1. EVDO Basic Principle EVDO Overview The Key Technologies of EVDO
The Commercial Application of EVDO
EVDO Network Structure
EVDO Channel
What is the EVDO

2. What is the EVDO ?
the advantages of the EVDO ;
the difference of the 1x and EVDO;

3. Abbreviations 1xEV － EVolution of cdma2000 1X
1xEV-DO － Data Only or Data Optimized
HDR － High Data Rate
HRPD － High Rate Packet Data
AN － Access Network
AT － Access Terminal
3GPP2 C.S0024: cdma2000 High Rate Packet Data Air Interface Standards

4. EV-DO Evolution IS-95A IS-95B 1xEV-DV CDMA2000 1xEV-DO
Release 0
Release A
Natural evolution of CDMA2000 1x
Enjoy surfing In 3G service ahead of time

5. 1xEV-DO basic features Allocate one 1.25MHz bandwidth, data only；
Forward link rate: from 38.4kbps to 2.4Mbps，Reverse link rate: from 9.6kbps to 153.6kbps；
Same RF characteristic with 1x/IS-95；
Adopting a series revolutionary technique in air interface to accelerate data traffic。

6. EV-DO Exciting Feature(1)
Feature Item
CDMA X(1.25M)
EV-DO(1.25M)
Service
Voice and data
Data only
Transfer rate
IS95<14.4kbps
1x<153.6kbps/307.2kbps
FL<2.4Mbps/3.1Mbps
RL<153.6kbps/1.8Mbps
Division multiplex
CDM for both
Forward: TDM+CDM,
reverse: CDM
Handoffs
Hard Handoff and Soft Handoff Both in FL，RL
VHO in FL
Soft Handoff in RL
Power Control and
Rate Control
Fast Power Control Both
In FL，RL
No Rate Control
Rate Control ＋Power Control in RL
Rate Control in FL
前向针对各个用户是时分的。但是前向每个时隙会有多个信道（导频信道，控制信道，业务信道，MAC 信道），是码分的。
Next through the comparision, let we learn from the EVDO related technique;

7. Backward and Forward Compatibility
Old handset can be used in new network, and new handset can be used in old network. Handset availability!

8. EV-DO Exciting Feature(2)
Leverage Current Investment:
Sharing the same RF with 95/1X
Insert new EVDO channel cards and software upgrade
Flexible Network Configuration:
Can be used as a stand-alone network or together with
an CDMA2000-1X network

9. More Advanced Features of Rev. A
Improved Forward Link
Larger Payloads Drive Data Rates To 3.1Mbps
Improved MAC Supports Over 100 Users Per Sector
Packet Division Multiplexing Improves Performance In Good Channel Conditions
Improved Reverse Link
Up 1.8 Mbps Data Rate
Throughput and Latency Gains With Hybrid ARQ
Improved Packing Efficiency
Enhanced Quality of Service (QoS)
Inter-User – Priority by User
Intra-User – Priority by Application
Error Reduction in BTS
Admission Control
Adaptive Scheduler for delay sensitive Applications
Quick Connect with Adaptive Quick Start
Broadcast/ Multicast (BCMCS)
Multimedia content to multiple users
Improved support for real-time packet applications, including VoIP, Gaming, Video Streaming
Can leverage advanced all-IP architectures, IMS support !
VoIP (Voice over Internet Protocol ).
Enhanced capabilities to enable service flexibility and new revenue generating features

10. the commercial application of EVDO

11. 1xEV-DO commercialization by CDMA operators

12. the CDMA Development Process of ZTE

13. In November 2001, launched large-scale research and development in cdma2000 1xEV-DO products.
In February 2002, launched research and development in cdma2000 base station system based on all-IP technology.
In June 2002, ZTE, for the first time, exhibited complete cdma2000 1x EV-DO equipment on Hong Kong 3G annual fair.
In October 2003, commissioned a field trial cdma2000 1x EV-DO.
In June 2004, had the capability to supply cdma2000 1x EV-DO products in batch.
In July 2004, commissioned a field trial cdma2000 1x Release A.
In November 2004, put cdma2000 1x Release A and cdma2000 1x EV-DO products into commercial operation.
In 2004, launched research and development in cdma2000 1x EV-DV products.

14. ZTE CDMA Wireless Solution
ZXRPT-C
Suburb or village
ZXC10-BSCB/PCF
ZXCBTS-M
ZXCBTS-R
ZXC10-BTSB I1
ZXC10-CBTS
Compact city zone
ZXCBTS-M800
ZXC10-BTSB I2
ZXCBTS-R
ZXCBTS-M+ZXICS-C

15. Zte cdma2000 gobale application
CIS
Russia
Tajikistan
Uzbekistan ……
Europe
Bulgaria
Norway
Turkey ……
Asia Pacific
China
Indonesia
Mongolia
Vietnam
North Africa
Algeria
Benin
Nigeria ……
South America
Brazil
Argentina
Nicaragua ……
Middle East
Egypt
Kuwait
Saudi Arabia ……
South Asia
Afghanistan
India
Pakistan
Nepal ……
South Africa
Kenya
Zambia
Angola
…...
For the zte ,the wireless equipments that the capabilities is 22 million lines have been deploying by more than 70 operators in 50 countries; as well as the EV-DO is concerned , 26 networks have been applied in large scales ,in 18 countries , and 9 of then belong to business network;
EV-DO
CDMA 1X
CDMA 1X＋GoTa
CDMA 1X＋EV-DO＋GoTa
CDMA 1X＋EV-DO

16. Zte cdma2000 gobale application
1.ZTE CDMA products have been successfully deployed in approximately 60 countries serving for approximately 100 operators, with a global capacity of 30 million lines for commercial use. Accordingly ZTE has become China’s largest telecommunication equipment exporter, and one of the leading CDMA equipment vendors in the world.
2.By December 2005, ZTE has captured 21.56% market share in China Unicom’s CDMA business, ranking third only next to Motorola (23.35%) and Lucent(22.14%).
3.ZTE’s GoTa products have found widespread applications in over 20 countries such as Russia, Norway, Malaysia, etc. ZTE’s GoTa has become China-made digital trunking system with the widest applications home and abroad.
ZTE has built over 40 CDMA2000 1xEV-DO systems for commercial or trial use in more than 30 countries and regions such as Philippine, Vietnam, Pakistan, Mongolia, etc.
从最新3GSM Cannes传出的信息看，WCDMA全球用户大约12m，跟EVDO差不多。不过如果把1X也算做3G的话，CDMA阵营的3G用户就比WCDMA多多了。

17. EVDO Network Structure

18. EVDO NETWORK STRUCTURE
HLR HA
AAA
MSC
A10/A11
PDSN AT
BTS
BSC
PCF
Access Network ( 1x and DO )
ANAAA
AT：access terminal
AN：access network，including BSC and BTS
AN AAA：AAA server for access network

19. Simple Network Structure (End to End IP)

20. Difference with 1x Reference Network
1xEV-DO is data only, so no interface to MSC/HLR
The Packet Data Domain equipment（PDSN、AAA、HA）is same as 1X
Independent Access network AAA server
Two A interfaces added:
- A12 for access system authentication
- A13 for AT roaming home AN and Foreign AN interaction

21. 1xEV-DO Channel Overview

22. 1xEV-DO Channel Overview
This picture mainly describles the reverse and forward channel categories;

23. 1xEV-DO Channel Overview

24. Forward Link Overview
The transmission rate is the rate requested by AT on the reverse link.
Dedicated to a single AT at any given instant of time.
Pilot is embedded in the traffic stream (as opposed to a continuous transmitted pilot in IS-95).
Paging and Sync Channels are combined into a single Control Channel whose messages are time multiplexed on the “single user” forward link.
Forward link transmission is organized as 26.66…ms frames. Each frame consists of sixteen 1.66…ms slots. Each slot contains 2048 chips. Each slot is divided into two half slots with 1024 chips each.
No soft handoff
TDMed, full power and variable rate (38.4 kbps ~ kbps)
Adaptive coding and modulation (R = ¼, 3/8, and ½; QPSK, 8PSK and 16QAM)
Interleaving, puncturing, repetition and symbol demultiplexing
Quadrature Spreading, baseband Filtering and up-converting

25. Forward Channel Structure
The 1xEV-DO forward channel structure is of a time multiplexed of the following channels
– Pilot channel used by AT for all the following
Initial acquisition
Phase & timing recovery
Coherent demodulation and maximal ratio combining
– Medium access Control (MAC) consists of three sub-channels:
Reverse activity channel (RA) carries reverse activity bit (RAB) stream
Reverse power control (RPC),
DRC Lock channel
–user packets Traffic channel carries
– Control channel carries messages
Pilot: common channel for all users to lock on the specific frequency
Control: page, signaling, channel assignment, schedule
Traffic: data
RAB: control the data rate of handsets in one sector to maintain the highest throughput of the whole sector (reduce the reverse interference in the mean time).

26. Forward Pilot Channel
A Pilot channel is transmitted at all times by the sector on each active forward channel.
The Pilot channel is an unmodulated BPSK signal assigned Walsh cover 0.
The Pilot channel is sent as 96 chip bursts, each of which is located at the center of each half slot.
The Pilot channel is transmitted at the full sector power.

27. Forward MAC Channel
MAC channel is a CDM of Reverse Activity (RA) channel and Reverse Power Control (RPC) channels/DRC.
MAC channel is composed of up to 64 orthogonal Walsh channels and distinguish its uses (control & traffic preamble etc.) .
The RPC Channel and the DRC Lock Channel shall be time-division multiplexed.

28. Forward MAC Channel
RA channel belongs to a kind of broadcast channel , it is used to carry RAB information , controlling the reverse link’s payload dynamic . When AN finds the reverse payload too large , AN will transmit RA to AT and request AT adjust AT’s data rate;
RPC channel is used to carry reverse power control information ;
DRC Lock Channel carrys the information whether AN have received AT’s message, when AN cann’t demodulate AT’s message which is sent through DRC,AN will show AT send message anew;
AN检测到反向负荷太大时，通过RA来指示AT降低反向数据速率 .

29. MAC Channel and Preamble Use Versus MACIndex
RPC subchannel and DRCLock subchannel is time-division multiplexed , they are identified through the same MAC channel ;
RA subchannel is code-divison multiplexed with RPC subchannel and DRCLock subchannel , it is identified through the MACindex ;
Forward traffic id combined through preamble and data , A traffic channel data is transmitted through multipled time slots; and the first slot will transmit traffic channel preamble . Different data rate is corresponded with different preamble;
Control channel shares a physical channel at time-division multipled with traffic channel, AT will judge that it is contol channel or traffic channel according to the channel MACindex ;

30. Forward Control Channel
The Control Channel Cycle period is 256 slots and synchronous with 1xEV-DO system time.
The AN transmits a Control Channel at a rate of 38.4 or 76.8kbps.
It is the combination of paging channel and sync channeling;

31. Time Division Multiplexed in FL
USER　LEVEL
In 1xEV-DO,the whole forward link is used as a shared “Fat Pipe”, TDMed by all users.
Specific time for which subscriber depending on the policy of forward transmission algorithm：Round Robin, maximize data throughput of sector.
Full power transmission on the forward link;
Full code space allocation;
Maximizes peak rates;

32. Reverse Link Overview Reverse link parameters
- Reverse channel frames are 26.66ms;
- Packet size is fixed at 26.66…ms;
- Each slot contains 2048 PN chips;
Output power characteristics are similar to CDMA2000 1X
- Access channel operation is similar to CDMA2000 1X
- Closed & open loop power controls the mean output power of pilot and MAC channels
- The power levels for data are adjusted based on selected data rate
Traffic channel
- In-phase component is a CDM of pilot/RRI and ACK channels
- Quad-phase component is a CDM of DRC and data channels
- Independent gains on DRC and ACK channel relative to pilot
DRC gain range (-9dB to +6dB)
ACK gain range (-3dB to +6dB)
Access channel is composed of pilot channel and data channel
- In-phase component consists of the pilot channel
- Quad-phase component consists of the data channel

33. Reverse Channel Structure
RRI: handset tells the BTS the reverse data rate
DRC: control the forward data rate
Each Traffic is direct sequence spread by a distinct user PN code sequence.
The Access channels are identified by a distinct Access channel PN sequence
per sector.
Code Multiple：Pilot＝W016，DRC=W816，ACK=W48，Data=W24

34. Reverse Access Channel
The Access Channel is used by the access terminal to initiate communication with the access network or to respond to an access terminal directed message.
The Access Channel consists of a Pilot Channel and a Data Channel.
The access terminal shall transmit information on the Access Channel at a fixed data rate of 9.6 kbps.

35. Reverse Traffic Channel Overview
Data channel:（Pilot）＋RRI＋DRC＋ACK＋Data
The Reverse Traffic Channel is used by the access terminal to transmit user-specific traffic or signaling information to the access network. The Reverse Traffic Channel consists of a Pilot Channel, an RRI Channel, a DRC Channel, an ACK Channel, and a Data Channel.
The access terminal shall support transmission of information on the Data Channel of the Reverse Traffic Channel at data rates of 9.6, 19.2, 38.4, 76.8, and kbps. The data rate used on the Data Channel is specified by the Reverse Traffic Channel MAC Protocol.

36. Reverse Traffic Pilot / RRI Channel
Pilot channel
– Unmoduated symbols with binary value .
– Giving an assistance coherent demodulation achieves better receiver performance (reduces the required Eb/No) .
RRI channel
– Reports data rate of the current reverse link data packet.
• Represented by 3-bit RRI symbol, sent once per data packet
• One-to-one mapped to reverse data rates
– Each RRI symbol maps into a 7-bit codeword.
– Time multiplexed with pilot symbols on every slot.

37. Reverse Traffic ACK Channel
The ACK channel transmits a ‘0’ bit if a data packet has been received successfully, and a ‘1’ if not in order to indicate whether a data packet on the forward traffic channel has been received successfully.
The ACK channel is generated by taking a single ACK bit, repeating this bit 128 times;
The ACK channel bit is transmitted at 9.6kbps in response to every FTC preamble that the AT detects is directed to it;
By using ACK channel in RL, AN can early terminate multi-slot packet transmission，and increased the actual throughput, it is HARQ;

38. Reverse Traffic DRC Channel
AT sends the request of the desired data rate and best serving sector on the forward channel to AN over the DRC channel.
Desired serving sector in the Active Set is indicated by one of eight 8-ary Walsh functions.
Data rate is block encoded to yield 8-bit bi-orthogonal codewords.
AT estimates C/I received forward channel and determines the supportable data rate and the requested sector for transmission in the active set.
Only the sector requested will transmit packets to the AT, after receiving 2 consecutive DRCs from AT.
The sector sends a data packet with a preamble to the AT at the rate requested by the DRC in the preceding slot.
Once the sector starts sending packets to an AT, it must continue to do so until the packet Tx is complete or an Ack bit is received.

39. Reverse Traffic Data Channel
Reverse traffic data can be transmitted from 9.6kbps to 153.6kbps.
All data transmitted on the reverse traffic channel shall be turbo encoded, block interleaved, sequence repeated, and orthogonally spread by Walsh function W24(++--).

40. Reverse Link Power Control
Reverse Link is power controlled similar to IS-95 / CDMA2000 1X.
AT transmitted power which is determined by both open-loop and close loop power control.
Based on measurements of reverse link signal quality, sector continually sends up/down power control bits to the AT .
Using closed loop power control achieved , AT adjusts its Pilot/MAC output power with 0.5 dB or 1.0dB step sizes, based on power control bit received on forward link from AN.
Open loop estimate based on received forward link power.

41. The key Technologies

42. Time Division Multiplexed in FL
In 1xEV-DO，the whole forward link is used as a shared “Fat Pipe”, TDMed by all users.
Full power transmission on the forward link;
Full code space allocation;
Maximizes peak rates;

43. Adaptive modulation and coding
1xEV-DO can automatically adjust its FL data rate, modulation scheme, coding rate according to the feedback of FL channel SINR provided by AT.
AT use DRC sub channel to inform AN

44. Fast Cell Site Selection
current sector forward data rate
Pilot/MAC on FWD link
Pilot/DRC/ACK/Traffic on REV Link
(AP’s in AT’s active set)
After handoff AP2 forward data rate
AP1
AP4
AP2
AP3
Server
before t1
At any instance there is only one serving sector that is transmitting data to a given AT；
The serving sector is decided by AT and changes as the Forward channel’s SINR changed.
AT use DRC sub channel to infrom AN who is the serving sector
Server
after t1
Only one sector transmits data to a user at any time;
AP1
AP2
Time
Serving AP t1
Serving
AP change

45. Serving Sector Selection illustration

46. Hybrid ARQ
By using ACK channel in RL, AN can early terminate multi-slot packet transmission，and increased the actual throughput.
Accuracy of a-priori CSI varies significantly with channel conditions and interference patterns.
Need a-posteriori CSI feedback to fine tune spectral efficiency
--the Ack channel on the reverse link
Data packets transmitted in multiple, non-contiguous time slots
--incremental redundancy;
--Partial decoding and ACK feedback;
--Earlier termination of packet transmission increase data rate;
Rely on conservative DRC requests for more unpredictable channels
ARQ means ( Automatic Error Request Equipment )

47. Reverse link rate control
In 1x EV-DO specifications, AT’s reverse rate can be freely adjusted by AT from 9.6kbit/s to 153.6kbits. In order to avoid all the AT become unavailable, the workload of reverse links must be constrained to prevent too many users in the same sector from transferring data to AN at a high rate.
Feedback control using the Reverse Activity (RA) channel;
Eliminate idle resource;
Minimize control overhead;

48. Reverse link Power control
Power control is essential to the system maximization. The forward power control is not required in 1x EV-DO because of its constant power. Therefore, power control is mainly adopted by reverse channels.
Reverse Power control includes
Opened-loop power control 、Closed-loop power control 、
Feedback control using the Reverse Activity (RA) channel;
Eliminate idle resource;
Minimize control overhead;

49. Virtual soft handoff in forward link
In The forward Virtual Handoff, there’s only one sector sends data to the terminals at a particular time in the AT active set. According to the quality of each received pilot, AT can use the DRC_Cover to specify the sectors which are expected to transfer data. In AN, all the sectors within the active set are listening to the reverse channels of the AT. AN decides which sector is the Serving Sector of the AT according to the DRC channel received.
There’s no signaling messages exchange between AN and AT in the forward Virtual Handoff as it is very quick. It only takes up one sector’s forward air resource at anytime. The usability of forward channels are improved significantly.
Feedback control using the Reverse Activity (RA) channel;
Eliminate idle resource;
Minimize control overhead;

50. Dual Mode Operation with 1x/DO
As 1xEV-DO supports only data traffic, a total voice and data solution needs integrating cdma2000 1x and 1xEV-DO；
Packet data traffic can be handoff from 1x to DO, and dual mode terminal can monitor both system’s control channel, so even active in DO system it will not lose any voice terminated calls in 1x system.

51. Thank You !