1. Overview of 3G Packet
Data
Salih Ergut
7/16/2003
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2. 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 (1xRTT Evolution for high-speed
integrated Data and Voice)
 Motivation, goals and basic principles
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3. Packet Data Architecture
SS7 HLR
Network
Telephon
VLR MSC PSTN e Network
AAA
Packet
BSC PCF PDSN Network
Home Home
Agent AAA
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4. 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
Packet
BSC PCF PDSN
Network PDSN
PCF
BSC
4

5. Mobile IP Registration
PDSN Packet
BSS Network Home Agent
(FA)
MIP-RRQ Mobile registers
MIP-RRQ its care of
address
MIP-RRP HA replies with
MIP-RRP lifetime
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Packet Data Tunnel (UDP over IP)

6. 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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7. 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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8. Mobile Originated Packet Data Call
UCSD Ericsson ///
MSC
BSC / PCF PDSN
Origination
Base Station Ack
CMServReq
SCCP-CC
Assign Request
TCH Setup
A11-RRQ
A8 /A10
A11-RRP
setup
Assign Complete
PPP Link Establishment and Mobile IP Registration
Packet
User Packet Data Network
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9. Control Plane – Signaling
A11 A11
UDP UDP
IP IP
Link Link
Phys Phys
BSC/PCF PDSN
9

10. User Plane – Relay Mode
IP IP IP IP
PPP PPP
GRE GRE
RLP RLP Link Link
RS-232
RS-232
IP IP
AIR AIR Link Link
Inter- Inter-
face face Phys Phys Phys Phys
End
BSC/PCF PDSN
Host
A10
10

11. User Plane – Network Mode
IP IP IP IP IP IP
SLIP or SLIP or
PPP PPP PPP PPP
GRE GRE
RLP RLP Link Link
RS-232
RS-232
IP IP
AIR AIR Link Link
Inter- Inter-
face face Phys Phys Phys Phys
End
BSC/PCF PDSN
Host
A10
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12. 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
Control/Hold Dormant
FCH
second minute
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13. 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
Control/Hold Dormant
FCH
second minute
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14. 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
Control/Hold Dormant
FCH
second minute
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15. 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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16. Inter BSC – Intra PDSN HHO
Source Target
MSC PDSN
BSC/PCF BSC/PCF
User Packet Data
HO Required
HO Request
Null Fwd Traffic
HO Request ACK
HO Command
HO Direction Msg
Rev Traffic
HO Commenced
HCM
Tear Down Channels
Clear Command A11 RRQ
A11 RRP
Clear Complete
Handoff Complete
A11 RRQ (Lifetime = 0)
User Packet Data
A11 RRP
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17. 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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18. 1x EV-DV
(1xRTT Evolution for
high-speed integrated
Data and Voice)
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19. 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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20. 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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21. 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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22. What’s needed?
 Radio resources should be optimally used
 Radio link control & resource allocation must
be optimized
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23. How is it achieved? (1/3)
100%
Residual power for 1x EV-DV
Base Station Power
1xEV-DV
overhead
Power for 1x voice and data
1x overhead
Time
Packet Data Common Channel is introduced
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24. 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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25. 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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26. 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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27. 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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