NORTEL NETWORKS CONFIDENTIAL 1
OBJECTIVES
This class is intended for anyone requiring an introduction
to 1x EV-DO.
At the conclusion of this class the student will be able to
discuss:
Nortel Networks implementation of 1x EV-DO
New equipment added to the network and its functionality
Theory of IS-856
Basic call flow
NORTEL NETWORKS CONFIDENTIAL 2
What is CDMA2000 1xEV-DO?
• CDMA2000 1xEV-DO stands for 1xRTT Evolution – Data
Only
—What this means is that it is an evolution from
CDMA2000 1X (IS-2000/CDMA2000) networks
—Where CDMA2000 1X has both data and voice
capabilities, CDMA2000 1xEV-DO is data only
(without the voice component)
• CDMA2000 1xEV-DO offers high-speed packet data
rates up to 2.45 Mbps where CDMA2000 1X has a
maximum data rate of 153.6 Kbps
NORTEL NETWORKS CONFIDENTIAL 3
What is CDMA2000 1xEV-DO? (continued)
• CDMA2000 1xEV-DO is overlaid on an existing
CDMA2000 1X network but requires a separate 1.25
MHz carrier and a dedicated T1/E1 backhaul from the
Metro Cell to the data only radio network controller
(DO-RNC)
• Shares the packet-data network with CDMA2000 1X
• CDMA2000 1xEV-DO is based on IS-856 / CDMA2000
1X is based on IS-2000
NORTEL NETWORKS CONFIDENTIAL 4
CDMA2000 1xEV-DO components
• As CDMA2000 1xEV-DO is overlaid on an existing
CDMA2000 1X network, there are many shared
components
• The shared components with CDMA2000 1X are:
— MetroCell
— PDSN
— AAA server (if not deploying AN-AAA)
NORTEL NETWORKS CONFIDENTIAL 5
CDMA2000 1xEV-DO components
(continued)
• The new components required for CDMA2000
1xEV-DO are:
—Data Only Module (DOM) located in the MetroCell
—Data Only Radio Network Controller (DO-RNC) located at the central office (CO)
—Data only element management subsystem (DO-EMS) and can be co-located at the CO with the DO-RNC and BSC
—Access network authorization, authentication and accounting (AN-AAA) server (optional)
NORTEL NETWORKS CONFIDENTIAL 6
CDMA2000 1xEV-DO components
(continued) Data Only Module (DOM)
• IS-856 module added to CEM
shelf in Metro Cell
• provides CDMA2000 1xEV-DO
modem capability.
• performs all the
encoding/decoding of the IP
packets
• Requires MFRM
• supports 30 connected sessions
per sector
NORTEL NETWORKS CONFIDENTIAL 7
CDMA2000 1xEV-DO components
(continued)
Data Only Radio Network Controller
(DO-RNC)
• at the core of the CDMA2000
1xEV-DO network
• manages the access terminal state,
handoffs and connections to the
packet data network through the
packet data switching node (PDSN).
• controlling the DOMs at multiple cell
sites over an IP-based backhaul
network
NORTEL NETWORKS CONFIDENTIAL 8
CDMA2000 1xEV-DO components
(continued) Data only element management
subsystem (DO-EMS)
• provides OA&M capability and controls the operation, administration, maintenance and provisioning (OAMP) operations for the CDMA2000 1xEV-DO radio access network (RAN).
• based on a Sun Netra 20 NEBS compliant platform and may be located at the central office (CO)
• stand-alone platform for performing OAM&P functionality within the CDMA2000 1xEV-DO network only
Sun Netra 20
Sun StorEdge 3310
Sun Blade 150
NORTEL NETWORKS CONFIDENTIAL 9
CDMA2000 1xEV-DO components
(continued)
Access network authorization, authentication and
accounting (AN-AAA) server
• optional requirement (as specified in IS-878) used for
access terminal authentication at the beginning of a
CDMA2000 1xEV-DO data session
• used for device level authentication
• terminates the point-to-point protocol (PPP) session
required for terminal authentication at the beginning of a
CDMA2000 1xEV-DO session
NORTEL NETWORKS CONFIDENTIAL 10
CDMA2000 1xEV-DO components
(continued)
Network upgrades from CDMA2000 1X
• Dedicated T1/E1 backhaul from the Metro Cell to the DO-
RNC
• Additional 1.25 MHz carrier for data only traffic
Note: More 1.25 carriers can be added for increased
users (additional DOMs need to be added for each
additional CDMA2000 1xEV-DO carrier)
NORTEL NETWORKS CONFIDENTIAL 13
The path to CDMA2000 1xEV-DO
CDMA2000 1X in the beginning:
• CDMA2000 1xEV-DO is an evolution from conventional IS-2000 (CDMA2000 1X) networks.
• CDMA2000 1X offers both voice and data capabilities compared to conventional CDMA (IS-95) networks (voice only)
• CDMA2000 1X high speed packet data
— Rates of up to 153.6 Kbps (144 Kbps user)
• New hardware for 3G (CDMA2000 1X):
— XCEM in Metro Cell
— SCI-S and ESEL in BSC
— Shasta BSN 5000 for PDSN and HA functionality
— AAA server, routers, hubs, for data network administration
NORTEL NETWORKS CONFIDENTIAL 14
The path to CDMA2000 1xEV-DO (continued)
Evolution to CDMA2000 1xEV-DO:
• CDMA2000 1xEV-DO offers data only capabilities compared to 1xRTT networks (voice and data)
• CDMA2000 1xEV-DO overlaid on existing CDMA2000 1x network and shares the following:
— Metrocell
— PDSN
— AAA server (if present)
• New components for CDMA2000 1xEV-DO
— data only module (DOM)
— data only radio network controller (DO-RNC)
— data only element management subsystem (DO-EMS)
NORTEL NETWORKS CONFIDENTIAL 15
The path to CDMA2000 1xEV-DO (continued)
CDMA2000 1xEV-DO offers:
• High speed packet data
— Rates of up to 2.45
Mbps
• Full time forward power
by time division
multiplexing
• No shared spectrum with
other users
• No soft hand-offs in
forward direction, soft
hand-off in reverse
NORTEL NETWORKS CONFIDENTIAL 16
The path to CDMA2000 1xEV-DO (continued)
Packet Data Network
The CDMA2000 1xEV-DO system
does not define a new packet
data network architecture.
In fact, both the CDMA2000
1xEV-DO and the CDMA2000
1X systems share the same
packet data network
infrastructure.
NORTEL NETWORKS CONFIDENTIAL 18
What is CDMA2000 1xEV-DO?
• CDMA2000 1xEV-DO (1xRTT evolution–data only) is a wireless
packet data-only technology
—Used for customer data applications where voice communication
is not required
• high-speed packet data support of variable rates up to 2.45 Mbps on
the forward link and up to 153.6 kbps on the reverse (upload) link
• CDMA2000 1xEV-DO uses time-division multiplexing (TDM) in the
forward direction, meaning there are no soft handoffs in the forward
direction and only one terminal receives data from each sector at a
given time
NORTEL NETWORKS CONFIDENTIAL 19
Benefits of CDMA2000 1xEV-DO
• Uses less bandwidth that UMTS (1.25 MHz rather that 5 MHz)
• Core network elements are shared with CDMA2000 1X meaning cost of upgrade is minimal
• No degradation of CDMA2000 1X voice calls since CDMA2000 1xEV-DO is deployed on separate 1.25 MHz carriers
• As CDMA2000 1xEV-DO uses TDM, there is full time full power as the bandwidth is not shared with other users like CDMA2000 1X
NORTEL NETWORKS CONFIDENTIAL 20
Data only element management subsystem
(DO-EMS) and client
DO-EMS Client
web-based client runs in standard web browsers, offering network administrators a familiar, easy-to-use interface to robust configuration, fault, and performance management tools
Provides:
• Network topology views
• Network database views
• Active device panel
• Performance statistics administration
• System administration
NORTEL NETWORKS CONFIDENTIAL 21
Data only element management subsystem
(DO-EMS) and client (continued)
DO-EMS Client (continued)
Provides
• Fault management tools
— alarm browser
— event browser
• Management tools
— MIB manager
— Policy manager
NORTEL NETWORKS CONFIDENTIAL 22
Access network authorization,
authentication and accounting (AN-AAA)
server
The access network authorization, authentication and
accounting (AN-AAA) server is an optional requirement
(as specified in IS-878) used for access terminal
authentication at the beginning of a CDMA2000
1xEV-DO data session.
If operators do not deploy an AN-AAA, they may use the
existing AAA Radius server currently used in the
CDMA2000 1X network.
NORTEL NETWORKS CONFIDENTIAL 23
Access network authorization,
authentication and accounting (AN-AAA)
server With an AN-AAA:
• The DO-RNC authenticates access terminals.
• The DO-RNC communicates with one or more AN-AAA
servers.
• The AN-AAA can act as a proxy server to determine the
Radius server for an access terminal that is roaming.
NORTEL NETWORKS CONFIDENTIAL 24
Access network authorization,
authentication and accounting (AN-AAA)
server Benefits of deploying AN-AAA
• Consistent IMSI (International Mobile Subscriber Identity)
for billing
• Control of authentication
• PDSN protection
• Theft of 1xEV-DO access
NORTEL NETWORKS CONFIDENTIAL 25
Hybrid access terminal
A new hybrid access terminal is required to support voice
on IS-2000 systems and packet data services on both IS-
2000 and IS-856 systems. The hybrid access terminal is
required to operate in both IS-856 and IS-2000 modes
and is capable of monitoring both the CDMA2000 1xEV-
DO and CDMA2000 1X systems simultaneously.
NORTEL NETWORKS CONFIDENTIAL 27
Introduction to IS-856
The TIA/EIA Engineering Committee TR-45 (Mobile and
Personal Communications Systems) has developed a
standard called IS-856 as a companion to the already
existing IS-2000 standard. These standards are the next
generation of wireless standards after the second-
generation (2G) CDMA standards, known as IS-95.
The IS-856 (CDMA2000 1xEV-DO) air interface standard
provides high rate packet data services between the
access terminal and the access network.
NORTEL NETWORKS CONFIDENTIAL 28
IS-856 Protocol Layers
The CDMA2000 1xEV-DO protocol layering does not conform to
the open system interconnection (OSI) seven layer model.
OSI seven layer protocol IS-856 seven layer protocol
Layer 7: Application layer Layer 7: Application layer
Layer 6: Presentation layer Layer 6: Stream layer
Layer 5: Session layer Layer 5: Session layer
Layer 4: Transport layer Layer 4: Connection layer
Layer 3: Network layer Layer 3: Security layer
Layer 2: Data Link Layer Layer 2: MAC layer
Layer 1: Physical layer Layer 1: Physical layer
NORTEL NETWORKS CONFIDENTIAL 29
IS-856 Protocol Layers
The CDMA2000 1xEV-DO air interface protocol layers (continued)
IS-856 seven layer
protocol
Description
Layer 7: Application layer Message routing, RLP, flow control
Layer 6: Stream layer Multiplex various application streams
Layer 5: Session layer Establishes/configures data sessions
Layer 4: Connection layer Establishes and manages radio
connection
Layer 3: Security layer Authentication and encryption
Layer 2: MAC layer Data rate controlling and scheduling
Layer 1: Physical layer Adaptive modulation and code
spreading
NORTEL NETWORKS CONFIDENTIAL 30
IS-856 Protocol Layers
The CDMA2000 1xEV-DO air interface protocol layers
IS-856 seven layer
protocol
Description
Layer 7: Application layer Message routing, RLP, flow control
Layer 6: Stream layer Multiplex various application streams
Layer 5: Session layer Establishes/configures data sessions
Layer 4: Connection layer Establishes and manages radio
connection
Layer 3: Security layer Authentication and encryption
Layer 2: MAC layer Data rate controlling and scheduling
Layer 1: Physical layer Adaptive modulation and code
spreading
NORTEL NETWORKS CONFIDENTIAL 31
Theory of operations
RF PHY
RF PHY
Layer 2
Layer 1
Ethernet Ethernet Ethernet
100BaseT 100BaseT 100BaseT
MAC
IP IP IP IP
GRE
A10/A11
GRE
A10/A11
GRE GRE
Abis Abis
MAC
RLP RLP
PPP PPP
AT Metro Cell (DOM) DO-RNC PDSN
NORTEL NETWORKS CONFIDENTIAL 32
IS-856 Physical Layer
Major improvements to the physical layer from IS-2000:
— Higher data rates : utilizes turbo coding in forward and reverse directions
— Dynamic turbo encoding rates : Turbo codes have been shown to perform better for high rate data services
— Source identification : no source identification in reverse direction
— Higher order modulation : adaptive modulation
NORTEL NETWORKS CONFIDENTIAL 33
IS-856 Physical Layer (continued)
Major improvements to the
physical layer from
IS-2000:
— Channelization :
forward link
channels time-
multiplexed (no
Walsh codes) not
code multiplexed
— Each access
terminal receives full
power for their time
rather than sharing
power across time
NORTEL NETWORKS CONFIDENTIAL 34
IS-856 Physical Layer (continued)
Major improvements to the
physical layer from
IS-2000:
— Forward link transmit
power : transmits at
maximum available
power all the time
— IS-856 channel
structure : forward
direction = time
division multiplexed,
reverse direction =
code division
multiplexed
NORTEL NETWORKS CONFIDENTIAL 35
IS-856 Forward link
Forward traffic flow travels
from the packet data
network/internet through the
CDMA2000 1xEV-DO radio
access network to the user.
NORTEL NETWORKS CONFIDENTIAL 36
IS-856 Forward link
Forward channel structure
• The access network
transmits the following
forward link channels at full
power in time-multiplexed
fashion. At a fixed position
in every physical layer slot,
these channels are
transmitted:
— pilot channel
— medium access control
— control channel
— traffic channel
NORTEL NETWORKS CONFIDENTIAL 37
IS-856 Forward link
Forward channel slot structure
In forward direction, there are two types of slots:
• Active Slot: When access network has either control information or user traffic to send, it sends this information along with MAC and pilot channel in a time-multiplexed fashion.
• Idle Slot: When access network does not have control information or user traffic to send, it still sends pilot and MAC channels in their given time at full power and does not transmit control/traffic information.
NORTEL NETWORKS CONFIDENTIAL 38
IS-856 Forward link
Paging/control channel slot structure
• access terminal (handset)
monitors both the CDMA2000
1xEV-DO and CDMA2000 1X
network simultaneously
• Paging channels for both
CDMA2000 1xEV-DO and
CDMA2000 1X are staggered
• If paging channels collide,
IS-856 assigns a different paging
slot
NORTEL NETWORKS CONFIDENTIAL 39
IS-856 Forward link
Forward frame structure
• Physical layer code spread
across 1.25 MHz –
identical to
IS-95/2000
• IS-856 only has one
physical channel and MAC,
control and traffic channels
are time multiplexed on the
single channel
NORTEL NETWORKS CONFIDENTIAL 40
IS-856 Forward link
Fat pipe scheduling
• using a large radio spectrum as a shared wireless link
• all terminals in sector share wireless link
• access network schedules transmission of packets over shared link
• packets are time division multiplexed not code multiplexed
NORTEL NETWORKS CONFIDENTIAL 41
Forward Traffic Channel Physical Layer
ENCODER
1/3 OR 1/5
SCRAMBLER
SYMBOL
PUNCTURING
CHANNEL
INTERLEAVER
MODULATOR
QPSK
8PSK
16QAM
DEMUX
16-ARY
WALSH
COVER
WALSH
GAIN
1/4
T
D
M
WALSH
CHIP
SUMMER
I
Q
I
Q
NORTEL NETWORKS CONFIDENTIAL 42
DATA RATE IN KBS
38.4
76.8
153.6
307.2
307.2
614.4
614.4
921.6
1288.8
1288.8
1843.2
2457.6
# BITS PER PACKET
1024
1024
1024
1024
2048
1024
2048
3072
2048
4096
2048
4096
MODULATION
QPS
K
QPS
K
QPS
K
QPS
K
QPS
K
QPS
K
QPS
K
8PS
K
QPSK
16QA
M
8PSK
16QA
M
CODING RATE
1/5
1/5
1/5
1/5
1/3
1/5
1/3
1/3
1/3
1/3
1/3
1/3
# OF SLOTS
16
8
4
2
4
1
2
2
1
2
1
1
# chips Preamble
Pilot
1024
3072
512
1536
256
768
128
384
128
768
64
192
64
384
64
384
64
384
64
384
64
192
64
192
# chips MAC
4096
2048
1024
512
1024
256
512
512
512
512
256
256
# chips DATA
24,5
76
12,2
88
6144
3072
6272
1536
3136
1536
3136
3136
1536
1536
FORWARD CHANNEL MODULATION
NORTEL NETWORKS CONFIDENTIAL 43
IS-856 Reverse link
Reverse traffic flow travels
from the user through the
CDMA2000 1xEV-DO radio
access network to the
packet data
network/internet .
NORTEL NETWORKS CONFIDENTIAL 44
IS-856 Reverse Link
• reverse link of IS-856 is
quite similar to the
reverse link in an
IS-2000 system
• reverse link power control
performed same as
IS-2000 (except at 600
times per second)
• access network sends
power control command
in every slot for all
connected ATs
NORTEL NETWORKS CONFIDENTIAL 45
IS-856 Reverse Link
• IS-856 and IS-2000 similarities
— power control and soft handoff supported
— BPSK modulation on I & Q (data & pilot) carrier to reduce
peak to average ratio
— distinct user PN sequence for source ID
— data rates from 9.6 to 153.6 Kbit/s
— transmits pilot and data channels
NORTEL NETWORKS CONFIDENTIAL 46
IS-856 Reverse Link
• IS-856 only operations
— transmits MAC and
ACK channels
— MAC information
— reverse rate indicator
(RRI)
— data rate control
(DRC)
NORTEL NETWORKS CONFIDENTIAL 47
IS-856 Reverse Link
Reverse channel structure
In the reverse direction, the access terminal can use access or traffic channel
— access and traffic channels are code multiplexed
Access channel mode:
— access terminal is idle and transmits pilot and data channels
Traffic channel:
— access terminal is connected and transmits MAC, data, pilot and ACK channels
NORTEL NETWORKS CONFIDENTIAL 48
IS-856 Reverse Link
Reverse channel usage
• Once connected, the access
terminal is either in idle or
connected state
• idle: monitors forward
control channel
• connected: monitors forward
traffic and control channels
NORTEL NETWORKS CONFIDENTIAL 49
IS-856 Reverse Link
Access channel
• consisting of a pilot and data channel
• used by the access terminal to initiate communication with the access network
• respond to an access terminal directed message
• access terminal sends a series of access probes (preamble followed by one or more access channel physical layer packets) until it receives a response from the access network access probe consists of a preamble followed by one or more access channel
• During preamble only pilot channel is transmitted
• During the access channel physical layer packet transmission, both the pilot channel and the data channel are transmitted
• physical layer packets transmitted at fixed data rate of 9.6 Kbps
NORTEL NETWORKS CONFIDENTIAL 50
IS-856 Reverse Link
Reverse traffic channel
• comprised of pilot, MAC,
ACK and data channels
• On the pilot channel, reverse
rate indicator bits are time-
multiplexed with the pilot bits
• ACK channel protected with
repetition followed by
spreading with 8-bit Walsh
code W4
• data rate control (DRC) bits
encoded and repeated for
proper data protection.
NORTEL NETWORKS CONFIDENTIAL 51
IS-856 Reverse Link
• Reverse rate indicator
The reverse rate indicator
(RRI) channel is used by
the access terminal to
indicate the data rate at
which the data channel is
transmitted.
• Reverse ACK channel
In the CDMA2000 1xEV-DO
system, acknowledgment
is provided at the physical
layer. This provides quick
response from the
receiver (access terminal)
to the transmitter (access
network).
NORTEL NETWORKS CONFIDENTIAL 52
IS-856 Reverse Link
Data rate control (DRC)
• DRC channel in the reverse traffic channel is used to indicate the selected serving sector and the requested data rate on the forward traffic channel
Reverse link parameters
• access terminal selects a data rate and sends the data traffic at the selected rate on the reverse traffic channel and it also sends reverse rate indicator (RRI) in time division multiplexed fashion with the pilot channel
Reverse link power control
• the power control command is repeated four times and sent in the MAC channel
NORTEL NETWORKS CONFIDENTIAL 53
IS-856 Reverse Link
Medium access control (MAC) layer
• responsible for determining scheduling and transmission policies
• MAC layer determines the best possible data rate on slot-by-slot basis in both directions
• physical layer is responsible for actual transmission procedures based on input from MAC layer
NORTEL NETWORKS CONFIDENTIAL 54
DATA RATE (kbps)
9.6
19.2
38.4
76.8
153.6
RATE INDEX
1
2
3
4
5
Bits per packet
256
512
1024
2048
4096
Packet duration (ms)
26.66
26.66
26.66
26.66
26.66
Code rate
¼
¼
¼
¼
½
Code Symbols per packet
1024
2048
4096
8192
8192
Symbol rate (KSPS)
38.4
76.8
153.6
307.2
307.2
Packet repeats
8
4
2
1
1
Mod symbol rate (KSPS)
307.2
307.2
307.2
307.2
307.2
Modulation
BPSK
BPSK
BPSK
BPSK
BPSK
PN CHIPS per packet bit
128
64
32
16
8
REVERSE CHANNEL MODULATION
NORTEL NETWORKS CONFIDENTIAL 55
IS-856 Medium access control
Medium access control (MAC) functions
• Forward direction
— Scheduling transmission for different access terminals based on input given by these terminals
— handles scheduling transmission for forward control channel and forward traffic channel
— responsible for providing input to access terminals on the reverse link so that the access terminal can adjust reverse link data rates.
NORTEL NETWORKS CONFIDENTIAL 56
IS-856 Medium access control
Medium access control (MAC) functions
• Reverse direction
— handles transmission and reception on access and traffic channel
— provides input to the access network on what is the best data rate and best sector based on the existing channel conditions.
— responsible for best possible data for transmission on the reverse link
NORTEL NETWORKS CONFIDENTIAL 57
IS-856 Medium access control
Medium access control (MAC) protocols
Each protocol defines procedures and messages for handling of one and
only one channel.
• access channel protocol
• control channel MAC protocol
• forward traffic channel MAC protocol
• reverse traffic channel MAC protocol
NORTEL NETWORKS CONFIDENTIAL 58
IS-856 Medium access control
Medium access control (MAC) states
• The FTC-MAC can be in one of the three states when the access terminal is activated. The various states are described briefly here:
— inactive state: when the access terminal is not assigned a forward traffic channel (not connected)
— variable rate state: when access terminal is assigned a forward traffic channel (connected)
— fixed rate state: the access terminal always receives traffic from one particular sector in its active set at a fixed rate
NORTEL NETWORKS CONFIDENTIAL 59
IS-856 Medium access control
Medium access control (MAC) schedulers
• Schedulers handle how data gets transmitted to the access terminals.
• Goal is to improve overall system throughput
• Bandwidth allocated to different access terminals based on reported data rates
• For 1xEV-DO, there are four different schedulers available:
— round-robin
— best rate
— equal opportunity
— proportional fairness
NORTEL NETWORKS CONFIDENTIAL 60
IS-856 Medium access control
Medium access control (MAC) schedulers
Round robin schedulers
• utilize first in, first out strategy
• Each request gets put into a queue and when it is at the top of the queue it receives the resource allocation requested.
NORTEL NETWORKS CONFIDENTIAL 61
IS-856 Medium access control
Medium access control (MAC) schedulers
Best rate schedulers
• goals are to process the requests in the buffer with the highest data rates first
• high system throughput since the highest requested data rates always get scheduled
• drawback is that users with low data rates can be withheld resources in favor of those with high data rates.
NORTEL NETWORKS CONFIDENTIAL 62
IS-856 Medium access control
Medium access control (MAC) schedulers
Equal opportunity scheduler
• Each user request is tracked in the buffer and the user with the lowest data rate receives the resource allocation requested.
• The disadvantage of this is that the overall throughput may be low especially if there are many low data rate users.
• Users with high data rates may be withheld resources since the lowest data rate users are processed first.
NORTEL NETWORKS CONFIDENTIAL 63
IS-856 Medium access control
Medium access control (MAC) schedulers
Proportional fairness scheduler
• The goal is to provide fairness to each user regardless of their data rates.
• The scheduler maintains a moving average of DRC (data rate control) values and the scheduler transmits data to the access terminal only when the DRC value is greater than or equal to the moving average.
• This increases overall throughput for individual users as well as the whole system.
NORTEL NETWORKS CONFIDENTIAL 65
Theory of operations
Evolving to CDMA2000 1xEV-DO
• Goals of CDMA2000 1xEV-DO
— provide efficient packet-based air interface
— Sharing components with CDMA 1X
— Reduced cost of ownership
NORTEL NETWORKS CONFIDENTIAL 66
Theory of operations
Evolving to CDMA2000 1xEV-DO (continued)
• IP network access
CDMA2000 1xEV-DO and CDMA2000 1X systems share the
same packet data network infrastructure
• Packet data model
—mobile switching center (MSC/MTX) and home location
registry (HLR) no longer required
—MSC/MTX, HLR are responsible for radio access
authentication and authorization functions not data functions
—packet data service authentication comes from a AAA (or
AN-AAA) server
NORTEL NETWORKS CONFIDENTIAL 67
Theory of operations
Evolving to CDMA2000
1xEV-DO
• Packet data calls in
CDMA2000 1xEV-DO
The CDMA2000
1xEV-DO networks
support the same two
IP addressing options
for packet data as
CDMA2000 1X
networks:
— simple IP
— mobile IP
NORTEL NETWORKS CONFIDENTIAL 68
Theory of operations
Handoffs
• IS-856 does not support soft handoffs in the forward link
• IS-95/2000 supports soft handoffs in the forward link
• IS-856 supports soft handoff In the reverse link similar to
IS-95 and IS-2000
NORTEL NETWORKS CONFIDENTIAL 69
Theory of operations
Time-division multiplexing
• TDM used in forward direction
• Each user given dedicated time slot on entire 1.25 MHz
carrier for their period of time
• Within each slot, spread spectrum processing is used
• TDM removes inefficiencies (overhead) of power control and
soft handoff
NORTEL NETWORKS CONFIDENTIAL 70
Theory of operations
Fixed power variable rate
The CDMA2000 1xEV-DO system based on fixed power variable rate
• sector transmits at full power to every access terminal
• data rate varies depending on the interference experienced by the access terminal
• access terminal reports receivable data rates based on interference conditions for every scheduling period
• network transmits to the access terminal at that rate during that period
• The time slot and data rate for each connected user is adaptively determined by the scheduler so as to enhance CDMA2000 1xEV-DO aggregate forward data throughput
NORTEL NETWORKS CONFIDENTIAL 72
1X EV-DO Basic Call Processing
This section will cover different call processing scenarios including:
• Registration
• Call Flow
• Handoffs
—DOM to DOM
—DOM to 1X
—1X to 1xEV-DO
NORTEL NETWORKS CONFIDENTIAL