Cdma2000 Radio Access Network .


53 views
Uploaded on:
Category: Animals / Pets
Description
cdma2000 Radio Access Network. Salih Ergut 7/7/2003. Outline. cdma2000 network architecture Call processing states and call flows CDMA evolution Essential elements in a CDMA system Power Control Mobility management Handoffs Registration Roaming Radio Admission Control.
Transcripts
Slide 1

cdma2000 Radio Access Network Salih Ergut 7/7/2003

Slide 2

Outline cdma2000 arrange design Call preparing states and call streams CDMA advancement Essential components in a CDMA framework Power Control Mobility administration Handoffs Registration Roaming Radio Admission Control

Slide 3

Network Architecture Black Mountain Packet Network PSTN PDSN MSC BSC Ericsson UCSD

Slide 4

Call Processing - Pilot First MS screens Pilot channel for Initial procurement Channel estimation Detection of multipaths for rake beneficiary Handoffs Pilot Ch

Slide 5

Call Processing - Sync Pilot channel is transmitted at all circumstances by the base station. MS utilizes it to bolt to Synch Channel to Synchronize to CDMA framework time Obtain design parameters, for example, Protocol Revision (P-REV) Network Identifier (NID) Pilot PN counterbalance Long-code state Paging channel information rate Sync Ch

Slide 6

Call Processing - Paging MS interprets the Paging Channel with the data got from the Sync Channel. Paging channel gives Overhead messages: frameworks parameter, get to parameter, neighborlist, channel list Mobile coordinated messages: page ask for, SMS Paging Ch

Slide 7

Call Processing – Access MS utilizes Access channel to start a call or to react to a page ask. Get to Channel is utilized as a part of an arbitrary get to design. Get to Ch

Slide 8

Call Processing - Traffic Base station doles out a forward and invert activity channel to the portable when it is in discussion Traffic Channel passes on flagging and movement data When MS is on activity channel it no longer listens to paging channel or uses the get to channel

Slide 9

Power Up Call start or page reaction Synchronization Initialization State Idle State Access State Traffic State Paging Loss Page reaction finished End of call Mobile Station States

Slide 10

Mobile Originated Voice Call Flow MSC BSC MS Overhead Info Paging Ch. Get to Ch. Beginning Msg BS Ack Order Paging Ch. CM Service Request Null Frames Fwd Traffic Ch. SCCP Connection Cfm Paging Ch. Channel Assign Msg Rev Traffic Ch. Preface BS Ack Order Fwd Traffic Ch. Task Request Rev Traffic Ch. MS Ack Order Service Connect Fwd Traffic Ch. Rev Traffic Ch. Benefit Conn Cmplt Assignment Complete

Slide 11

CDMA Evolution (1/3) IS-95A (2G) First CDMA convention, distributed in May\'99 14.4/9.6 kbps circuit/bundle information IS-95B (2.5G) Most simple data is evacuated Some specialized remedies New Capabilities, for example, higher information rate 64 kbps parcel information

Slide 12

CDMA Evolution (2/3) CDMA2000 1X High speed information (144 kbps bundle information with Mobile IP) Coding (Turbo) and Modulation (Hybrid QPSK) New committed and basic channels Enhanced Power Control Reverse connection location Forward connection balance

Slide 13

CDMA Evolution (3/3) 1X EV-DO ( 1x RTT Ev olution for rapid incorporated D ata O nly) The goal is to give the biggest handy number of clients to run fast bundle information applications 2.4 Mbps parcel information 1X EV-DV ( 1x RTT Ev olution for rapid coordinated D ata and V oice) Voice and High Speed Data blended on one transporter Backward-perfect with CDMA2000 1X 3.1 Mbps bundle information

Slide 14

Dedicated band amid whole call Each client transmits in the meantime, at a similar recurrence with a novel code Certain recurrence, time-opened Multiple Access Methods

Slide 15

B E An A G C B An A G An A F D An E F An A Frequency Re-utilize Patterns FDMA and TDMA vs. CDMA

Slide 16

Channelization is given by orthogonal Walsh codes cdma2000 utilizes variable length Walsh codes for supplemental channel information administrations Walsh codes can be of length 8, 16, 32, 64, and 128

Slide 17

Walsh Codes Walsh codes are orthogonal to each other The shorter the code the higher the information rate since the chip rate is kept steady

Slide 18

A Code Channel Example Forward Traffic Channel Generation Power Control bit 1.2288 Mcps MUX Encoder and Repetition Block Interleaver 19.2 ksps Wt 1.2288 Mcps 800 Hz Long Code PN Generator Decimator

Slide 19

Cell Separation Walsh code spreading is trailed by quadrature spreading utilizing PN chips with time balances Adjacent cells have distinctive PN balances. This averts impedance since time moved PN successions are orthogonal to each other I-PN cos wot Wt Baseband Filter Baseband Filter Q-PN sin wot

Slide 20

Use of Multipath in CDMA Systems FDMA/TDMA (contract band) multipath harms equalizers are utilized to wipe out multipath CDMA (wide-band) can segregate between the multipath entries Rake collectors are utilized to join multipath signs to lessen mistake rate at the recipient

Slide 21

Near – Far Problem a client close to the base station would stick the client a long way from the base station

Slide 22

Power Control – Motivation Overcomes close far issue CDMA wouldn\'t work without it Copes with way misfortune and blurring

Slide 23

Power Control – Algorithm Capacity is expanded By having every client transmitting recently adequate SNR to keep up an objective FER Open Loop Estimate Initial transmit influence level for the versatile is controlled by the gotten pilot quality Closed Loop Power Control Base station controls the influence level on the portable by the got quality data.

Slide 24

Mobility administration A CDMA framework gives versatility: Handoff – coherence of the administration crosswise over nearby cells Registration – finding the portable client Roaming – progression of the administration crosswise over various specialist co-ops

Slide 25

Handoff Handoffs between cells are upheld while the versatile is in activity or sit out of gear MS ceaselessly continues hunting down new cells as it moves over the system MS keeps up dynamic set, neighbor set, and staying set and also hopeful set There are 4 sorts of handoffs: Idle Handoff Access Handoff Soft/Softer Handoff Hard Handoff

Slide 26

Handoff Parameters (1/2) If a pilot quality (P) is more prominent than T_ADD it will be included into the competitor set If pilot quality is not exactly T_DROP for T_TDROP, it will be moved from dynamic set to neighbor set If the new pilot quality is T_COMP units more prominent current pilots a Pilot Strength Measurement Message will be send

Slide 27

Handoff Parameters (2/2) Pilot Strength Cell A Cell B T_ADD T_DROP T_TDROP Time

Slide 28

Soft Handoff Black Mountain Both cells have a similar recurrence PDSN MSC BSC Ericsson UCSD

Slide 29

Soft Handoff Make-before-break Both cells are at a similar recurrence Reduces number of call drops Increases the general limit Mobile transmit power is decreased Voice quality close to the phone limits are enhanced MS reports the SNR of the applicant sets

Slide 30

Soft Handoff Gain Power (dBm) Cell A Cell B Total at MS Distance

Slide 31

Hard Handoff Break-before-make Handoff between various frequencies, non-synchronized or disjoint cells which are controlled by various BSCs

Slide 32

Registration It is adequate to know the phone or the locale that a MS is dynamic for steering purposes Mobile station identifier, craved paging opening cycle, and enlistment sort is passed on Cell/LAC based paging is liked to surge paging

Slide 33

Registration Types Autonomous Registration: control up, shut down, clock based, separate based, zone-based enrollment. Parameter-change enlistment Ordered enrollment Implicit enrollment Traffic channel enrollment

Slide 34

Roaming Users that are outside their home region can get benefit from another framework by paying some extra charges Mobile station can be: Home state (not wandering) Network meandering System wandering Network 2 Network 1 Network 3 System

Slide 35

Radio Admission Control cdma2000 dispenses assets progressively Admission control is critical to guarantee nature of administration for the current clients when new assets are asked for another demand can be call setup, supplemental channel set-up, handoff, information rate change Available Walsh codes, lingering power in the forward and switch connections are considered before giving a demand

Slide 36

Summary (1/2) cdma2000 underpins both voice and information benefits in a similar bearer gives upgraded voice limit Forward connection Fast power control in forward/invert joins Lower code rates New code channels Reverse Link Coherent discovery

Slide 37

Summary 2/2 Higher information rates: 1x up to 153.6 kbps and 1x EV-DV up to 3.09 Mbps Battery life is enhanced Introduction of Turbo codes gives better connection quality to supplemental stations

Recommended
View more...