CDMA 1X Air Interface

CDMA 1X Air InterfaceCDMA 1X Air Interface

Study ObjectiveStudy Objective

Learn the hierarchical air interface

structure

Master the names and functions of different

channels of the air interfaces

Master the structure and functions of the

physical layer

Master the structure and functions of the

link layer

Learn the differences between the CDMA

1X channels and the IS95 channels

After the study of this course, you should:

Contents of CourseContents of Course

Chapter 1 Air Interface (Um) and Hierarchical Structure

Chapter 2 Physical Layer

Chapter 3 Media Access Control Layer

Chapter 4 Link Access Control Layer

Chapter 5 Layer 3

References



Air Interface Um

Hierarchical Air Interface Structure

• Um interface - Stipulate the contents, such as the physical layer structure and

signaling of the radio interface, which are a series of stipulations upon the signal transmission on the radio channel to realize the interconnection of the BTS with the MS.

• Characteristics the Um interface stipulates: - Channel structure and access capability - MS-BSS communication protocol - Maintenance and operation characteristics - Performance characteristics - Service characteristics

Air Interface (Um)Air Interface (Um)

Um



Air Interface Um

Hierarchical Air Interface Structure

Layer 3 (L3)

Link access control layer (LAC)

Media access control layer (MAC)

Layer 1 (physical layer)

Layer 2 (link layer)

Hierarchical air interface structureHierarchical air interface structure

• Physical layer - Be responsible for the conversion between the high layer

information and the air radio signals via various physical channels. - Perform the processing of various physical channels, including

data encoding & decoding, modulation & demodulation, etc.• Link layer - Link access control layer: Mainly provide the mechanism that

can guarantees the reliable transmission of signaling. - Media access control layer: Be responsible for the multiplexing

of services on logical channels, QOS (quality of service) and other functions.

• L3 - Include the signaling layer structure, service interface with the

signaling layer 2, layer 3 signaling control, signaling application & format.

Hierarchical air interface structureHierarchical air interface structure

SummarySummary

This chapter describes the definition and layer structure of the

air interface and also introduces the main contents of each

layer.






Chapter 5 Layer 3

References

Chapter 2 Physical LayerChapter 2 Physical Layer

Spreading rate

CDMA2000 frequency assignment

Naming and mapping of channel

Characteristics of forward/reverse link

& physical layer

Radio configuration

Forward channel

Reverse channel

Comparison of CDMA 1X channel with

IS95 channel

Quality control of physical layer

0 3 MHz 5 MHz4 MHz2 MHz1 MHz


1.25 MHz


1.25 MHz


1.25 MHz

Spreading rate 1 and spreading rate 3Spreading rate 1 and spreading rate 3

Spreading rate 1 (SR1)Spreading rate 1 (SR1) Spreading rate 3 (SR3)Spreading rate 3 (SR3)

Reverse link

Reverse link

Forward link

Forward link


Spreading rate




& physical layer

Radio configuration

Forward channel

Reverse channel


IS95 channel


CDMA2000 frequency assignmentCDMA2000 frequency assignment

Band Class uplink（MHz） Downlink（MHz）

0 824～849 869～894

1 1850～1910 1930～1990

2 872～915 917～960

3 832～870 887～925

4 1750～1780 1840～1870

5 412～460 420～493

6 1920～1980 2110～2170

7 746～764 776～794

5

Frequency assignment --- Band Class0Frequency assignment --- Band Class0

Frequency band

Spreading rate (SR)

Preferred channel

A 1 283、691 3 37、78、119、160、201、

242 B 1 384、777 3 425、466、507、548、

589

Frequency band

Preferred channel

A 37、160、283

B 384、507、630

CDMA preferred channel No.CDMA preferred channel No.

Preferred synchronous channel No. for SR3

Preferred synchronous channel No. for SR3

Frequency assignment --- Band Class1 and SR1Frequency assignment --- Band Class1 and SR1

Frequency band

Availability Channel No.

Transmitting frequency

MS BS

A (15MHz)

Unavailability 0 ~ 241850.000 ~ 1851.200

1930.000 ~ 1931.200

Availability 25~2751851.250 1863.750

1931.250 ~ 1943.750

Conditional availability

276~2991863.800 ~ 1864.950

1943.800 ~ 1944.950

D (5MHz)


300 ~ 3241865.000 ~ 1866.200

1945.000 ~ 1946.200

Availability 325 ~ 3751866.250 ~ 1868.750

1945.600 ~ 1948.750


376 ~ 3991868.800 ~ 1869.950

1948.800 ~ 1948.950

B (15MHz)


400 ~ 4241870.000 ~ 1871.200

1950.000 ~ 1951.200

Availability 425 ~ 6751871.250 ~ 1883.750

1951.250 ~ 1963.750


676 ~ 6991883.800 ~1884.950

1963.800 ~ 1964.950

E (5MHz)


700 ~ 7241885.000 ~ 1886.200

1965.000 ~ 1966.200

Availability 725 ~7751886.250 ~ 1888.750

1966.250 ~ 1968.750


776 ~ 7991888.800 ~ 1889.950

1968.800 ~ 1969950

F (5MHz)Conditional availability

800 ~ 8241890.000 ~ 1891.200

1970.000 ~ 1971.200


Spreading rate




& physical layer

Radio configuration

Forward channel

Reverse channel


IS95 channel


Naming of logic channel in the CDMA2000:Naming of logic channel in the CDMA2000:

First letter Second letter Third letter

f=Forward

r=Reverse

d=Dedicated

c=Common

t=Traffic

s=Signaling

ch

last two letters

Naming of physical channel in CDMA2000Naming of physical channel in CDMA2000

Channel name

F/R-FCH

F/R-DCCH

F/R-SCCH

F/R-SCH

F-PCH

F-QPCH

R-ACH

F/R-CCCH

Physical channel

Forward/Reverse Fundamental Channel

Forward/Reverse Dedicated Control Channel

Forward/Reverse Supplemental Code Channel

Forward/Reverse Supplemental Channel

Forward Paging Channel

Forward Quick Paging Channel

Reverse Access Channel

Forward/Reverse Common Control Channel

Naming of physical channel in CDMA2000 (Continued)Naming of physical channel in CDMA2000 (Continued)

Channel name

F/R-PICH

F-APICH

F-TDPICH

F-ATDPICH

F-SYNC

F-CPCCH

F-CACH

R-EACH

Physical channel

Forward/Reverse Pilot Channel

Forward Dedicated Auxiliary Pilot Channel

Forward Transmit Diversity Pilot Channel

Auxiliary Transmit Diversity Pilot Channel

Forward Sync Channel

Forward Common Power Control Channel

Forward Common Assignment Channel

Reverse Enhanced Access Channel

F-BCCH Forward Broadcast Control Channel

CDMA2000 TechnologyCDMA2000 Technology

Physical channelLogic channel Information

F/R-FCH f/r-dschL3 signaling message

f/r-dtchSubscriber data (voice/data service)

F/R-SCH f/r-dtchSubscriber data (data service)

F/R-DCCH f/r-dschL3 signaling message

f/r-dtchSubscriber data (voice/data service)

F-SYNC f-cschSynchronous channel message

F-CCCH f-cschMS indication message

F-BCCH f-cschBroadcast message

F-PCH f-cschPaging channel message (compatible with TIA/EIA-95)

R-EACH r-cschMS access message

R-ACH r-cschMS access message (compatible with TIA/EIA-95)


Spreading rate




& physical layer

Radio configuration

Forward channel

Reverse channel


IS95 channel


Key characteristics of forward link physical channelKey characteristics of forward link physical channel

•The orthogonality of channels is realized through the Walsh function.• Support the quasi-orthogonal function• QPSK data modulation• Forward correction -Convolutional code (K=9) is used for the voice service and the average rate data service. - Turbo code is used to supplement the high-speed data service on channels• Forward link synchronization• Forward quick power control (800 times/second)• Forward transmit diversity• Enhanced channel structure• Flexible frame size

Characteristics of reverse link physical layerCharacteristics of reverse link physical layer

• The reverse link adopts the long code to distinguish MS.• Adopt the 64-order orthogonality and the BPSK data modulation mode• Reverse error correction - Convolutional code (K=9), used for voice service and average rate data service - Turbo code (K=4), used for high-speed data service on supplemental channels• Reverse quick power control• Flexible frame size• Reverse link coherent modulation


Spreading rate




& physical layer

Radio configuration

Forward channel

Reverse channel


IS95 channel


Radio Configuration (RC)

- It refers to the working mode of a series of forward or reverse

traffic channels. Each RC supports a set of data rate and the

difference between RC lies in the parameters of the physical

channel, including the modulation characteristics and SR

(spreading rate).

CDMA2000 radio configuration

- Forward RC1 ~ RC9

- Reverse RC1 ~ RC6

Radio ConfigurationRadio Configuration

Radio Configuration

Spreading Rate

Max Data Rate* (kbps)

Effective FEC Code Rate

OTD Allowed

FEC Encoding Modulation

1** 1 9.6 1/2 No Conv BPSK 2** 1 14.4 3/4 No Conv BPSK

3 1 153.6 1/4 Yes Conv and Turbo QPSK4 1 307.2 1/2 Yes Conv and Turbo QPSK5 1 230.4 3/8 Yes Conv and Turbo QPSK6 3 307.2 1/6 Yes Conv and Turbo QPSK7 3 614.4 1/3 Yes Conv and Turbo QPSK8 3 460.8 1/4 or 1/3 Yes Conv and Turbo QPSK9 3 1036.8 1/2or 1/3 Yes Conv and Turbo QPSK

RC of forward link traffic channelRC of forward link traffic channel

Radio Configuration

Spreading Rate

Max Data Rate* (kbps)

Effective FEC Code Rate

OTD Allowed

FEC Encoding Modulation

1** 1 9.6 1/3 No Conv 64-ary ortho 2** 1 14.4 1/2 No Conv 64-ary ortho

3 1 153.6 1/4 Yes Conv or Turbo BPSK(307.2) (1/2)

4 1 230.4 3.8 Yes Conv or Turbo BPSK5 3 153.6 1/4 Yes Conv or Turbo BPSK

(614.4) (1/3)6 3 460.8 1/4 Yes Conv or Turbo BPSK

(1036.8) (1/2)

RC of reverse link traffic channelRC of reverse link traffic channel

• RC1 and RC2 correspond to rate set 1 and rate set 2 in the IS-95A/B, respectively.•CDMA 1X forward: RC1 ~ RC5; reverse: RC1 ~ RC4•Combination rules

RC 1

RC 2

RC 3

RC 4

RC 5

RC 1

RC 2

RC 3

RC 4

RC 5

RC 3

RC 4

RC 4

RC 3

F-FCH RCs

R-DCCH/SCH RCsF-DCCH/SCH RCs

R-FCH RCs

RC matching requirement of forward/reverse channel

RC matching requirement of forward/reverse channel


Spreading rate




& physical layer

Radio configuration

Forward channel

Reverse channel


IS95 channel


Forward CDMA channel(SR1 and SR3)

Pilot channel

Synchronous channel

Paging channel SR1

Common control channel

Traffic channel

0 ~ 1 Fundamental channel

Common control subchannel

0 ~ 7 Supplemental code channel (RC1 ~ 2)

0 ~ 2 Supplemental channel (RC3 ~ 9)

Broadcast control channel

Quick paging channel

Common power control channel

Common assignment channel

Forward pilot channel

Transmit diversity pilot channel

Assistant pilot channel

Transmit diversity assistant pilot channel

0 ~ 1 Dedicated control channel

Backward compatible forward link channelBackward compatible forward link channel

Common physical channel of forward link --- pilot channel

Common physical channel of forward link --- pilot channel

All “0”s information, spread with Walsh 0 code, and directly modulated with a short PN. BTS continuous transmission pilot channel Function of pilot channel Help the MS to capture the system Multipath search Provide the phase information of the short PN and help the MS to estimate the channel and perform the coherent modulation. At the time of handoff, the MS will measure the pilot channel and then compare the pilot strength.

The MS keeps synchronous with the system via the synchronous chan

nel.

The synchronous channel provides System time SYS_TIME

Long code state LC_STATE

Basic network configuration parameters

The rate of the synchronous channel is fixed as 1200bps.

The frame size of the synchronous channel is 80/3ms, and 3 frames

make up of a superframe of 80ms.

Common physical channel of forward link ---- synchronous channel

Common physical channel of forward link ---- synchronous channel

The BTS broadcasts the common overhead

message on the paging channel.

System parameter message

Access parameter message

List of adjacent cells

List of CDMA channels

Via the paging channel, the BTS

Page the MS

Assign traffic channels

The rate of the paging channel is 9600bps or

4800bps

The frame size of the paging channel is 20ms.

Common physical channel of forward link --- paging channel

Common physical channel of forward link --- paging channel

New forward link common channelsNew forward link common channels


Pilot channel

Synchronous channel

Paging channel SR1


Traffic channel














Low delay

Reduce the transmit power of the BTS

More flexible

Reduce the transmit power of the MS

and prolong the standby time

What are the new channels added for?

New forward link common channel (continued)New forward link common channel (continued)

New pilot channelsNew pilot channels

Transmit diversity pilot channel F-TDPICH

- It is used together with the pilot channel when the transmit diversity is adopted.

Forward assistant pilot channel F-APICH

- It is used when the smart antenna is adopted.

Forward assistant transmit diversity pilot channel F-ATDPICH

- It is used when the transmit diversity is adopted and the BTS adopts the F-APICH.

Common physical channel of forward link --- broadcast control channel

Common physical channel of forward link --- broadcast control channel

The BTS broadcasts on the broadcast control channel

- Common overhead message

- Short message

The data rate of the F-BCCH can be 38400bps, 19200bps or

9600bps.

When the data rate of the F-BCCH is low, the F-BCCH can

repeat the transmission with a low transmit power. The MS

obtains the gain of the time diversity by merging the repeated

information.

The reduction of the transmit power of the F-BCCH can help to

improve the total capacity of the forward link.

• F-QPCH (forward quick paging channel) Designate the monitoring mode of the idle MS: Adopt offset orthogonal keying (OOK) modulation mode. Adopt 80ms as a timeslot, which is divided into paging indicator (PI), configuration change indicator (CCI) and broadcast indicator (BI).

• The F-QPCH can prolong the standby time of the MS.• The F-QPCH can perform the soft handoff.

Common physical channel of forward link --- quick paging channel

Common physical channel of forward link --- quick paging channel

It is used to control the power of multiple R-CCCH and R-EACH. The BTS can support one or more F-CPCCH. The F-CPCCH includes multiple power control subchannels. Each power control subchannel is a bit and mutually works in the time division multiplexing mode. The power control subchannel controls one R-CCCH or R-EACH. - In the power control access mode, it controls the transmit power of the R-EACH. - In the reservation access or designated access mode, it controls the transmit power of the R-CCCH.

Common physical link of forward link --- common power control channel

Common physical link of forward link --- common power control channel

Common physical link of forward link --- common assignment channel

Common physical link of forward link --- common assignment channel

Functions Send the assignment information that is a quick response to the reverse link channel Provide the support of the random access packet transmission of the reverse link In the reservation access mode: control the R-CCCH and the related F-CPCCH. In the power control access mode: provide the quick response acknowledgement Congestion control

Common physical link of forward link --- common control channel

Common physical link of forward link --- common control channel

It is used to send the specific MS message. Paging message Acknowledgement Channel assignment message (ECAM) Short data bursts (SDBs) The functions of the F-CCCH are the same as those of the paging channel in the IS-95, but the data rate is higher and more reliable. The data rate supports: 9600 bps (frame of 20ms), 19200 bps (frame of 10ms or 20ms) and 38400 bps (frame of 5ms, 10ms or 20ms)

New dedicated channels of forward linkNew dedicated channels of forward link


Pilot channel

Synchronous channel

Paging channel SR1


Traffic channel














Dedicated physical channel of forward link --- dedicated control channel

Dedicated physical channel of forward link --- dedicated control channel

Forward dedicated control channel F-DCCH

It can not form a traffic channel independently.

It is mainly used to transfer the specific subscriber signaling information during the

call.

It can also be used to transfer the burst data service on condition that the signaling

transfer is not affected.

Each forward traffic channel can posses one F-DCCH

Support the frames of 5ms and 20ms

Data rate: 14.4kbps(20ms), 9600bps (5ms and 20ms)

The discontinuous transmission must be supported

A forward link power control subchannel can be attached.

Forward fundamental traffic channel F-FCH Transfer subscriber information and signaling information Frames of 5ms and 20ms. The frame of 20ms is used for the voice service, while the frame of 5ms is used for the quick transfer of control signaling. Flexible adjustable rate data transfer It can independently form a default traffic channel to transfer voice. Usually, other dedicated channels will be added only when there are not enough F-FCH.

Dedicated physical channel of forward link --- fundamental traffic channel

Dedicated physical channel of forward link --- fundamental traffic channel

Dedicated physical channel of forward link—supplemental channel

Dedicated physical channel of forward link—supplemental channel

Supplemental channel F-SCH It is used for high-speed data transmission. And F-SCH only applies to RC3 ~ 9Data transmission rate is defined by the BTS, thus rate detection is unnecessary.Support combinations of multiple supplemental channels to complete different services;Support high-speed and packet data transmission;The independent FER setting facilitates FER control according to the service requirements and the condition of resource application;Support burst data mode.

Forward CDMA channelForward CDMA channel

Channel type Maximum numberForward pilot channel

Transmit diversity pilot channelSupplemental pilot channel

Supplemental transmit diversity pilot channel

Synchronization channel

Paging channel

Broadcast channel




Forward common control channel

Forward dedicated control channel

Forward fundamental channel

Forward supplemental code channel (Only RC1 and 2)

Forward supplemental code channel (Only RC3 and 5)

1

1

No requirements

No requirements

1

7

8

37

7

7

1*

1*

7*

2*

* Each forward traffic channel

Structure of forward channelStructure of forward channel

Pilot channel, synchronization channel and paging channel for SR1Pilot channel, synchronization channel and paging channel for SR1


Broadcast channel for SR1Broadcast channel for SR1


Quick paging channel for SR1Quick paging channel for SR1


Common power control channel for SR1Common power control channel for SR1


Common assignment channel for SR1Common assignment channel for SR1


Forward traffic channelForward traffic channel


Forward dedicated channelForward dedicated channel


Spreading rate




& physical layer

Radio configuration

Forward channel

Reverse channel


IS95 channel


Enhanced Access Channel (RC 1 or 2)

Reverse

Common Control

Channel

Reverse Traffic Channel (RC1 or

RC2)

Reverse Traffic

Channel (RC 3 to 6)

Reverse Pilot Channel

Reverse Fundamental

ChannelEnhanced Access

ChannelReverse Common Control Channel

0~7 Reverse Supplemental Code Channel

Physical Channel of Reverse LinkPhysical Channel of Reverse Link

Reverse CDMA Channel

(SR1 and SR3)

Access channel



0 or 1 Reverse Dedicated Control

Channel

0 or 1 Reverse Fundamental

Channel0~2 Reverse Supplemental

Channel

Reverse Power Control Subchannel

Reverse Pilot functions Initial capture Trace Reverse coherent demodulation Power control measurement

When R-EACH, R-CCCH or RC3

– 6 is used for the RL traffic channel,

R-PICH should be sent.

When the prefix of R-EACH, R-

CCCH or RL traffic channel is sent,

R-PICH should be sent.

MUX A

Pilot(all '0's)

Power ControlBit

N is the Spreading Rate number

PilotPowerControl

1 Power Control Group= 1536 NPN Chips

384 NPN Chips

Common Physical Channel of reverse link—Reverse Pilot Channel

Common Physical Channel of reverse link—Reverse Pilot Channel

Common Physical Channel of Reverse Link—Reverse Access Channel

Common Physical Channel of Reverse Link—Reverse Access Channel

Reverse Access ChannelIt is compatible with IS-95, and it is used for initiating the communication with the BTS or responding the messages of the paging channel.Reverse CDMA channel can include 32 R-ACH at most;For each F-PCH of the forward CDMA channel, there should be at least 1 reverse access channel in the corresponding reverse channelIt is used to initiate the initial call probe. The contents of the message are comparatively short. And the reliability of the message transfer is comparatively low.The access channel is composed of the access probe, which in turn is composed of the access prefix and a series of access channel frames.

Physical Channel of Reverse Link --- Reverse enhanced Access Channel

Physical Channel of Reverse Link --- Reverse enhanced Access Channel

Reverse Enhanced Access ChannelIt is used for initiating the communication with the BTS or responding to the message specially sent to the MS.It is used for initiating the initial call probe. The contents of the message are comparatively short, and the reliability of message transfer is comparatively low;It can be used for fundamental access mode, power control access mode and reservation access mode.- Fundamental access mode: The access probe is composed of prefix and data;- Power control access mode: The access probe is composed of prefix, access header and data;- Reservation access mode: The access probe is composed of prefix and access header, and data is sent by the reverse common control channel;The reverse pilot channel related to the enhanced access channel doesn’t include the reverse power control subchannel: There is no FL traffic channel for transmission during access.

Physical Channel of Reverse Link –Reverse Enhanced Access Channel (continued)

Physical Channel of Reverse Link –Reverse Enhanced Access Channel (continued)

R-EACH probe structureR-EACH probe structure

Physical Channel of Reverse Link—Common Control Channel (continued)


Common Control ChannelIt is used for sending the subscriber information & signaling information to the BTS;It can be used for reservation access mode and designated access mode;The transmit power is controlled by BTSSoft handoff can be performed.The contents of the message are comparatively long, and the reliability is high. It is more applicable to the data service.



Prefix of reverse common control channel and data transmissionPrefix of reverse common control channel and data transmission

Dedicated Physical Channel of Reverse LinkDedicated Physical Channel of Reverse Link

Fundamental Channel (R-FCH)It is used for service connection between a certain MS and the BTS.It can form traffic channel independently. And it can be used for transmitting the default voice service. Dedicated Control Channel (R-DCCH)It is similar to F-DCCH in functions. And it is used for transmitting the subscriber and signaling information to BTS.It can perform discontinuous transmission. Supplemental Channel (R-SCH)It is similar to F-DCCH in functions. And it is used for transmitting the subscriber information to BTS during conversation.It only applies to reverse RC3-6The reverse traffic channel can only include 2 R-SCH at most.

Physical Channel of Reverse Link (continued)Physical Channel of Reverse Link (continued)

Supplemental Code Channel (R-SCCH)It is similar to F-SCCH in functions. And it is used for transmitting the subscriber information to BTS during conversation.It only applies to reverse RC1 ~ 2.The reverse traffic channel can include maximum 7 R-SCCH.The long code masks of the interrelated F-SCCH in the same MS traffic channel are the same, but there is little difference for the reverse channel.

Reverse CDMA channel for SR1Reverse CDMA channel for SR1

Channel type Maximum numberReverse pilot channel

Access channelEnhanced access channel

Reverse common control channel

Reverse dedicated control channel

Reverse fundamental channel

Reverse supplemental code channel(only RC1 and 2)

Reverse supplemental code channel(only RC3 - 5)

1

1

1

1

1

1

7

2

Structure of reverse channel of SR1Structure of reverse channel of SR1

Frame quality indication bit added

8 encoder tail bits added to each frame

Convolutional encoder or Turbo encoder

Reservation bit added

Symbol repetition

Symbol deletion

Block interweaving

Modulation symbol

Information bit

The 1st virtual frame: Only available to the reverse traffic channel of RC4.The 2nd virtual frame: Except the reverse dedicated control channel of RC3, available to all reverse traffic channels of RC3~RC4

R-FCH and R-SCH channel structures of R-EACH, R-CCCH, R-DCCH and RC3~RC4.

R-FCH and R-SCH channel structures of R-EACH, R-CCCH, R-DCCH and RC3~RC4.

Structure of reverse channel of SR1Structure of reverse channel of SR1

Structure of mapping between I and Q of R-PICH, R-EACH, R-CCCH, R-FCH of RC3~RC4.

Structure of mapping between I and Q of R-PICH, R-EACH, R-CCCH, R-FCH of RC3~RC4.


Spreading rate




& physical layer

Radio configuration

Forward channel

Reverse channel


IS95 channel


Channel comparison between CDMA 1X and IS-95Channel comparison between CDMA 1X and IS-95


Spreading rate




& physical layer

Radio configuration

Forward channel

Reverse channel


IS95 channel


Quality control mechanism of physical layerQuality control mechanism of physical layer

Radio resource management mechanismPower control as representativeInvisible diversity mechanismSpread spectrum modulation technology: Spread the signal energy to the very wide band to realize invisible frequency diversity and overcome the channel selectivity fading.Channel interleaving technology: Overcome the fading of radio channel that varies with the time so that error bit in the radio channel can be evenly distributed.Error control mechanismError correction coding technology: Convolutional code, Turbo code






Chapter 5 Layer 3

References

Chapter 3 Media Access Control LayerChapter 3 Media Access Control Layer

Structure of media access control layer

Status control of CDMA2000 access

process

Media access control sublayer (MAC)Best effort delivery: The radio link protocol is used to provide high reliability to ensure reliable transmission in the radio linkMux and QoS control function: Through coordinating the conflict requests generated by the competitive services as well as arranging proper priority for the access requests, the implementation of the coordinated QOS level can be ensured.Completing specific mapping conversion between the logical channel and physical channel.

Media access control sublayer (MAC)Media access control sublayer (MAC)

Structure of media access control sublayer (MAC)




Functional entities of MAC sublayer mainly include:SRBP related to short data burst - SRBP submits the short data burst to the Mux sublayer - SRBP is an entity providing connectionless protocol to signaling message - SRBP is related to the operation of the common channel of the Mux sublayerRLP for MAC transmitting data service - RLP mainly completes the transfer of data service - RLP is connection-oriented and NAK-based data transmission protocolMux and QOS sublayer - After receiving the information of the logical channel, the Mux sublayer will firstly multiplex it according to the QoS requirements, and then map it to the physical channel according to the resource application condition and at last pack it as PDU of the physical channel in the physical layer for transmission.

Chapter 3 Media Access Control LayerChapter 3 Media Access Control Layer

Structure of media access control layer

Status control of CDMA2000 access

process

cdma2000cdma2000

The access process of IS-2000 is closely related to the realization of MAC sublayer






Chapter 5 Layer 3

References

Chapter 4 Link Access Control LayerChapter 4 Link Access Control Layer

Processing of data Unit of LAC Layer

Structure of LAC Sublayer Protocol

ARQ protocol

Processing of data unit of LAC layerProcessing of data unit of LAC layer

Link Access Control Sublay

er (LAC)Processing of logical channel related to signaling and data burstProvision of signaling service for the upper layer

Processing of data unit of LAC layerProcessing of data unit of LAC layer

The LAC sublayer mainly includes: Authentication sublayer: It only applies to the access channel to complete certain authentication function (The other authentication functions are completed in Layer 3);ARQ sublayer: It provides the logical channel with reliable SDU transmission;Addressing sublayer: It only applies to the common channel to provide identification for specific MS;Functional sublayer: It performs assembly/disassembly of LAC PDU;SAR sublayer: During transmission, the SAR sublayer adds length identification and CRC to LAC PDU, and then segments the processed PDU into the data fragment suitably processed by the MAC layer. During receiving, SAR combines the data fragment sent from the lower layer for CRC verification.;




ARQ protocol

LAC

U tility S ub laye r

LowerLayers

S A P

ControlPlane

Signaling Plane

Layer 3

T ransm iss ion/R eception

A ddress ing S ub layer

A u then tica tion S ub laye r

r-csch

A R Q S ub layer

S A P

S A R S ub layer

Structure of LAC sublayer protocol of r_csch (Access channel)

Structure of LAC sublayer protocol of r_csch (Access channel)

LAC


LowerLayers

S A P

ControlPlane

Signaling Plane

Layer 3


A ddress ing S ub laye r

f-csch

A R Q S ub laye r

S A P

S A R S ub laye r

Structure of LAC sublayer protocol of f_csch (paging channel)

Structure of LAC sublayer protocol of f_csch (paging channel)

LAC


LowerLayers

S A P

ControlPlane

Signaling Plane

Layer 3


f-dsch and r-dsch

A R Q S ub layer

S A P

S A R S ub layer

Structure of LAC sublayer protocol of f/r_dsch (Traffic channel)

Structure of LAC sublayer protocol of f/r_dsch (Traffic channel)




ARQ protocol

ARQ protocolARQ protocol

Repetitive detection allowedTwo kinds of services

- Acknowledged transmission - Unacknowledged transmission

The ARQ sublayer completes the main functions of the quality control process

of the LAC sublayer: Different protocol control parameters are adopted for ARQ

protocol according to the QOS requirements, different logical channels, and for

mats of different protocol data units (PDU). This ensures the accurate and reliab

le transmission of signaling messages and at the same time guarantees efficien

t application of system resources. Thus, best balance between quality and effici

ency can be ensured.

ARQ protocol of common channelARQ protocol of common channel

Reverse common channel (R-ACH/R-EACH/R-CCCH) - Working in the acknowledged transmission mode - The retransmission window is 1 - Threshold value of the retransmission timer is specified by BTS - On no acknowledgement received, MS will increase certain transmit power to retransmit the access probe; - Random delay between probes is related to the types of PDU Forward common channel (F-PCH/F-CCCH) - Working in the acknowledged transmission mode or unacknowledged transmission mode - Message sequential No. (MSG_SEQ):3 bits - Detection time of repetitive frame of acknowledged mode is 2.2s

ARQ protocol of dedicated channelARQ protocol of dedicated channel

Dedicated channel Working in the acknowledged transmission or unacknowledged transmission mode - Two kinds of PDUs available: 20ms PDU and 5ms PDU - 20ms PDU: Message sequential No. (MSG_SEQ): 3bits Size of retransmission window: 4 - 5ms PDU: Message sequential No. (MSG_SEQ): 2bits Size of retransmission window: 2

ARQ protocol parameter of dedicated channelARQ protocol parameter of dedicated channel

Unacknowledged mode - Detection time of repetitive frame of acknowledged mode: 0.32s (20ms PDU), 0.02s (5ms PDU)Acknowledgement mode (20ms PDU) - Threshold of retransmission timer: 0.4s - Maximum delay before transmitting response: 0.2s - Maximum retransmission times: 13Acknowledgement mode (5ms PDU) - Threshold of retransmission timer: 0.12s (the first 6 transmission), 0.4s (in the latter transmission) - Maximum delay before response: 0.06s - Maximum retransmission times: 17






Chapter 5 Layer 3

References

Main contents of layer 3 signalingMain contents of layer 3 signaling

The layer 3 signaling protocol mainly describes:Structure of Layer 3 signaling message and interaction flowSecurity and authentication specificationsControl and application of Layer 3 signaling-Call process, handoff, authentication and encryption, and mobility management are the main part of Layer 3.






Chapter 5 Layer 3

References

ReferencesReferences

cdma2000 technology

CDMA system design and optimization

TIA/EIA/IS-2000

China telecom department technical prescription: 800MHz CD

MA/AMPS technical requirements in air interface of digital cell

ular mobile communication network

Documents

CDMA 1X Air Interface