Presentation on theme: "Part 2: Principle and Implementation of EVDO Systems WLL SHORT TRAINING."— Presentation transcript:
Part 2: Principle and Implementation of EVDO Systems WLL SHORT TRAINING
UNIT 1 UNIT 2
EVDO Theory Unit 1
1X EVDO Network Structure
Comparison of EVDO and 1x Networks MS/AN HLR PDSN AAA BTSBBSCBPCF MSC ANAAA
Changed Parts in Upgrading 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
Changed Parts in Upgrading (Cont.) BSC side: add EVDO processing part, upgrade related software - EVDO Signaling -Increased EVDO data capacity
UNIT 1 UNIT 2
EVDO Channel Structure & Key Techniques Forward Link Channel Structure Reverse Link Channel Structure Key Techniques
Forward Channel Structure
Forward Data Time Slot
Forward Pilot Channel 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.
Forward MAC Channel The Reverse Power Control Channel (RPC channel) and the DRCLock Channel are time-division multiplexed. RPC channel is used for reverse power control. DRCLock is used to indicate if the reverse Date Rate Control (DRC) channel message is received or not. Reverse Activity (RA) channel is CDMed with RPC channel + DRCLock channel Reverse Activity Bit (RAB) is transmitted in RA channel, which is broadcasted by AN to inform ATs the current reverse traffic channel status.
Forward Control Channel
Data rate is 38.4 or 76.8kbps. The Control Channel Cycle is of 256 slots. Broadcast Overhead messages and Page messages are always delivered by using Synchronous Capsule (AC). Asynchronous Capsule (AC) used to deliver ACK messages and RLP Control messages, may be sent at any time during which the AN is not sending a synchronous capsule.
Forward Traffic Channel Supported data rates: 38.4, 76.8, 153.6, 307.2, 614.6, 921.6, , , and Kbps. QPSK, 8PSK and 16-QAM are used. Channel encoders with different code rates are used. Physical layer packets are of four different lengths: 1024 bits, 2048 bits, 2072 bits and 4096 bits. A preamble is attached as the header of each physical layer packet. The transmitted packet = preamble + physical layer packet