2003 salih 3_gdata1
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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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Packet Data Architecture
BSC
MSC PSTNVLR
HLR
PCF PDSN
AAA
Packet Network
Telephone Network
HomeAgent
HomeAAA
SS7 Network
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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 PDSNPacket
Network
BSC
PCF
PDSN
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Mobile IP Registration
Mobile registers its care of address
HA replies with lifetime
PDSN(FA)
Packet Network Home AgentBSS
MIP-RRQ
MIP-RRQ
MIP-RRPMIP-RRP
Packet Data Tunnel (UDP over IP)
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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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Assign Complete
Mobile Originated Packet Data Call
MSCPDSNBSC / PCF
Origination
Base Station AckCMServReq
SCCP-CC
Assign RequestTCH Setup
A11-RRQ
A11-RRP
User Packet Data
PPP Link Establishment and Mobile IP Registration
A8 /A10 setup
Packet Network
UCSD Ericsson ///
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User Plane – Relay Mode
BSC/PCF PDSN
RS
-232
RLPRS
-232
GRE
AIRInter-face
RLP
AIRInter-face
IP
Link
Phys
EndHost
IP
PPP
A10
IP
PPP
IP
Link
Phys
IP
Link
Phys
GRE
IP
Link
Phys
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User Plane – Network Mode
BSC/PCF PDSN
RS
-232
RLPRS
-232
GRE
AIRInter-face
RLP
AIRInter-face
IP
Link
Phys
EndHost
IP
SLIP orPPP
A10
IP
PPP
IP
Link
Phys
IP
Link
Phys
GRE
IP
Link
Phys
SLIP or PPP
IP
PPP
IP
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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
Control/Hold Dormantsecond minute
ActiveFCH
ActiveSCH
millisecond
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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
Control/Hold Dormantsecond minute
ActiveFCH
ActiveSCH
millisecond
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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
Control/Hold Dormantsecond minute
ActiveFCH
ActiveSCH
millisecond
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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
MSC PDSNSource
BSC/PCF
HO Required
HO Command
User Packet Data
HO Request
HO Request ACK
HO Commenced
TargetBSC/PCF
HO Direction Msg
Null Fwd Traffic
Rev Traffic
HCMTear Down Channels
Clear Command
Clear Complete
A11 RRQ (Lifetime = 0)
A11 RRP
A11 RRQ
A11 RRP
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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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)
1x overhead
Residual power for 1x EV-DV
1xEV-DV overhead
Power for 1x voice and data
Bas
e S
tatio
n P
ower
100%
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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