Rate Vocoder
Full rate during speech
Low rates in speech pauses
Increased capacity
more natural sound
Voice, signaling, and user secondary data may bemixed in CDMA frames
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Variable Rate VocoderVocoder Data Rates
Rate set 1: 9600bps Tx Rate
Vocoder Data Rates
Rate set 2: 14.4Kbps Tx Rate
VocoderRate Tx Rate
Full 8550 9600
Half 4000 4800
Quarter 2000 2400
Eighth 800 1200
VocoderRate Tx Rate
Full 13300 14400
Half 6200 7200
Quarter 2700 3600
Eighth 1000 1800
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Variable Rate Vocoder
24 bits 48 bits 96 bits 96 bits 192 bits
Eighth Quarter Half Half Full
Rate Rate Rate Rtae Rate
20 msec 20 msec 20 msec 20 msec 20 msec
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Rate Sets
80 bits 8 bit CRC 8 Tail bits
40 bits 8 Tail bits
16 bits 8 Tail bits
Mode bit
Full Rate
HalfRate
QuarterRtae
Eighth Rate
1 171 bits 12 bit CRC 8 Tail bits
Rate Set 1
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