The 3GPP evolution for the 3G mobile system created the new base station system, called Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) and a new core network, called Evolved Packet Core (EPC) as a result of two standardisation projects: Long Term Evolution (LTE) and System Architecture Evolution (SAE). Under these specifications a mobile phone gets access to higher bandwidth with low latency in an improved and more efficient network architecture. The standards define an all-IP network as a base for the E-UTRAN/EPC. The E-UTRAN/EPC does not have a separate PS data traffic and CS voice network, both communicate over the same new Evolved Packet System (EPS) network. LTE/EPS Technology course is an intermediate technical course, which covers all aspects of architecture and functionality of the EPS.
“Signalling in GSM BSS” course focuses on signalling between GSM nodes within Base Station
System (BSS). During the course all protocols and signalling procedures on all interfaces within BSS
are presented in details. The organisation of channels of air interface and cell parameters is also
widely covered in the course. The course also describes parts of the Signalling System No. 7 that are
relevant for BSS and presents co-operation between Core Network and BSS during procedures like
call set-up and location update.
This document analyzes the effects of carrier frequency offset (CFO) and fading branch correlation (FBC) on the performance of an asynchronous multi-carrier coded-division multiple-access (MC-CDMA) system. It establishes models for an MC-CDMA system with transmitter and receiver, and examines how CFO and FBC impact the bit error rate (BER) performance. Equations are derived relating CFO and FBC, and simulation results are presented showing which parameter, CFO or FBC, has a greater influence on system performance.
Combining SFBC_OFDM Systems with SVD Assisted Multiuser Transmitter and Multi...IOSR Journals
Abstract: In this work, we exploit the SVD assisted multiuser transmitter (MUT) and multiuser detector (MUD) technique, using downlink (DL) preprocessing transmitter and DL postprocessing receiver matrice .In combination with space frequency block coding (SFBC). And also propose the precoded DL transmission scheme, were the both proposed schemes take advantage of the channel state information (CSI) of all users at the base station (BS), but only of the mobile station (MS)’s own CSI, to decompose the MU MIMO channels into parallel single input single output (SISO), these two proposed schemes are compared to the vertical layered space time (V_BLAST) combined with SFBC (SFBC_VBLAST). Our Simulation results show that the performance of the proposed scheme with DL Zero Forcing (ZF) transmitter for interference canceller outperforms the SFBC_VBLAST and the precoded DL schemes with ZF receiver in frequency selective fading channels. Keywords – Post processing, Preprocessing,, SFBC, SVD, ZF.
This document discusses a mini-fiber node (mFN) technology for upgrading cable networks to support two-way broadband services in a more cost-effective way than traditional approaches. The mFN architecture uses low-cost fiber optic nodes connected to small sections of the existing coaxial cable network to provide clean bandwidth and simplify medium access control protocols. Local contention resolution at each mFN improves efficiency and quality of service support compared to existing centralized standards. The mFN approach provides abundant high-speed bandwidth while radically simplifying service provisioning and enabling standard-compatible MAC protocols for mixed asynchronous and synchronous transmission.
This document summarizes an article that proposes adaptive error concealment algorithms for 3D multi-view video transmitted over noisy channels. It proposes adaptive algorithms for intra-frames and inter-frames that adapt to the motion characteristics and error patterns. For intra-frames, it proposes adaptive time domain, space domain, and hybrid algorithms. For inter-frames, it proposes adaptive inter-view, time domain, and joint time and inter-view algorithms. The algorithms aim to improve video quality by exploiting correlations between frames, views, and domains. Simulation results showed the adaptive algorithms can significantly improve objective and subjective video quality compared to previous methods.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
1) The document describes the implementation of a high performance carry save adder using domino logic. Domino logic reduces power consumption and improves speed compared to static logic.
2) A carry save adder is designed using two full adders in domino logic by changing the transistor states. This reduces the number of transistors needed.
3) Performance analysis shows that a multiplier using a carry save adder has lower delay and power consumption than one using a carry propagate adder.
Report AdvancedCodingFinal - Pietro SantoroPietro Santoro
The document provides a summary of a student's laboratory sessions on advanced wireless communications. It includes:
1) Implementation of a C++ class for a sliding window soft-input soft-output decoder with binary log-likelihood ratios as input and output.
2) Simulation of a binary convolutional coded system using the SISO decoder, 2-PAM modulation over an AWGN channel. Bit error rates are computed at the input and output of the SISO decoder.
3) Comments on the SISO decoder class and simulation results for convolutional codes with rates of 1/2, 1/4, and 1/8, reporting the four bit error rates versus Eb/N0.
“Signalling in GSM BSS” course focuses on signalling between GSM nodes within Base Station
System (BSS). During the course all protocols and signalling procedures on all interfaces within BSS
are presented in details. The organisation of channels of air interface and cell parameters is also
widely covered in the course. The course also describes parts of the Signalling System No. 7 that are
relevant for BSS and presents co-operation between Core Network and BSS during procedures like
call set-up and location update.
This document analyzes the effects of carrier frequency offset (CFO) and fading branch correlation (FBC) on the performance of an asynchronous multi-carrier coded-division multiple-access (MC-CDMA) system. It establishes models for an MC-CDMA system with transmitter and receiver, and examines how CFO and FBC impact the bit error rate (BER) performance. Equations are derived relating CFO and FBC, and simulation results are presented showing which parameter, CFO or FBC, has a greater influence on system performance.
Combining SFBC_OFDM Systems with SVD Assisted Multiuser Transmitter and Multi...IOSR Journals
Abstract: In this work, we exploit the SVD assisted multiuser transmitter (MUT) and multiuser detector (MUD) technique, using downlink (DL) preprocessing transmitter and DL postprocessing receiver matrice .In combination with space frequency block coding (SFBC). And also propose the precoded DL transmission scheme, were the both proposed schemes take advantage of the channel state information (CSI) of all users at the base station (BS), but only of the mobile station (MS)’s own CSI, to decompose the MU MIMO channels into parallel single input single output (SISO), these two proposed schemes are compared to the vertical layered space time (V_BLAST) combined with SFBC (SFBC_VBLAST). Our Simulation results show that the performance of the proposed scheme with DL Zero Forcing (ZF) transmitter for interference canceller outperforms the SFBC_VBLAST and the precoded DL schemes with ZF receiver in frequency selective fading channels. Keywords – Post processing, Preprocessing,, SFBC, SVD, ZF.
This document discusses a mini-fiber node (mFN) technology for upgrading cable networks to support two-way broadband services in a more cost-effective way than traditional approaches. The mFN architecture uses low-cost fiber optic nodes connected to small sections of the existing coaxial cable network to provide clean bandwidth and simplify medium access control protocols. Local contention resolution at each mFN improves efficiency and quality of service support compared to existing centralized standards. The mFN approach provides abundant high-speed bandwidth while radically simplifying service provisioning and enabling standard-compatible MAC protocols for mixed asynchronous and synchronous transmission.
This document summarizes an article that proposes adaptive error concealment algorithms for 3D multi-view video transmitted over noisy channels. It proposes adaptive algorithms for intra-frames and inter-frames that adapt to the motion characteristics and error patterns. For intra-frames, it proposes adaptive time domain, space domain, and hybrid algorithms. For inter-frames, it proposes adaptive inter-view, time domain, and joint time and inter-view algorithms. The algorithms aim to improve video quality by exploiting correlations between frames, views, and domains. Simulation results showed the adaptive algorithms can significantly improve objective and subjective video quality compared to previous methods.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
1) The document describes the implementation of a high performance carry save adder using domino logic. Domino logic reduces power consumption and improves speed compared to static logic.
2) A carry save adder is designed using two full adders in domino logic by changing the transistor states. This reduces the number of transistors needed.
3) Performance analysis shows that a multiplier using a carry save adder has lower delay and power consumption than one using a carry propagate adder.
Report AdvancedCodingFinal - Pietro SantoroPietro Santoro
The document provides a summary of a student's laboratory sessions on advanced wireless communications. It includes:
1) Implementation of a C++ class for a sliding window soft-input soft-output decoder with binary log-likelihood ratios as input and output.
2) Simulation of a binary convolutional coded system using the SISO decoder, 2-PAM modulation over an AWGN channel. Bit error rates are computed at the input and output of the SISO decoder.
3) Comments on the SISO decoder class and simulation results for convolutional codes with rates of 1/2, 1/4, and 1/8, reporting the four bit error rates versus Eb/N0.
Designing of a AMBA-AHB Multilayer Bus matrix Self-Motivated Arbitration schemeIOSR Journals
Abstract: The AMBA-AHB Multilayer Bus matrix Self-Motivated Arbitration scheme proposed three methods for data transmiting from master to slave for on chip communication. Multilayer advanced high-performance bus (ML-AHB) busmatrix employs slave-side arbitration. Slave-side arbitration is different from master-side arbitration in terms of request and grant signals since, in the former, the master merely starts a burst transaction and waits for the slave response to proceed to the next transfer. Therefore, in the former, the unit of arbitration can be a transaction or a transfer. However, the ML-AHB busmatrix of ARM offers only transfer-based fixed-pri-ority and round-robin arbitration schemes. In this paper, we propose the design and implementation of a flexible arbiter for the ML-AHB busmatrix to support three priority policies fixed priority, round robin, and dynamic priority and three data multiplexing modes transfer, transaction, and desired transfer length. In total, there are nine possible arbitration schemes. The proposed arbiter, which is self-motivated (SM), selects one of the nine possible arbitration schemes based upon the priority-level notifications and the desired transfer length from the masters so that arbitration leads to the maximum performance. Experimental results show that, although the area overhead of the proposed SM arbitration scheme is 9%–25% larger than those of the other arbitration schemes, our arbiter improves the throughput by 14%–62% compared to other schemes.
Load balancing In Wireless Mesh Networks Using liquid–Simulated AlgorithmIJSRED
The document proposes a hierarchical routing framework and liquid-simulated algorithm for load balancing in wireless mesh networks. Key points:
- The framework forms clusters with wireless mesh routers (WMRs) as cluster heads and simplifies clustering procedures. It uses limited topology broadcasting to allow WMRs to choose best paths between adjacent clusters.
- The liquid-simulated algorithm aims to keep load balanced between WMRs by treating load as a liquid level and allowing flows between nodes to equalize levels across the network.
- The framework uses a proactive routing approach within this load balancing algorithm, with topology broadcasting constrained within clusters and adjacent clusters to reduce overhead.
Building impedance matching network based on s parameter from manufacturerJournal Papers
The document describes a method for building an impedance matching network for a transistor using S-parameter data and optimization tools in ADS simulation software. The transistor of interest operates from 220-270 MHz, where reference designs are unavailable. Input and output impedances are extracted from S-parameter files. An existing matching network design at a nearby frequency is used as a starting point. Optimization replaces ideal components with real ones, achieving over 30 dB return loss while degrading slightly from the ideal simulation. The method demonstrates synthesizing a matching network when reference designs are unavailable.
The document proposes a load-aware routing scheme for wireless mesh networks to balance traffic load and enhance network capacity. It divides the network into clusters, with each cluster head estimating traffic load and increasing routing metrics for overloaded links. This causes users to route around overloaded areas, achieving overall load balancing in a distributed manner. Simulation results show the proposed scheme outperforms routing using expected transmission time as a metric.
The efficient interleaving of digital-video-broadcasting-satellite 2nd genera...TELKOMNIKA JOURNAL
The DVB-S2 system is designed as a toolbox to permit the execution of the satellite programs. Interleaver is an essential part of the DVB-S2 system. The current general block interleaver in DVB-S2 is not best, which leads to high BER and maybe not satisfy the requirements of the system. The purpose of this paper is to study the several interleaver types and comparative analyses are done between them to find which of these give better performance. Simulations results obtained prove that the 2D interleavers minimize BER more than other interleavers of DVB-S2. Further, the performance of 2D interleaver is better on a system that required a low SNR.
Multi-Criterion Decision Making and Adaptation for Multi-path Video Streaming...Eswar Publications
It is suggested that multi-path routing is advantageous for applications with high traffic data characteristics, especially in the WSN environment. Sensor networks which transmit video will have to respond to the high data characteristic inherent in video data. Throughput, delay and packet loss are important metrics when considering video traffic. This work measures the performance of four multi-path routing protocols, MAOMDV, AOMDV, AntHocNet and MP-DSR in the WSN environment. It is shown that MAOMDV outperforms the other multi-path routing protocols in terms of the aforementioned metrics.
A circuit-switched network consists of switches connected by physical links, where each link is divided into channels. A connection uses a dedicated path and channel. In circuit switching, resources are reserved during setup and remain dedicated until teardown. In a packet-switched network, packets are sent without resource reservation and resources are allocated on demand. A virtual-circuit network has characteristics of both, where packets traveling between the same source and destination follow the same dedicated path but resources are allocated on demand.
PERFORMANCE COMPARISON DCM VERSUS QPSK FOR HIGH DATA RATES IN THE MBOFDM UWB ...csandit
This document compares the performance of dual carrier modulation (DCM) versus quadrature phase shift keying (QPSK) for high data rates in a multiband orthogonal frequency division multiplexing (MB-OFDM) ultra wideband (UWB) system. Simulation results show that using DCM provides better performance than QPSK, with a gain of around 0.7 dB for a bit error rate of 10-3 at 320 Mbps data rates. DCM offers additional diversity and coding gains over QPSK, making it more efficient for high data transmission rates in MBOFDM UWB systems.
This document summarizes the simulation steps for investigating the performance of three multi-carrier code division multiple access (MC-CDMA) techniques: conventional MC-CDMA, orthogonal wavelet packet based MC-CDMA (WP-MC-CDMA), and Huang Hilbert Transformation (HHT) based MC-CDMA. The steps include designing the three systems, simulating them with different modulation techniques under fading channels, and comparing their bit error rate performance. Numerical and simulation results are presented to validate the proposed schemes.
This document summarizes the simulation steps for investigating the performance of three multi-carrier code division multiple access (MC-CDMA) techniques: conventional MC-CDMA, orthogonal wavelet packet based MC-CDMA (WP-MC-CDMA), and Huang Hilbert Transformation (HHT) based MC-CDMA. The steps include designing the three systems, simulating them with different modulation techniques under fading channels, and comparing their bit error rate performance. Numerical and simulation results are presented to validate the proposed schemes.
Heterogeneous LTE Networks and Inter-Cell Interference Coordination - Dec 201...Eiko Seidel
This document discusses heterogeneous LTE networks and inter-cell interference coordination (ICIC). It begins by explaining that initial LTE networks consisted of homogeneous macro cell deployments but that heterogeneous networks using smaller pico and femto cells are now being implemented to improve capacity and coverage. This introduces new interference challenges. The document then outlines various ICIC methods like frequency reuse and power control techniques that can help mitigate interference. It provides simulation results showing the benefits of heterogeneous networks and techniques like range expansion.
The document discusses Variable Coding and Modulation (VCM) tuners for satellite receivers. VCM allows a transponder to transmit multiple transport streams, with each stream able to use different error correction coding rates. This provides flexibility to prioritize streams, such as transmitting premium HD channels with weaker error correction only in the center of the satellite footprint. A VCM tuner can receive these signals by determining the coding rates of each stream. The tuner's architecture is similar to conventional tuners but includes additional components to process the multiple streams and their varying coding rates transmitted by VCM.
The document discusses Variable Coding and Modulation (VCM) in DVB-S2 satellite transmissions. VCM allows a single transponder to transmit multiple transport streams, with each stream using a different modulation type and forward error correction rate. This makes it possible to provide stronger error correction for basic channels while using weaker correction for premium channels. A VCM-compatible tuner can determine the coding rates being used and properly demodulate the different streams. This provides more flexible use of satellite bandwidth than conventional systems with a single coding scheme per transponder.
The document provides an overview of Huawei's Core-CS Network and the evolution of WCDMA networks from Release 99 to Release 5. It discusses key aspects of MSC pool networks including improved resource utilization, enhanced network reliability, and reduced signaling traffic. It also covers AOIP and AOTDM, noting that AOIP allows for end-to-end Transcoder Free Operation and uses lower-cost IP networks for transmission on the A interface user plane.
This document presents a study on using IP multicasting over DVB-T/H and e-MBMS networks. Seven different distribution schemes are designed and analyzed: unicasting over MFN, broadcasting over MFN, IP multicasting over MFN, broadcasting over SFN, IP multicasting over CT-DSFN, IP multicasting over non-SFN DCA, and IP multicasting over NCT-DSFN. The results show that IP multicasting provides better spectrum efficiency than broadcasting. Using a single frequency network (SFN) further improves coverage probability, spectrum efficiency, and multiuser spectrum efficiency. Dynamic SFNs that allow transmitter shut off provide additional gains. IP multicasting over dynamic SFNs can
This thesis examines methods for improving power control in GSM/EDGE networks. The author develops and simulates several algorithms for an outer power control loop that would dynamically adjust the target quality value (qdes) based on additional network information. Simulation results show that an algorithm using transmitted power distribution across users provides more promising results than one based on error measurement reports, as it better maintains the essential power back-off principle without compromising quality of service. The thesis concludes there is high correlation between satisfied users and those within the regulating power window, indicating this approach could effectively optimize power control in varying network conditions.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
High Speed Low Power CMOS Domino or Gate Design in 16nm Technologycsandit
Dynamic logic circuits provide more compact designs with faster switching speeds and low power consumption compared with the other CMOS design styles. This paper proposes a wide
fan-in circuit with increased switching speed and noise immunity. Speed is achieved by quickly removing the charge on the dynamic node during evaluation phase, compared to the other
circuits. The design also offers very less Power Delay Product (PDP). The design is exercised for 20% variation in supply voltage.
Deadlock Preventive Adaptive Wormhole Routing on k-ary n-cube Interconnection...fbinard
This document discusses deadlock prevention in adaptive wormhole routing on k-ary n-cube interconnection networks. It examines two planar-adaptive routing schemes: the Turn Model and Chien and Kim's partially adaptive routing algorithm. The Turn Model restricts certain turns to ensure deadlock freedom using only two virtual channels regardless of network size. Chien and Kim's algorithm uses increasing and decreasing virtual networks to guarantee deadlock freedom using a fixed number of virtual channels that is independent of network dimensions. Both schemes allow for adaptive routing while preventing deadlock more cost-effectively than fully adaptive approaches.
Recently proposed wireless mesh routing metrics
based on awareness of congestion, load or interference typically
employ queue occupancy of a node's wireless interface to
estimate traffic load. Queue occupancy, however, does not
directly reflect the impact of channel contention from neighbor
nodes. We propose an alternative called the channel load-aware
(CLAW) routing metric that takes into consideration not only
the traffic load within the node itself, but also the degree of
interference and contention within the channel. CLAW uses
local information from a node's MAC layer to estimate channel
busyness and contention levels. It does not require complex
computations, nor the exchange of link-level statistics with
neighbors. Our preliminary results show that CLAW can
identify congested regions within the network and thus enable
the determination of routes around these congested areas. We
present the results of simulations we conducted to evaluate the
use of CLAW in mesh-wide routing.
LTE specifications support the use of multiple antennas at both transmitter (tx) and receiver (rx). MIMO (Multiple Input Multiple
Output) uses this antenna configuration.
LTE specifications support up to 4 antennas at the tx side and up to 4 antennas at the rx side (here referred to as 4x4 MIMO
configuration).
In the first release of LTE it is likely that the UE only has 1 tx antenna, even if it uses 2 rx antennas. This leads to that so called
Single User MIMO (SU-MIMO) will be supported only in DL (and maximum 2x2 configuration).
The document describes CSFB (CS fallback) and SMSoSGs (SMS over SGs) procedures in EPS. It discusses:
1. The protocol stack used on the SGs interface between MME and MSC, including SGsAP over SCTP.
2. Key SGs procedures like location update and detach to coordinate EPS and CS domain location information between MME and VLR.
3. How the MME allocates TAIs and LAIs to help optimize CSFB handovers between E-UTRAN and GERAN/UTRAN.
Designing of a AMBA-AHB Multilayer Bus matrix Self-Motivated Arbitration schemeIOSR Journals
Abstract: The AMBA-AHB Multilayer Bus matrix Self-Motivated Arbitration scheme proposed three methods for data transmiting from master to slave for on chip communication. Multilayer advanced high-performance bus (ML-AHB) busmatrix employs slave-side arbitration. Slave-side arbitration is different from master-side arbitration in terms of request and grant signals since, in the former, the master merely starts a burst transaction and waits for the slave response to proceed to the next transfer. Therefore, in the former, the unit of arbitration can be a transaction or a transfer. However, the ML-AHB busmatrix of ARM offers only transfer-based fixed-pri-ority and round-robin arbitration schemes. In this paper, we propose the design and implementation of a flexible arbiter for the ML-AHB busmatrix to support three priority policies fixed priority, round robin, and dynamic priority and three data multiplexing modes transfer, transaction, and desired transfer length. In total, there are nine possible arbitration schemes. The proposed arbiter, which is self-motivated (SM), selects one of the nine possible arbitration schemes based upon the priority-level notifications and the desired transfer length from the masters so that arbitration leads to the maximum performance. Experimental results show that, although the area overhead of the proposed SM arbitration scheme is 9%–25% larger than those of the other arbitration schemes, our arbiter improves the throughput by 14%–62% compared to other schemes.
Load balancing In Wireless Mesh Networks Using liquid–Simulated AlgorithmIJSRED
The document proposes a hierarchical routing framework and liquid-simulated algorithm for load balancing in wireless mesh networks. Key points:
- The framework forms clusters with wireless mesh routers (WMRs) as cluster heads and simplifies clustering procedures. It uses limited topology broadcasting to allow WMRs to choose best paths between adjacent clusters.
- The liquid-simulated algorithm aims to keep load balanced between WMRs by treating load as a liquid level and allowing flows between nodes to equalize levels across the network.
- The framework uses a proactive routing approach within this load balancing algorithm, with topology broadcasting constrained within clusters and adjacent clusters to reduce overhead.
Building impedance matching network based on s parameter from manufacturerJournal Papers
The document describes a method for building an impedance matching network for a transistor using S-parameter data and optimization tools in ADS simulation software. The transistor of interest operates from 220-270 MHz, where reference designs are unavailable. Input and output impedances are extracted from S-parameter files. An existing matching network design at a nearby frequency is used as a starting point. Optimization replaces ideal components with real ones, achieving over 30 dB return loss while degrading slightly from the ideal simulation. The method demonstrates synthesizing a matching network when reference designs are unavailable.
The document proposes a load-aware routing scheme for wireless mesh networks to balance traffic load and enhance network capacity. It divides the network into clusters, with each cluster head estimating traffic load and increasing routing metrics for overloaded links. This causes users to route around overloaded areas, achieving overall load balancing in a distributed manner. Simulation results show the proposed scheme outperforms routing using expected transmission time as a metric.
The efficient interleaving of digital-video-broadcasting-satellite 2nd genera...TELKOMNIKA JOURNAL
The DVB-S2 system is designed as a toolbox to permit the execution of the satellite programs. Interleaver is an essential part of the DVB-S2 system. The current general block interleaver in DVB-S2 is not best, which leads to high BER and maybe not satisfy the requirements of the system. The purpose of this paper is to study the several interleaver types and comparative analyses are done between them to find which of these give better performance. Simulations results obtained prove that the 2D interleavers minimize BER more than other interleavers of DVB-S2. Further, the performance of 2D interleaver is better on a system that required a low SNR.
Multi-Criterion Decision Making and Adaptation for Multi-path Video Streaming...Eswar Publications
It is suggested that multi-path routing is advantageous for applications with high traffic data characteristics, especially in the WSN environment. Sensor networks which transmit video will have to respond to the high data characteristic inherent in video data. Throughput, delay and packet loss are important metrics when considering video traffic. This work measures the performance of four multi-path routing protocols, MAOMDV, AOMDV, AntHocNet and MP-DSR in the WSN environment. It is shown that MAOMDV outperforms the other multi-path routing protocols in terms of the aforementioned metrics.
A circuit-switched network consists of switches connected by physical links, where each link is divided into channels. A connection uses a dedicated path and channel. In circuit switching, resources are reserved during setup and remain dedicated until teardown. In a packet-switched network, packets are sent without resource reservation and resources are allocated on demand. A virtual-circuit network has characteristics of both, where packets traveling between the same source and destination follow the same dedicated path but resources are allocated on demand.
PERFORMANCE COMPARISON DCM VERSUS QPSK FOR HIGH DATA RATES IN THE MBOFDM UWB ...csandit
This document compares the performance of dual carrier modulation (DCM) versus quadrature phase shift keying (QPSK) for high data rates in a multiband orthogonal frequency division multiplexing (MB-OFDM) ultra wideband (UWB) system. Simulation results show that using DCM provides better performance than QPSK, with a gain of around 0.7 dB for a bit error rate of 10-3 at 320 Mbps data rates. DCM offers additional diversity and coding gains over QPSK, making it more efficient for high data transmission rates in MBOFDM UWB systems.
This document summarizes the simulation steps for investigating the performance of three multi-carrier code division multiple access (MC-CDMA) techniques: conventional MC-CDMA, orthogonal wavelet packet based MC-CDMA (WP-MC-CDMA), and Huang Hilbert Transformation (HHT) based MC-CDMA. The steps include designing the three systems, simulating them with different modulation techniques under fading channels, and comparing their bit error rate performance. Numerical and simulation results are presented to validate the proposed schemes.
This document summarizes the simulation steps for investigating the performance of three multi-carrier code division multiple access (MC-CDMA) techniques: conventional MC-CDMA, orthogonal wavelet packet based MC-CDMA (WP-MC-CDMA), and Huang Hilbert Transformation (HHT) based MC-CDMA. The steps include designing the three systems, simulating them with different modulation techniques under fading channels, and comparing their bit error rate performance. Numerical and simulation results are presented to validate the proposed schemes.
Heterogeneous LTE Networks and Inter-Cell Interference Coordination - Dec 201...Eiko Seidel
This document discusses heterogeneous LTE networks and inter-cell interference coordination (ICIC). It begins by explaining that initial LTE networks consisted of homogeneous macro cell deployments but that heterogeneous networks using smaller pico and femto cells are now being implemented to improve capacity and coverage. This introduces new interference challenges. The document then outlines various ICIC methods like frequency reuse and power control techniques that can help mitigate interference. It provides simulation results showing the benefits of heterogeneous networks and techniques like range expansion.
The document discusses Variable Coding and Modulation (VCM) tuners for satellite receivers. VCM allows a transponder to transmit multiple transport streams, with each stream able to use different error correction coding rates. This provides flexibility to prioritize streams, such as transmitting premium HD channels with weaker error correction only in the center of the satellite footprint. A VCM tuner can receive these signals by determining the coding rates of each stream. The tuner's architecture is similar to conventional tuners but includes additional components to process the multiple streams and their varying coding rates transmitted by VCM.
The document discusses Variable Coding and Modulation (VCM) in DVB-S2 satellite transmissions. VCM allows a single transponder to transmit multiple transport streams, with each stream using a different modulation type and forward error correction rate. This makes it possible to provide stronger error correction for basic channels while using weaker correction for premium channels. A VCM-compatible tuner can determine the coding rates being used and properly demodulate the different streams. This provides more flexible use of satellite bandwidth than conventional systems with a single coding scheme per transponder.
The document provides an overview of Huawei's Core-CS Network and the evolution of WCDMA networks from Release 99 to Release 5. It discusses key aspects of MSC pool networks including improved resource utilization, enhanced network reliability, and reduced signaling traffic. It also covers AOIP and AOTDM, noting that AOIP allows for end-to-end Transcoder Free Operation and uses lower-cost IP networks for transmission on the A interface user plane.
This document presents a study on using IP multicasting over DVB-T/H and e-MBMS networks. Seven different distribution schemes are designed and analyzed: unicasting over MFN, broadcasting over MFN, IP multicasting over MFN, broadcasting over SFN, IP multicasting over CT-DSFN, IP multicasting over non-SFN DCA, and IP multicasting over NCT-DSFN. The results show that IP multicasting provides better spectrum efficiency than broadcasting. Using a single frequency network (SFN) further improves coverage probability, spectrum efficiency, and multiuser spectrum efficiency. Dynamic SFNs that allow transmitter shut off provide additional gains. IP multicasting over dynamic SFNs can
This thesis examines methods for improving power control in GSM/EDGE networks. The author develops and simulates several algorithms for an outer power control loop that would dynamically adjust the target quality value (qdes) based on additional network information. Simulation results show that an algorithm using transmitted power distribution across users provides more promising results than one based on error measurement reports, as it better maintains the essential power back-off principle without compromising quality of service. The thesis concludes there is high correlation between satisfied users and those within the regulating power window, indicating this approach could effectively optimize power control in varying network conditions.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
High Speed Low Power CMOS Domino or Gate Design in 16nm Technologycsandit
Dynamic logic circuits provide more compact designs with faster switching speeds and low power consumption compared with the other CMOS design styles. This paper proposes a wide
fan-in circuit with increased switching speed and noise immunity. Speed is achieved by quickly removing the charge on the dynamic node during evaluation phase, compared to the other
circuits. The design also offers very less Power Delay Product (PDP). The design is exercised for 20% variation in supply voltage.
Deadlock Preventive Adaptive Wormhole Routing on k-ary n-cube Interconnection...fbinard
This document discusses deadlock prevention in adaptive wormhole routing on k-ary n-cube interconnection networks. It examines two planar-adaptive routing schemes: the Turn Model and Chien and Kim's partially adaptive routing algorithm. The Turn Model restricts certain turns to ensure deadlock freedom using only two virtual channels regardless of network size. Chien and Kim's algorithm uses increasing and decreasing virtual networks to guarantee deadlock freedom using a fixed number of virtual channels that is independent of network dimensions. Both schemes allow for adaptive routing while preventing deadlock more cost-effectively than fully adaptive approaches.
Recently proposed wireless mesh routing metrics
based on awareness of congestion, load or interference typically
employ queue occupancy of a node's wireless interface to
estimate traffic load. Queue occupancy, however, does not
directly reflect the impact of channel contention from neighbor
nodes. We propose an alternative called the channel load-aware
(CLAW) routing metric that takes into consideration not only
the traffic load within the node itself, but also the degree of
interference and contention within the channel. CLAW uses
local information from a node's MAC layer to estimate channel
busyness and contention levels. It does not require complex
computations, nor the exchange of link-level statistics with
neighbors. Our preliminary results show that CLAW can
identify congested regions within the network and thus enable
the determination of routes around these congested areas. We
present the results of simulations we conducted to evaluate the
use of CLAW in mesh-wide routing.
LTE specifications support the use of multiple antennas at both transmitter (tx) and receiver (rx). MIMO (Multiple Input Multiple
Output) uses this antenna configuration.
LTE specifications support up to 4 antennas at the tx side and up to 4 antennas at the rx side (here referred to as 4x4 MIMO
configuration).
In the first release of LTE it is likely that the UE only has 1 tx antenna, even if it uses 2 rx antennas. This leads to that so called
Single User MIMO (SU-MIMO) will be supported only in DL (and maximum 2x2 configuration).
The document describes CSFB (CS fallback) and SMSoSGs (SMS over SGs) procedures in EPS. It discusses:
1. The protocol stack used on the SGs interface between MME and MSC, including SGsAP over SCTP.
2. Key SGs procedures like location update and detach to coordinate EPS and CS domain location information between MME and VLR.
3. How the MME allocates TAIs and LAIs to help optimize CSFB handovers between E-UTRAN and GERAN/UTRAN.
- Circuit Switched Fallback (CSFB) allows LTE devices to use circuit-switched voice and SMS services through GSM or other circuit-switched networks, as LTE is an all-IP packet-based network incapable of supporting circuit-switched calls. When making or receiving a voice call or SMS, the LTE device "falls back" to the 3G or 2G network.
- CSFB was specified in 3GPP Release 8 and requires upgrading operators' core and radio networks. It is considered an interim solution until Voice over LTE (VoLTE) is fully implemented for delivering voice services over LTE networks.
Switching and multicast schemes in asynchronous transfer mode networksEditor Jacotech
This document summarizes various switching and multicast schemes used in asynchronous transfer mode (ATM) networks. It discusses shared memory ATM switching architectures and different approaches for supporting multicast traffic in shared memory switches including replication-at-receiving, replication-at-sending, multiple write multiple read, and single write single read schemes. It also covers requirements for ATM multicast and compares these schemes in terms of advantages and disadvantages related to memory usage and switching performance.
Implementing database lookup method in mobile wimax for location management a...ijdpsjournal
This document summarizes a research paper that proposes implementing a database lookup method for location management in a mobile WiMAX network to reduce handover delay and improve bandwidth utilization and throughput. The paper introduces using location management areas (LMAs) within multicast and broadcast service (MBS) zones to minimize handover delay. Existing methods use paging groups to track user locations, increasing bandwidth usage and delay. The proposed method eliminates paging groups and instead stores user location data in a database accessed by an authentication, authorization, and accounting (AAA) server. Simulation results using the OPNET tool show the proposed method reduces handover delay and increases throughput compared to existing methods.
LTE QOS DYNAMIC RESOURCE BLOCK ALLOCATION WITH POWER SOURCE LIMITATION AND QU...IJCNCJournal
3GPP has defined the long term evolution (LTE) for 3G radio access in order to maintain the future
competitiveness for 3G technology, the system provides the capability of supporting a mixture of services
with different quality of service (QoS) requirements. This paper proposes a new cross-layer scheduling
algorithm to satisfy better QoS parameters for real time applications. The proposed algorithm takes care of
allocating resource blocks (RBs) with different modulation and coding schemes (MCS) according to target
bit error rate (BER), user equipment supportable MCS, queue stability constraints and available transmit
power constraints. The proposed algorithm has been valued, compared with an earlier allocation algorithm
in terms of service rate and packet delay and showed better performance regards the real time
applications.
Interference mitigation by dynamic self power control in femtocellYara Ali
This document presents a summary of a research paper on interference mitigation using dynamic self-power control in femtocell scenarios in LTE networks. It discusses how interference is a problem in femtocell networks due to the random placement of small base stations. The research proposes using dynamic power control to find an optimal tradeoff between interference and throughput. Simulation results show that controlling transmission power levels can improve quality of service by reducing interference effects, especially with increasing numbers of neighboring femtocells. Future work could focus on including interference from macrocells in the simulation scenarios.
This document provides an overview of Single Radio Voice Call Continuity (SRVCC) functionality on the MME. It describes:
1) How SRVCC allows VoIP subscribers on an LTE network to handover a voice call to a circuit-switched network like 2G/3G when moving out of LTE coverage, without needing dual-radio capability.
2) The key SRVCC architecture components including an Sv interface between the MME and MSC.
3) The SRVCC features supported by the MME like MSC selection using DNS, MSC pool areas, fallback procedures, and compliance with relevant 3GPP standards.
PERFORMANCE AND REKEYING ANALYSIS OF MULTICAST SECURITY IN LTEIJCNCJournal
This document analyzes the performance and rekeying of multicast security in LTE networks. It compares two security solutions for multimedia broadcast multicast services (MBMS) in LTE - Group Security Association (GSA) and Secure Multicast Overlay (SMO). It models parameters for different multicast services like TV channels, Twitter, and Facebook. It calculates the computational and storage costs for rekeying using logical key hierarchy (LKH) tree with and without dynamic rekeying, and for changing the tree degree or height. The goal is to assess the performance of GSA and SMO solutions and determine which is more appropriate based on different parameters and services.
The document describes several components that make up a base station controller (BSC) in a GSM network:
1. The BSC controls base transceiver stations (BTSs) and interfaces with the mobile switching center (MSC) and operations center. It performs dynamic channel allocation for mobile calls.
2. Components within the BSC shelves include processors, switching matrices, and interfaces that connect to the MSC terrestrial links and control the BTSs. Clocks synchronize components across sites.
3. Additional components described are the code storage facility processor (CSFP) that facilitates software updates, multiple serial interfaces (MSI) that connect to E1/T1 links, generic clocks (G
This white paper discusses Single Radio Voice Call Continuity (SRVCC) which allows for seamless handover of voice calls between LTE and circuit switched networks like UTRAN or GERAN. It describes the key challenges of delivering voice services over LTE networks and why SRVCC is an important solution. SRVCC uses IMS to anchor voice calls and switches them to use circuit switched networks when the user moves outside of LTE coverage, maintaining continuity of the voice call with only a single radio in the user equipment. The paper provides details on how SRVCC is implemented between LTE and UTRAN/GERAN networks using various 3GPP defined interfaces and reference points.
The document provides an overview of LTE architecture, interfaces, network elements, radio network and protocols. It describes the main LTE interfaces like Uu, S1, X2 and S5. The network elements discussed are eNB, MME, SGW and PGW. The radio network section covers physical layer technologies used in LTE like OFDMA, MIMO and QAM. It also explains transport channels, logical channels and layer 2 architecture in LTE.
Some of the key driving forces behind the transition from the UMTS based cellular system to the Long Term Evolution Advanced (LTE-A) are to improve the mean and the cell-edge throughput, improve the user fairness, and improve the quality of service (QoS) satisfaction for all users. In the latter system, relays appear as one of the most prominent enabler for improving the cell-edge user experience while increasing the system’s fairness.
In this white paper, we present the basics of relay deployments in LTE-A networks. Moreover, we analyze resource allocation problem for Relay Nodes (RN) deployments and present some of the solutions for improvement in system resource usage and QoS satisfaction. Afterwards, we introduce the capabilities of NOMOR’s LTE-A system level simulator and evaluate the performance of LTE-A relay systems under the described solutions.
Comparison of Csma Based MAC Protocols of Wireless Sensor Networkspijans
This document compares several CSMA-based MAC protocols for wireless sensor networks: S-MAC, T-MAC, B-MAC, B-MAC+, X-MAC, and D-MAC. It implements these protocols in TOSSIM simulator and evaluates their energy consumption and performance under different traffic loads. The key findings are that T-MAC consumes less energy than S-MAC due to its adaptive timeout, while B-MAC+ and X-MAC improve over B-MAC by reducing long preambles. D-MAC aims for low-latency data delivery using a staggered wakeup schedule but does not perform well under high traffic.
NetSim Long Term Evolution (LTE) Networks library includes LTE/LTE-A networks, LTE
Femto Cell, LTE D2D and LTE VANET. The LTE libraray allows you to connect, if required,
with Internetwork devices such as Routers, Switches etc running Ethernet, Wireless LAN, IP
Routing, TCP / UDP.
Distributed Utility-Based Energy Efficient Cooperative Medium Access Control...IJMER
Cooperative communication, that utilizes near terminals to relay the overhearing
information to grasp the variability gains, choices a nice potential to strengthen the transmission
potency in wireless networks. to the subsume the hard medium access interactions evoked by relaying
and leverage the advantages of such cooperation, associate economical Cooperative Medium Access
management (CMAC) protocol is required. throughout this paper, we've got an inclination to tend to
propose a completely unique cross-layer Wide unfold Energy-adaptive Location-based CMAC
protocol, notably WEAL-CMAC, for Mobile Ad-hoc Networks (MANETs). the design objective of
WEAL-CMAC is to strengthen the performance of the MANETs in terms of network amount and
energy potency. a wise energy consumption model is used throughout this paper, that takes the energy
consumption on each transceiver instrumentation and transmit instrumentation into thought. A
distributed utility-based best relay different strategy is incorporated, that selects the most effective
relay supported location information and residual energy. moreover, with the aim of enhancing the
spacial apply, associate innovative network allocation vector setting is provided to the subsume the
variable transmission power of the beginning and relay terminals. we've got an inclination to tend to
point that the planned WEAL-CMAC considerably prolongs the network amount below varied
circumstances even for prime instrumentation energy consumption cases by comprehensive simulation
study
This document compares three channel models used for MIMO simulations: the 3GPP Spatial Channel Model (SCM), its extension (SCME), and models developed by WINNER. The SCM was originally designed for 2 GHz frequencies and 5 MHz bandwidth. SCME extended SCM to support higher frequencies and bandwidths up to 100 MHz but remained backward compatible. WINNER models are based on measurements covering 2-6 GHz and bandwidths up to 100 MHz, supporting more scenarios. Key differences between the models include supported frequency ranges, number of scenarios, cluster parameters, and time evolution assumptions. Performance analyses show similar fading distributions and autocorrelation properties across the models.
This document presents a novel Cross-layer Mesh Router Placement (CMRP) scheme for wireless mesh networks. CMRP aims to minimize network deployment cost while meeting user demands. It considers various factors such as antenna types, wireless link characteristics, MAC scheduling, routing, and equipment costs. CMRP encapsulates these cross-layer factors into three attributes - Local Coverage, Backbone Residual Capacity, and Deployment Cost. It uses these attributes to select mesh router locations that maximize coverage and backbone capacity while minimizing costs. Simulations show CMRP outperforms existing schemes in cost performance ratio and feasibility for planning wireless mesh networks.
This document analyzes the effect of different velocities on handover delay in WiMAX systems. It studies location management area based multimedia and multicast/broadcast handover. The study compares the number of cells and size of location areas using a simulation to see how these parameters are affected by different mobile WiMAX velocities. It presents an analytical model and discusses numerical results analyzing handover delay with modifications to reduce delay by focusing on different mobile WiMAX mobility velocities and comparing to the convergence area size of location management areas.
This document analyzes the effect of different velocities on handover delay in WiMAX systems. It studies location management area based multimedia and multicast/broadcast handover and compares how modifying mobile WiMAX velocity levels and the size of location areas affect handover delay. The study finds that as mobile velocity increases, the rate of cell and location area boundary crossings increases, leading to more handovers and higher handover delay. Parameters like location area size, user distribution, and session popularity also impact average service disruption time during handovers.
UiPath Test Automation using UiPath Test Suite series, part 5DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 5. In this session, we will cover CI/CD with devops.
Topics covered:
CI/CD with in UiPath
End-to-end overview of CI/CD pipeline with Azure devops
Speaker:
Lyndsey Byblow, Test Suite Sales Engineer @ UiPath, Inc.
Full-RAG: A modern architecture for hyper-personalizationZilliz
Mike Del Balso, CEO & Co-Founder at Tecton, presents "Full RAG," a novel approach to AI recommendation systems, aiming to push beyond the limitations of traditional models through a deep integration of contextual insights and real-time data, leveraging the Retrieval-Augmented Generation architecture. This talk will outline Full RAG's potential to significantly enhance personalization, address engineering challenges such as data management and model training, and introduce data enrichment with reranking as a key solution. Attendees will gain crucial insights into the importance of hyperpersonalization in AI, the capabilities of Full RAG for advanced personalization, and strategies for managing complex data integrations for deploying cutting-edge AI solutions.
Removing Uninteresting Bytes in Software FuzzingAftab Hussain
Imagine a world where software fuzzing, the process of mutating bytes in test seeds to uncover hidden and erroneous program behaviors, becomes faster and more effective. A lot depends on the initial seeds, which can significantly dictate the trajectory of a fuzzing campaign, particularly in terms of how long it takes to uncover interesting behaviour in your code. We introduce DIAR, a technique designed to speedup fuzzing campaigns by pinpointing and eliminating those uninteresting bytes in the seeds. Picture this: instead of wasting valuable resources on meaningless mutations in large, bloated seeds, DIAR removes the unnecessary bytes, streamlining the entire process.
In this work, we equipped AFL, a popular fuzzer, with DIAR and examined two critical Linux libraries -- Libxml's xmllint, a tool for parsing xml documents, and Binutil's readelf, an essential debugging and security analysis command-line tool used to display detailed information about ELF (Executable and Linkable Format). Our preliminary results show that AFL+DIAR does not only discover new paths more quickly but also achieves higher coverage overall. This work thus showcases how starting with lean and optimized seeds can lead to faster, more comprehensive fuzzing campaigns -- and DIAR helps you find such seeds.
- These are slides of the talk given at IEEE International Conference on Software Testing Verification and Validation Workshop, ICSTW 2022.
Driving Business Innovation: Latest Generative AI Advancements & Success StorySafe Software
Are you ready to revolutionize how you handle data? Join us for a webinar where we’ll bring you up to speed with the latest advancements in Generative AI technology and discover how leveraging FME with tools from giants like Google Gemini, Amazon, and Microsoft OpenAI can supercharge your workflow efficiency.
During the hour, we’ll take you through:
Guest Speaker Segment with Hannah Barrington: Dive into the world of dynamic real estate marketing with Hannah, the Marketing Manager at Workspace Group. Hear firsthand how their team generates engaging descriptions for thousands of office units by integrating diverse data sources—from PDF floorplans to web pages—using FME transformers, like OpenAIVisionConnector and AnthropicVisionConnector. This use case will show you how GenAI can streamline content creation for marketing across the board.
Ollama Use Case: Learn how Scenario Specialist Dmitri Bagh has utilized Ollama within FME to input data, create custom models, and enhance security protocols. This segment will include demos to illustrate the full capabilities of FME in AI-driven processes.
Custom AI Models: Discover how to leverage FME to build personalized AI models using your data. Whether it’s populating a model with local data for added security or integrating public AI tools, find out how FME facilitates a versatile and secure approach to AI.
We’ll wrap up with a live Q&A session where you can engage with our experts on your specific use cases, and learn more about optimizing your data workflows with AI.
This webinar is ideal for professionals seeking to harness the power of AI within their data management systems while ensuring high levels of customization and security. Whether you're a novice or an expert, gain actionable insights and strategies to elevate your data processes. Join us to see how FME and AI can revolutionize how you work with data!
In his public lecture, Christian Timmerer provides insights into the fascinating history of video streaming, starting from its humble beginnings before YouTube to the groundbreaking technologies that now dominate platforms like Netflix and ORF ON. Timmerer also presents provocative contributions of his own that have significantly influenced the industry. He concludes by looking at future challenges and invites the audience to join in a discussion.
Maruthi Prithivirajan, Head of ASEAN & IN Solution Architecture, Neo4j
Get an inside look at the latest Neo4j innovations that enable relationship-driven intelligence at scale. Learn more about the newest cloud integrations and product enhancements that make Neo4j an essential choice for developers building apps with interconnected data and generative AI.
Communications Mining Series - Zero to Hero - Session 1DianaGray10
This session provides introduction to UiPath Communication Mining, importance and platform overview. You will acquire a good understand of the phases in Communication Mining as we go over the platform with you. Topics covered:
• Communication Mining Overview
• Why is it important?
• How can it help today’s business and the benefits
• Phases in Communication Mining
• Demo on Platform overview
• Q/A
Cosa hanno in comune un mattoncino Lego e la backdoor XZ?Speck&Tech
ABSTRACT: A prima vista, un mattoncino Lego e la backdoor XZ potrebbero avere in comune il fatto di essere entrambi blocchi di costruzione, o dipendenze di progetti creativi e software. La realtà è che un mattoncino Lego e il caso della backdoor XZ hanno molto di più di tutto ciò in comune.
Partecipate alla presentazione per immergervi in una storia di interoperabilità, standard e formati aperti, per poi discutere del ruolo importante che i contributori hanno in una comunità open source sostenibile.
BIO: Sostenitrice del software libero e dei formati standard e aperti. È stata un membro attivo dei progetti Fedora e openSUSE e ha co-fondato l'Associazione LibreItalia dove è stata coinvolta in diversi eventi, migrazioni e formazione relativi a LibreOffice. In precedenza ha lavorato a migrazioni e corsi di formazione su LibreOffice per diverse amministrazioni pubbliche e privati. Da gennaio 2020 lavora in SUSE come Software Release Engineer per Uyuni e SUSE Manager e quando non segue la sua passione per i computer e per Geeko coltiva la sua curiosità per l'astronomia (da cui deriva il suo nickname deneb_alpha).
Why You Should Replace Windows 11 with Nitrux Linux 3.5.0 for enhanced perfor...SOFTTECHHUB
The choice of an operating system plays a pivotal role in shaping our computing experience. For decades, Microsoft's Windows has dominated the market, offering a familiar and widely adopted platform for personal and professional use. However, as technological advancements continue to push the boundaries of innovation, alternative operating systems have emerged, challenging the status quo and offering users a fresh perspective on computing.
One such alternative that has garnered significant attention and acclaim is Nitrux Linux 3.5.0, a sleek, powerful, and user-friendly Linux distribution that promises to redefine the way we interact with our devices. With its focus on performance, security, and customization, Nitrux Linux presents a compelling case for those seeking to break free from the constraints of proprietary software and embrace the freedom and flexibility of open-source computing.
TrustArc Webinar - 2024 Global Privacy SurveyTrustArc
How does your privacy program stack up against your peers? What challenges are privacy teams tackling and prioritizing in 2024?
In the fifth annual Global Privacy Benchmarks Survey, we asked over 1,800 global privacy professionals and business executives to share their perspectives on the current state of privacy inside and outside of their organizations. This year’s report focused on emerging areas of importance for privacy and compliance professionals, including considerations and implications of Artificial Intelligence (AI) technologies, building brand trust, and different approaches for achieving higher privacy competence scores.
See how organizational priorities and strategic approaches to data security and privacy are evolving around the globe.
This webinar will review:
- The top 10 privacy insights from the fifth annual Global Privacy Benchmarks Survey
- The top challenges for privacy leaders, practitioners, and organizations in 2024
- Key themes to consider in developing and maintaining your privacy program
Let's Integrate MuleSoft RPA, COMPOSER, APM with AWS IDP along with Slackshyamraj55
Discover the seamless integration of RPA (Robotic Process Automation), COMPOSER, and APM with AWS IDP enhanced with Slack notifications. Explore how these technologies converge to streamline workflows, optimize performance, and ensure secure access, all while leveraging the power of AWS IDP and real-time communication via Slack notifications.
HCL Notes and Domino License Cost Reduction in the World of DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-and-domino-license-cost-reduction-in-the-world-of-dlau/
The introduction of DLAU and the CCB & CCX licensing model caused quite a stir in the HCL community. As a Notes and Domino customer, you may have faced challenges with unexpected user counts and license costs. You probably have questions on how this new licensing approach works and how to benefit from it. Most importantly, you likely have budget constraints and want to save money where possible. Don’t worry, we can help with all of this!
We’ll show you how to fix common misconfigurations that cause higher-than-expected user counts, and how to identify accounts which you can deactivate to save money. There are also frequent patterns that can cause unnecessary cost, like using a person document instead of a mail-in for shared mailboxes. We’ll provide examples and solutions for those as well. And naturally we’ll explain the new licensing model.
Join HCL Ambassador Marc Thomas in this webinar with a special guest appearance from Franz Walder. It will give you the tools and know-how to stay on top of what is going on with Domino licensing. You will be able lower your cost through an optimized configuration and keep it low going forward.
These topics will be covered
- Reducing license cost by finding and fixing misconfigurations and superfluous accounts
- How do CCB and CCX licenses really work?
- Understanding the DLAU tool and how to best utilize it
- Tips for common problem areas, like team mailboxes, functional/test users, etc
- Practical examples and best practices to implement right away
“An Outlook of the Ongoing and Future Relationship between Blockchain Technologies and Process-aware Information Systems.” Invited talk at the joint workshop on Blockchain for Information Systems (BC4IS) and Blockchain for Trusted Data Sharing (B4TDS), co-located with with the 36th International Conference on Advanced Information Systems Engineering (CAiSE), 3 June 2024, Limassol, Cyprus.
Best 20 SEO Techniques To Improve Website Visibility In SERPPixlogix Infotech
Boost your website's visibility with proven SEO techniques! Our latest blog dives into essential strategies to enhance your online presence, increase traffic, and rank higher on search engines. From keyword optimization to quality content creation, learn how to make your site stand out in the crowded digital landscape. Discover actionable tips and expert insights to elevate your SEO game.
Best 20 SEO Techniques To Improve Website Visibility In SERP
LTE/EPS Technology
1. 5 Core Network
117
ChapterChapterChapterChapter 5555
Core NetworkCore NetworkCore NetworkCore Network
TopicTopicTopicTopic PagePagePagePage
MME in Pool.................................................................................................. 119
Signalling Transport (SIGTRAN).................................................................. 124
User data transfer ........................................................................................... 131
Diameter......................................................................................................... 135
Quality of Service .......................................................................................... 137
3. 5 Core Network
119
MME in PoolMME in PoolMME in PoolMME in Pool
The Intra Domain Connection of RAN Nodes to Multiple CN Nodes,
introduced in UMTS R5, overcomes the strict hierarchy, which restricts the
connection of a RAN node to just one CN node. This restriction in
GSM/UMTS results from routing mechanisms in the RAN nodes which
differentiate only between information to be sent to the PS or to the CS
domain CN nodes and which do not differentiate between multiple CN nodes
in each domain. The Intra Domain Connection of RAN Nodes to Multiple CN
Nodes introduces a routing mechanism (and other related functionality),
which enables the RAN nodes to route information to different CN nodes
within the CS or PS domain, respectively.
RNC RNC RNCRNC
SGSN SGSN
GGSN
RNCRNC
SGSN
GGSN
Figure 5-1 Network hierarchy GSM/UMTS R4-
The Intra Domain Connection of RAN Nodes to Multiple CN Nodes
introduces further the concept of ‘pool-areas’ which is enabled by the routing
mechanism in the RAN nodes. A pool-area is comparable to an MSC or
SGSN service area as a collection of one or more RAN node service areas. In
difference to an MSC or SGSN service area a pool-area is served by multiple
CN nodes (MSCs or SGSNs) in parallel which share the traffic of this area
between each other. Furthermore, pool-areas may overlap which is not
possible for MSC or SGSN service areas. From a RAN perspective a
pool-area comprises all LA(s)/RA(s) of one or more RNC/BSC that are served
by a certain group of CN nodes in parallel. One or more of the CN nodes in
this group may in addition serve LAs/RAs outside this pool-area or may also
serve other pool-areas. This group of CN nodes is also referred to as MSC
pool or SGSN pool respectively.
4. LTE/EPS Technology
120
GGSN GGSN
SGSN SGSN SGSN
RNC RNC RNCRNC RNCRNC
Pool area 1
Pool area 2
Figure 5-2 Network hierarchy GSM/UMTS R5+
The Intra Domain Connection of RAN Nodes to Multiple CN Nodes enables a
few different application scenarios with certain characteristics. The service
provision by multiple CN nodes within a pool-area enlarges the served area
compared to the service area of one CN node. This results in reduced inter CN
node updates, handovers and relocations and it reduces the HSS update traffic.
The configuration of overlapping pool-areas allows to separate the overall
traffic into different MS moving pattern, e.g. pool-areas where each covers a
separate residential area and all the same city centre. Other advantages of
multiple CN nodes in a pool-area are the possibility of capacity upgrades by
additional CN nodes in the pool-area or the increased service availability as
other CN nodes may provide services in case one CN node in the pool-area
fails.
A user terminal is served by one dedicated CN node of a pool-area as long as
it is in radio coverage of the pool-area.
The fact that the BSC can co-operate with the several SGSN does not implies
that the separate physical interfaces are required since the IP network can be
used between BSCs and SGSNs to switch the traffic delivered on the same
physical interfaces to different recipients connected to that network.
IP network
SGSN2SGSN1 SGSN3
BSC6BSC5BSC4BSC3BSC2BSC1
Figure 5-3 SGSNs in Pool (physical view with Gb/IP)
5. 5 Core Network
121
Similarly to GSM/UMTS, where the MSC/SGSN in Pool is already quite
popular solution, the EPS network may utilise the solution called MME in
Pool. However, some aspects of the CN nodes pool solution for GSM/UMTS
and EPS networks are different:
• There is only one CN domain in EPS, that is PS domain, so there is
only necessity for the MME nodes to be pooled,
• The MME in Pool concept is introduced in the first release of the
standard for the EPS network, so right from the beginning all
MMEs/eNBs can support MME in Pool specific procedures. (In
GSM/UMTS there was a necessity to solve backward compatibility
problems between MSCs/SGSNs capable and non-capable of
supporting pool area concept.)
• The temporary UE identity GUTI that holds the binding between the
UE and it’s serving MME in EPS has a structure that directly supports
the concept of the MME in Pool, in contradiction to GSM/UMTS
where TMSI/P-TMSI structure was modified for that purpose. Since
new R5 TMSI/P-TMSI structure has to be backward compatible with
R4, the solution is slightly less efficient, introduces some extra
signalling load and in some cases may result in the situation where
subscriber are not subjected to inter MSC/SGSN load distribution.
MME in Pool
only PS domain in EPS
no problems with backward compatibility
GUTI structure supports the MME in Pool concept
MME in Pool
only PS domain in EPS
no problems with backward compatibility
GUTI structure supports the MME in Pool concept
Figure 5-4 MME in Pool
Pool areaPool areaPool areaPool area
A pool-area is an area within which a UE may roam without a need to change
the serving MME node. A pool-area is served by one or more MMEs nodes in
parallel. The complete service area of a eNB (i.e. all the cells being served by
one eNB) belongs to the same one or more pool-area(s). A eNB service area
may belong to multiple pool-areas, which is the case when multiple
overlapping pool-areas include this eNB node service area. If TA spans over
multiple eNB service areas then all these eNB service areas have to belong to
the same MME pool-area. Additionally, when the TA list, the UE is registered
to, spans over multiple eNB service areas then also all these eNB service
areas have to belong to the same MME pool area.
6. LTE/EPS Technology
122
An MME pool-area is an area within which an MS roams
without a need to change the serving MME.
MME
MME
MME
eNB
eNB
eNB
eNB eNB
Figure 5-5 MME pool area
MME selection and aMME selection and aMME selection and aMME selection and addressingddressingddressingddressing
Each time the UE leaves the current MME pool area, the eNB runs MME
selection function. The MME selection function selects an available MME for
serving a UE. The selection is based on network topology, i.e. the selected
MME serves the UE’s location and in case of overlapping MME service
areas, the selection may prefer MMEs with service areas that reduce the
probability of changing the MME.
The selected MME allocates a Globally Unique Temporary Identity (GUTI)
to the UE. The GUTI has two main components:
• Globally Unique MME Identifier (GUMMEI) uniquely identifying the
MME which allocated the GUTI,
• M-TMSI uniquely identifying the UE within the MME that allocated
the GUTI.
GUMMEI
MCC MNC MMEGI MMEC M-TMSI
MMEI
S-TMSI
GUMMEI Globally Unique MME Identifier
MMEI MME Identifier
MMEGI MME Group ID
MMEC MME Code
Figure 5-6 GUTI structure
7. 5 Core Network
123
The GUTI structure directly supports the concept of the MME pool area.
Since during each identification the UE, not only identifies itself but also the
MME that has allocated its temporary identity. Therefore, even in case of
intra MME pool area mobility, each eNB easily can route the data from the
UE to the MME which holds the user subscription and session information.
eNB
eNB
GUTI (GUMMEI #2)
(GUMMEI #1)
MME selection
GUTI/GUMMEI allocation
GUMMEI routing
MME
MME
(GUMMEI #2)
MME
(GUMMEI #3)
GUTI (GUMMEI #2)
Figure 5-7MME in Pool and GUTI
In case of inter MME pool area mobility the new eNB, can easily discover
that the UE is coming from another pool area, the eNB is not a part of. In that
case the eNB runs the MME selection process that will choose the new MME
for the UE, which in turn allocates the new GUTI. The new GUTI (that
includes the new MME’s identity) is used from that moment to route
signalling messages from the UE to the selected MME, until the MME pool
area is changed.
Load BalancingLoad BalancingLoad BalancingLoad Balancing
The MME Load Balancing functionality permits UEs that are entering into an
MME Pool Area to be directed to an appropriate MME in a manner that
achieves load balancing between MMEs. This is achieved by setting an MME
weight factor (called MME Relative Capacity) for each MME, such that the
probability of the eNB selecting an MME is proportional to its capacity. The
MME Relative Capacity parameter is typically set according to the capacity of
an MME node relative to other MME nodes.
8. LTE/EPS Technology
124
MME
MME
MME
eNB
10
10
20
MME relative capacity
Figure 5-8 Load balancing
The MME Load Re-balancing functionality permits UEs that are registered on
an MME (within an MME Pool Area) to be moved to another MME.
An example use for the MME Load Re-balancing function is for the O&M
related removal of one MME from an MME Pool Area.
MME
MME
MME
Figure 5-9 Load re-balancing
SignallSignallSignallSignalling Transing Transing Transing Transport (SIGTRAN)port (SIGTRAN)port (SIGTRAN)port (SIGTRAN)
Signalling Transport (SIGTRAN) is a new set of standards defined by the
International Engineering Task Force (IETF). This set of protocols has been
defined in order to provide the architectural model of signalling transport over
IP networks.
9. 5 Core Network
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SCTPSCTPSCTPSCTP
To reliably transport signalling messages over IP networks, the IETF
SIGTRAN working group devised the Stream Control Transmission Protocol
(SCTP). SCTP allows the reliable transfer of signalling messages between
signalling endpoints in an IP network.
MultihomingMultihomingMultihomingMultihoming
Opposed to TCP connection, an SCTP association can take advantage of a
multihomed host using all the IP addresses the host owns. This feature is one
of the most important ones in SCTP as it gives some network redundancy that
is really valuable when dealing with signalling. In the older signalling
systems, like SS7, every network component is duplicated, and the idea of
loosing a TCP connection due to the failure of one of the network cards was
one of the major problems that made SCTP necessary.
IP
TCP
TCPuser
IP
TCP
TCPuser
IP
TCP
TCPuser
connection
endpoint/socket = IP address + TCP port number
IP path
Figure 5-10 Singlehomed protocol (TCP)
SCTPuser
IP
SCTP
IP
SCTPuser
IP
SCTP
IP
SCTPuser
IP
SCTP
IP
SCTPuser
IP
SCTP
IP
endpoint/socket = IP addresses + SCTP port number
IP paths
association
Figure 5-11 Multihomed protocol (SCTP)
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StreamsStreamsStreamsStreams
IP signalling traffic is usually composed of many independent message
sequences between many different signalling endpoints. SCTP allows
signalling messages to be independently ordered within multiple streams
(unidirectional logical channels established from one SCTP endpoint to
another) to ensure in-sequence delivery between associated endpoints. By
transferring independent message sequences in separate SCTP streams, it is
less likely that the retransmission of a lost message will affect the timely
delivery of other messages in unrelated sequences (problem called
head-of-line blocking). Because TCP/IP does enforce head-of-line blocking,
the SCTP is better suited, rather than TCP/IP, for the transmission of
signalling messages over IP networks.
TCP connection
2 1
buffered
345
2
3
4
5
1Re-Tx
application
Figure 5-12 Head-Of-Line (HOL) blocking – single TCP connection
Stream
2
Stream
1
45
46
buffered
5
62
delivered delivered
12
56
4546
SCTP
association
Stream 0
Stream 1
Stream 2
SCTP user
Stream
0
Figure 5-13 SCTP association with several streams
Message oriented protocolMessage oriented protocolMessage oriented protocolMessage oriented protocol
TCP is stream oriented, and this can be also an inconvenience for some
applications, since usually they have to include their own marks inside the
stream so the beginning and end of their messages can be identified. In
addition, they should explicitly make use of the push facility to ensure that the
complete message has been transferred in a reasonable time.
11. 5 Core Network
127
TCP
user
TCP TCP
TCP
user
Figure 5-14 Stream oriented protocol (TCP)
Opposed to TCP, an SCTP is message oriented. This means that the SCTP is
aware of the upper layer protocol data structures, thus always a complete
messages, well separated from each other are deliver to the SCTP user on the
receiving side.
SCTP
user
SCTP SCTP
SCTP
user
Figure 5-15 Message oriented protocol (SCTP)
SecuritySecuritySecuritySecurity
SCTP is using and new method for association establishment. It completely
removed the problem of the so-called SYN attack in TCP. This attack is very
simple and can affect any system connected to the Internet providing
TCP-based network services (such as an HTTP, FTP or mail server).
Let us see in short how this basic attack is performed. In TCP, the
establishment phase consists of a three-way handshake. These three packets
are usually called SYN (from Synchronisation, as it has the SYN flag set,
used only during the establishment), SYN-ACK (it has both the SYN and
ACK flags set) and ACK (this is a simple acknowledgement message with the
ACK flag set).
The problem is that the receiver of the SYN not only sends back the
SYN-ACK but also keeps some information about the packet received while
waiting for the ACK message (a server in this state is said to have a half-open
connection).
12. LTE/EPS Technology
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SYN Ack No. = 0, Seq. No. = Tag A
SYN ACK Ack No. = Tag A, Seq. No. =Tag B
ACK Ack No. = Tag B, ...
Client Server
TCB
Figure 5-16 Establishment procedure (TCP)
The memory space used to keep the information of all pending connections is
of finite size and it can be exhausted by intentionally creating too many
half-open connections. This makes the attacked system unable to accept any
new incoming connections and thus provokes a denial of service to other
users wanting to connect to the server. There is a timer that removes the
half-open connections from memory when they have been in this state for so
long, and that will eventually make the system to recover, but nothing will
change if the attacker continues sending SYN messages.
SYN Fake IP address A
SYN Fake IP address B
SYN Fake IP address C
SYN Fake IP address ...
SYN ACK
SYN ACK
SYN ACK
SYN
ACK
RST RST
R
ST
Figure 5-17 SYN attack in TCP
As we see, the attacker uses IP spoofing, making it unable to receive the
SYN-ACK segments produced, which is not a problem since it will never
answer them. All those SYN-ACK segments will be lost unless there is any
host with TCP service listening to the port and addresses used as the source of
the SYN segment. In that case that host will answer with a segment carrying
the RST (from Reset) flag set and the attacked system will delete the
information for that specific half-open connection.
SCTP gives no chance of success to this kind of attacks with its cookie
mechanism. When the designers of SCTP started to think about how to deal
13. 5 Core Network
129
with SYN flooding, they quickly saw that two things were necessary in order
not to make a new transport protocol with the same weakness:
• The server (the initiate of a new association) should not use even a
byte of memory until the association is completely established.
• There must be a way to recognise that the client (the initiator of the
association) is using its real IP address.
Usually, to meet the second requirement, the server sends some kind of key
number to the client who will only receive that information if the source
address used in its IP datagram is the real one. Once the client has that
information, it can then send a confirmation to the server using that key
number thus proving that it was telling the truth. This means that the server
needs to save somewhere that key number as well so there is a way it can
verify that the key number was the right one. But then comes the problem of
being forced to store that value somewhere and using some memory resources
while waiting for the answer that might never come.
Therefore, the idea was: why not instead of storing that information in our
system we make it to stay all the time in the network or in the client's
memory? Of course, one immediately thinks that if a datagram coming from
the client is the one that is going to provide us the information to check
against the client's answer, we have not done anything but making worse the
situation. The client will tell us whatever it wants and then it could just
completely open an association sending us a simple message.
But this is not necessarily true if we manage to convert the two problems into
another one: the server has to sign with a secret key the information sent to
the client. So, when it receives that information back from the client, it can
recognise due to the signature and using the secret key, that it did send exactly
that information, which is unmodified, and so we can be as confident on it as
if it had never left the server's buffers.
INIT
INIT ACK (COOKIE)
COOKIE ECHO (COOKIE)
Client Server
COOKIE ACK
TCB
COOKIE
TCB
Figure 5-18 Cookie (SCTP association establishment)
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SIGTRAN in GSM/UMTSSIGTRAN in GSM/UMTSSIGTRAN in GSM/UMTSSIGTRAN in GSM/UMTS
Traditionally, on all the interfaces in GSM/UMTS CN, as well as, on
interfaces connecting CN with the RAN, the SS7 is used. However the
traditional SS7 protocols stack is not a good solution for the networks with IP
transport since it still requires traditional TDM based interfaces to carry SS7
signalling links. That is way, majority of the GSM/UMTS operators are
replacing traditional SS7 protocol stack with SIGTRAN. However, since it is
just the modification of the traditionally SS7 protocol stack, only the MTP
and sometimes additionally SCCP protocols are replaced by SIGTRAN,
whereas the upper layers remains unchanged. This requires an extra set of
protocols called the SIGTRAN User Adaptation Layers (UALs) introducing
some extra cost, consuming processing power of the signalling nodes and
adding also some complexity to the system. In fact, SIGTRAN in the today
networks is only emulating the behaviour of the transport layers of the SS7.
IP
SCTP
MTP3
M2UAM2PA IUA V5UA
SCCP
TCAP
ISUP BSSAP MAP CAP Q.931 V5.2
SIGTRAN protocols
SS7 protocols
SIGTRAN protocols
SS7 protocols
M3UA SUA
Figure 5-19 SIGTRAN protocol suite
The User Adaptation Layers are named according to the service they replace,
rather than the user of that service. For example, M3UA adapts SCTP to
provide the services of MTP3, rather then providing a service to MTP3.
SIGTRSIGTRSIGTRSIGTRAN in EPSAN in EPSAN in EPSAN in EPS
Since EPS is introducing a completely new set of the signalling protocols,
these protocols were designed to operate directly on top of SCTP, without
need for any User Adaptation Layers. Hence, the protocol stack is not only
more elegant, but also it is much more efficient. Instead of emulating the
15. 5 Core Network
131
behaviour of the traditional SS7 the, the SCTP can provide its services
directly to the top most protocols, so they are now ready to fully utilise
capabilities of the SCTP. Thanks to the fact, that there is less protocols in the
stack the new system behaves better in terms of both, transmission bandwidth
utilisation, as well as processing power consumption in the end devices.
IP
SCTP
S1AP X2AP SGsAP Diameter
Figure 5-20 SIGTRAN in EPS
User data transferUser data transferUser data transferUser data transfer
The EPS nodes are interconnected via a private IP network of the operator,
thus when communicating between each other they are using IP addresses
from that private IP network.
The IP address allocated to the user is in fact belonging to the external PDN
addressing space, as it is used between the UE and the servers in the external
network.
eNB S-GW P-GW
IP private
IP IP IP IPIP IP
IP address allocation
IP private or
public
Figure 5-21 Tunnelling
This means that on the interface which carries user data, user IP packets going
to and from PDN have to be send inside other IP packets going between EPS
nodes.
16. LTE/EPS Technology
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S-GW P-GW
IP IPIPIP IP
Figure 5-22 User IP packet encapsulation
GTPGTPGTPGTP
GPRS Tunnelling Protocol (GTP) is a group of IP-based communications
protocols used to carry user IP packets within GSM, UMTS and EPS
networks. GTP can be decomposed into two separate protocols: GTP-C and
GTP-U.
GTPv2-C is used within the EPC for signalling between S-GW, P-GW, SGSN
and SRVCC enhanced MSC server. This allows the EPC to activate a session
on a user's behalf (EPS bearer), to deactivate the same session, to adjust QoS
parameters, or to update a session for a subscriber changing S-GW or SGSN.
Additionally, GTPv2-C is used to perform PS to CS handover between MME
and SRVCC enhanced MSC (see Chapter 10 for more details).
GTPv1-U is used for carrying user data within the EPC, between eNBs and
S-GWs (S1 interface) and between neighbouring eNBs (X2 interface).
UE is connected to an eNB without being aware of GTP.
TunnelsTunnelsTunnelsTunnels
GTP tunnels are used between two nodes communicating over a GTP based
interface, to separate traffic into different communication flows.
L1
L2
IP
UDP
GTP
L1
L2
IP
UDP
GTP
L1
L2
IP
UDP
GTP
L1
L2
IP
UDP
GTP
S1/S3/S4/S5/S8/
S10/S11/S12/Sv/X2
Figure 5-23 GTP protocol stack
17. 5 Core Network
133
A GTP tunnel is identified in each node with a Tunnel Endpoint Identifier
(TEID), an IP address and a UDP port number. The receiving end side of a
GTP tunnel locally assigns the TEID value the transmitting side has to use.
The TEID values are exchanged between tunnel endpoints using GTP-C,
S1-MME or X2-eNB messages.
eNB S-GW P-GW
SGSNRNC
GTP-U
MME
GTP-U
GTP-U
S1AP
RANAP
GTP-C
GTP-CGTP-C
eNB
GTP-U
GTP-U
X2AP
Figure 5-24 Tunnel control protocols
TunnelTunnelTunnelTunnel establishmentestablishmentestablishmentestablishment
The generic GTP-C/GTP-U tunnel establishment procedure is shown in
Fig.-5-25.
Node 1
Data
Node 2
Create Tunnel Request ( )
Control
Create Tunnel Response ( )
TEID & IP @ Node 1 for data
TEID & IP @ Node 1 for signalling
TEID & IP @ Node 2 for data
TEID & IP @ Node 2 for signalling
Figure 5-25 Generic tunnel establishment procedure
18. LTE/EPS Technology
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The node that is initiating the tunnel establishment sends to the terminating
node the Create Tunnel Request message; the message among many other
procedure specific parameters includes:
• Tunnel Endpoint Identifier (TEID) for User Plane that specifies
a TEID for GTP-U, chosen by the originating node. The terminating
node includes this TEID in the GTP-U header of all subsequent
GTP-U packets, send in the backward direction.
• Tunnel Endpoint Identifier (TEID) for Control Plane that specifies
a TEID for control plane message, chosen by the originating node. The
terminating node includes this TEID in the GTP-C header of all
subsequent GTP-C packets, send in the backward direction. Those
packets can carry messages used to complete the tunnel establishment,
modify the already existing tunnel or to release the existing tunnel,
• Originating node’s IP address for User Plane,
• Originating node’s IP address for Control Plane.
The terminating node answers with the Create Tunnel Response message
which contains:
• Tunnel Endpoint Identifier (TEID) for User Plane that specifies
a TEID for GTP-U, chosen by the terminating node. The originating
node includes this TEID in the GTP-U header of all subsequent
GTP-U packets, send in the forward direction.
• Tunnel Endpoint Identifier (TEID) for Control Plane that specifies
a TEID for control plane messages, chosen by the terminating node.
The originating node includes this TEID in the GTP-C header of all
subsequent GTP-C packets, sent in the forward direction.
• Terminating node’s IP address for User Plane,
• Terminating node’s IP address for Control Plane.
From that moment the user communication context on one side of the tunnel
is associated with the corresponding context on the other side of the tunnel.
This association is kept thanks to allocation of flow specific pairs of IP
addresses and TEIDs for both user data and control messages.
19. 5 Core Network
135
DiameterDiameterDiameterDiameter
Diameter is an AAA (Authentication, Authorisation and Accounting) protocol for
applications such as network access or IP mobility. The basic concept is to
provide a base protocol that can be extended in order to provide AAA services to
new access technologies. Diameter is intended to work in both local and roaming
AAA situations.
Diameter sessions consist of exchange of commands and Attribute Value
Pairs (AVPs) between authorised Diameter Clients and Servers. Some of the
command values are used by the Diameter protocol itself, while others deliver
data associated with particular applications that employ Diameter.
The base protocol provides basic mechanisms for reliable transport, message
delivery and error handling. It must be used along with a Diameter
application. A Diameter application uses the services of base protocol in order
to support a specific type of service. The Diameter Base Protocol defines
basic and standard behaviour of Diameter nodes as well-defined state
machines and also provides an extensible messaging mechanism that allows
information exchange among Diameter Nodes. Diameter Applications
augment the Base Protocol state machines with application-specific behaviour
to provide new AAA capabilities.
Diameter applicationsDiameter applicationsDiameter applicationsDiameter applications
There are two kinds of applications: IETF standards track applications and
vendor specific applications. The 3GPP Diameter application, relevant to
EPS, are listed in Fig. 5-26.
vPCRF ↔ hPCRFS916777267
MME/SGSN ↔ EIRS13/S13’16777252
MME ↔ HSSS6a16777251
PCRF ↔ PCEF (P-GW)Gx16777238
PCRF ↔ AFRx16777236
Nodes
Application
(interface)
Application
Identifier
vPCRF ↔ hPCRFS916777267
MME/SGSN ↔ EIRS13/S13’16777252
MME ↔ HSSS6a16777251
PCRF ↔ PCEF (P-GW)Gx16777238
PCRF ↔ AFRx16777236
Nodes
Application
(interface)
Application
Identifier
Figure 5-26 3GPP Diameter applications
The Diameter peers are communicating with each other over transport
connection provided by SCTP (SCTP association).
20. LTE/EPS Technology
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L1
L2
IP
SCTP
Diameter
L1
L2
IP
SCTP
Diameter
L1
L2
IP
SCTP
Diameter
L1
L2
IP
SCTP
Diameter
S6a/S13/S9/Rx/Gx
Figure 5-27 Diameter protocol stack
Proxy/Relay agentProxy/Relay agentProxy/Relay agentProxy/Relay agent
The Diameter base protocol defines two types of Diameter agent, namely
Diameter Relay agent and Diameter Proxy agent.
Diameter Relay is a function specialised in message forwarding, i.e.:
• A Relay agent does not inspect the actual contents of the message.
• When a Relay agent receives a request, it will route messages to next-
hop Diameter peer based on information found in the message e.g.
application ID and destination address.
Diameter Proxy includes the functions of Diameter Relay and additionally it
can inspects the actual contents of the message to perform admission control,
policy control, add special information elements handling.
The use of Proxy and Relay agent is especially important in case of roaming
scenarios to support scalability, resilience and maintainability and to reduce
the export of network topologies.
PCRF
Proxy/
Relay
Proxy/
Relay
PCRF
IMSI
Update Location Request,
Destination Realm: epc.mnc<MNC>.mcc<MCC>.3gppnetwork.org.
User Name: IMSI
GRX/IPX
vPLMN
hPLMN
HSS
MME
MME MME
HSS
HSS
Figure 5-28 Diameter Proxy/Relay agent
Please, note that without usage of Diameter Proxy/Relay agents it would be
necessary to provide a separate Diameter connection (SCTP association)
between each MME of the VPLMN and each HSS of every possible HPLMN.
21. 5 Core Network
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QQQQualityualityualityuality ooooffff SSSServiceerviceerviceervice
The EPS provides IP connectivity between a UE and a PLMN external packet
data network. This is referred to as PDN Connectivity Service. The PDN
Connectivity Service supports the transport of one or more Service Data
Flows (SDFs).
EPS bearerEPS bearerEPS bearerEPS bearer
For E-UTRAN access to the EPC the PDN connectivity service is provided by
an EPS bearer.
An EPS bearer uniquely identifies an SDF aggregate between a UE and a
P-GW.
An EPS bearer is the level of granularity for bearer level QoS control in the
EPC/E-UTRAN. That is, SDFs mapped to the same EPS bearer receive the
same bearer level packet forwarding treatment (e.g. scheduling policy, queue
management policy, rate shaping policy, RLC configuration, etc.). Providing
different bearer level QoS to two SDFs thus requires that a separate EPS
bearer is established for each SDF.
eNB S-GW P-GW
PDN
EPS Bearer #1 (bearer QoS1)
EPS Bearer #2 (bearer QoS2)
Service Data Flow (PCC parameters)
Figure 5-29 EPS bearer
One EPS bearer is established when the UE connects to a PDN, and that
remains established throughout the lifetime of the PDN connection to provide
the UE with always-on IP connectivity to that PDN. That bearer is referred to
as the default bearer. Any additional EPS bearer that is established to the
same PDN is referred to as a dedicated bearer.
22. LTE/EPS Technology
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eNB S-GW P-GW
PDN
Dedicated Bearer (additional bearer, GBR or non-GBR)
Default Bearer (created as a part of Attach proc., non-GBR)
Figure 5-30 Default & dedicated bearer
An UpLink/DownLink Traffic Flow Template (UL/DL TFT) is a set of
UL/DL packet filters. Every EPS bearer is associated with an UL TFT in the
UE and a DL TFT in the P-GW (i.e. PCEF).
UE eNB S-GW P-GW
PDN
EPS Bearer #1
EPS Bearer #2
FiltersFilters
Figure 5-31 Traffic Flow Template (TFT)
The initial bearer level QoS parameter values of the default bearer are
assigned by the network, based on subscription data (in case of E-UTRAN the
MME sets those initial values based on subscription data retrieved from HSS).
The PCEF may change those values based in interaction with the PCRF or
based on local configuration.
The decision to establish or modify a dedicated bearer can only be taken by
the EPC, and the bearer level QoS parameter values are always assigned by
the EPC. Therefore, the MME does not modify the bearer level QoS
parameter values received on the S11 reference point during establishment or
modification of a dedicated bearer. Instead, the MME only transparently
forwards those values to the E-UTRAN. Consequently, ‘QoS negotiation’
between the E-UTRAN and the EPC during dedicated bearer establishment /
modification is not supported. The MME may, however, reject the
establishment or modification of a dedicated bearer (e.g. in case the bearer
level QoS parameter values sent by the PCEF over an S8 roaming interface do
not comply with a roaming agreement).
23. 5 Core Network
139
eNB S-GW P-GW
Bearer establishment direction
no QoS negotiation
PCRF
AF
‘Bearer establishment trigger’
Figure 5-32 Bearer establishment direction
An EPS bearer is referred to as a GBR bearer if dedicated network resources
related to a Guaranteed Bit Rate (GBR) value that is associated with the EPS
bearer are permanently allocated (e.g. by an admission control function in the
eNB) at bearer establishment/modification. Otherwise, an EPS bearer is
referred to as a Non-GBR bearer.
A dedicated bearer can either be a GBR or a Non-GBR bearer. A default
bearer is a Non-GBR bearer.
An EPS bearer is realised by the following elements:
• An UL TFT in the UE maps an SDF to an EPS bearer in the UL
direction. Multiple SDFs can be multiplexed onto the same EPS bearer
by including multiple UL packet filters in the UL TFT;
• A DL TFT in the P-GW maps an SDF to an EPS bearer in the DL
direction. Multiple SDFs can be multiplexed onto the same EPS bearer
by including multiple DL packet filters in the DL TFT;
• A radio bearer transports the packets of an EPS bearer between a UE
and an eNB. There is a one-to-one mapping between an EPS bearer
and a radio bearer;
• An S1 bearer transports the packets of an EPS bearer between an eNB
and a S-GW;
• An S5/S8 bearer transports the packets of an EPS bearer between a
S-GW and a P-GW;
• A UE stores a mapping between an UL packet filter and a radio bearer
to create the mapping between an SDF and a radio bearer in the UL;
• A P-GW stores a mapping between a DL packet filter and an S5/S8
bearer to create the mapping between an SDF and an S5/S8 bearer in
the DL;
24. LTE/EPS Technology
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• An eNB stores a one-to-one mapping between a radio bearer and an
S1 to create the mapping between a radio bearer and an S1 bearer in
both the UL and DL;
• A S-GW stores a one-to-one mapping between an S1 bearer and an
S5/S8 bearer to create the mapping between an S1 bearer and an S5/S8
bearer in both the UL and DL.
QoS parametersQoS parametersQoS parametersQoS parameters
The bearer level (i.e. per bearer or per bearer aggregate) QoS parameters are
QCI, ARP, GBR, MBR, and AMBR described in this section.
Each EPS bearer (GBR and Non-GBR) is associated with the following bearer
level QoS parameters:
• QoS Class Identifier (QCI);
• Allocation and Retention Priority (ARP).
A QCI is a scalar that is used as a reference to access node-specific
parameters that control bearer level packet forwarding treatment (e.g.
scheduling weights, admission thresholds, queue management thresholds, link
layer protocol configuration, etc.), and that have been pre-configured by the
operator owning the access node (e.g. eNB).
The primary purpose of ARP is to decide whether a bearer establishment /
modification request can be accepted or needs to be rejected in case of
resource limitations (typically available radio capacity in case of GBR
bearers). In addition, the ARP can be used (e.g. by the eNB) to decide which
bearer(s) to drop during exceptional resource limitations (e.g. at handover).
Once successfully established, a bearer's ARP has no any impact on the bearer
level packet forwarding treatment (e.g. scheduling and rate control). Such
packet forwarding treatment should be solely determined by the other bearer
level QoS parameters: QCI, GBR, MBR, and AMBR.
Video telephony is one use case where it may be beneficial to use EPS bearers
with different ARP values for the same UE. In this use case an operator could
map voice to one bearer with a higher ARP, and video to another bearer with
a lower ARP. In a congestion situation (e.g. cell edge) the eNB can then drop
the ‘video bearer’ without affecting the ’voice bearer’. This would improve
service continuity.
25. 5 Core Network
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Each GBR bearer is additionally associated with the following bearer level
QoS parameters:
• Guaranteed Bit Rate (GBR);
• Maximum Bit Rate (MBR).
The GBR denotes the bit rate that can be expected to be provided by a GBR
bearer. The MBR limits the bit rate that can be expected to be provided by a
GBR bearer (e.g. excess traffic may get discarded by a rate shaping function).
Each APN is associated with the ‘per APN Aggregate Maximum Bit Rate
(APN-AMBR)’ IP-CAN session level QoS parameter. The APN-AMBR is a
subscription parameter stored per APN in the HSS. It limits the aggregate bit
rate that can be expected to be provided across all Non-GBR bearers and
across all PDN connections of the same APN (e.g. excess traffic may get
discarded by a rate shaping function). Each of those Non-GBR bearers could
potentially utilise the entire APN-AMBR, e.g. when the other Non-GBR
bearers do not carry any traffic. GBR bearers are outside the scope of
APN-AMBR. The P-GW enforces the APN-AMBR in downlink.
Enforcement of APN-AMBR in uplink is done in the UE and additionally in
the P-GW.
Each UE is associated with the ‘per UE Aggregate Maximum Bit Rate
(UE-AMBR)’ bearer level QoS parameter. The UE-AMBR is limited by a
subscription parameter stored in the HSS. The MME sets the used UE-AMBR
to the sum of the APN-AMBR of all active APNs up to the value of the
subscribed UE-AMBR. The UE-AMBR limits the aggregate bit rate that can
be expected to be provided across all Non-GBR bearers of a UE (e.g. excess
traffic may get discarded by a rate shaping function). Each of those Non-GBR
bearers could potentially utilise the entire UE-AMBR, e.g. when the other
Non-GBR bearers do not carry any traffic. GBR bearers are outside the scope
of UE-AMBR. The E-UTRAN enforces the UE-AMBR in uplink and
downlink.
The GBR and MBR denote bit rates of traffic per bearer while UE-AMBR/
APN-AMBR denote bit rates of traffic per group of bearers. Each of those
QoS parameters has an uplink and a downlink component. On S1_MME the
values of the GBR, MBR, and AMBR refer to the bit stream excluding the
GTP-U/IP header overhead of the tunnel on S1_U.
One 'EPS subscribed QoS profile' is defined for each APN permitted for the
subscriber. It contains the bearer level QoS parameter values for that APN's
default bearer (QCI and ARP) and the APN-AMBR.
26. LTE/EPS Technology
142
EPS bearer
GBR bearer non-GBR bearer
QCI
ARP
GBR
MBR
UE-AMBR APN-AMBR
Figure 5-33 EPS bearer related QoS parameters
Mapping betweenMapping betweenMapping betweenMapping between QQQQCCCCI and UMTS QoS parametersI and UMTS QoS parametersI and UMTS QoS parametersI and UMTS QoS parameters
A recommended mapping for QoS Class Identifier to/from UMTS QoS
parameters is shown in Fig. 5-34.
---background9
-no3interactive8
-no2interactive7
-no1interactive6
-yes1interactive5
unknown--streaming4
speech--streaming3
unknown--conversational2
speech--conversational1
source statistics
descriptor
signalling
indication
THPtraffic class
UMTS QoS parameters
QCI
---background9
-no3interactive8
-no2interactive7
-no1interactive6
-yes1interactive5
unknown--streaming4
speech--streaming3
unknown--conversational2
speech--conversational1
source statistics
descriptor
signalling
indication
THPtraffic class
UMTS QoS parameters
QCI
Figure 5-34 QCI to UMTS QoS parameters mapping