Salih Ergut
7/16/2003
1

Outline
 cdma2000 packet data
 architecture and network elements
 Simple IP/Mobile IP
 Packet Network Nodes
 State Machines
 MAC Layer
 Packet Data Call Flows
 1x EV-DV ( 1x RTT Ev olution for high-speed integrated D ata and V oice)
 Motivation, goals and basic principles
2

Packet Data Architecture
SS7
Network
HLR
VLR MSC PSTN
BSC PCF
AAA
PDSN
Packet
Network
Telephone
Network
Home
Agent
Home
AAA
3

Simple IP vs. Mobile IP
 Mobile station’s IP address will be changed as the subscriber moves to different cells
 Mobile station will be able to use a constant
IP even when moving across different cells
BSC PCF PDSN
Packet
Network PDSN
PCF
BSC
4

Mobile IP Registration
BSS
PDSN
(FA)
Packet
Network Home Agent
MIP-RRQ
MIP-RRQ
MIP-RRP
MIP-RRP
Packet Data Tunnel (UDP over IP)
Mobile registers its care of address
HA replies with lifetime
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Packet Network Nodes


PCF (Packet Control Function)
 A required IP element in cdma2000 networks


Provides relay to mobile from PDSN
Keeps track of registration lifetime expiration and ensures that the sessions are renewed as necessary


Controls the available radio resources
Buffers data received from PDSN until radio resources becomes available
 Controls dormancy
PDSN (Packet Data Serving Node)




PPP datalink layer to mobile is terminated
Interfaces with PCF
IP packets are routed
In MIP network acts as a FA
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Packet Network Nodes
 AAA (Authentication, Authorization, and
Accounting)
 Stores accounting information and authenticates/authorizes mobiles
 Provides security to FA and Foreign AAA.
 HA (Home Agent)
 Establishes a secure packet-data tunnel with the FA to provide MIP services and routes the packets destined to the mobile to the FA
 Authenticates MIP registrations
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Mobile Originated Packet Data Call
UCSD Ericsson ///
MSC
BSC / PCF PDSN
Origination
Base Station Ack
CMServReq
SCCP-CC
Assign Request
TCH Setup
A11-RRQ
A11-RRP
A8 /A10 setup
Assign Complete
PPP Link Establishment and Mobile IP Registration
User Packet Data
Packet
Network
8

Control Plane – Signaling
A11
UDP
IP
Link
Phys
BSC/PCF
A11
UDP
IP
Link
Phys
PDSN
9

User Plane – Relay Mode
IP
PPP
RLP
AIR
Interface
GRE
RLP
IP
AIR
Interface
Link
Phys
BSC/PCF
A10
IP
PPP
IP
GRE
Link
IP
Link
Phys Phys
PDSN
IP
Link
Phys
End
Host
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User Plane – Network Mode
IP
SLIP or
PPP
IP
SLIP or
PPP
IP
PPP
RLP
AIR
Interface
GRE
RLP
IP
AIR
Interface
Link
Phys
BSC/PCF
A10
IP
PPP
IP
GRE
Link
IP
Link
Phys Phys
PDSN
IP
Link
Phys
End
Host
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MAC States (1/3)
 Active Mode and DTX
 Data traffic flows
 Reverse pilot is not gated
 MS and BS can discontinue traffic for 10-20 frames (~200ms) without tearing down traffic channel
Active
SCH millisecond
Active
FCH
Control/Hold Dormant second minute
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MAC States (2/3)
 Control Hold





Triggered when the data traffic is idle ~1-2 seconds
Signaling only
Power control is maintained
Reverse pilot can be gated
MS Stores radio information
Active
SCH millisecond
Active
FCH second
Control/Hold minute
Dormant
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MAC States (3/3)
 Dormancy
 Triggered when data traffic is idle ~1-2 minutes
 Traffic channels and A8 (BSC-PCF) connection is released
 A10 (PCF-PDSN) connection and PPP is maintained
Active
SCH millisecond
Active
FCH second
Control/Hold minute
Dormant
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Dormant Mode
 Initiation
 BSC initiates when inactivity timer is expired or RF failure occurred
 MS initiates when inactivity timer is expired or TCH is released
 Reactivation
 Initiated when network or MS has data to send
 Since PPP is maintained no extra control plane signaling required
 User data is exchanged after reactivation
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Inter BSC – Intra PDSN HHO
Source
BSC/PCF
MSC
User Packet Data
HO Required
PDSN
HO Request
HO Request ACK
HO Command
Target
BSC/PCF
HO Direction Msg
Null Fwd Traffic
Rev Traffic
HO Commenced
Tear Down Channels
Clear Command
Clear Complete
A11 RRQ (Lifetime = 0)
A11 RRP
HCM
A11 RRP
A11 RRQ
Handoff Complete
User Packet Data
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Quality of Service
 Still standardization is continuing
 Air interface is bottleneck for an end-to-end
QoS
 Some parameters are defined such as

User’s priority level (14 possible levels)

Minimum acceptable data rate (2x, 4x, …)
 Acceptable FER (1%, 2%, 5%, 10%)
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1x EV-DV
( 1x RTT Ev olution for high-speed integrated
D ata and V oice)
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Motivation
 CDMA 1x supplemental channel scheduling is slow (~2-4 secs) and data rate is not satisfactory (~144 kbps)
 Forward link has priority due to asymmetric nature of the data applications
 Flexibility against short term and long term voice and data demands
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Design Goals
 Backward compatibility with cdma2000 1x
 cdma2000 1x features, applications and services and voice/data capabilities are maintained
 Minimal effect on the terminals and infrastructure for cdma2000 1x customers
 increase battery life as a side goal
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Design Requirements
 FL peak data rate > 2.4 Mbps
 RL peak data rate > 1.25 Mbps
 Average throughput in FL and RL > 600 kbps
 Peak data rate and average throughput is at least as much as 1X EV-DO
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What’s needed?
 Radio resources should be optimally used
 Radio link control & resource allocation must be optimized
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How is it achieved? (1/3)
100%
Residual power for 1x EV-DV
1xEV-DV overhead
Power for 1x voice and data
1x overhead
Time
Packet Data Common Channel is introduced
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How is it achieved? (2/3)
 Left-over power is used, hence no power control
 Rate control (higher order modulation and coding) is used to maintained link quality
 Optimally schedule delay tolerant data

Favor the user with good channel quality

Serve users both in parallel (CDM) and serial
(TDM) while TDM is preferred if possible
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How is it achieved? (3/3)
 Fast sector switching
 Fast channel quality indicator send by MS
 Fast physical layer ARQ (Automatic Repeat
Request) which also provides error correction
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What’s next?
 Reverse link data enhancements are necessary to meet the requirements, i.e. 1.25
Mbps
 Common services and mobility with different type of network access technologies, such as
Wireless LANs, DSL, satellites etc.
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4G
 Higher data rates ~2-20 Mbps
 New air interface needs to be developed
 Potential candidate OFDM
 Smart antennas can form directed beams to increase strength of the desired signal
 A new spectrum needs to be assigned
 Software radio can transmit over different air interface technologies
 All-IP vision: base stations become an access router
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