CDMA 2000 forward channel

CDMA 2000 user is assigned a forward channel that consists of the following combination :
  1. Forward fundamental channel  (F-FCH)
  2. 0-7: Forward supplemental code channel (F-SCHs) for both RC1 and RC2
  3. 0-2: Forward supplemental code channel (F-SCHs) for both RC3 and RC
The different forward/downlink physical channel are : 
  1. Forward pilot channel (F-PICH)
  2. Forward auxiliary pilot channel (F-APICH)
  3. Forward transmit diversity pilot channel (F-TDPICH)
  4. Forward sync channel (F-SYNC)
  5. The forward paging channel (F-PCH)
  6. Forward broadcast channel (F-BCH)
  7. The forward quick paging channel (F-QPCH)
  8. The forward common power control channel (F-CPCCH)
  9. Forward supplemental channel (F-SCH)
  10. Forward common assignment channel (F-CACH)
  11. The forward dedicated control channel (F-DCCH)
  12. The forward data traffic channel 
1. Forward pilot channel (F-PICH)
This channel is used to get multipath fading and channel conditions. This channel is shared by mobile nodes to obtain the above mentions information.

2. Forward auxiliary pilot channel (F-APICH)
Every channel is allocated a unique Walsh code under the code-multiplexed method in a downlink.

3. Forward transmit diversity pilot channel (F-TDPICH)
When increased RF capacity this channel is used. In these channels are intended for synchronization by the mobile with a specific cell.

4. Forward sync channel (F-SYNC)
For providing initial synchronization related data to the mobile station this channel is used. 

These are two types of forwarding sync channel that are used :
  • Shared sync channel
  • Wide-band sync channel
5. The forward paging channel (F-PCH)
The base station uses this channel in order to transmit the mobile station specific message and the overhead message. 

These are two types of forwarding paging channel are used :
  • Shared paging channel
  • Wide-band paging channel
6.  Forward broadcast channel (F-BCH)
It is intended to transmit control information to the respective mobile stations effectively that have not been allocated a traffic channel.

7. The forward quick paging channel (F-QPCH)
This quick paging channel is used by the paging channel for providing control information to the mobile stations.

8. The forward common power control channel (F-CPCCH)
The necessary power control information of uplink common control channel is conveyed by base stations using this channel.

9. Forward supplemental channel (F-SCH)
Up to two F-SCHs can be assigned to a single mobile unit for high-speed data ranging from 9.6 to 153.6 kbps in release 0.

10. Forward common assignment channel (F-CACH)
The quick assignment of a reverse common control channel is done by the base station using this channel.

11. Forward common assignment channel (F-CACH)
 It is used to send high layer message to the mobile units. This channel is used by the base station.

12. The forward dedicated control channel (F-DCCH)
  • It replaces the dim and burst and blank and burst
  • It is used for messaging and control for data calls
  • In addition to these channel forward data, a traffic channel is also used in forwarding channels in the CDMA 2000 standard

The minimum configuration consists of a reverse pilot channel to enable the base station (BS) to perform synchronous detection and reverse fundamental channel for voice.

Advantages and disadvantages of electrical transducer

An electrical transducer is one type of device which is capable of converting the physical quantity into a some of proportional to the electrical quantity such as voltage or must be electric current. Hence it covert any quantity to be measured into the usable electrical signal. This post gives the advantages and disadvantages of an electrical transducer to better understand this topic.

Advantages of electrical transducer


  • The power requirement of the transducer is very small. The electrical system can be controlled with a very small level of power
  • Electrical signals can  be easily  attenuated or must be amplified  to the signal and can be brought up to a level suitable for a various device with the help of static device FGK
  • An amplifier may be used for amplifying the electrical signal according to the which types of uses or requirement
  • The electrical output of the transducer can be easily used, transmitted and also easily processed for the purpose of measurement.
  • Mass inertia effects are minimized
  • The signal can be conditioned or mixed to obtain any combination with the output of similar transduces or control signals
  • The data transmission through mechanical mean is eliminated. Thus no mechanical wear and tear and no possibility of mechanical failures exist
  • The reduce effects of friction and other mechanical non-linearities
  • Due to the integrated circuit technology, the electrical and electronic system is compact having less weight and portable
  • The output can be indicated and must be recorded remotely from the sensing element

Disadvantages of the electrical transducer


The electrical transducer is sometimes less reliable than mechanical type because of the aging and drift of the active components. Also, the sensing elements and the associated signal processing circuitry are comparatively more expensive. With the use of better materials, its improved technology, and better for circuitry design, the range of accuracy and stability has been increased for electrical transducer while using negative feedback techniques the accuracy of measurement and the stability of the system are improved but main is that all at the expense of increased circuit complexity more space and obviously more cost.
  • The electrical transducer has costly
  • While designing the circuit the effects of aging and also drifts of parameters of active components must be considered. This makes the design is too much complicated

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Applications of transducer

Application of the transducer is more widely. Some of the used in medicine, such as in sonography machine, While some of the used in music engineering and recording, some of the used in complex mechanical systems and even in safety system like train brakes, Some of the application in different electronics components.  Here this post to cover almost each and every application and uses of the transducer.

Application and uses of the transducer are given below:
  • Transducer measure the load on the engines
  • It is used as a sensor device for knowing the engine knock
  • Measuring inlet, outlet or system pressure in the engine test setup
  • Measuring fluid height or level in tanks
  • Measuring pressure drop in a line for preventive maintenance
  • Sanitary pressure transducer in the bio or pharmaceutical industry
  • Measuring the pressure of slurry or slush using a flush diaphragm pressure transducer
  • It converts the temperature of the devices into an electrical signal or called as  mechanical work
  • It is used for detecting the movement of muscles which is called acceleromyograph
  • The transducer is used in the speaker for converting the electrical signal into acoustic sound
  • It is also used in the ultrasound machine. It receives the sound wave of the patient by emitting their sound waves and pass the signal to the CPU
  • It is used in the antenna for converting the electromagnetic  wave into an electrical signal
  • The transducer measures the pressure  of the gas and liquid by converting it into an electrical signal
  • The classification of the transducer depends on the various factor like by transduction the converting signal from AC or DC, etc
Here this post also gives some common application of transducer in a different part of electronics :
  • Thermistor/ Thermocouple
  • Optocoupler
  • LDR
  • Microphone
  • Hall effect
  • Speaker
  • Magnetic pickup
  • Flame or smoke
  • Pizzo
  • Strain gauge
  • Vibration
  • Magnetism
  • Force
  • Torque
  • Power
  • Current
  • Magnetic flux
  • Position 
  • Humidity
  • Displacement
  • Pressure
  • Velocity
  • Temperature 
  • Pressure
  • Data transfer

Bluetooth range

There are three types of classes in different Bluetooth specification.

Class 1 - Range of fewer than 10 meters
Class 2 - Range of 10 meters (33 feet)
Class 3 - Range of 100 meters (328 feet)

Facts :
  • The range depends on atmospheric, geographic, urban conditions.
  • The range not only depends on the transmitter but also on the mobile phone which is receiving files.
  • The bigger the range, the slower transmission speed.
  • Here above Bluetooth range described above. There are three types of classes. class 1 devices transmit at 1 mW with the range of fewer than 10 meters. Class 2 devices transmit at 2.5 mW with a range of 10 meters or 33 feet. Class 3 devices transmit at 100 mW with the range of 100 meters or 328 feet.

Difference between active transducer and passive transducer

The transducer which generates the output in the form of voltage or current, without any external energy source is known as an active transducer, while in passive transducer means that the like capacitance, resistance, and inductance changes because of the input signal. Here this post we understand the difference between an active transducer and a passive transducer.

The main key difference between an active transducer and a passive transducer given below.

 Difference : 
  • The transducer which gives the electrical output without any external source known as the active transducer while in physical transducer whose physical properties varies because of the input or measured signal known as the passive transducer.
  • The active transducer is also called a self-generating type transducer while the passive transducer is also called an externally powered transducer.
  • The active transducer does not require any additional source while the passive transducer requires the additional energy source.
  • Active transducer does not require any auxiliary power supply, Passive transducer require an auxiliary power supply for transduction.
  • The active transducer, the signal conversion is simpler, while in passive transducer the signal conversion is more complicated.
  • Active transducer the energy to produce output obtained from the physical quantity, while in passive transducer they also derived part of the power required the conversion from physical quantity under measurement.
  • The latest example of the active transducer is bourdon tube, Passive transducer is LVDT.
  • It generated electric current or voltage directly in response to environmental stimulation, while in passive transducer gives a change in some passive electrical quantity, such as capacitance, resistance or inductance as a result of the stimulation.
  • The design of the active transducer is simple as compared to the passive transducer.
  • The resolution of the active transducer is low while that of a passive transducer is high.
  • Active transducer draws energy from the measured source and gives the electrical output while in passive transducer the transduction can be done by changing the physical of the material.

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Transistor advantages and disadvantages

Basically, the transistor is nothing bur solid-state equivalent of a triode valve which was used in radio and early computers. It is made of three-layer semiconductor materials. Common semiconductor two materials in transistor construction are silicon and germanium. It basically acts as an insulator and a conductor. This page almost covers the advantages and disadvantages of the transistor to better understand this topic. 

Advantages of transistor:
  • It is used for fast switching applications
  • Smaller mechanical sensitivity
  • It is used as a current controlled current gain
  • It is available at very low cost
  • It is very smaller in size
  • Fast switching
  • It has a longer lifeLow operating voltage for greater safety, lower costs and  tighter clearances
  • Extremely long life
  • The transistor is very easy to turn ON and turn OFF the power transistor
  • The power transistor can carry large currents in ON state and it blocks very high voltage in OFF state mode
  • ON state voltage drops across power transistor is  very low
  • The power transistor can be operated at switching frequencies in the range of around 10 to 15 KHz
  • There is no power consumption by the cathode heater
  • It uses low voltage for its operation hence it offers more safety
  • It can be used to control the power delivered to the load in inverters and choppers
Disadvantages of transistor:
  • It has reverse blocking capacity is very low
  • It can be damaged due to the thermal runaway or second breakdown
  • Manufacturing techniques are very complex and require a clean room environment
  • Due to its small size, it is difficult to trace out faulty ones due to failure. Moreover, it is very difficult to unsolder and replace new ones
  • Power transistor cannot be operating satisfactorily above switching frequency of  around 15 KHz

Advantages and disadvantages of manometer

The manometer is measured an unknown pressure by balancing in against gravitational force of liquid heads. It can be used to measure dynamic pressures and differential pressures. It can be measure pressure ranging from low to high. Here this page covers the advantages and disadvantages of the manometer  to better understand this topic. 

Advantages of  manometer:
  • It has a low cost
  • The manometer is suitable for low-pressure applications
  • It is simple in construction
  • It has better sensitivity
  • It has good accuracy
  • It has simple operation and construction
  • It does not have to be calibrated against any standard, the pressure difference can be calculated from the first principles
  • The manometer is available for a large range of filling fluids of varying specific gravity
Disadvantages of manometer:
  • It is large in size and bulky
  • It needs leveling
  • No fixed reference is available
  • In manometer, the error is introduced due to condensation
  • It has no over range protection
  • The manometer has a poor dynamic response
  • They have a smaller operating range which is on the order 1000 KN/meter.meter
  • They are fragile and hence offer less portability
  • The manometric fluids density depends on temperature. Hence errors may result due to change in the temperature
  • It has a slow response which makes it unsuitable for measuring fluctuating pressures  

Difference between PCM and DPCM

We have to learn about this topic first let we understand the full form of PCM and DPCM full form. PCM and DPCM are the methods of the procedures used for transformation analog signal into a digital signal. These methods are different as the PCM method are represents sample value by code words whereas in DPCM the original and sample values depend on the previous samples. Here this post gives information about the main comparison between PCM and DPCM to better understand this topic.

The main key difference between PCM and DPCM are given below:
  • PCM stands for pulse code modulation, DPCM stands for differential pulse code modulation.
  • PCM can be required the highest bandwidth but  DPCM required small bandwidth. 
  • PCM is comprised of complex notation as to when DPCM has simple notation.
  • PCM  can be used 4,8,16 bit per sample, DPCM can be uses 2 or 3 bit per sample.
  • In PCM the quantization error depends on a number of levels, While in DPCM slop overload distortion and quantization noise is present.
  • PCM has a better signal to noise ration while DPCM has an average signal to noise ratio.
  • In PCM the number level depends on the number of bits, While in DPCM has fixed number of levels are used.
  • Both PCM and DPCM techniques suffer quantization error and distortion but different extent.
  • PCM has no feedback in transmitter or receiver, but in DPCM feedback is present.
  •  PCM is used in audio, video, and telephony, while in DPCM is used in speech and video application.
  • If we talk about efficiency DPCM is a step ahead of PCM method.
We conclude that the above difference is that PCM procedure sample and convert analog waveform into a digital waveform directly with the help of an analog to digital more covert. On the other hand, DPCM does similar work but uses multibit difference value.

 Explore more information:

  1. Difference between PCM and DM
  2. Difference between PCM and DPCM
  3. Difference between DWDM and CWDM
  4. Difference between DM and PCM

Difference between time domain and frequency domain

We all know that, the time domain is the domain in which all the signals are to be represented. Time domain signal can be tested or verified with the use of an oscilloscope while in the frequency domain is useful to do a deeper analysis of the time domain signal. Frequency domain helps to study contents of the discrete time domain signals as well as continuous time domain signal.  While in frequency domain signal can be analyzed with the use of spectrum analyzer. Here this page gives information about the difference between time domain to better understand this topic.

The main key difference between time domain and frequency domain are listed below:
  • A time domain graph shows how a signal changes over time while the frequency domain graph shows how much of the signal lies within each given frequency band over a range of frequencies.
  • The main advantages of time domain are that they are relatively fast and require less memory than inverting the Helmholtz operator, While in frequency domain main advantages are that the frequency domain allows for techniques which could be used to determine the main of stability of the system.
  • Time domina is the domain for analysis of the mathematical function or signals with respect to time, Whereas the frequency domain is the domain for analysis of the mathematical function or signals with respect to frequency.
  • The time domain systems tend to use photon counting detectors which are slow but too much highly sensitive, while frequency domain system is relatively inexpensive, easy to develop and use and can provide a very fast temporal sampling. 
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Advantages and disadvantages of atm

First, let us understand what is the full form of ATM. To operate the ATM card, the customer has to insert the card in the machine. He has to enter the password number. The authentication or password number is correct, The ATM  permits a customer to make entries for withdrawals or for the deposits on completion of the transaction, the customer's card is ejected from the ATM. This post gives information about the advantages and disadvantages of ATM to better understand this topic.

Advantages of ATM:
  • Withdrawing money
  • Round the clock services: ATM provides banking services to its customers round the clock 24 hours a day, 7 days a week and 365 days a year
  • ATM device can check how much money is remaining in the account
  • It is possible to withdraw from many regional and global banks. ATMs are a method of the deal because they are internationally acknowledged
  • Checking recent or past bank statements
  • Nowadays almost every shopping mall, restaurant, and other organizations are accepting debit or credit card payments
  • ATM machine will provide expansion of services to any corner of the world
  • It may also be used in foreign countries
  • It reduces the hustle and bustle required when performing a transaction via a teller. Since there is no usage of slides in ATMs there is no stressful filling of forms
  • ATMs very beneficial for travelers
  • ATMs provide privacy in banking transactions
  • No more filling out a deposit slip as well as withdrawal slip
  • ATM  is  to much faster less hassle
  • ATM card is protected by a PIN keeping our money is totally safe
  • Can monitor or track the account
  • Can withdraw anytime, day or night at any locations as long as the ATM card is also linked in the other bank, so its good for people
  • ATMs reduce the work pressure on bank staff and avoid queues in bank premises
  • Access to bank from any part of the world called as an essential banking service like deposits, withdrawals, transfer of funds, etc can be accessed by customers from any part of the world
Disadvantages of ATM:
  • The machine may not recognize your credit card
  • Maybe no ATMs nearby
  • If someone watches or hacks an ATM machine your details may be taken, so lots of hugs will be created
  • If the problem with a credit card you can not withdraw your money
  • If someone watches or hacks ATM machine details may be taken if you forget your PIN number you cannot use the card
  • Cannot be provided in rural areas like in our country like India where banks are having a large number of rural and noncomputerized branches ATM services cannot be provided
  • Limitation of cash withdrawals
  • The cash deposit facility is restricted and not safe as the dropping of envelope and ATM  is not advisable
  • Possibility of missing ATM card
  • Loos of personal touch with the banks
  • The risk to robbery when withdrawing a money
  • Some charges of other banks are expensive
  • ATM has run out of cash

Difference between voltage amplifier and power amplifier

The function of the voltage amplifier is to raise the voltage level of the signal. In order to achieve high voltage amplification, the transistor should have a thin base input resistance should have a thin base, input resistance should be low as compared to the collector resistance and the transistor should be able to take or permit higher collector load. In the power amplifier, the main function is to deliver a large amount of power and handle a large current. In order to achieve this high power amplification the transistor used are of a large size so as to dissipate the heat produced, It is based should be thick so as to carry a large current of the order of 100mA,  This post gives information about the difference between the voltage amplifier and the power amplifier to better understand this topic.

The main key difference between a voltage amplifier and the power amplifier are listed below.

 Difference :

  • Voltage amplifier is the amplitude of the input AC signal is small, the Power Amplifier is the amplitude of the input AC signal is large.
  • The voltage amplifier is the collector current is low about 1mA, while in power amplifier the collector current is very high above greater than 100 mA.
  • Voltage amplifier is transistor used can dissipate less heat produced during its operation, while in power amplifier used can dissipate more heat produced as compared to voltage amplifier during its operation.
  • RC coupling is used in a voltage amplifier, In power amplifier invariably transformer coupling is used.
  • In voltage amplifier transistor used has a thin base to handle low current, power amplifier used has a thick base to handle the large current.
  • In the voltage amplifier the AC power output is low, In power amplifier the AC power output is high.
  • The physical size of transistor used is usually small and is known as low or medium power transistor while in power amplifier size of transistor used is usually large and is known as a power transistor.
  • In a voltage amplifier, the collector load has high resistance typically 4 kilo-ohms to 10-kilo-ohms while in power amplifier the collector load has low resistance typically 5 ohms to 20 ohms.
  • Voltage amplifier has a high voltage gain, while the power amplifier has a high power gain.
  • In most voltage amplifier current gain is very low while the power amplifier has significant current gain which results in the power gain.
  • Voltage amplifier dissipated relatively less heat than power amplifier, therefore, the voltage amplifier has higher power efficiency than a power amplifier. Also, power amplifier requires additional; cooling mechanism due to this fact.
  • A voltage amplifier is designed to achieve maximum voltage amplification however it is not important to raise the power level, On the other hand, while in a power amplifier is designed to obtain maximum output power.
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ATM full name

What is the full form of ATM?

  • Automated Teller Machine

 What does ATM mean?

ATM stands for automated teller machine, it is an electro-mechanical machine that is used for making financial transactions from a bank account. These machines are used to withdraw money from your personal bank accounts. Link in a bank branch cashier, officially known as teller counts cash and handover it to the customer, in the same manner, the machine does it for you. Hence it is called Automated teller machine.

RISC full form

What is the full form of RISC?

  • Reduced Instruction Set Computer

What does RISC mean?

A RISC represents a CPU  design method to simplify instruction which does less but provides higher performance by making instruction execute very fast. RISC  is a type of microprocessor that has a limited number of instructions.  They can execute their instruction very fast because the instructions are very small and simple.  RISC chip requires additional transistors and circuitry. Most instructions are completed in one cycle, which allows the processor to handle many instructions at the same time.

Related full form:

Full form of CISC

What is the full form of CISC?

  • Complex Instruction Set Computer

What does CISC mean?

A CISC stands for complex instruction set computer, CISC is a computer instrument in which in single instructions can execute several low-level operations as a load from memory, some different arithmetic operations, and a memory store or is accomplished by multi-step processes or addressing modes in a single instruction as its name propose complex instruction set.

Related terms:

Full form of DLL

What is the full form of DLL?

  • Dynamic Link Library

 What does DLL mean?

DLL is a file contains a library of the function and other information that can be accessed by a windows program. When a program has launched a link to the necessary .dll files are created. The .dll files will be in use as long as the program is active. If a dynamic link is created the. DLL files will only be used when needed. Dynamic links help programs use resources, such as memory and also hard drive space, more efficiently

A DLL can be used by several applications like at the same time. Some DLLs are provided with the Windows operating systems and available for any windows application. 

MAPI full form

What is the full form of MAPI?Outlook

  • Message Application Program Interface

 What does MAPI mean?

MAPI is a windows proprietary protocol, It works windows applications like outlook. It is used to send email in a way IMAP does. An application that takes advantage of MAPI includes the word, graphics, e-mail note, MAPI include word processor.  While MAPI is designed to be independent of the protocol, it is usually to communicate with Microsoft exchange server.
The distributing features od MAPI is, It allows you to send an email from windows system by attaching the document you are working on.

IMAP full form

What is the full form of IMAP?


Answer:

  • Internet Message Access Protocol


What does IMAP mean?


IMAP is an internet message standard protocol. It is used by e-mail clients to retrieve the e-mail message from a mail over a TCP/IP connection. As its name allows to access your e-mail message wherever you are much more time. It is accessed via the internet. Basically, the email message is stored on servers. Whenever you check your inbox message, your email client contacts the server to connect you with your message. When you read an email message using IMAP protocol devices, you aren't actually downloading or storing it on your computer, instead, you are reading it off the server. As a result of its possible to check your different devices without missing a thing.
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  1. Full form of PPP

POP full form

What is the full form of POP?

Answer:

  • Post Office Protocol


What does POP mean?

POP stands for post office protocol. It is most commonly used as a protocol to retrieve e-mail from a mail server. Most of the e-mail application is used as a POP protocol, although some can use the newer IMAP access protocol. 

There are two versions of POP called POP2 and POP3. The first called POP2 became a standard in the mid-'80s and it requires SMTP to send a message. The second one and newer version POP3 can be used with or without SMTP.

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  1. Full form of SMTP

Difference between dwdm and cwdm

CWDM and DWDM both are effective methods to solve the increasing bandwidth capacity of information transmission at present. The main development goals of CWDM and DWDM are both high capacity and also low cost. but the difference between CWDM and DWDM is as given below:

The main key difference between DWDM and DWDM is listed below:
  • DWDM stands for dense wavelength division multiplexing, CWDM stands for coarse wavelength division multiplexing, 
  • CWDM defined by wavelength, DWDM defined by frequencies.
  • CWDM has lower capacity, DWDM has higher capacity.
  • CWDM has lower cost, DWDM has a higher cost.
  • CWDM has short-range communication, DWDM has long-range communication.
  • CWDM has used a wide range of frequencies, DWDM uses a narrow range of frequencies.
  • In DWDM cooled laser may be used due to tighter control of wavelength, Whereas in CWDM uncooled laser is used due to the longer channel spacing 
  • In CWDM break spectrum is large in a large section, While in DWDM break spectrum in smaller sections
  • CWDM is more wavelength spacing, While DWDM has less wavelength spacing.
  • DWDM precision laser is needed to keep channels on the target, while in CWDM wavelength drift is possible.
  • CWDM has Mux and Demux systems are developed to be used in multiplexing multiple, CWDM channels into one or two fibers.
  • In CWDM no of active wavelength per fiber is fewer than 8 while DWDM more than 8.
  • DWDM is used for application for light signal amplification.
  • DWDM systems are capable to fit more than forty different data streams in the amount akin to that of fiber used for two data streams in a CWDM system.
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CWDM full form

What is the full form of CWDM?

  • Coarse Wavelength Division Multiplexing

What does CWDM mean?

CWDM is a wavelength multiplexing technology for the city and also it accesses the network. Transmission is realized using a total of 18 channel wavelengths between 1270 nm and 1610 nm. Due to the channel spacing of around 20 nm, cost-effective lasers can be used. The channel width itself is 13 nm. The remaining 7 nm designed to secure the space to the next channel.

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