Cdma presentation

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ZTE

Basic knowledge of CDMAMSC Based WLL

(BSNL)

Compiled by: M.Pandian, Divisional Engineer

CDOT Installation, Salem-1

E-Mail: [email protected]

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Advantages of CDMA

• Frequency reuse• Large coverage• High spectrum capacity• High Privacy• Soft Handoff• Good Voice quality (using Voice

Coding)• Perfect Power Control• Smooth migration to 3G

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Advantages of CDMA

Frequency reuse facto is 1;network design and expanding become much easier

Frequency reuse facto is 1;network design and expanding become much easier

AMPS, D-AMPS, N-AMPS

CDMA

30 30 10 kHz

200 kHz

1250 kHz

1 3 1 Users

8 Users

20 Users1

1

11

1

11

11

1

11

1

1

12

34

43

2

56

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Typical Frequency Reuse N=7



Vulnerability:C/I 17 dB

Vulnerability:C/I 12-14 dB

Vulnerability:Eb/No 6--7 dB

GSM

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Advantages of CDMA

large coveragealmost 2 times than GSM, save money for operator

large coveragealmost 2 times than GSM, save money for operator

Example:cover 1000 km2： GSM need 200 BTS ， CDMA only need 50 BTS

Attention: exact result need “Link Budget ”

Example:cover 1000 km2： GSM need 200 BTS ， CDMA only need 50 BTS

Attention: exact result need “Link Budget ”

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Advantages of CDMAHigh spectrum capacity: 8--10 times than AMPS, 4—6 times than GSM

High spectrum capacity: 8--10 times than AMPS, 4—6 times than GSM

FDMA---Different user use different frequency

TACS 、 AMPS

TDMA---Different user use different time slot of one frequency

GSM 、 DAMPS

CDMA---Different user use same frequency at the same time,but with different spreading code

FrequencyTime

Power

FrequencyTime

Power

FrequencyTime

Power

FDMA

TDMA

CDMA

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Advantages of CDMA

High privacy,hard to wiretappingHigh privacy,hard to wiretapping

Spread code

Informationsignal

TX

Demodulatedsignal

RX

Spread code

Spread signalEach user is below the noise deeply

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Advantages of CDMA

CDMA: “make before break”---soft handoffOther systems: “make after break”---hard handoff

CDMA: “make before break”---soft handoffOther systems: “make after break”---hard handoff

Use soft handoff, decrease drop-call rateUse soft handoff, decrease drop-call rate

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Advantages of CDMA

Good voice quality, use 8k,13K(QCELP,EVRC)voice coding—the best coding method in the world.

Good voice quality, use 8k,13K(QCELP,EVRC)voice coding—the best coding method in the world.

Voice quality(MOS)

64kPCM

13kGSM

8kCDMA

13kCDMA

8kEVRCCDMA

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Advantages of CDMA

Perfect Power Control and voice activation make the MS

Power low, healthy for humanbody—green mobile phone.

Perfect Power Control and voice activation make the MS

Power low, healthy for humanbody—green mobile phone.

Mean Power Max Power

GSM: 125mW 2W

CDMA: 2mW 200mW

Mean Power Max Power

GSM: 125mW 2W

CDMA: 2mW 200mW

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Advantages of CDMA

95A 95B Software update Replace MS to

get new service

95B 1X Add 1X channel

board Software update Replace MS to ge

new service

1X 1XEV Add 1XEV

channel board Software update Replace MS to

get new service

inexpensive

TechnicalScheme:

Smooth migration to 3G and the operator’s benefit is protected at the most

Smooth migration to 3G and the operator’s benefit is protected at the most

Almost free inexpensiveEconomicScheme:

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ZTE’s Activities in CDMA• In 1995, CDMA mobile telecommunication project was started

• In November, 1999, ZTE signed the “Agreement on CDMA R&D” with Qualcomm

• In August, 2000, the first field trial was set up.

• In September, 2000, ZTE presented the first CDMA handset with UIM in the world.

• In January, 2001, the first cdma2000-1x call was passed through in lab

• In March, 2001, ZTE cdma2000-1x realized the integrated transmission of voice, data & image. The data rate reach up to 153.6Kbps.

• The certificates acquired:– CDMA 800M ZXC10-MSC/VLR, HLR/AUC,BSC, BTS network access licenses– CDMA 800M/1.9G ZXC10-BTS type approval certificates

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ZTE - CDMA

2G/3G 终端

Abis

Abis

Abis

PSTN/PLMN

BSC/ PCF (1X)

Internet

路由器路由器IP

IP

BTS （ IS-95）

BSC （ IS-95）

Abis

E1Um

IS95

Um

IS2000E1 STM-1

E1 STM-1

Ethernet

MSC/VLR HLR/AUC

PDSN/FA

AAA

HA

OMC

SC

WINBTS （ IS-95

）

BSC/ PCF (1X)

BTS （ 1X）

BTS （ 1X）

E1

业务服务器

Ethernet

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ZXC10 MSC / VLR

• ZXC10 MSC/VLR/SSP 1X stands for The CDMA mobile switching center/visitor location register product.

• MSC is a functional entity that performs the controlling and switching of mobile subscribers within the area it serves, and it is automatic switching equipment for the traffic between MSCs or between MSC of CDMA network and switches of other public networks.

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ZXC10 MSC / VLR

• MSC performs the common signaling function and billing function, and offers network interfaces.

• It performs the management of signaling system, wireless resource and A interface signaling between BSS and MSC.

• It also sets up the calling route for the called mobile subscribers if the function of GMSC has been integrated.

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ZXC10 MSC / VLR

• VLR is a database and responsible for the storage and updating of data of mobile subscribers that roam to the service area of this VLR.

• The information includes user number, property, and location identification and service parameters.

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Technical specifications

• MSC system capacity: 600,000• Max Number of subscribers: 600,000

(64K*64K) • Call Processing Capacity for Single Module:

500K BHCA • Max Call Processing Capacity: 5,000K BHCA • Max Traffic: 21,000Erl • Max Number of No.7 signaling links: 640

links • VLR System Capacity: 800,000

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Architecture of CDMA system

Um E

Abis A

Q C

B

N

N

MS

BTS BSC

PSTN MSC

MS C/SSP VLR

HLR AUC MC

D

MC

M

MSS

BSS

Ai

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•MS: Mobile Station

•BSC: Base Station Controller

•BTS: Base Transceiver Station

•MSC: Mobile Switching Center

•VLR: Visitor Location Register

•HLR: Home Location Register

•AUC: Authentication Center

•OMC: Operation and Maintenance Center

•MC: Message Center


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Other Terminologies used

• PLMN: Public Land Mobile Network• ESN: Electronic Serial Number• MIN: Mobile Station Identification Number• IMSI: International Mobile Subscriber

Identification• MSIN: Mobile Station Identification Number• MCC: Mobile Country Code• MNC: Mobile Network Code• SID: System Identification• NID: Network Identification

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Main components of CDMA

•MSS (Mobile Switching Sub-system)

•BSS (Base Station Sub-system)

•MS (Mobile Station)

•OMC (Operation and Maintenance Center)


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1. Base Station Sub-system

•Function: It provides trunks between

wireless part and fixed part of PLMN

network.---BSC

BSC performs the controlling function and management.

---BTS

BTS is in charge of wireless transmission.


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•Function:

•CDMA switching function

—Manage mobile subscriber data

—Manage database for mobile service

—Interface between CDMA network and

other network (such as PSTN, other PLMN

etc.).

•It includes 4 function units:

---MSC ---VLR

---HLR ---AUC

2. Mobile Switching Sub-system


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•It is responsible for setting up, managing and clearing connections as well as routing the calls to the proper user.

• It provides the network interfaces, the charging function and the function of processing the signaling.

• MSC get data for call handling from 3 databases: VLR/HLR/AUC


1) Mobile Switching Center(MSC)

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2) Visitor Location Register(VLR)• VLR is a dynamic database used by MSC for

information index. It stores all related information of mobile subscribers that enter its coverage area, which enables MSC to set up incoming and outgoing calls.

• Subscriber parameters include: subscriber number, location area identity(LAI), user’s status, services which subscriber can use and so on.

• When the subscriber leaves this area, it should register in another VLR, and the previous VLR will delete all the data about this subscriber.

• VLR can be built together with the MSC or set separately


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• HLR: It is a static database. When a user apply for mobile service, all data about this subscriber will be stored in HLR.

•Information:----Subscriber information (ESN, MDN, IMSI, MIN), service information and valid term.

----The mobile subscriber location (MSC/VLR address), so as to set up the call route to the MS.

• HLR can be built together with the MSC or set

separately.

3) Home Location Register (HLR)


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4) Authentication Center• Conception: It is an entity to prevent illegal

subscribers from accessing CDMA network. It can generate the parameter to confirm the subscriber’s identity. At the same time it can encrypt user’s data according to user’s request.

• Composition:

— Database: save MIN,ESN, authentication key)

— Generator of random number

— Algorithm(CAVE algorithm)

— AUC can be built separately or together with HLR


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Operation and Maintenance Center (OMC)

OMC provides operation and maintenance services to the network operator, manages the registered subscriber information and conducts network planning to enhance the overall working efficiency and service quality of the system.

Based on the main maintenance functions, there are two types of operation and maintenance centers: OMC-S and OMC-R. The OMC-S is mainly responsible for maintenance of MSS while the OMC-R is mainly for BSS.

We also call OMC as background.


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ZXC10 BSC

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ZXC10 BSC-FEATURES

• Two layer high rate packet network structure based on ATM technology

• Circuit-supporting data service such as asynchronous data, G3 fax.

• Supporting various types of voice conversion algorithm: QCELP (IS-95), 13kbps Pure Voice (IS-733), EVRC (IS-127) and echo cancellation.

• Built-in PCF, which supports high rate packet data service primarily based on mobile IP

• Providing E1/STM-1, which supports A3 and A7 interfaces defined by IOS4.0 and implements the interconnection of BSCs.

• Providing E1/STM-1, which supports A1, A2 and A5 interfaces defined by IOS4.0 and implements the interconnection of MSCs.

• Providing Fast Ethernet/ATM., which supports A10 and A11 interfaces defined by IOS4.0 and implements the interconnection of PDSNs.

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The basic performances of ZXC10 BSC

• Each BSC owns a HIRS network providing 256 high rate serial ports. Each serial port affords 10Mbps transmission capacity.

• Each BSC/PCF provides 240 E1 links with MSC maximum.

• Each BSC/PCF provides 380 E1 inks with BTSs maximum.

• Each BSC/PCF supports 7200-selectors/ vocoders maximum.

• Each BSC/PCF has the maximum traffic processing capacity of 5040 Erl.

• Each BSC/PCF processes 170,000 voice users maximum (based on 0.03Erl/sub)

• Each BSC/PCF can connect with 380 BTSs (single carrier/single sector) maximum.

• The BSC/PCF supports packet data services. Each Supports 1260 active PPP connections and 24,000 dormant PPP connections.

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ZXC10 BTS

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The basic performances-BTS

– RAKE receiving, diversity sending, and smart antenna – Softer handoff between sectors, soft handoff, and hard

handoff – Cell breathing, blossoming, wilting, and TPTL – High efficient wireless resource management – Hot standby for key components – Automatic and periodical performance test to ensure

reliability – All boards can be hot swapped, supporting on line

maintenance – Module function is relatively independent. Single rack of

BTS can accomplish 1,2,3 and 4 carriers, supporting Omni-, 2-sector, 3-sector and 6-sector cell. Supporting capacity expansion in stacking method

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The basic performances-BTS• Supporting 128 forward channels among which 55

channels are traffic channels with data rate of 9.6kbps (Practically 40 x 3 = 120 traffic channels per ‘3sector’ BTS is possible.)

• All the channel units in a rack form a sharing pool • Providing optic fiber interface between base band

digital subsystem and radio frequency subsystem. • Base station supports indoor modules, outdoor

modules and remote RF modules in various packing styles

• Supporting two types of clock systems: GPS and GLONASS Simultaneously

• Supporting voice services and mobile IP-based high rate packet data services

• Providing E1 or STM-1 links between BTS and BSC according to the capacity of BTS

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BDS: Base band Digital Subsystem

• CHM: Channel Processing Module • CCM: Communication Control

Module • RFIM: RF Interface Module • SAM: Site alarm module BTS_CDSU: BTS-side CDSU module

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TFS:Timing Frequency Subsystem

• GPSTM:GPS Timing Module • FDM: Frequency Distribution

Module • TCM: Timing Control Module

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RFS:RF Subsystem

• TRX: RF Transceiver • HPA: High Power Amplifier• RFE: RF Front End • RFCM: RF Control Module • BTM: Base station testing

module

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CDMA Forward Traffic Channels

•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 7 Paging channel.

•This leaves each CDMA frequency with at least 55 traffic channels.

•Unused paging channels can provide up to 6 additional channels.

Forward Traffic Channel


Sync

Paging



Pilot

CDMA Cell Site

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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 reusewithin 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

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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

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Sync Channel Message (cont.)• Leap Seconds (LP_SEC) – Number of leap seconds that have

occurred since the start of system time (January 6, 1980 at 00:00:00 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)

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Paging Channels

Paging Channel

Used by the base station to transmit system overhead informationand mobile station-specific messages.

Used by the base station to transmit system overhead informationand 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

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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 bps13 Kbps vocoder

•Rate Set 2 - 14400, 7200, 3600, 1800 bps

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Access Channels

• 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

4800 bps

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CDMA MS Call ProcessingPower-UpPower-Up

InitializationInitialization

IdleIdle

SystemAccess

SystemAccess

TrafficTraffic

Mobile station has fully acquired

system timing

Mobile station receives a Paging Channel message requiring ACK or response, originates a call, or

performs registration

Mobile station is directed to a Traffic Channel

Mobile station ends use of the Traffic Channel

Mobile station receives an ACK to an Access Channel transmission

other than an Origination Message or a Page Response Message

Mobile station is in idle handoff with NGHBR_CONFG equal to

‘011’ or is unable to receive Paging Channel Message

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Field Problems• ZTE Instruments reading the Primary

Channel 42 and 83 in the same instrument; example felt at Namakkal and Attur.

• Cell Demarcation: Subscriber of one SDCA has to work in the BTS located in the other SDCA with the dominated signal. Example at Kandhampayam and Puduchathiram. This has been experimented at Madurai MSC and to be tried at Pondichery MSC also.

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Thanks for listening

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04272452266

Cdma presentation

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