CDMA2000 Network Configuration

CDMA2000 Network Configuration

The CDMA2000 1X/1xEV-DO networks consist of the Access Network(AN), Data Core Network(DCN), and the Voice Core Network(VCN).

Voice Core Network (VCN)

VCN is configured with Mobile Switching Center(MSC), Home Location Register(HLR), and Interworking Function(IWF). VCN processes the voice and circuit data of MS, which has been received through AN.

Mobile Switching Center (MSC)

MSC performs switching in the CDMA2000 network. MSC connects mobile subscribers in the network with subscribers in another network, and authorizes MSs in the CDMA2000 1X network. Also, MSC inter-works with various supplementary system devices to provide mobile subscribers with additional services.

Home Location Register (HLR)

HLR is a database where information on CDMA2000 mobile communication

subscribers is archived. HLR can be fault tolerant seamlessly and process database in real-time. HLR inter-works with MSC, the SMS center, network administration center, and customer center.

Interworking Function (IWF)

IWF provides mobile subscribers with circuit data communication services such as facsimile and modem communications, and has a modem pool.

Once IWF receives a request for circuit data service from a mobile subscriber or Public Switched Telephone Network(PSTN), IWF allocates resources of the modem pool to provide services.

Data Core Network (DCN)

DCN is configured with Packet Data Serving Node(PDSN), Home Agent(HA), Authorization, Authentication and Accounting(AAA), and Element Management System(EMS). DCN processes packet data on MS and sends or receives the packet data through AN.

Packet Data Serving Node (PDSN)

PDSN connects AN to DCN in the CDMA2000 1X or 1xEV-DO network. PDSN sets, maintains, or releases MS and PPP. PDSN functions as Foreign Agent(FA) for HA to provide mobile Internet Protocol(IP) services.

Home Agent (HA)

HA connects to the private network or another network in order to allow mobile IP users to connect to internet. HA exchanges data with FA(PDSN) in a variety of encryption methods.

Authorization, Authentication and Accounting (AAA)

AAA performs the authorization and authentication functions as well as billing for packet data communication service subscribers. AN-AAA performs authorization for MS, while AAA performs authorization for subscribers. PDSN and HA make a request for information on user authorization and authentication to AAA if required, and delivers the billing information to AAA periodically.

AAA supports authorization in accordance with the user profiles saved in the database.

Element Management System (EMS)

EMS supports the interface function for the DCN components. EMS performs I/O of the operator commands, displays an error/configuration/status/performance messages, restarts the system, and downloads the system software blocks.

Access Network (AN)

The AN is composed of the Base station Transceiver System(BTS), Base Station Controller(BSC), General ATM switch Network(GAN), Access Network-Authorization, Authentication and Accounting(AN-AAA ), and Data Location Register/DLR Local Manager(DLR/DLM).

The AN provides voice service through the VCN and delivers the packet data received from the Mobile Station(MS) to the DCN.

Base station Transceiver System (BTS)

BTS provides an air interface for Mobile Station(MS), and transmits or receives wireless data and signal data to or from MSs under the CDMA2000 1X/1xEV-DO standard.

BTS sends the data received from MSs to the core network through BSC, or conversely sends the data received from the core network to MSs through BSC. To serve as a wireless transceiver mentioned above, BTS manages radio resources such as FA and Walsh, schedules Radio Frequency(RF), or controls power.

The BTS of a single 1xEV-DO network is called Access Network Transceiver System (ANTS).

Base Station Controller (BSC)

BSC interfaces with several BTSs. Also, BSC interfaces with MSC to process voice and circuit data calls, and interfaces with GAN and DCN to process packet data calls.

Also, BSC inter-works with BSM to perform operation and maintenance functions in Base Station System(BSS). BSC performs vocoding for voice calls, and performs Radio Link Protocol(RLP) for data calls. BSC supports the Select and Distribute Unit(SDU) function for voice and data calls to enable soft handoff in MSs.

The BSC of a single 1xEV-DO network is called Access Network Controller(ANC).

General ATM switch Network (GAN)

GAN provides communication paths between BSCs. GAN interfaces with several BSCs to enable handoff between BSCs, and to enable BSM to communicate with BSC and BTS connected to each BSC through GAN. Also, packet data calls can be transmitted from BSC to PDSN through GAN.

Also, GAN manages subscriber mobility and session data, and provides a path between BSC and DLR/AN-AAA for the authorization of MS in 1xEV-DO.

Base Station Manager (BSM)

BSM provides an operator interface so that the operator can control or manage BSC and BTS. BSM provides commands that enable system failure/status/performance data retrieval, system configuration management, and system parameter control, which are required for the operation and maintenance of BSC or BTS. BSM operates on a conventional workstation platform, and is implemented by using Graphical User Interface(GUI), enabling the operator to check or control the system status conveniently.

Access Network-Authorization, Authentication and Accounting (AN-AAA)

The AN-AAA server authenticates the MS in the 1xEV-DO network. Once AN-AAA receives a request for authorization, AN-AAA assigns International Mobile Station Identity(IMSI) to MS based on Network Access Identifier(NAI) of MS, and manages mapping data on IMSI and NAI of MS.

Data Location Register/DLR Local Manager (DLR/DLM)

DLR, which performs mobility management for the wireless subscribers of the 1xEV-DO network, provides the terminal location information management, Unicast Access Terminal Identifier(UATI) assignment request process, International Mobile Station Identity(IMSI), session control/management of the MS, and the paging function for the MS.

DLM provides the operator interface for the DLR and provides the input/output for the operator’s commands, displays fault/configuration/status/performance messages, restarts the system, and downloads the software blocks.

CDMA2000 System

Mobile communication has expanded its service area from voice to data, evolving from the first generation analog mobile communications, to the second generation digital mobile communications and then to the third generation CDMA2000 mobile communications of today.

Especially, with the explosive growth of internet, many people have become interested in high-speed radio transmission technologies required for various multimedia services.

In order to provide these services in today’s internet environment, Samsung has developed the CDMA2000 1X/1xEV-DO system, which is a high-speed radio transmission technology based on the same frequency bandwidth(1.25 MHz) as that of previous technologies, using this technology and onsite experience to be the first to commercialize the CDMA mobile communication service in the world.

Samsung CDMA2000 1X/1xEV-DO systems support voice service, high-speed circuit data service, and high-speed packet data service. Thus, internet services such as web surfing and e-commerce, various contents-providing services such as Video On Demand(VOD) and MP3, and video services including video telephony and video conference can be supported stably and future demands for various multimedia services can be met.

Using the channels of the IS series(e.g., IS-95, IS-2000, and IS-856), the CDMA2000 1X/1xEV-DO systems support backward compatibility for the vocoding, low-speed data service, facsimile service, Short Message Service(SMS), medium-speed data service, handoff functions, which were also provided by the traditional systems.

Samsung CDMA 2000 system provides high-speed multimedia IT services that require various application services as well as voice and data services, and can also be efficiently applied to the migration of mobile communications.

Spreading from a Frequency-Domain View

• Traditional technologies try to squeeze signal into minimum required bandwidth
• CDMA uses larger bandwidth but uses resulting processing gain to increase capacity
• 

How Does CDMA Work? Introduction to Basic Principles

Claude Shannon:

The Einstein of Information Theory

• The core idea that makes CDMA possible was first explained by Claude Shannon, a Bell Labs research mathematician
• Shannon's work relates amount of information carried, channel bandwidth, signal-to-noise-ratio, and detection error probability. It shows the theoretical upper limit attainable

SHANNON’S CAPACITY EQUATIONC= Bωlog2[1 + ]S N Bω= bandwidth in HertzC = channel capacity in bits/secondS = signal powerN = noise power.

In 1948 Claude Shannon published his landmark paper on information theory, A Mathematical Theory of Communication. He observed that "the fundamental problem of communication is that of reproducing at one point either exactly or approximately a message selected at another point." His paper so clearly established the foundations of information theory that his framework and terminology are standard today.Shannon died Feb. 24, 2001, at age 84.

February, 2005 Technical Introduction to CDMA

Optimizing in Two Worlds

Circuit-Switched Voice Traffic

• Some operators are implementing 1xRTT mainly to gain capacity for additional voice traffic
• Their optimization techniques remain about the same as for 2G voice networks today - Keep network adequately dimensioned – Control RF environment – Monitor and manage capacity utilization
  

IP Data Traffic

• Operators adding IP traffic to upgraded voice networks
• Conventional optimization techniques are still appropriate for general
  

RF environment and circuit-switched network performance

• New IP and QoS issues require a new optimization focus for the blended total network - IP performance depends on both IP and RF factors - IP and Voice performance involve competitive tradeoffs

The Big Picture Optimization Issues CDMA 1xRTT

1xRTT services may include both traditional circuit-switched voice and new fast IP data connections

• A User's link is in multiple jeopardy, both radio and packet worlds

Radio environment portion

• Problems: FER, drops, access failures, capacity woes
• Causes: mainly in the RF world, because of mainly RF problems
  

Packet environment

• Problems: Setup failures, dropped connections, low throughput
• Causes: could be IP-related, or could be RF related
  

Optimization Issues
Network Design and Configuration

• Coverage holes, excessive coverage overlap

Call Processing Problems due to Misconfiguration

• Neighbor Lists
• Search Windows
• Power control parameters
  

Physical Problems/Hardware Problems

• Mismatched multicarrier sector coverage

Capacity Issues

• Forward and Reverse Power Control Overload
• Physical resource congestion : Channel elements, packet pipes - IP network congestion
  

Managing A New Dimension: circuit-switched and IP traffic blend

• QoS-related competitive issues

PERFORMANCE MONITORING OR GROWTH MANAGEMENT

PERFORMANCE MONITORING

benchmark existing performance : dropcall % , access failure % , traffic levels.
identify problem cells and clusters : weigh cells and clusters against one another.
look for signs of overload : TCE or walsh minutes - excessive ? soft handoff excessive ?
required number of channel elements - excessive?
forward power overload : originations , handoff blocked
Traffic trending and projection : track busy hour traffic on each sector ; predict exhaustion.
develope plant for expansion, multiple carriers.

Optimization Requirements

• performance optimization requires several things :

1. a stable system
2. performance expectation and performance goals
3. a good understanding of CDMA2000 : general RF technology , transmitter and receiver basics CDMA signal characteristics ; a) the different CDMA channels and what they do. b) how mobile and base station power are regulated during a call. c) the basic steps of how a call is set up, how handoffs happen, etc. d) how noise and interfering signals affect the call.
4. a good data measurement / analysis capability

• improving performance in one area should not degrade performance in some other area.
  

Access Failure Rate and Drop Call Rate

Access Failure Rate

The mobile origination failure rate is defined as the number of origination failures devided by the total number of origination attempts

• mobile originations are mobile to and (MTOL) calls
• a typical performance target of <>
• a rate of <>

the mobile termination failure rate is defined as the number of termination failures divided by total number of valid termination attempts.

• mobile termination are land to mobile (LTOM) calls
• a typical performance target of <>
• a rate of <>

Drop call Rate

A drop call is defined as a traffic channel that is released by either the base station or the mobile without the consent of the mobile.
the dropped call rate is defined as the total number of dropped calls divided by the total number of successful call completions during a spesified period.
a performance target of <2% ( plus a confidence interval ) in deemed accptable.

FER ( frame Error Rate )

a frame error is defined as a frame that is received with bit errors detected ( a failed CRC check ) or an erasure ( a frame with insufficient quality to make a frame rate determination ).

FER is normally measured y counting onlu full rate frame errors divided by the number of full rate frames. FER should be measured over the period of the typical call, about 100 120 seconds. A common performance FER target for voice would be 1% plus a confidence interval.

FER :

• on forward channel (realized at handset )
• on reverse channel ( realized at base station )
• FER is an excellent call quality " summary " statistic

FER is the end result of the whole transmission link

• if FER is good, the any other problems aren't having much effect
• if FER is bad , that's the problem
  

BTS transmitter output Measurement BSM ( base station manager ) and spectrum analyzer

BTS transmitter output Measurement. The objective of this test is to verify the bts transmitter power by each FA. If this test is finished in the bts installation step by the bts examination team , this test may be omitted by agreement with both parties. Otherwise , the sample BTSs will be selected to verify the BTS transmit power. The number of all BTSs, all sector , and all FA shall be mutually agreed with both parties.
Required tools and devices

BSM ( base station manager ) and a spectrum analyzer are required for measuring RF transmitter power in BTS. BSM shall be used in inputtung several parametters shall be connected through RF cable, and used to measure RF transmitter power. Another FA should be turned off during this test. test diagram for measuring RF transmitter power in BTS is described below.

Measurement method

• verify the dB_index parameter of overhead channel using BSM pilot of overhead channel is generally 15 %.
• setup ocns ( orthogonal channel noise simulator ) as follows.
• measure the BTS transmitter power using the spectrum analyser
• verify if the measured value meets the standard
• when the measured value is different from the standard, adjust trasmitter power gain in TRXA so that it can meet the standard.
• measure this test in the order of alpha, beta, and gamma , and repeat the test for each FA.
  

test tool bluerose and IDA from samsung

there are test Tool and Equipments Descriptions. There are two types of test tool when performing the field test. It is composed of Forward Link Analysis tool and Reverse Link Analysis tool. The specification, manufacturer, quantity of each equipment will be provided in detail in separated document. Forward Link test tool and equipment descriptions Test tool and equipment are as follows when analyzing the data on the forward link.

1. BlueRose : from Will’ Tek = Mobile station monitoring and Data Logging tool on the forward link for 1x and EVDO.
2. IDA : from Will’ Tek = Analyzing the logged data for 1x and EVDO.
3. Test Van : Test Tool setup and mobility
4. PC : Test Tool setup and Parameter change
5. Data cable : The interface cable between mobile and PC
6. Spectrum Analyzer : BTS Transmit power measurement
7. Angle Detector compass : Antenna Installation Check
   

It is possible to analyze the system performance and trouble using above forward link analysis tool. It is important to check the logging mask according to the test objectives when collecting the data.

Radio Frequency Optimization

this blog will share article about radio frequency optimization. my name mulyono, i am the admin of this blog.

overview about radio frequency optimization. radio frequency can give our easy to communication with all person in the world. for example. if you live in american and your friend live in indonesian. you will need radio frequency for example handphone. you can telephone your friend and communication white her. oke, i will give many point to study about radio frequency optimization.

Stage 1 : Single Cell Function test

Stage 1 is for verifying whether individual BTS works well or not, by making a single cell function test of BTS hardware and software.

Essential items to be tested are as follows:

1. BTS Transmitter Output Measurement Test
2. Initial parameter establishment (Pilot PN/System ID/Site ID/Frequency, Neighbor List)
3. Call Origination and Termination Test
4. Softer Handoff Test/Antenna installation check (Direction, Tilt, Transmission Line)
5. Single Cell Coverage Test
6. Noise Floor Test
   

Stage 2 : Cluster Optimization

Stage 2 is for testing several BTSs in cluster, in order to verify the inter-work and performance between BTSs. Stage 2 is aimed at checking basic field functions and performance in mobile communication system, assuring primary safety in system and network, and verifying conditions for maintaining the best quality of call and optimization in service aspects.

1. Basic Service Area Establishment
2. Voice Coverage Optimization
3. Data Coverage Optimization
4. FER optimization
5. Voice Handoff Optimization
6. Data Handoff Optimization
7. Shadow Area Optimization(if needed)
8. Pilot Pollution Area Optimzation(if needed)
   

Stage 3 : System Optimization Completion

Stage 3 is for verifying finally comprehensive performance in network. Essential tests to be performed at stage 3 are as follows:

1. Call Quality Optimization
2. System Capacity test