GSM Digital Mobile System (Transmission Chain and Reception Chain)
PPT File (https://drive.google.com/file/d/1FQVB3jAMDazkFoMhQGzfSnJU3L9ow6BO/view?usp=sharing)
Reference: Eng. Waleed El-Safoury Presentations
The document provides an overview of GSM RF interview questions and answers. It covers topics such as the three services offered by GSM (teleservices, bearer services, and supplementary services), spectrum allocation for GSM-900 and DCS-1800, carrier frequencies and separation, ciphering and authentication algorithms, equalization, interleaving, speech coding, channel coding, frequency reuse, cell splitting, interfaces (Um, Abis, A), LAPD and LAPDm, WPS, MA, MAIO, frequency hopping types, DTX, DRX, gross data rate, Erlangs and grade of service, coverage differences between GSM900 and DCS1800, time advance, location area and location update
This document provides an overview of 4G technology, including its key features and evolution. It discusses the applications of 4G, the telecom companies developing 4G networks, the infrastructure required, and technologies used such as OFDM. The document also summarizes the effects of radio communications and concludes that 4G will converge networks and technologies, providing opportunities for carriers while changing people's lives.
This document discusses capacity planning for GSM networks. It covers topics like trunking, traffic theory including traffic intensity, grade of service, busy hour, and request rate. It describes how to dimension traffic channels and SDCCH channels based on factors like traffic intensity and grade of service. It also discusses connectivity planning between network elements like MSC, BSC, transcoder, and BTS. It provides details on air interface, Abis interface between BSC and BTS, and different LAPD modes for signaling concentration over Abis. The objective is to estimate the optimal number of resources needed to meet performance requirements based on traffic analysis and engineering principles.
Frequency shift keying (FSK) is a digital modulation technique that encodes digital information by shifting the frequency of a carrier wave. There are different types of FSK including binary FSK, which uses two discrete frequencies to represent binary 1 and 0, and double frequency shift keying (DFSK), which uses four frequencies to transmit two independent data streams simultaneously. FSK modulation can be demodulated using either FM detector demodulators, which treat the FSK signal as an FM signal, or filter-type demodulators, which use optimal filters matched to the FSK signal parameters. The filters are used to detect the mark and space frequencies, and a decision circuit then determines which was transmitted.
The document describes the call flow procedures for mobile originating and mobile terminating calls in a GSM network.
For a mobile originating call, the MS requests a dedicated channel and indicates it wants to set up a call. The MSC receives the call setup message and checks for call barring before establishing a link with the BSC. The BSC assigns a traffic channel for the call.
For a mobile terminating call, the call is routed to the GMSC serving the called subscriber's home network. The GMSC queries the HLR for routing information. The HLR provides a roaming number to route the call to the subscriber's current MSC. The MSC pages the subscriber through the BSCs in their
Public Switched Telephone Network (PSTN)J.T.A.JONES
The document discusses various aspects of the Public Switched Telephone Network (PSTN). It covers topics like modulation/demodulation schemes used to convert between analog and digital signals, the bandwidth of telephone lines, traditional modem standards like V.32, V.90, ADSL, techniques used for multiplexing like TDM and WDM, and components within switching offices. It provides technical details on how analog voice signals are converted to digital, transmitted through digital trunks, and switched within the network.
The document contains questions and answers related to GSM and LTE drive test parameters. It discusses key topics like reference signal receive power (RSRP), reference signal receive quality (RSRQ), signal to noise ratio (SINR), received signal strength indicator (RSSI), physical cell ID (PCI), channel quality indicator (CQI), block error rate (BLER), downlink and uplink throughput, and WCDMA/3G questions and answers related to link budget, TMA, processing gain, and calculating maximum number of users.
The document provides an overview of GSM RF interview questions and answers. It covers topics such as the three services offered by GSM (teleservices, bearer services, and supplementary services), spectrum allocation for GSM-900 and DCS-1800, carrier frequencies and separation, ciphering and authentication algorithms, equalization, interleaving, speech coding, channel coding, frequency reuse, cell splitting, interfaces (Um, Abis, A), LAPD and LAPDm, WPS, MA, MAIO, frequency hopping types, DTX, DRX, gross data rate, Erlangs and grade of service, coverage differences between GSM900 and DCS1800, time advance, location area and location update
This document provides an overview of 4G technology, including its key features and evolution. It discusses the applications of 4G, the telecom companies developing 4G networks, the infrastructure required, and technologies used such as OFDM. The document also summarizes the effects of radio communications and concludes that 4G will converge networks and technologies, providing opportunities for carriers while changing people's lives.
This document discusses capacity planning for GSM networks. It covers topics like trunking, traffic theory including traffic intensity, grade of service, busy hour, and request rate. It describes how to dimension traffic channels and SDCCH channels based on factors like traffic intensity and grade of service. It also discusses connectivity planning between network elements like MSC, BSC, transcoder, and BTS. It provides details on air interface, Abis interface between BSC and BTS, and different LAPD modes for signaling concentration over Abis. The objective is to estimate the optimal number of resources needed to meet performance requirements based on traffic analysis and engineering principles.
Frequency shift keying (FSK) is a digital modulation technique that encodes digital information by shifting the frequency of a carrier wave. There are different types of FSK including binary FSK, which uses two discrete frequencies to represent binary 1 and 0, and double frequency shift keying (DFSK), which uses four frequencies to transmit two independent data streams simultaneously. FSK modulation can be demodulated using either FM detector demodulators, which treat the FSK signal as an FM signal, or filter-type demodulators, which use optimal filters matched to the FSK signal parameters. The filters are used to detect the mark and space frequencies, and a decision circuit then determines which was transmitted.
The document describes the call flow procedures for mobile originating and mobile terminating calls in a GSM network.
For a mobile originating call, the MS requests a dedicated channel and indicates it wants to set up a call. The MSC receives the call setup message and checks for call barring before establishing a link with the BSC. The BSC assigns a traffic channel for the call.
For a mobile terminating call, the call is routed to the GMSC serving the called subscriber's home network. The GMSC queries the HLR for routing information. The HLR provides a roaming number to route the call to the subscriber's current MSC. The MSC pages the subscriber through the BSCs in their
Public Switched Telephone Network (PSTN)J.T.A.JONES
The document discusses various aspects of the Public Switched Telephone Network (PSTN). It covers topics like modulation/demodulation schemes used to convert between analog and digital signals, the bandwidth of telephone lines, traditional modem standards like V.32, V.90, ADSL, techniques used for multiplexing like TDM and WDM, and components within switching offices. It provides technical details on how analog voice signals are converted to digital, transmitted through digital trunks, and switched within the network.
The document contains questions and answers related to GSM and LTE drive test parameters. It discusses key topics like reference signal receive power (RSRP), reference signal receive quality (RSRQ), signal to noise ratio (SINR), received signal strength indicator (RSSI), physical cell ID (PCI), channel quality indicator (CQI), block error rate (BLER), downlink and uplink throughput, and WCDMA/3G questions and answers related to link budget, TMA, processing gain, and calculating maximum number of users.
This document outlines the process for mobile originated and terminated calls in 3G networks. It describes the steps for a mobile originating call in 3 parts and a mobile terminated call in 3 parts, including setting up the GTP tunnel for transport. The document breaks down the end-to-end call flows for 3G connections.
This document provides parameters for radio network configuration in a Nokia wireless network. It contains over 100 parameters organized in sections for the BSC, BCF, BTS, adjacent cells, and other settings. The parameters define thresholds, timers, and options that control functions like call handling, congestion management, handover processing, and radio resource allocation. The document is intended only for Nokia customers and subject to change without notice.
This document discusses digital modulation techniques including PSK. It performed experiments in MATLAB to generate waveforms for BPSK and QPSK. For BPSK, the phase of the carrier shifts between two phases, 0 degrees and 180 degrees, representing binary 1 and 0. QPSK uses four phases, 0, 90, 180, and 270 degrees to encode pairs of bits. It was concluded that QPSK provides higher bandwidth efficiency than BPSK by transmitting twice as much data per symbol.
The document discusses various resources in an LTE network that need to be monitored to ensure capacity and quality of service. It describes several key performance indicators (KPIs) related to resources like connected users, traffic volume, paging messages, processor usage, and provides thresholds and solutions to address issues.
This document summarizes the various interfaces in a GSM network and their functions. It describes:
- The MS-BTS interface (Um interface) and its layers and protocols.
- The BTS-BSC interface (Abis interface) and its layers.
- The BSC-MSC interface (A interface) and its protocols for administration and control of radio resources.
- Other interfaces like MSC-VLR (B), MSC-HLR (C), VLR-HLR (D), MSC-MSC (E), MSC-EIR (F), VLR-VLR (G), HLR-AUC (H), and BSC-TR
The document discusses SDCCH (Standalone Dedicated Control Channel) configuration and usage in GSM networks. It describes possible SDCCH configurations including SDCCH/8 and SDCCH/4. It also discusses SDCCH holding times for different functions, reasons for SDCCH congestion, and methods to prevent congestion through proper dimensioning of SDCCH resources.
This document discusses cellular communication systems and the cellular concept. It introduces cellular networks as using multiple low-power transmitters and frequency reuse to improve spectrum efficiency and user capacity compared to single high-power transmitters. Key aspects covered include hexagonal cell shapes, frequency reuse patterns, cluster size calculations, co-channel interference management through channel assignment strategies, and an overview of the base station subsystem, network switching subsystem and their components.
This document provides guidance on optimizing the paging success rate key performance indicator (KPI) in GSM base station subsystem (BSS) networks. It defines paging success rate as the ratio of paging responses received to paging requests sent. The document outlines potential causes of low paging success rates such as hardware faults, transmission problems, parameter misconfiguration, interference, coverage issues, and uplink/downlink imbalance. It then provides detailed analysis and optimization procedures to address each cause. Case studies demonstrate how to resolve real-world paging success rate issues.
This document describes a Matlab Simulink simulation of frequency-shift keying (FSK) modulation and demodulation. The simulation implements binary FSK (BFSK) using blocks like a Bernoulli binary generator, switch, charge pump PLL, and scope. It aims to prove and easily implement BFSK modulation and demodulation on hardware. The simulation adds noise to make it more realistic. The conclusion verifies that the simulation demonstrates the phenomenon of BFSK.
The document discusses technical specifications and parameters related to LTE and UMTS networks, including:
- Typical NodeB and UE sensitivity levels range from -115dBm to -125dBm and -105dBm to -120dBm respectively.
- NodeB maximum output power is usually 20W or 40W (43dBm or 46dBm). UE maximum transmit power is typically 21dBm.
- Antenna gain depends on the antenna model but is typically around 17dBi. Maximum path loss in urban areas is 135-140dB and 150-160dB in rural areas.
- Other topics covered include Eb/No targets, channelization codes, soft handover gain
GSM is the globel system of organation . It consists of
M.S,BSC MSC ,OMC,FIXED Phone.Mobile station is carried by
the subscriber.and base station subsystem control the radio
link with mobile station . The main part of system is
mobile switching center perform switching of calls between
the mobile and fixed or mobile network use. and operational
and maintainence center oversees the proper operation and
set up of the network. The MS and BSC communicate across
the um link or air interface and BSC&MSC communicate across
A interface.
The document provides information on basic GSM principles and comparisons between TACS, GSM 900, and DCS 1800 mobile networks. It discusses topics like uplink and downlink frequencies, carrier separation, number of channels, access methods, logical channels, control channels, cell identities, and other key GSM concepts and terms. The document also includes detailed descriptions and explanations of terms like IMSI, TMSI, LAI, CGI, BSIC, SIM, and concepts like cell selection, location updating, and pin management.
System information messages contain data about the mobile network that mobile stations need to communicate with the network. There are 12 different types of system information messages that provide information like cell channel descriptions, neighboring cell information, location area identities, and parameters for random access channel control. These messages are continuously broadcast on common control channels to both idle and active mobile stations.
The document discusses drive test analysis for mobile networks. It describes the key elements of an effective drive test program including understanding network performance using call and data metrics. The drive test process involves defining test routes and clusters, collecting data, analyzing key performance indicators (KPIs) like call setup success rate and throughput, and troubleshooting issues. Defining test cases, KPIs, and categorizing failures is important for understanding genuine network problems versus measurement errors.
RRC protocols in LTE help manage radio resources and signaling between the UE and network. Key aspects include:
1. RRC defines two UE states - RRC_CONNECTED for active data transfer and RRC_IDLE for idle/paging.
2. Signaling Radio Bearers (SRBs) carry RRC and NAS messages using different logical channels.
3. System information is broadcast on common channels, informing UEs of network configurations and neighbor cells.
4. Handover between cells is supported through the X2 interface for intra-LTE handovers and inter-RAT handovers to other technologies like UMTS or GSM.
This document summarizes GSM architecture and call flows, including inter-MSC and intra-MSC call flows. Inter-MSC call flow occurs between two different MSCs, while intra-MSC call flow is between two BSCs within the same MSC. The inter-MSC call flow involves signaling between the BSC, MSC-O, MSC-T, HLR, and RNC to set up and release the call bearers. The intra-MSC call flow involves signaling between the MS-O, BSC-O, MSC/VLR, MGW, HLR, BSC-T, and MS-T to authenticate, set up, and release call bearers within a single MSC
We are going to cover complete list of VoLTE IMS KPI and performance Indicators . This includes :-
VoLTE IMS Control Plane KPI
- RSR : Registration Success Ratio (%)
- CSSR : Call Setup Success Rate (%)
- CST : Call Setup Time (s)
- MHT/ACD : Average Call duration (s)
VoLTE IMS User Plane KPI
- Mute Rate (%)
- MOS Score (1-5)
- RTP Packet Loss (%)
- One Way Calls (%)
Packet Core 4G Network LTE KPI
- Volte Attach Success Rate (%)
- VoLTE QCI=5 Paging Success Rate (%)
- Dedicated Bearer Activation Success Rate (%)
- IMS IP POOL Utilization (%)
- Create Bearer Success Rate (%)
Radio VoLTE KPI
- Call Drop rate (%)
- SRVCC Success Rate (%)
- Handover SR (%)
This document contains parameters related to 2G cell configuration for an Axis network with 2247 sites and 19 BSCs. It includes common cell data parameters like AGBLK, MFRMS, ACCMIN, INDOOR_CELL values. It also includes locating cell filter data parameters like BSPWR, BSTXPWR, MSRXMIN, BSRXMIN for path loss calculation. Finally, it contains locating urgency cell data parameters like TALIM, PSSBQ, PTIMBQ, QLIMDL for handling call quality issues. The parameters need to be optimized for Axis' coverage-limited network.
This document discusses the key elements of digital mobile communication systems like GSM. It describes the end-to-end transmission chain including speech encoding, channel encoding, interleaving, burst assembly, ciphering, modulation, and the reception chain in reverse order. It also covers predictive coding, discontinuous transmission, channel coding, interleaving techniques, security aspects like authentication and ciphering, and Gaussian minimum shift keying modulation used in GSM.
The document discusses Global System for Mobile Communication (GSM) technology. It covers various radio problems in wireless communication like fading and time dispersion. It explains how GSM solves these problems using techniques like increasing fading margin, antenna diversity, frequency hopping, and increasing carrier-to-reflection ratio. It also describes the GSM transmission process which includes speech coding, channel coding, interleaving, encryption, analog-to-digital conversion, burst formatting, and modulation for digital transmission of voice calls over the cellular network.
This document outlines the process for mobile originated and terminated calls in 3G networks. It describes the steps for a mobile originating call in 3 parts and a mobile terminated call in 3 parts, including setting up the GTP tunnel for transport. The document breaks down the end-to-end call flows for 3G connections.
This document provides parameters for radio network configuration in a Nokia wireless network. It contains over 100 parameters organized in sections for the BSC, BCF, BTS, adjacent cells, and other settings. The parameters define thresholds, timers, and options that control functions like call handling, congestion management, handover processing, and radio resource allocation. The document is intended only for Nokia customers and subject to change without notice.
This document discusses digital modulation techniques including PSK. It performed experiments in MATLAB to generate waveforms for BPSK and QPSK. For BPSK, the phase of the carrier shifts between two phases, 0 degrees and 180 degrees, representing binary 1 and 0. QPSK uses four phases, 0, 90, 180, and 270 degrees to encode pairs of bits. It was concluded that QPSK provides higher bandwidth efficiency than BPSK by transmitting twice as much data per symbol.
The document discusses various resources in an LTE network that need to be monitored to ensure capacity and quality of service. It describes several key performance indicators (KPIs) related to resources like connected users, traffic volume, paging messages, processor usage, and provides thresholds and solutions to address issues.
This document summarizes the various interfaces in a GSM network and their functions. It describes:
- The MS-BTS interface (Um interface) and its layers and protocols.
- The BTS-BSC interface (Abis interface) and its layers.
- The BSC-MSC interface (A interface) and its protocols for administration and control of radio resources.
- Other interfaces like MSC-VLR (B), MSC-HLR (C), VLR-HLR (D), MSC-MSC (E), MSC-EIR (F), VLR-VLR (G), HLR-AUC (H), and BSC-TR
The document discusses SDCCH (Standalone Dedicated Control Channel) configuration and usage in GSM networks. It describes possible SDCCH configurations including SDCCH/8 and SDCCH/4. It also discusses SDCCH holding times for different functions, reasons for SDCCH congestion, and methods to prevent congestion through proper dimensioning of SDCCH resources.
This document discusses cellular communication systems and the cellular concept. It introduces cellular networks as using multiple low-power transmitters and frequency reuse to improve spectrum efficiency and user capacity compared to single high-power transmitters. Key aspects covered include hexagonal cell shapes, frequency reuse patterns, cluster size calculations, co-channel interference management through channel assignment strategies, and an overview of the base station subsystem, network switching subsystem and their components.
This document provides guidance on optimizing the paging success rate key performance indicator (KPI) in GSM base station subsystem (BSS) networks. It defines paging success rate as the ratio of paging responses received to paging requests sent. The document outlines potential causes of low paging success rates such as hardware faults, transmission problems, parameter misconfiguration, interference, coverage issues, and uplink/downlink imbalance. It then provides detailed analysis and optimization procedures to address each cause. Case studies demonstrate how to resolve real-world paging success rate issues.
This document describes a Matlab Simulink simulation of frequency-shift keying (FSK) modulation and demodulation. The simulation implements binary FSK (BFSK) using blocks like a Bernoulli binary generator, switch, charge pump PLL, and scope. It aims to prove and easily implement BFSK modulation and demodulation on hardware. The simulation adds noise to make it more realistic. The conclusion verifies that the simulation demonstrates the phenomenon of BFSK.
The document discusses technical specifications and parameters related to LTE and UMTS networks, including:
- Typical NodeB and UE sensitivity levels range from -115dBm to -125dBm and -105dBm to -120dBm respectively.
- NodeB maximum output power is usually 20W or 40W (43dBm or 46dBm). UE maximum transmit power is typically 21dBm.
- Antenna gain depends on the antenna model but is typically around 17dBi. Maximum path loss in urban areas is 135-140dB and 150-160dB in rural areas.
- Other topics covered include Eb/No targets, channelization codes, soft handover gain
GSM is the globel system of organation . It consists of
M.S,BSC MSC ,OMC,FIXED Phone.Mobile station is carried by
the subscriber.and base station subsystem control the radio
link with mobile station . The main part of system is
mobile switching center perform switching of calls between
the mobile and fixed or mobile network use. and operational
and maintainence center oversees the proper operation and
set up of the network. The MS and BSC communicate across
the um link or air interface and BSC&MSC communicate across
A interface.
The document provides information on basic GSM principles and comparisons between TACS, GSM 900, and DCS 1800 mobile networks. It discusses topics like uplink and downlink frequencies, carrier separation, number of channels, access methods, logical channels, control channels, cell identities, and other key GSM concepts and terms. The document also includes detailed descriptions and explanations of terms like IMSI, TMSI, LAI, CGI, BSIC, SIM, and concepts like cell selection, location updating, and pin management.
System information messages contain data about the mobile network that mobile stations need to communicate with the network. There are 12 different types of system information messages that provide information like cell channel descriptions, neighboring cell information, location area identities, and parameters for random access channel control. These messages are continuously broadcast on common control channels to both idle and active mobile stations.
The document discusses drive test analysis for mobile networks. It describes the key elements of an effective drive test program including understanding network performance using call and data metrics. The drive test process involves defining test routes and clusters, collecting data, analyzing key performance indicators (KPIs) like call setup success rate and throughput, and troubleshooting issues. Defining test cases, KPIs, and categorizing failures is important for understanding genuine network problems versus measurement errors.
RRC protocols in LTE help manage radio resources and signaling between the UE and network. Key aspects include:
1. RRC defines two UE states - RRC_CONNECTED for active data transfer and RRC_IDLE for idle/paging.
2. Signaling Radio Bearers (SRBs) carry RRC and NAS messages using different logical channels.
3. System information is broadcast on common channels, informing UEs of network configurations and neighbor cells.
4. Handover between cells is supported through the X2 interface for intra-LTE handovers and inter-RAT handovers to other technologies like UMTS or GSM.
This document summarizes GSM architecture and call flows, including inter-MSC and intra-MSC call flows. Inter-MSC call flow occurs between two different MSCs, while intra-MSC call flow is between two BSCs within the same MSC. The inter-MSC call flow involves signaling between the BSC, MSC-O, MSC-T, HLR, and RNC to set up and release the call bearers. The intra-MSC call flow involves signaling between the MS-O, BSC-O, MSC/VLR, MGW, HLR, BSC-T, and MS-T to authenticate, set up, and release call bearers within a single MSC
We are going to cover complete list of VoLTE IMS KPI and performance Indicators . This includes :-
VoLTE IMS Control Plane KPI
- RSR : Registration Success Ratio (%)
- CSSR : Call Setup Success Rate (%)
- CST : Call Setup Time (s)
- MHT/ACD : Average Call duration (s)
VoLTE IMS User Plane KPI
- Mute Rate (%)
- MOS Score (1-5)
- RTP Packet Loss (%)
- One Way Calls (%)
Packet Core 4G Network LTE KPI
- Volte Attach Success Rate (%)
- VoLTE QCI=5 Paging Success Rate (%)
- Dedicated Bearer Activation Success Rate (%)
- IMS IP POOL Utilization (%)
- Create Bearer Success Rate (%)
Radio VoLTE KPI
- Call Drop rate (%)
- SRVCC Success Rate (%)
- Handover SR (%)
This document contains parameters related to 2G cell configuration for an Axis network with 2247 sites and 19 BSCs. It includes common cell data parameters like AGBLK, MFRMS, ACCMIN, INDOOR_CELL values. It also includes locating cell filter data parameters like BSPWR, BSTXPWR, MSRXMIN, BSRXMIN for path loss calculation. Finally, it contains locating urgency cell data parameters like TALIM, PSSBQ, PTIMBQ, QLIMDL for handling call quality issues. The parameters need to be optimized for Axis' coverage-limited network.
This document discusses the key elements of digital mobile communication systems like GSM. It describes the end-to-end transmission chain including speech encoding, channel encoding, interleaving, burst assembly, ciphering, modulation, and the reception chain in reverse order. It also covers predictive coding, discontinuous transmission, channel coding, interleaving techniques, security aspects like authentication and ciphering, and Gaussian minimum shift keying modulation used in GSM.
The document discusses Global System for Mobile Communication (GSM) technology. It covers various radio problems in wireless communication like fading and time dispersion. It explains how GSM solves these problems using techniques like increasing fading margin, antenna diversity, frequency hopping, and increasing carrier-to-reflection ratio. It also describes the GSM transmission process which includes speech coding, channel coding, interleaving, encryption, analog-to-digital conversion, burst formatting, and modulation for digital transmission of voice calls over the cellular network.
The document summarizes research on multiple description coding for audio and speech to provide redundancy and improve quality over lossy networks. It describes a multiple description speech coder based on the AMR-WB standard that splits bits between two descriptions. It also discusses applying multiple description correlating transforms to perceptual audio coding to achieve better quality than a single description when packets are lost. The research was evaluated using simulations and subjective listening tests.
Overview of VoIP (Voice over IP) and FoIP (Fax over IP) technologies like Session Initiation Protocol and H.323.
Even though voice over IP (VoIP) was hailed as a technological innovation, the idea to transport real-time traffic over TCP/IP networks was not new back in the 1990s when VoIP started being deployed in networks. Chapter 2.5 of the venerable RFC793 (TCP) shows both data oriented application traffic as well as voice being transported over IP based networks.
Nevertheless, VoIP puts high demands on signal and protocol processing capabilities so it became possible at reasonable costs only in the 1990s.
VoIP can be roughly split into two main functions. Signaling protocols like SIP (Session Initiation Protocol), H.323 and MGCP/H.248 are used to establish a conference session and the data path for transporting real-time voice data packets. SIP has largely supplanted H.323 in recent years to its simpler structure and packet sequences. MGCP and H.248 are mostly used in carrier backbone networks.
Protocols like RTP (Real Time Protocol) transport voice packets and provide the necessary information for receivers to equalize packet flow variations to provide a smooth playback of the original voice signal.
Voice codecs are one of the core functions of the data path. Voice compression reduces the bandwidth required to transport voice over an IP based network. Compression may be less of a concern in local area networks with gigabit speeds, on slower links like 3G (UMTS, LTE) it still makes a lot of sense.
The algorithms used in different codecs make use of various characteristics of the characteristics of human speech recognition. Redundant information is removed from the signals thus slightly reducing the quality, but greatly reducing the required bandwidth.
In VoIP networks, the echo problem is typically compounded by the increased delay incurred by packetization of voice signals. To counteract the echo problem, VoIP gear (hard phones, soft phones, gateways) include echo cancelers to remove echo signals from the transmit signal.
To transport facsimile over an IP based network, even more technology is needed. Facsimile protocols are very susceptible to delay and delay variation and thus need more compensation algorithms. Protocols like T.38 terminate facsimile protocols like T.30 (analog facsimile) and transport the fax images as digitized pictures over IP based networks.
This document provides an overview of digital communication systems and Integrated Services Digital Network (ISDN). It discusses digitization of analog signals, digital transmission systems, advantages and disadvantages of digital communication, classification of digital communication systems, and an introduction to ISDN including its principles, services, and protocol reference model. The key aspects covered are sampling, quantization, coding techniques like PCM, multiplexing, protocols like LAPD used in ISDN, and basic and supplementary services supported on ISDN networks.
This document provides information about voice interfaces, including FXO/FXS and E&M interfaces. It discusses the signaling and voice paths for these interfaces, common signaling types and protocols, and coding standards like PCM. FXO and FXS interfaces connect to phone systems, while E&M interfaces use separate paths for voice and signaling and support ground start and various supervisory signaling types. The document also covers related topics like coding methods, CAS signaling, and E&M configuration on the QX3440 card.
The document describes the key steps in the GSM transmission process:
1. Analog to digital conversion involves sampling, quantization, and coding the analog speech signal into digital bits.
2. Speech coding further compresses the digital signal from 13 kbps to 13 kbps using encoding techniques.
3. Channel coding and interleaving are then applied to add error correction and protection against transmission errors before modulation and transmission over the air interface.
This document provides an overview of PCM communication systems, specifically focusing on E1 and T1 systems. It describes key characteristics of E1 and T1 including sampling frequency, number of samples per signal, PCM frame length, number of bits per code word, number of timeslots per frame, encoding methods, and bit rates. The document then discusses components of the PCM signal including sampling, quantization, encoding, framing, framing signals, signalling, cyclic redundancy checks, alarms, line codes, and interfaces. It provides information on the building blocks of modern digital communication networks.
The document provides information about baseband transmission in digital communication. It discusses various concepts related to baseband transmission including: pulse code modulation (PCM) systems, source encoding, sampling, quantization, channel encoding, digital modulation, and line coding techniques such as NRZ and RZ. The key steps in baseband transmission are described as: converting the analog signal to digital using sampling and quantization, encoding the digital signal, modulating the encoded digital signal to transmit over the channel, and demodulating and decoding at the receiver to reconstruct the original analog signal.
Base band transmission
*Wave form representation of binary digits
*PCM, DPCM, DM, ADM systems
*Detection of signals in Gaussian noise
*Matched filter - Application of matched filter
*Error probability performance of binary signaling
*Multilevel base band transmission
*Inter symbol interference
*Eye pattern
*Companding
*A law and μ law
*Correlation receiver
The document discusses digital transmission fundamentals, including:
- Digital representation of analog signals involves sampling, quantization, and pulse code modulation.
- The sampling rate must be at least twice the bandwidth of the signal to allow perfect reconstruction.
- Quantization maps samples to discrete levels, introducing quantization error. More levels reduce error but increase transmission bandwidth needs.
- Digital transmission enables long distance communication by regeneration of the digital signal rather than analog amplification, overcoming distance limitations of analog systems.
Global System for Mobile (GSM) is a 2G digital cellular network standard. It uses Time Division Multiple Access (TDMA) and Frequency Division Duplexing (FDD) on radio carriers divided into 200 kHz channels. Each carrier can carry 8 voice channels using time division. GSM introduced digital voice coding, encryption, authentication and roaming between networks. Its architecture includes the Mobile Station (MS), Base Transceiver Station (BTS), Base Station Controller (BSC) and Mobile Switching Center (MSC) connected via standardized interfaces. GSM also uses frequency hopping and has various logical channels for control and traffic.
The document discusses UMTS planning and dimensioning processes. It describes:
1) The overall planning process which includes system dimensioning, radio network planning, pre-launch optimization, performance monitoring, and post-launch optimization.
2) The inputs, assumptions, and steps used for air interface dimensioning which includes uplink and downlink link budget analysis to determine coverage requirements and capacity needs.
3) Traffic modelling and load calculation methods to estimate subscriber traffic per cell based on factors like subscriber density, traffic profiles, and cell area.
40Gb/s Bidi QSFP+ Transceiver Hot Pluggable, Duplex LC, +3.3V, 850/900nm, 100...Allen He
SHQP-40G-SR-BD is a Four-Channel QSFP+ package optical transceiver for 40 Gigabit Ethernet Applications. It
multiplexes internally an XLPPI 4x10G interface into two 20Gb/s electrical channels, transmitting and receiving data at
850 and 900nm wavelength, up to the distance of 100m on OM3 / 150m on OM4. It is a high performance module for
short-range duplex data communication and interconnection applications.
Features:
Four lane aggregated bandwidth up to 40Gbps
10.3125 Gbps per electrical channel with 64b/66b encoded data
Hot-pluggable
Duplex LC
100m on OM3 / 150m on OM4
Compliant with QSFP+ SFF-8436 Specification
Compliant with QSFP MSA
Compliant witch 40GbE XLPPI electrical specification per IEEE 802.3ba-2010
Built-in digital diagnostic functions
Power Supply :+3.3V
Power consumption: <3.5W
Temperature Range: 0~ 70°C
RoHS Compliant
Applications:
40GBASE Ethernet
Fiber channel
Data center
This document provides an overview of Code Division Multiple Access (CDMA) technology, including its implementation, network architecture, concepts, cell structure, and voice paths. Key aspects covered include how CDMA uses direct sequence spreading to allow frequency reuse, its use of Walsh codes and long codes to channelize signals, soft handoff capabilities, and forward and reverse voice paths involving vocoding, error correction, and power control. The document is intended to explain the basic workings and advantages of CDMA wireless networks to readers.
The document discusses various digital communication techniques including linear vs nonlinear PCM encoding, idle channel noise reduction methods, coding methods like level-at-a-time, digit-at-a-time and word-at-a-time. It also discusses analog companding using A-law and μ-law, digital companding, vocoders, delta modulation, DPCM, intersymbol interference causes and eye patterns.
In this presentation, production of digital audio is discussed. Also brief introduction about digital audio broadcast, recording techniques and stereo phony is given.
The document provides an overview of SCADA (Supervisory Control and Data Acquisition) systems used in power system management. It discusses:
1) SCADA allows remote monitoring and control of equipment by collecting data from devices in the field and presenting it for user-friendly monitoring and analysis.
2) In power systems, SCADA is used to monitor generation stations, substations, transmission lines to efficiently manage the system.
3) Key components include RTUs (Remote Terminal Units) that interface with field devices to collect data, communication networks to transmit data to control centers, and HMI software for operators.
This document provides specification sheets for three models of the Motorola ASTRO XTS 5000 Digital Portable Radio. Model I is the basic radio with no display or keypad and 16/48 channels. Model II adds a full bitmap display, 1000 channels, and programmable soft keys. Model III is the same as Model II but also includes a 4x3 keypad. The radios are designed for public safety professionals and offer features such as digital encryption, GPS compatibility, and ruggedized housing options. They are available in VHF, UHF, and 700/800 MHz frequency bands.
This document discusses various audio compression techniques including:
1. Differential Pulse Code Modulation (DPCM) which encodes differences between samples to reduce bitrate.
2. Third-order predictive DPCM which uses predictions of past 3 samples to improve accuracy over DPCM.
3. Adaptive Differential PCM (ADPCM) which varies the number of bits used based on signal amplitude.
It then covers more advanced techniques like Linear Predictive Coding (LPC) which analyzes perceptual features of audio to further reduce bitrates.
Design and optimization of ion propulsion dronebjmsejournal
Electric propulsion technology is widely used in many kinds of vehicles in recent years, and aircrafts are no exception. Technically, UAVs are electrically propelled but tend to produce a significant amount of noise and vibrations. Ion propulsion technology for drones is a potential solution to this problem. Ion propulsion technology is proven to be feasible in the earth’s atmosphere. The study presented in this article shows the design of EHD thrusters and power supply for ion propulsion drones along with performance optimization of high-voltage power supply for endurance in earth’s atmosphere.
Build the Next Generation of Apps with the Einstein 1 Platform.
Rejoignez Philippe Ozil pour une session de workshops qui vous guidera à travers les détails de la plateforme Einstein 1, l'importance des données pour la création d'applications d'intelligence artificielle et les différents outils et technologies que Salesforce propose pour vous apporter tous les bénéfices de l'IA.
Software Engineering and Project Management - Software Testing + Agile Method...Prakhyath Rai
Software Testing: A Strategic Approach to Software Testing, Strategic Issues, Test Strategies for Conventional Software, Test Strategies for Object -Oriented Software, Validation Testing, System Testing, The Art of Debugging.
Agile Methodology: Before Agile – Waterfall, Agile Development.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Digital Twins Computer Networking Paper Presentation.pptxaryanpankaj78
A Digital Twin in computer networking is a virtual representation of a physical network, used to simulate, analyze, and optimize network performance and reliability. It leverages real-time data to enhance network management, predict issues, and improve decision-making processes.
Discover the latest insights on Data Driven Maintenance with our comprehensive webinar presentation. Learn about traditional maintenance challenges, the right approach to utilizing data, and the benefits of adopting a Data Driven Maintenance strategy. Explore real-world examples, industry best practices, and innovative solutions like FMECA and the D3M model. This presentation, led by expert Jules Oudmans, is essential for asset owners looking to optimize their maintenance processes and leverage digital technologies for improved efficiency and performance. Download now to stay ahead in the evolving maintenance landscape.
Use PyCharm for remote debugging of WSL on a Windo cf5c162d672e4e58b4dde5d797...shadow0702a
This document serves as a comprehensive step-by-step guide on how to effectively use PyCharm for remote debugging of the Windows Subsystem for Linux (WSL) on a local Windows machine. It meticulously outlines several critical steps in the process, starting with the crucial task of enabling permissions, followed by the installation and configuration of WSL.
The guide then proceeds to explain how to set up the SSH service within the WSL environment, an integral part of the process. Alongside this, it also provides detailed instructions on how to modify the inbound rules of the Windows firewall to facilitate the process, ensuring that there are no connectivity issues that could potentially hinder the debugging process.
The document further emphasizes on the importance of checking the connection between the Windows and WSL environments, providing instructions on how to ensure that the connection is optimal and ready for remote debugging.
It also offers an in-depth guide on how to configure the WSL interpreter and files within the PyCharm environment. This is essential for ensuring that the debugging process is set up correctly and that the program can be run effectively within the WSL terminal.
Additionally, the document provides guidance on how to set up breakpoints for debugging, a fundamental aspect of the debugging process which allows the developer to stop the execution of their code at certain points and inspect their program at those stages.
Finally, the document concludes by providing a link to a reference blog. This blog offers additional information and guidance on configuring the remote Python interpreter in PyCharm, providing the reader with a well-rounded understanding of the process.
Applications of artificial Intelligence in Mechanical Engineering.pdfAtif Razi
Historically, mechanical engineering has relied heavily on human expertise and empirical methods to solve complex problems. With the introduction of computer-aided design (CAD) and finite element analysis (FEA), the field took its first steps towards digitization. These tools allowed engineers to simulate and analyze mechanical systems with greater accuracy and efficiency. However, the sheer volume of data generated by modern engineering systems and the increasing complexity of these systems have necessitated more advanced analytical tools, paving the way for AI.
AI offers the capability to process vast amounts of data, identify patterns, and make predictions with a level of speed and accuracy unattainable by traditional methods. This has profound implications for mechanical engineering, enabling more efficient design processes, predictive maintenance strategies, and optimized manufacturing operations. AI-driven tools can learn from historical data, adapt to new information, and continuously improve their performance, making them invaluable in tackling the multifaceted challenges of modern mechanical engineering.
Software Engineering and Project Management - Introduction, Modeling Concepts...Prakhyath Rai
Introduction, Modeling Concepts and Class Modeling: What is Object orientation? What is OO development? OO Themes; Evidence for usefulness of OO development; OO modeling history. Modeling
as Design technique: Modeling, abstraction, The Three models. Class Modeling: Object and Class Concept, Link and associations concepts, Generalization and Inheritance, A sample class model, Navigation of class models, and UML diagrams
Building the Analysis Models: Requirement Analysis, Analysis Model Approaches, Data modeling Concepts, Object Oriented Analysis, Scenario-Based Modeling, Flow-Oriented Modeling, class Based Modeling, Creating a Behavioral Model.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
4. GSM Transmission Chain (MSC IC BMC):
Speech
Encoder
Channel
Encoder
Interleaver
Ciphering
Burst Assembling
& Multiplexing
Modulator
13 Kbps
22.8 Kbps
22.8 Kbps
22.8 Kbps
33.85 Kbps
Channel
Microphone
Digital
Speech
Signal
Analog
Electrical
Speech
Signal
Acoustic
Signal
5. GSM Coding:
speech coding must give :
1. Low bit rate
2. Preserving the essential elements of speech quality
3. An acceptable cost of the equipment
GSM sends information about speech not the speech itself
25. Authentication Center (AUC):
It is a processor system that performs the authentication function
RAND
Database
IMSI, KI
𝑨 𝟑 𝑨 𝟖
RAND SRES 𝑲 𝒄
Triplet
Triplet
Request for
Triplet from
HLR, VLR
IMSI
Ki
AUC
32. Interleaving:
second level: Burst interleaving
Normal Burst has 2 of 57b blocks
If Burst is lost 𝑩𝑬𝑹 = 𝟐𝟓%
To reduce it to 12.5% we put 2 blocks of two 20 msec
20 msec speech
8x57=456 bits
20 msec speech
8x57=456 bits
20 msec speech
8x57=456 bits
57 data bits 57 data bits57 data bits