CDMA 2000 1xEV-DO System Overview2

V7.4 NORTEL NETWORKS CONFIDENTIAL

CDMA 2000 1xEV-DO

System Overview

Course # 0890AEN

Version 01.02

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


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


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


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)



(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)



(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



(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



(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



(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



(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)


Lesson 2:

The evolution to

CDMA2000 1xEV-DO


The evolution to CDMA2000 1xEV-DO


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


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)



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



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.


Lesson 3:

What is CDMA2000

1xEV-DO?


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


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


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


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


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.




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.




server Benefits of deploying AN-AAA

• Consistent IMSI (International Mobile Subscriber Identity)

for billing

• Control of authentication

• PDSN protection

• Theft of 1xEV-DO access


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.


Lesson 4:

Introduction to IS-856


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.


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



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



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


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


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


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


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


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.


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


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.


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


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


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


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


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


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 .


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


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


IS-856 Reverse Link

• IS-856 only operations

— transmits MAC and

ACK channels

— MAC information

— reverse rate indicator

(RRI)

— data rate control

(DRC)


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


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


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


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.


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).


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


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


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


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.



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



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



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



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




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.




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.




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.




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.


Lesson 5:




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



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



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



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



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



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


Appendix A:

Call processing


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


Access Terminal Registration


Access terminal call origination


PDSN call origination


Handoff DOM to DOM


Handoff DOM to 1X system


Handoff 1X to 1X EV-DO System

Documents

CDMA 2000 1xEV-DO System Overview2