CDMA CHANNEL STRUCTURE AND MODULATION 2004 10 3

CDMA CHANNEL STRUCTURE AND MODULATION 2004. 10. 3 Copyright 2003, ZTE CORPORATION

Objectives Upon completion of this lesson, the student will be able to master: -- The forward channel in IS-95 Pilot ; Sync ; Paging and Traffic -- The reverse channel in IS-95 Access; Traffic -- CDMA Call Processing -- New Channels in CDMA 20001 X Copyright 2003, ZTE CORPORATION

CDMA Forward Traffic Channels CDMA Cell Site Pilot Forward Traffic Channel Sync � Forward Traffic Channel Paging Forward Traffic Channel • Used for the transmission of user and signaling information to a specific mobile station during a call. • Maximum number of traffic channels: 64 minus one Pilot channel, one Sync channel, and 1 Paging channel. – This leaves each CDMA frequency with at least 55 traffic channels. – Unused paging channels can provide up to 6 additional channels. Copyright 2003, ZTE CORPORATION

Forward Traffic Channel Generation 8 kb Vocoding bits symbols chips I PN CHANNEL ELEMENT 9600 bps 4800 bps 2400 bps 1200 bps (Vocoder) R = 1/2, K=9 19. 2 ksps Convolutional Encoding and Repetition User Address Mask (ESN-based) Copyright 2003, ZTE CORPORATION Block Interleaving 1. 2288 Long PN Code Mcps Decimator Generation Power Control Bit Scrambling Walsh function M U X 19. 2 ksps Decimator 1. 2288 Mcps Q PN 800 Hz

Rate 1/2, k=9 Convolutional Encoding g 0 Data Bit Input 1 2 3 4 5 6 7 8 g 1 c 0 Code Symbol Output c 1 • Symbols generated as the information bits transit through the encoder, are related to all the bits currently in the register. • Each information bit contributes to multiple symbols. • Pattern of inter-relationships helps detect and correct errors. • The length of shift register is called constraint (K=9) length. – The longer the register, the better coding can correct bursty errors – Reduces power required to achieve same accuracy with coding • Here, two symbols are generated for every bit input (Rate 1/2). Copyright 2003, ZTE CORPORATION

Full Rate Block Interleave Array Symbols are Written In 16 Columns 24 Rows Symbols are Read Out • The 384 modulation symbols in a frame are input into a 24 by 16 block interleave array read down by columns, from left to right • The modulation symbols are then read out of the array in rows Copyright 2003, ZTE CORPORATION

Full Rate Block Interleave Symbols are Written In 16 Columns 24 Rows Symbols are Read Out • Adjacent symbols are now separated in time – This separation combats the effect of fast fading • A burst of errors could effect the area in red above and after the frame is written into the block de-interleave function at the mobile we see the errors are spread out instead of being in consecutive order. Copyright 2003, ZTE CORPORATION

Data Scrambling 19. 2 Ksps Modulation Symbols Block Interleaver User Address Mask (ESN) Long Code PN Generator 19. 2 Ksps 1. 2288 Mcps 19. 2 Ksps To Power Control Mux Decimator Divide by 64 • Every 64 th PN chip is modulo-2 added to a symbol • Randomize transmitted data – Effects of all 1 s’ or 0 s' traffic (impulse-like) is reduced • Eliminates probability of Pilot Reuse Error – Mobile might demodulate a distant cell with same PN offset Copyright 2003, ZTE CORPORATION

Power Control Subchannel Power Control Bit (800 bps) Data Scrambling M U X 19. 2 Ksps from Block Interleaver 1. 2288 Mcps User Long Code 19. 2 Ksps Decimator Scrambled Modulation Symbol or Power Control Bit 800 Hz Mux Timing • Base station receiver estimates received signal strength of mobile over a 1. 25 ms period (800/s) • A power control subchannel is transmitted continuously – A power up/down command is sent 800 times a second • A puncturing technique sends Power Control Bits at full power and uncoded Copyright 2003, ZTE CORPORATION

Orthogonal Spreading Power Control Bit (800 bps) Scrambled Data 800 Hz Mux Timing M U 19. 2 Ksps X 1. 2288 Mcps To Quadrature Spreading Wt Walsh Function from Index • Each symbol output from the Mux is exclusive OR’d by the assigned Walsh function • Walsh function has fixed chip rate of 1. 2288 Mcps • Result is 64 chips output for each symbol input • Channels are distinguished from each other by Walsh function • Bandwidth used greatly exceeds source rate Copyright 2003, ZTE CORPORATION

Quadrature Spreading & Baseband Filtering I-Channel Pilot PN Sequence 1. 2288 Mcps Baseband Filter I 19. 2 ksps from Power Control Mux 1. 2288 Mcps Walsh Function Q cos(2 pfct) G A I N Baseband Filter sin(2 pfct) I Q Q-Channel Pilot PN Sequence 1. 2288 Mcps • The forward traffic channel is combined with two different PN sequences: “I” and “Q” • Baseband filtering ensures the waveforms are contained within the 1. 25 MHz frequency range • The final step is to convert the two baseband signals to radio frequency (RF) in the 800 MHz or 1900 MHz range Copyright 2003, ZTE CORPORATION PCM Voice Vocoder Processing Convolutional Encoding Code Symbol Repetition (Symbol Puncturing) Block Interleaving Data Scrambling Power Control Subchannel Orthogonal Spreading Quadrature Spreading Baseband Filtering Baseband Traffic to RF Section

Composite “I” and “Q” • Each CHM has a combiner and works in a serial array to combine the I and Q signals for all forward channels in a partition sector or cell. Walsh Code “Q” PN Code Pilot Channel Walsh Code Sync Channel Walsh Code Paging Channel(s) Walsh Code Forward Traffic Channel(s) Copyright 2003, ZTE CORPORATION “I” PN Code Composite “I” Composite “Q”

Quadrature Phase Shift Key (QPSK) Modulation cos ( 2 pfct ) “I” PN Code “Q” PN Code Every Channel Å: XOR Å Å Å S : Analog sum Ä: Baseband x Carrier Baseband filter Ä S Gain Control Walsh code S S Ä sin (2 pfct ) I 1 cos ( 2 p fc t ) + I 2 cos (2 p fc t ) = ( I 1 + I 2 ) cos ( 2 p fc t ) Q 1 sin (2 p fc t ) + Q 2 sin (2 p fc t ) = ( Q 1 + Q 2 ) sin (2 p fc t ) Copyright 2003, ZTE CORPORATION

Forward Traffic Channel Generation (13 kb Vocoding) symbols bits chips I PN CHANNEL ELEMENT 14400 bps 7200 bps 3600 bps 1800 bps (Vocoder) Power Control Bit R = 1/2, K=9 Symbol Convolutional Block Puncturing Encoding and 28. 8 (13 kb only) 19. 2 Interleaving Repetition ksps User Address Mask (ESN-based) Copyright 2003, ZTE CORPORATION 1. 2288 Long PN Code Mcps Generation Scrambling Walsh function M U X 19. 2 ksps Decimator 1. 2288 Mcps Q PN 800 Hz

Forward Channel Demodulation Digital Rake Receiver Chips Receiver RF Section IF, Detector RF Duplexer Traffic Correlator PN xxx Walsh xx Open Loop AGC RF Transmitter RF Section Symbols Traffic Correlator PN xxx Walsh xx Symbols Viterbi Decoder Packets Traffic Correlator PN xxx Walsh xx Audio Messages Pilot Searcher PN xxx Walsh 0 Transmit Gain Adjust Transmitter Digital Section Long Code Gen. CPU Vocoder Audio Messages IS-95 A/J-STD-008 requires a minimum of four processing elements that can be independently directed: • Three elements must be capable of demodulating multipath components • One must be a “searcher” that scans and estimates signal strength at each pilot PN sequence offset Copyright 2003, ZTE CORPORATION

Pilot Channel • Used by the mobile station for initial system acquisition • Transmitted constantly by the base station • The same Short PN sequences are shared by all base stations – Each base station is differentiated by a phase offset • Provides tracking of: – Timing reference – Phase reference • Separation by phase provides for extremely high reuse within one CDMA channel frequency • Acquisition by mobile stations is enhanced by: – Short duration of Pilot PN sequence – Uncoded nature of pilot signal • Facilitates mobile station-assisted handoffs – Used to identify handoff candidates – Key factor in performing soft handoffs Copyright 2003, ZTE CORPORATION

Pilot Channel Generation Walsh Function 0 Pilot Channel (All 0’s) I PN 1. 2288 Mcps Q PN • The Walsh function zero spreading sequence is applied to the Pilot • The use of short PN sequence offsets allows for up to 512 distinct Pilots per CDMA channel • The PN offset index value (0 -511 inclusive) for a given pilot PN sequence is multiplied by 64 to determine the actual offset – Example: 15 (offset index) x 64 = 960 PN chips – Result: The start of the pilot PN sequence will be delayed 960 chips x 0. 8138 microseconds per chip = 781. 25 microsecond Copyright 2003, ZTE CORPORATION

Pilot Channel Acquisition Pilot Channel (Walsh Code 0) 00… 01 00… 01 • The mobile station starts generating the I and Q PN short sequences by itself and correlating them with the received composite signal at every possible offset. • In less than 15 seconds (typically 2 to 4 seconds) all possibilities (32, 768) are checked. – The mobile station remembers the offsets for which it gets the best correlation (where the Ec/Io is the best. • The mobile station locks on the best pilot (at the offset that results in the best Eb/N 0), and identifies the pattern defining the start of the short sequences (a ‘ 1’ that follows fifteen consecutive ‘ 0’s). • Now the mobile station is ready to start de-correlating with a Walsh code. Copyright 2003, ZTE CORPORATION

What is Ec/Io? • Ec/Io – Measures the “strength” of the pilot – Foretells the readability of the associated traffic channels – Guides soft handoff decisions – Is digitally derived as the ratio of good to total energy seen by the search correlator at the desired PN offset – Never appears higher than Pilot’s percentage of serving cell’s transmitted energy – Can be degraded by strong RF from other cells, sectors – Can be degraded by noise Copyright 2003, ZTE CORPORATION -25 -10 Ec/Io 0 d. B Ec Energy of desired pilot alone Io Total energy received

Sync Channel • Used to provide essential system parameters • Used during system acquisition stage • Bit rate is 1200 bps • Sync channel has a frame duration of 26 2/3 ms – Frame duration matches the period of repetition of the PN Short Sequences – Simplifies the acquisition of the Sync Channel once the Pilot Channel has been acquired • Mobile Station re-synchronizes at the end of every call Copyright 2003, ZTE CORPORATION (Acquired Pilot) Sync Channel

Sync Channel Generation Modulation Symbols Bits Chips Walsh Function 32 I PN R = 1/2 K=9 1200 bps Convolutional Encoder and Repetition 4800 sps Block Interleaver 4800 sps 1. 2288 Mcps Q PN Copyright 2003, ZTE CORPORATION

Sync Channel Message Body Format Field Copyright 2003, ZTE CORPORATION Length (bits) MSG_TYPE (‘ 00000001’) 8 P_REV 8 MIN_PREV 8 SID 15 NID 16 PILOT_PN 9 LC_STATE 42 SYS_TIME 36 LP_SEC 8 LTM_OFF 6 DAYLT 1 PRAT 2 CDMA_FREQ 11 Total : 170

Sync Message Parameters • Message Type (MSG_TYPE) – Identifies this message and determines its structure (set to the fixed value of ‘ 00000001’) • Protocol Revision Level (P_REV) – Shall be set to ‘ 00000001’ • Minimum Protocol Revision Level (MIN_P_REV) – 8 -bit unsigned integer identifying the minimum protocol revision level required to operate on the system. Only mobile stations that support revision numbers greater than or equal to this field can access the system. • System ID (SID) – 16 -bit unsigned integer identifying the system • Network ID (NID) – 16 -bit unsigned integer identifying the network within the system (defined by the owner of the SID) • Pilot PN Sequence Offset Index (PILOT_PN) – Set to the pilot PN offset for the base station (in units of 64 chips), assigned by the network planner • Long Code State (LC_STATE) – Provides the mobile station with the base station long code state at the time given by the SYS_TIME field, generated dynamically • System Time (SYS_TIME) – GPS system-wide time as 320 ms after the end of the last superframe containing any part of this message, minus the pilot PN offset, in units of 80 ms, generated dynamically Copyright 2003, ZTE CORPORATION

Sync Channel Message Parameters (cont. ) • Leap Seconds (LP_SEC) – Number of leap seconds that have occurred since the start of system time (January 6, 1980 at 00: 00 hours) as given in the SYS_TIME field, generated dynamically • Local Time Offset (LTM_OFF) – Two’s complement offset of local time from system time in units of 30 minutes, generated dynamically – Current local = SYS_TIME – LP_SEC + LTM_OFF • Daylight savings time indicator (DAYLT) – Determined by the network planner – 1 if daylight savings in effect in this base station – 0 otherwise • Paging Channel Data Rate (PRAT) – The data rate of the paging channel for this system, determined by the network planner – 00 if 9600 bps – 01 if 4800 bps • CDMA Frequency Assignment (CDMA_FREQ) Copyright 2003, ZTE CORPORATION

Paging Channels Paging Channel Used by the base station to transmit system overhead information and mobile station-specific messages. • There is one paging channel per sector per CDMA carrier • The Paging Channel uses Walsh function 1 • Two rates are supported: 9600 and 4800 bps Copyright 2003, ZTE CORPORATION

Paging Channel Generation Walsh function R = 1/2 K=9 9600 bps 4800 bps Convolutional Encoder & Repetition Paging Channel Address Mask • • • Block Interleaving 1. 2288 Long PN Code Mcps Generator 19. 2 Ksps Scrambling Decimator I PN 1. 2288 Mcps 19. 2 Ksps Q PN Walsh code #1 is used to spread the data. This results in an increase to 1. 2288 Mcps – That is, 24, 576 9600 [4800] bps x 0. 020 s = 192 [96] bits in a Paging Channel frame. The Rate 1/2 convolutional encoder doubles the bit rate, resulting 384 [192] code symbols in a Paging Channel frame. If the 4800 bps rate is used, the repetition process doubles the rate again, so that, at either rate, 384 modulation symbols per Paging Channel frame result 384 modulation symbols per frame times 50 frames per second = 19. 2 Ksps chips per Paging Channel frame, or 128 [256] chips per original bit at 9600 [4800] bps Copyright 2003, ZTE CORPORATION

Paging Channel Time Slot Structure SCI 163. 84 s 7 6 5 4 3 2 1 0 = Slot Cycle Index T = Slot Cycle Length in 1. 28 s SCI units Copyright 2003, ZTE CORPORATION 80 ms

MS How to Watch Paging Channel System Time 1. 28 seconds 2047 0 1 2 3 4 • • • 12 13 14 15 16 17 Paging Channel Slots Mobile Station in Non-Active State Re-acquisition of CDMA System Assigned Paging Channel Slot 80 ms Copyright 2003, ZTE CORPORATION Mobile Station in Non-Active State

Paging Channel Overhead Messages ACC_MSG_SEQ Access Parameters Message Overhead Messages CONFIG_MSG_SEQ System Parameters Message Paging Messages Configuration Parameter Messages Mobile-Station. Directed Messages Copyright 2003, ZTE CORPORATION CDMA Channel List Message Extended System Parameters Message Extended Neighbor List Message Global Service Redirection Message

CDMA Reverse Traffic Channels Reverse Traffic Channel • Used when a call is in progress to send: – Voice traffic from the subscriber – Response to commands/queries from the base station – Requests to the base station • Supports variable data rate operation for: – 8 Kbps vocoder • Rate Set 1 - 9600, 4800, 2400 and 1200 bps – 13 Kbps vocoder • Rate Set 2 - 14400, 7200, 3600, 1800 bps Copyright 2003, ZTE CORPORATION

Reverse Traffic Channel Generation at 8 kb Vocoding 9600 bps 4800 bps 2400 bps 1200 bps I PN (no offset) R=1/3, K=9 28. 8 Convolutional ksps Encoder & Repetition Block Interleaver 28. 8 307. 2 ksps Orthogonal kcps Data Burst Randomizer Modulation 1. 2288 Mcps 1/2 PN Chip Delay D User Address Mask Copyright 2003, ZTE CORPORATION Long PN Code Generator 1. 2288 Mcps Q PN (no offset) Direct Sequence Spreading

Rate 1/3 Convolutional Encoder g Code Symbols (OUTPUT) 0 + Information bits (INPUT) 1 2 3 4 g 1 + 5 6 7 8 Code Symbols (OUTPUT) + g 2 Copyright 2003, ZTE CORPORATION Code Symbols (OUTPUT)

Reverse Traffic Channel Block Interleaving 28. 8 ksps From Coding & Symbol Repetition Input Array (Normal Sequence) 32 x 18 Output Array (Reordered Sequence) 32 x 18 • 20 ms symbol blocks are sequentially reordered • Combats the effects of fast fading • Separates repeated symbols at 4800 bps and below – Improves survivability of symbol data – “Spreads” the effect of spurious interference Copyright 2003, ZTE CORPORATION 28. 8 ksps to Orthogonal Modulation

Reverse Traffic Channel: 64 -ary Orthogonal Modulation 44 35 Walsh Lookup Table 101100 100011 Symbols 64 Chip Pattern of Walsh Code # 35 10001. . . 11010 • For every six symbols in, 64 Walsh Chips are output • Six symbols are converted to a decimal number from 0 -63 • The Walsh code that corresponds to the decimal number becomes the output Copyright 2003, ZTE CORPORATION

Reverse Traffic Channel: Direct Sequence Spreading 307. 2 kcps Data Burst Randomizer User Address Mask Long Code PN Generator 1. 2288 Mcps To Quadrature Spreading 1. 2288 Mcps • Output of the randomizer is direct sequence spread by the long code • The mobile station can use one of two unique long code masks: – A public long code mask based on the ESN – A private long code mask Copyright 2003, ZTE CORPORATION

Offset Quadrature Spreading & Baseband Filtering RF Converters I-Channel Pilot PN Sequence 1. 2288 Mcps Baseband Filter I From Data Burst Randomizer I cos(2 pfct) � 1. 2288 Mcps PN chip 1. 2288 Mcps Q PN D Baseband Filter 1/2 PN Chip Time Delay Q sin(2 pfct) • The channel is spread by a pilot PN sequence with a zero offset • Baseband filtering ensures that the waveform is contained within the required frequency limits • Baseband signals converted to radio frequency (RF) in the 800 MHz or 1900 MHz range Copyright 2003, ZTE CORPORATION

Reverse Traffic Channel Generation at 13 kb Vocoding I PN 14400 bps 7200 bps 3600 bps 1800 bps (no offset) R=1/2, K=9 Convolutional Encoder & Repetition 28. 8 ksps Block Interleaver 28. 8 ksps Orthogonal Modulation 307. 2 kcps Data Burst Randomizer 1. 2288 Mcps 1/2 PN Chip Delay D User Address Mask Copyright 2003, ZTE CORPORATION Long PN Code Generator 1. 2288 Mcps Q PN (no offset) Direct Sequence Spreading

Reverse Channel Demodulation Search Correlator Demodulator Search Correlator Combiner BTS Receiver BSC De-Interleaver Power Control Decision Viterbi Decoder Vocoder Speech Output U/D Command PN+ t User Long Code • IS-95 A/J-STD-008 requires a process that is complementary to the mobile station modulation process • CDMA processing benefits from multipath components – Signals from several receive elements can be combined to improve receive signal quality Copyright 2003, ZTE CORPORATION

Access Channels 4800 bps • Used by the mobile station to: – Initiate communication with the base station – Respond to Paging Channel messages • Has a fixed data rate of 4800 bps • Each Access Channel is associated with only one Paging Channel • Up to 32 access channels (0 -31) are supported per Paging Channel Copyright 2003, ZTE CORPORATION

Access Channel Generation I PN (No Offset) Access Channel Information (88 bits/Frame) 4. 8 kpbs R = 1/3 Convolutional Encoder & Repetition 28. 8 ksps Block Interleaver 28. 8 ksps Orthogonal Modulation 307. 2 kcps 1. 2288 Mcps 1/2 PN Chip Delay D Access Channel Long Code Mask Long PN Code Generator 1. 2288 Mcps Direct Sequence Spreading Q PN (No Offset) • Message attempts are randomized to reduce probability of collision • Two message types: – A response message (in response to a base station message) – A request message (sent autonomously by the mobile station) Copyright 2003, ZTE CORPORATION

Access Channel Long Code Mask An Access Channel is scrambled by the long code, offset by a mask constructed as follows: 41 33 32 110001111 28 27 25 24 ACN PCN 9 8 BASE_ID 0 PILOT_PN Where: ACN is the Access Channel Number, PCN is the Number of the associated Paging Channel BASE_ID is the base station identification number, and PILOT_PN is the Pilot short PN code offset index Copyright 2003, ZTE CORPORATION

Access Channel Probing Access Probe 1 + NUM_STEP (16 max) Access Probe 1 PI ACCESS PROBE SEQUENCE Access Probe 1 PI IP (Initial Power) Access Probe 1 System Time TA RT TA Select Access Channel (RA) See previous initialize transmit power figure Copyright 2003, ZTE CORPORATION RT TA

Access Channel Probing See previous figure Access Channel Slot and Frame Boundary ONE ACCESS CHANNEL SLOT ACCESS CHANNEL PREAMBLE (Modulation Symbol 0) ACCESS CHANNEL MESSAGE CAPSULE System Time ACCESS PROBE ACH Frame (20 ms) 1 + PAM_SZ (1 - 16 frames) 3 + MAX_CAP_SZ (3 - 10 frames) 4 + PAM_SZ + MAX_CAP_SZ (4 - 26 frames) ACTUAL ACCESS PROBE TRANSMISSION PN Randomization Delay = RN chips = RN x 0. 8138 µs Copyright 2003, ZTE CORPORATION

Access Channel Probing Access Attempt Access Probe Sequence 1 Seq 2 Seq 3 Seq 4 Seq MAX_RSP_SEQ (15 max) RESPONSE ATTEMPT System Time RS RS RS Response message ready for transmission Access Attempt Access Probe Sequence 1 Seq 2 Seq 3 Seq MAX_REQ_SEQ (15 max) REQUEST ATTEMPT System Time PD RS PD Request message ready for transmission Copyright 2003, ZTE CORPORATION RS PD

Access Channel Probing Parameters • • RA - Access Channel Number. Random value between 0 and ACC_CHAN; generated before every sequence (maximum range is 0 - 31). IP – Initial Open-Loop Power. Calculated in d. Bm as follows: IP = k - Mean Input Power (d. Bm) + NOM_PWR (d. B) - NOM_PWR_EXT x 16 (d. B) + INIT_PWR (d. B) where k = -73 for 800 MHz Cellular and -76 for 1900 PCS. PI – Power Increment. Equal to PWR_STEP in d. B (range is 0 to 7 d. B). TA – Acknowledgment Response Timeout (timeout from the end of the slot). Calculated in ms as follows (range is 160 to 1360 ms): TA = 80 x (2 + ACC_TMO) RT – Probe Backoff. Random value between 0 and 1 + PROBE_BKOFF; generated before every sequence (maximum range is 0 - 16 slots). RS – Sequence backoff. Random value between 0 and 1 + BKOFF; generated before every sequence (except the first sequence). Maximum range of values is 0 to 16 slots PD – Persistence delay. (Value used to implement the “persistence test”). RN – PN Randomization Delay. (0 to 511 chips). Generated before every sequence, between 0 and 2 PROBE_PN_RAN - 1, by hash, using ESN_S. Copyright 2003, ZTE CORPORATION

CDMA MS Call Processing Power-Up Initialization Mobile station has fully acquired system timing Mobile station is in idle handoff with NGHBR_CONFG equal to ‘ 011’ or is unable to receive Paging Channel Message Mobile station ends use of the Traffic Channel Idle Mobile station receives a Paging Channel message requiring ACK or response, originates a call, or performs registration Mobile station receives an ACK to an Access Channel transmission other than an Origination Message or a Page Response Message System Access Mobile station is directed to a Traffic Channel Copyright 2003, ZTE CORPORATION Traffic

Mobile Station Originated Call Mobile Station Base Station Switch • Detects user-initiated call • Sends Origination Message • Stops probing ACCESS PAGING • Sends message with this information to the switch • Sends Base Station Acknowledgement Order • Sets up Traffic Channel • (FW null traffic is arriving but the mobile station does not know on what channel; therefore, the mobile station cannot start decoding it) • Sets up Traffic Channel • Receives N 5 m=2 consecutive valid frames • Begins sending the Reverse Traffic Channel Preamble • Begins transmitting null Reverse Traffic Channel Data • Sends Service Request Message for Service Option 1 Copyright 2003, ZTE CORPORATION FW TRAFFIC PAGING • Begins sending null traffic • Sends Channel Assignment Message RV TRAFFIC • Acquires the Reverse Traffic Channel FW TRAFFIC RV TRAFFIC • Sends Base Station Acknowledgement Order • Allocates resources for Service Option 1 • Allocates resources

Mobile Station Originated Call Base Station Mobile Station • Begins processing primary traffic in accordance with Service Option 1 • Sends Service Connect Completion Message Optional • Sends Origination Continuation Message Switch • Allocates resources for Service Option 1 FW TRAFFIC • Sends Service Connect Message RV TRAFFIC Optional • Applies ring back from audio path FW TRAFFIC Optional • Removes ring back from audio path FW TRAFFIC Optional • Sends Alert With Information Message (ring back tone) Optional • Sends Alert With Information Message (tones off) • Message sent to the switch indicating that the mobile station is ready (User Conversation) Copyright 2003, ZTE CORPORATION • Completes the call (User Conversation)

Switch Mobile Station Terminated Call Mobile Station • Sends Page Response Message • Stops probing PAGING Base Station • Sends General Page Message ACCESS PAGING • Sends Base Station Acknowledgement Order • Sends message to switch indicating that the mobile station has responded • Sets up Traffic Channel • (FW null traffic is arriving but the mobile station does not know on what channel; therefore, the mobile station cannot start decoding it) • Sets up Traffic Channel • Receives N 5 m=2 consecutive valid frames • Begins sending the Reverse Traffic Channel Preamble FW TRAFFIC PAGING RV TRAFFIC FW TRAFFIC • Begins transmitting null Traffic Channel data Copyright 2003, ZTE CORPORATION Switch RV TRAFFIC • Begins sending null Traffic Channel data • Sends Channel Assignment Message • Acquires the Reverse Traffic Channel • Sends Base Station Acknowledgement Order • Allocates resources

Mobile Station Terminated Call. Switch Mobile Station • Begins transmitting null Traffic Channel data Base Station RV TRAFFIC FW TRAFFIC • Allocates resources for Service Option 1 • Sends Service Response Message accepting Service Option 1 RV TRAFFIC FW TRAFFIC • Begins processing primary traffic in accordance with Service Option 1 • Sends Service Connect Completion Message FW TRAFFIC RV TRAFFIC (User Conversation) Copyright 2003, ZTE CORPORATION • Sends Service Connect Message RV TRAFFIC • Starts ringing • User answers call • Stops ringing • Sends Connect Order • Sends Service Request Msg for Service Option 1 • Sends Alert With Information Message (ring) • Sends message to the switch indicating that the mobile station is ready • Call proceeds (User Conversation)

CDMA 20001 XRtt New Channel Structure Copyright 2003, ZTE CORPORATION

Benefits of the CDMA 2000 1 x Standards • Increased mobile standby battery life (via Quick Paging Channel) • Total backward compatibility to reuse switch and call processing features • 2 -3 d. B better coverage • High speed 153. 6 kbps packet data capabilities CDMA 2000 1 x = 1. 25 MHz Radio Transmission Technology Copyright 2003, ZTE CORPORATION

Backward Compatible with IS-95 Air Interface IS-95 mobiles are supported in the IS-2000 standard for 1 x. RTT: • No need to change any RF infrastructure • Capacity improvements will not be realized until most IS 95 subscribers disappear Copyright 2003, ZTE CORPORATION

Cdma 2000 1 x. Rtt Channel(Qualcomm) Copyright 2003, ZTE CORPORATION

Channel List: 1 x. RTT vs. IS-95 • IS-95 B built on the IS-95 A channels, and introduced two new channels – Fundamental channel was the same as IS-9 A traffic channel – Supplemental code channels assigned to support rates above 14. 4 Kbps • IS-2000 1 x. RTT continue to build on the IS-95 channels – IS-95 channels continue to be supported in IS-2000 to support IS 95 mobiles Forward Reverse IS-95 A Pilot channel Sync channel Paging channel Forward Traffic Channel Access channel Reverse Traffic Channel IS-95 B Fundamental channel Supplemental Code channel (F-SCCH) Fundamental channel Supplemental Code channel (R-SCCH) 1 x. RTT Supplemental channel (F-SCH) Quick Paging channel (F-QPCH) Supplemental channel (R-SCH) Reverse Pilot channel (R-PICH) Copyright 2003, ZTE CORPORATION

Forward Supplemental Channel (F-SCH) • Assigned for high-speed packet data (>9. 6 kbps) in the forward direction; (FCH is always assigned to each call) • Up to 2 F-SCH can be assigned to a single mobile – SCH cannot exist without having a fundamental channel established • F-SCH supports Walsh code lengths of 4 - 1024 depending on data rate and chip rate SCH-1 File transfer at 144 kbps Mobile 1 FCH Copyright 2003, ZTE CORPORATION Voice, power control and link continuity

Reverse Supplemental Channel (R-SCH) • Used for high-speed packet data (>9. 6 kbps) • Difference between F-SCH and R-SCH is in Walsh code based spreading – F-SCH supports Walsh code lengths of 4 to 128 (1 x. RTT) or 1024 (3 x. RTT) depending on data rate and chip rate – R-SCH uses either a 2 -digit or 4 -digit Walsh code; rate matching done by repetition of encoded and interleaved symbols • Walsh code allocation sequence is pre-determined and common to all mobiles • Users are differentiated using long PN code with user mask Copyright 2003, ZTE CORPORATION

Reverse Pilot Channel (R-PICH) • Mobile transmits well-known pattern (pilot) • Allows base station to do timing corrections without having to guess where mobile is (in search window) • Mobile can transmit at lower power, reducing interference to others Copyright 2003, ZTE CORPORATION

Quick Paging Channel (F-QPCH) • More efficient monitoring of paging channel by mobile, enhancement to slotted paging • Mobile monitors QPCH to determine if there is a page forthcoming on paging channel in its slot (looks at 1 -bit paging indicator) • If no flag, then mobile goes back to sleep; if flag, then mobile monitors appropriate slot and decodes general page message • Without QPCH, mobile must monitor regular paging channel slot and decode several fields to determine whether page is for it or not; this drains mobile batteries quickly The main purpose of QPCH is to save mobile battery life. Copyright 2003, ZTE CORPORATION

The End! Copyright 2003, ZTE CORPORATION