CDMA 2000 1x EVDO

CDMA 2000 1x EVDO

�EV-DO is the abbreviation of Evolution Data Only.

� It is a dedicated technology for high speed data transfer.

�1xEV-DO is considered as the upgraded version of 1x.

�1x EV-DO is based on IS-856 specification which was developed by Qualcomm and Lucent.

� The System Structure of 1xEV-DO can be

regarded as a combination of the 1x system

with an extra wireless component.

� 1x provides voice and other low speed

services while 1xEV-DO is focus on the high

speed packet data services.

� In addition, 1x EV-DO and 1x use different

carrier frequency to transfer data

�This feature helps optimize both the voice services and the high speed packet data services and ensure them the best performances.

� 1xEV-DO uses the same frequency bandwidth as narrow band CDMA. The highest data transfer rate is 2.4Mbit/s.

�Take the inheritance from 1x system into account, the 1x EV-DO is compatible with the 1x in wireless features.

� It can be seen as a new frequency point of 1x.

�This makes the RF equipment of 1x EV-DO and 1x system are replaceable to each other.

The 1x EV-DO system structure

The Differences from the 1x system:

� 1x EV-DO is data only, so there is no interface to MSC/HLR.

� Packet Data Domain equipment (PDSN, AAA, HA), same as 1x.

� Independent Access Network AAA server is added.

� 2 A interfaces are added. A12 for access system authentication, and A13 for interaction between AT roaming home AN, foreign AN.

A A A A –––– Interfaces between different elements of CDMA 2000 1x:Interfaces between different elements of CDMA 2000 1x:Interfaces between different elements of CDMA 2000 1x:Interfaces between different elements of CDMA 2000 1x:

A A A A –––– Interfaces between different elements of CDMA 2000 1x EV Interfaces between different elements of CDMA 2000 1x EV Interfaces between different elements of CDMA 2000 1x EV Interfaces between different elements of CDMA 2000 1x EV –––– DO:DO:DO:DO:

Changed parts in upgrading to CDMA 2000 1x EV Changed parts in upgrading to CDMA 2000 1x EV Changed parts in upgrading to CDMA 2000 1x EV Changed parts in upgrading to CDMA 2000 1x EV –––– DO:DO:DO:DO:

BTS side:BTS side:BTS side:BTS side:

� If new EVDO carrier is added

�Add EVDO base band processing part

�Add related Radio transmission part, keep antenna and feeder.

� If upgrading 1x carrier to EVDO carrier : Add EVDO base band processing part, Keep antenna and feeder no change

BSC side:BSC side:BSC side:BSC side:

�Add EVDO processing part, upgrade related software

�EVDO Signaling

PCF Side:PCF Side:PCF Side:PCF Side:

�Add data processing module considering

� Increased capacity when upgrading

Dual Mode Operation with 1x/EVDODual Mode Operation with 1x/EVDODual Mode Operation with 1x/EVDODual Mode Operation with 1x/EVDO

� As 1xEV-DO supports only data traffic, a total voice and data solution needs integrating Cdma2000 1x and 1xEV-DO

� Dual mode handset keeps same IMSI any time.

� Dual mode handset can simultaneously monitor two systems paging message.

� When dual mode handset is in active state under 1xEVDO, it will periodically monitor 1X system paging channel to guarantee not to miss 1X voice call.

� Packet data service handoff can happen between 1x and EVDO

CDMA 2000 1x EV CDMA 2000 1x EV CDMA 2000 1x EV CDMA 2000 1x EV –––– DO Channel Structure:DO Channel Structure:DO Channel Structure:DO Channel Structure:

Pilot channel:Pilot channel:Pilot channel:Pilot channel:

� The pilot channel is used for the pilot signal transmission from Access network to Access terminal.

Forward MAC channel:Forward MAC channel:Forward MAC channel:Forward MAC channel:

� The forward MAC channel is composed of Reverse Power Control (RPC) channel, Reverse Activation (RA) channel and Data Rate control Locking channel.

� RPC channel is used for power control of AT which is transferring data on the Reverse channel.

� Reverse Activation channel is used to dynamically control the work load of Reverse channel. When overload is detected, the bit stream in RA channel forces the AT which are transmitting data on RA randomly lower their reverse data rate in order to reduce the emission power and the collisions when terminals accessing.

� In case the AN can not receive the DRCsignals from an AT, the DRC channel will stop the particular AT from sending data to AN.

Forward Traffic Channel:Forward Traffic Channel:Forward Traffic Channel:Forward Traffic Channel:

� Forward Traffic channel is used by AN to send data. It works at full power when sending data.

Forward Control Channel:Forward Control Channel:Forward Control Channel:Forward Control Channel:

� Forward control channel is used to send broadcasting common configuration parameters from AN to AT. It also sends signaling messages to a particular AT in case the traffic channels are not activated.

Reverse Channel Structure:Reverse Channel Structure:Reverse Channel Structure:Reverse Channel Structure:

Reverse ChannelsReverse ChannelsReverse ChannelsReverse Channels

�The reverse channels provide connections between AT and AN. They have the following features.

�Data Rates up to 153.6 kbits/s

�Dynamic Power control

�Work load of reverse channels is adjusted by rate control.

Reverse Access ChannelsReverse Access ChannelsReverse Access ChannelsReverse Access Channels

1. Reverse Access Channels (Reverse pilot channels and Data channels):Reverse Access Channels are used by AT, to initiate calls or respond to AN paging messages.

Reverse Traffic channelsReverse Traffic channelsReverse Traffic channelsReverse Traffic channels

� Reverse Traffic channels (pilot channels,

MAC channels, Data channels, ACK

channels):

� Pilot channel for demodulation

� DRC sub channel is used by AT to give

instructions to AN. These instructions

include the required data rate of forward

traffic channels and the service areas

selected by forward channels

�PRI channels are used to indicate the data rate of in operation reverse data channels.

�Data Channels are used to transfer reverse data packets.

�ACK sub-channels are used by AT to AN to confirm the delivery of data packets in forward traffic channels