This document discusses jitter, latency, and delay in network communications. It provides definitions and explanations of these terms:
1. Jitter is the variation in the delay of received packets caused by network congestion, queuing, or errors, rather than packets being transmitted at an even pace. This can cause gaps in audio if packets are missing.
2. Delay and latency refer to the time it takes a bit to be transmitted from source to destination. Jitter is a type of delay that varies over time.
3. Solutions to reduce jitter include increasing the receive jitter buffer size and delay, using larger RTP packets, and lowering audio quality.
This document provides a troubleshooting guide for LTE inter-radio access technology (IRAT) handovers. It describes why IRAT is needed as voice revenues remain important while data revenues grow. It also outlines the applications of IRAT, delivery policies for idle mode, connected mode, and voice services. Signaling procedures for IRAT handovers including reselection, redirection, and PS handover are defined. Key performance indicators for IRAT including control plane delays and user plane interruption times are also defined to help diagnose IRAT issues.
The document discusses LTE network architecture including nodes like the eNodeB, MME, SGW and PGW, and their functions. It also outlines the basic LTE call flows for initial call setup, detach procedures, idle-to-active transitions, and handovers. Key call flow steps include attach request, authentication, context setup, and establishment of bearers between the UE and PDN gateway.
The document discusses VoLTE optimization services including RAN and EPC analysis using various tools. It details accomplishments like optimizing sites for carriers and analyzing problems like VoLTE drop issues. The key services described are VoLTE parameter audits, drive log analysis, UETR analysis, and end-to-end VoLTE call tracing. Case studies provided examine issues like QCI profile not defined, RRC drops without VoLTE drops, and improvements gained from features like ICIC and parameter changes.
The document discusses LTE system signaling procedures. It begins with objectives of understanding LTE architecture, elementary procedures of interfaces like S1, X2 and Uu, and procedures for service setup, release and handover. It then covers topics like system architecture, bearer service architecture, elementary procedures on Uu including connection establishment and release, and procedures on S1 and X2 interfaces. The document aims to help readers understand LTE signaling flows and procedures.
This document provides an overview and detailed descriptions of Circuit Switched Fallback (CSFB) features in an evolved Radio Access Network (eRAN). It describes CSFB procedures for falling back from an LTE network to UTRAN or GERAN networks to support circuit switched services like voice calls. The document includes sections on CSFB architectures, handover decisions and executions, related interfaces, engineering guidelines, parameters and troubleshooting.
The document provides an overview of LTE (Long Term Evolution) network architecture and transmission schemes. It describes the simplified LTE network elements including eNB, MME, S-GW and P-GW. It explains the downlink transmission scheme using OFDMA and reference signal structure. It also covers uplink transmission using SC-FDMA, control and data channels as well as frame structure in both FDD and TDD modes.
The document discusses Inter-Radio Access Technology (IRAT) handover and cell change, which allows the transition of 3G voice and data services between WCDMA and GSM networks to maintain connections and prevent dropped calls. It describes the IRAT handover evaluation process based on UE measurement reports and covers topics like coverage monitoring, event reporting, parameters, handover sequences, cell change procedures, and directed retry to offload traffic between networks.
The document describes the signaling flow and messages exchanged between the various network entities during the LTE attach procedure and default bearer activation for a UE. It provides details on the S1AP, S6a, S11 and NAS messages with information elements like IMSI, GUTI, QoS parameters, GTP tunneling endpoints etc. exchanged at each step of the procedure to establish the default data path for a UE attaching to the network.
This document provides a troubleshooting guide for LTE inter-radio access technology (IRAT) handovers. It describes why IRAT is needed as voice revenues remain important while data revenues grow. It also outlines the applications of IRAT, delivery policies for idle mode, connected mode, and voice services. Signaling procedures for IRAT handovers including reselection, redirection, and PS handover are defined. Key performance indicators for IRAT including control plane delays and user plane interruption times are also defined to help diagnose IRAT issues.
The document discusses LTE network architecture including nodes like the eNodeB, MME, SGW and PGW, and their functions. It also outlines the basic LTE call flows for initial call setup, detach procedures, idle-to-active transitions, and handovers. Key call flow steps include attach request, authentication, context setup, and establishment of bearers between the UE and PDN gateway.
The document discusses VoLTE optimization services including RAN and EPC analysis using various tools. It details accomplishments like optimizing sites for carriers and analyzing problems like VoLTE drop issues. The key services described are VoLTE parameter audits, drive log analysis, UETR analysis, and end-to-end VoLTE call tracing. Case studies provided examine issues like QCI profile not defined, RRC drops without VoLTE drops, and improvements gained from features like ICIC and parameter changes.
The document discusses LTE system signaling procedures. It begins with objectives of understanding LTE architecture, elementary procedures of interfaces like S1, X2 and Uu, and procedures for service setup, release and handover. It then covers topics like system architecture, bearer service architecture, elementary procedures on Uu including connection establishment and release, and procedures on S1 and X2 interfaces. The document aims to help readers understand LTE signaling flows and procedures.
This document provides an overview and detailed descriptions of Circuit Switched Fallback (CSFB) features in an evolved Radio Access Network (eRAN). It describes CSFB procedures for falling back from an LTE network to UTRAN or GERAN networks to support circuit switched services like voice calls. The document includes sections on CSFB architectures, handover decisions and executions, related interfaces, engineering guidelines, parameters and troubleshooting.
The document provides an overview of LTE (Long Term Evolution) network architecture and transmission schemes. It describes the simplified LTE network elements including eNB, MME, S-GW and P-GW. It explains the downlink transmission scheme using OFDMA and reference signal structure. It also covers uplink transmission using SC-FDMA, control and data channels as well as frame structure in both FDD and TDD modes.
The document discusses Inter-Radio Access Technology (IRAT) handover and cell change, which allows the transition of 3G voice and data services between WCDMA and GSM networks to maintain connections and prevent dropped calls. It describes the IRAT handover evaluation process based on UE measurement reports and covers topics like coverage monitoring, event reporting, parameters, handover sequences, cell change procedures, and directed retry to offload traffic between networks.
The document describes the signaling flow and messages exchanged between the various network entities during the LTE attach procedure and default bearer activation for a UE. It provides details on the S1AP, S6a, S11 and NAS messages with information elements like IMSI, GUTI, QoS parameters, GTP tunneling endpoints etc. exchanged at each step of the procedure to establish the default data path for a UE attaching to the network.
The document discusses various resources in an LTE network that need to be monitored to ensure capacity and quality of service. It describes several key performance indicators (KPIs) related to resources like connected users, traffic volume, paging messages, processor usage, and provides thresholds and solutions to address issues.
1-NSA Basical Precedure Introduction -trainning 5G RADIO FREQUENCY EMERSON E...EMERSON EDUARDO RODRIGUES
1. The document discusses NSA (non-standalone) architecture and mobility procedures, including SgNB addition, change, and release.
2. It describes the NSA anchoring feature which aims to keep UEs anchored to preferred anchor points as much as possible to improve user experience.
3. Key aspects of EN-DC carrier management and mobility are explained, such as independent anchor selection in both idle and connected modes.
This document discusses LTE CS Fallback features which allow LTE networks to reuse CS infrastructure to provide voice and other circuit switched services. CS Fallback enables LTE terminals to redirect to 2G/3G networks when initiating CS services like voice calls. The key aspects covered include the CS Fallback network architecture using the SGs interface, the combined attach procedure used for location updates, advantages/disadvantages of different CS Fallback mechanisms, and signaling flows for CS Fallback and paging.
This document specifies 5G RRC parameters including message definitions and information elements for timers, counters, constants, and UE variables. It defines RRC messages that may be sent on different logical channels and provides descriptions of message fields. It also specifies bandwidth part configurations, measurement reporting, reconfiguration messages, and beam failure recovery resources.
Umts network protocols and complete call flowssivakumar D
This document provides an overview of the network architecture and signalling protocols in UMTS networks. It describes the main network elements of UTRAN, UE and CN. It explains the interfaces between these elements and the protocols used for communication, including RRC for UE-RNC signalling, RANAP for RNC-CN signalling, and NAS protocols for non-access signalling between UE and CN. It also summarizes the protocol stacks used over the Iu interfaces between RNC and CN for circuit-switched and packet-switched domains.
1. The document provides Huawei's mobility strategy recommendations for Maxis' LTE network, which involves LTE, UMTS, and GSM networks.
2. The strategy addresses cell selection and reselection procedures in both idle and connected modes between the different RATs and frequencies. It aims to optimize coverage and load balancing through configuration of various priority and threshold parameters.
3. Over multiple revisions from 2012 to 2018, the strategy has been updated based on trials and discussions between Maxis and Huawei to refine the parameter settings and push more users to preferred frequencies like L2600.
The document provides an overview of LTE and its evolution from previous cellular standards. It discusses the targets of LTE including high data rates up to 100 Mbps, low latency, high spectral efficiency, and flexibility in spectrum and bandwidth. It also describes the EPS architecture with E-UTRAN, EPC, and the air interface structure of LTE including OFDMA in the downlink and SC-FDMA in the uplink. Key layers like the PHY, MAC, and RLC layers are also summarized.
This document summarizes the key procedures and signal flows in setting up an LTE session for a UE:
1) The UE establishes an RRC connection with the eNodeB through random access and preamble signaling.
2) The UE then attaches to the core network through the MME, and authentication procedures are performed.
3) Finally, the default bearer for user data is established through signaling between the UE, eNodeB, MME, SGW and PGW. Once complete, user data sessions can be exchanged.
Sharing session huawei network optimization january 2015 ver3Arwan Priatna
This document discusses 2G/3G network optimization. It begins with an introduction to 3G WCDMA and outlines the structure and principles of 2G/3G networks, including the evolution from 2G to 3G. It then describes various 2G/3G radio network optimization tools and methodologies, as well as presenting some case studies of 2G/3G neighboring cell analysis.
This document describes CSFB (Circuit Switch Fallback), which allows LTE users to fallback to 2G/3G networks to make voice calls or SMS when out of LTE coverage. It outlines the network architecture and call flows for CSFB, including mobile terminating calls, SMS-MO, and SMS-MT. Key interfaces involved are LTE-Uu, S1-MME, Iu-CS, SGs. CSFB supports fallback to UTRAN or GERAN networks for circuit switched services when the UE is in E-UTRAN but not able to receive CS services over the LTE network.
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).
This document provides an overview of the network architecture and signalling protocols in UMTS networks. It describes the main network elements of UTRAN, UE and CN. It explains the interfaces between these elements and the protocols used for communication, including RRC for UE-RNC signalling, RANAP for RNC-CN signalling, and NAS protocols for non-access signalling between UE and CN. It also summarizes the protocol stacks used over the Iu interfaces between RNC and CN for circuit-switched and packet-switched domains.
1. The document discusses NSA mobility management for Huawei's 5G network, including procedures for adding, changing, and releasing the secondary node (SgNB).
2. Key procedures covered include SgNB addition triggered by the MeNB, intra-SgNB and inter-SgNB PSCell changes, and intra-MeNB and inter-MeNB handovers.
3. NSA mobility is anchored to the LTE network, with the eNodeB delivering NR measurement configurations and processing measurement reports.
The document provides an overview of cellular communications signaling for LTE, LTE-A, and 4G technologies. It describes the LTE architecture including functions of the evolved node B, mobility management entity, serving gateway, home subscriber server, and PDN gateway. It also provides details on the LTE physical layer including OFDMA modulation, reference signal measurements for handover, and an example handover procedure using the X2 interface. In conclusion, it discusses key criteria for designing handovers and aspects for further research.
4G-LTE Paging is made simple and easy. How is paging handled in NAS, RRC and Physical layer. With DRX cycle, how will UE NOT miss any paging and synchronised? How to implement paging in RRC?
It is a handbook of UMTS/LTE/EPC CSFB call flows.
This document is originally edited by Justin MA and it is free to share to everyone who are interested.
All reference/resource are from internet. If there is any copy-right issue, please kindly inform Justin by majachang@gmail.com.
Thanks for your reading!
LTE Location Management and Mobility Managementaliirfan04
Provides an overview of power management (connected and idle mode) and mobility management (both idle-mode mobility (cell selection and re-selection) and active mode (handovers).
- To support CS services like voice in LTE networks, different phases of evolution have been proposed including CSFB and VoLTE.
- CSFB allows CS services to work by falling back to legacy 2G/3G networks, while VoLTE supports native voice over IP capabilities in LTE.
- SRVCC allows seamless handover of VoLTE calls between LTE and legacy networks by transferring sessions between the core networks.
This document summarizes a research paper that proposes a clustered conduction of VoIP routing (CCVR) topology for 802.11 wireless local area networks to improve quality of service. The CCVR topology clusters VoIP data packets into different buffers based on their properties. It introduces a novel scheduling mechanism to differentiate packet loss and transmission delay. Simulation results showed that the CCVR approach achieved better frame delivery ratios and less frame overhead compared to existing single buffer and scheduling strategies. The clustering and prioritization of buffers and adaptive scheduling of traffic flows helped meet various quality of service guarantees for delay, packet loss and bandwidth utilization.
Ocgrr a new scheduling algorithm for differentiated services networks(synop...Mumbai Academisc
OCGRR is a new scheduling algorithm that supports differentiated services in network core routers. It schedules packets from different traffic classes in small rounds within a frame to reduce jitter and latency. OCGRR sends only one packet per class in each round and can adjust permissions to avoid starvation of lower priority classes. It aims to fairly schedule IP packets, reduce packet bursts from the same stream, and give all streams equal bandwidth access.
The document discusses various resources in an LTE network that need to be monitored to ensure capacity and quality of service. It describes several key performance indicators (KPIs) related to resources like connected users, traffic volume, paging messages, processor usage, and provides thresholds and solutions to address issues.
1-NSA Basical Precedure Introduction -trainning 5G RADIO FREQUENCY EMERSON E...EMERSON EDUARDO RODRIGUES
1. The document discusses NSA (non-standalone) architecture and mobility procedures, including SgNB addition, change, and release.
2. It describes the NSA anchoring feature which aims to keep UEs anchored to preferred anchor points as much as possible to improve user experience.
3. Key aspects of EN-DC carrier management and mobility are explained, such as independent anchor selection in both idle and connected modes.
This document discusses LTE CS Fallback features which allow LTE networks to reuse CS infrastructure to provide voice and other circuit switched services. CS Fallback enables LTE terminals to redirect to 2G/3G networks when initiating CS services like voice calls. The key aspects covered include the CS Fallback network architecture using the SGs interface, the combined attach procedure used for location updates, advantages/disadvantages of different CS Fallback mechanisms, and signaling flows for CS Fallback and paging.
This document specifies 5G RRC parameters including message definitions and information elements for timers, counters, constants, and UE variables. It defines RRC messages that may be sent on different logical channels and provides descriptions of message fields. It also specifies bandwidth part configurations, measurement reporting, reconfiguration messages, and beam failure recovery resources.
Umts network protocols and complete call flowssivakumar D
This document provides an overview of the network architecture and signalling protocols in UMTS networks. It describes the main network elements of UTRAN, UE and CN. It explains the interfaces between these elements and the protocols used for communication, including RRC for UE-RNC signalling, RANAP for RNC-CN signalling, and NAS protocols for non-access signalling between UE and CN. It also summarizes the protocol stacks used over the Iu interfaces between RNC and CN for circuit-switched and packet-switched domains.
1. The document provides Huawei's mobility strategy recommendations for Maxis' LTE network, which involves LTE, UMTS, and GSM networks.
2. The strategy addresses cell selection and reselection procedures in both idle and connected modes between the different RATs and frequencies. It aims to optimize coverage and load balancing through configuration of various priority and threshold parameters.
3. Over multiple revisions from 2012 to 2018, the strategy has been updated based on trials and discussions between Maxis and Huawei to refine the parameter settings and push more users to preferred frequencies like L2600.
The document provides an overview of LTE and its evolution from previous cellular standards. It discusses the targets of LTE including high data rates up to 100 Mbps, low latency, high spectral efficiency, and flexibility in spectrum and bandwidth. It also describes the EPS architecture with E-UTRAN, EPC, and the air interface structure of LTE including OFDMA in the downlink and SC-FDMA in the uplink. Key layers like the PHY, MAC, and RLC layers are also summarized.
This document summarizes the key procedures and signal flows in setting up an LTE session for a UE:
1) The UE establishes an RRC connection with the eNodeB through random access and preamble signaling.
2) The UE then attaches to the core network through the MME, and authentication procedures are performed.
3) Finally, the default bearer for user data is established through signaling between the UE, eNodeB, MME, SGW and PGW. Once complete, user data sessions can be exchanged.
Sharing session huawei network optimization january 2015 ver3Arwan Priatna
This document discusses 2G/3G network optimization. It begins with an introduction to 3G WCDMA and outlines the structure and principles of 2G/3G networks, including the evolution from 2G to 3G. It then describes various 2G/3G radio network optimization tools and methodologies, as well as presenting some case studies of 2G/3G neighboring cell analysis.
This document describes CSFB (Circuit Switch Fallback), which allows LTE users to fallback to 2G/3G networks to make voice calls or SMS when out of LTE coverage. It outlines the network architecture and call flows for CSFB, including mobile terminating calls, SMS-MO, and SMS-MT. Key interfaces involved are LTE-Uu, S1-MME, Iu-CS, SGs. CSFB supports fallback to UTRAN or GERAN networks for circuit switched services when the UE is in E-UTRAN but not able to receive CS services over the LTE network.
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).
This document provides an overview of the network architecture and signalling protocols in UMTS networks. It describes the main network elements of UTRAN, UE and CN. It explains the interfaces between these elements and the protocols used for communication, including RRC for UE-RNC signalling, RANAP for RNC-CN signalling, and NAS protocols for non-access signalling between UE and CN. It also summarizes the protocol stacks used over the Iu interfaces between RNC and CN for circuit-switched and packet-switched domains.
1. The document discusses NSA mobility management for Huawei's 5G network, including procedures for adding, changing, and releasing the secondary node (SgNB).
2. Key procedures covered include SgNB addition triggered by the MeNB, intra-SgNB and inter-SgNB PSCell changes, and intra-MeNB and inter-MeNB handovers.
3. NSA mobility is anchored to the LTE network, with the eNodeB delivering NR measurement configurations and processing measurement reports.
The document provides an overview of cellular communications signaling for LTE, LTE-A, and 4G technologies. It describes the LTE architecture including functions of the evolved node B, mobility management entity, serving gateway, home subscriber server, and PDN gateway. It also provides details on the LTE physical layer including OFDMA modulation, reference signal measurements for handover, and an example handover procedure using the X2 interface. In conclusion, it discusses key criteria for designing handovers and aspects for further research.
4G-LTE Paging is made simple and easy. How is paging handled in NAS, RRC and Physical layer. With DRX cycle, how will UE NOT miss any paging and synchronised? How to implement paging in RRC?
It is a handbook of UMTS/LTE/EPC CSFB call flows.
This document is originally edited by Justin MA and it is free to share to everyone who are interested.
All reference/resource are from internet. If there is any copy-right issue, please kindly inform Justin by majachang@gmail.com.
Thanks for your reading!
LTE Location Management and Mobility Managementaliirfan04
Provides an overview of power management (connected and idle mode) and mobility management (both idle-mode mobility (cell selection and re-selection) and active mode (handovers).
- To support CS services like voice in LTE networks, different phases of evolution have been proposed including CSFB and VoLTE.
- CSFB allows CS services to work by falling back to legacy 2G/3G networks, while VoLTE supports native voice over IP capabilities in LTE.
- SRVCC allows seamless handover of VoLTE calls between LTE and legacy networks by transferring sessions between the core networks.
This document summarizes a research paper that proposes a clustered conduction of VoIP routing (CCVR) topology for 802.11 wireless local area networks to improve quality of service. The CCVR topology clusters VoIP data packets into different buffers based on their properties. It introduces a novel scheduling mechanism to differentiate packet loss and transmission delay. Simulation results showed that the CCVR approach achieved better frame delivery ratios and less frame overhead compared to existing single buffer and scheduling strategies. The clustering and prioritization of buffers and adaptive scheduling of traffic flows helped meet various quality of service guarantees for delay, packet loss and bandwidth utilization.
Ocgrr a new scheduling algorithm for differentiated services networks(synop...Mumbai Academisc
OCGRR is a new scheduling algorithm that supports differentiated services in network core routers. It schedules packets from different traffic classes in small rounds within a frame to reduce jitter and latency. OCGRR sends only one packet per class in each round and can adjust permissions to avoid starvation of lower priority classes. It aims to fairly schedule IP packets, reduce packet bursts from the same stream, and give all streams equal bandwidth access.
This document discusses quality of service (QoS) in wireless networks. It describes how QoS is defined using parameters like QCI, ARP, GBR and MBR. It then explains some key QoS-related concepts and parameters in more detail, including QCI, bearers, scheduling, and default vs dedicated bearers. It also provides examples of commands used to configure QoS settings for UEs in a wireless test system.
Design and implementation of low latency weighted round robin (ll wrr) schedu...ijwmn
Today’s wireless broadband networks are required to provide QoS guarantee as well as fairness to
different kinds of traffic. Recent wireless standards (such as LTE and WiMAX) have special provisions at
MAC layer for differentiating and scheduling data traffic for achieving QoS. The main focus of this paper is
concerned with high speed packet queuing/scheduling at central node such as base station (BS) or router to
handle network traffic. This paper proposes novel packet queuing scheme termed as Low Latency
Weighted Round Robin (LL-WRR) which is simple and effective amendment to weighted round robin (WRR)
for achieving low latency and improved fairness. Proposed LL-WRR queue scheduling scheme is
implemented in NS-2 considering IEEE 802.16 network [1] with real time video and Constant Bit Rate
(CBR) audio traffic connections. Simulation results show improvement obtained in latency and fairness
using LL-WRR. The proposed scheme introduces extra complexity of computing coefficient but its overall
impact is very small.
Quality of Service for Video Streaming using EDCA in MANETijsrd.com
Mobile Ad-hoc network(MANET) is a collection of wireless terminals that are able to dynamically form a temporary network. To establish such a network no fixed infrastructure is required. Here, it is the responsibility of network nodes to forward each other's packets and thus these nodes also act as routers. In such a network resources are limited and also topology changes dynamically. So providing Quality of service(QoS) is also necessary. QoS is more important for real time applications for example Video Streaming. IEEE 802.11e network standard supports QoS through EDCA technique. This technique does not fulfill the requirements of QoS. So, in this project modified EDCA technique is proposed to enhance QoS for Video Streaming application. This technique is implemented in NS2 and compared with traditional EDCA.
QOS-BASED PACKET SCHEDULING ALGORITHMS FOR HETEROGENEOUS LTEADVANCED NETWORKS...ijwmn
The number of LTE (Long-Term Evolution) users and their applications has increased significantly in the
last decade, which increased the demand on the mobile network. LTE-Advanced (LTE-A) comes with many
features that can support this increasing demand. LTE-A supports Heterogeneous Networks (HetNets)
deployment, in which it consists of a mix of macro-cells, remote radio heads, and low power nodes such as
Pico-cells, and Femto-cells. Embedding this mix of base-stations in a macro-cellular network allows for
achieving significant gains in coverage, throughput and system capacity compared to the use of macrocells only. These base-stations can operate on the same wireless channel as the macro-cellular network,
which will provide higher spatial reuse via cell splitting. Also, it allows network operators to support
higher data traffic by offloading it to smaller cells, such as Femto-cells. Hence, it enables network
operators to provide their growing number of users with the required Quality of Service (QoS) that meets
with their service demands. In-order for the network operators to make the best out of the heterogeneous
LTE-A network, they need to use QoS-based packet scheduling algorithms that can efficiently manage the
spectrum resources in the HetNets deployment. In this paper, we survey Quality of Service (QoS) based
packet scheduling algorithms that were proposed in the literature for the use of packet scheduling in
Heterogeneous LTE-A Networks. We start by explaining the concepts of QoS in LTE, heterogeneous LTE-A
networks, and how traffic is classified within a packet scheduling architecture for heterogeneous LTE-A
networks. Then, by summarising the proposed QoS-based packet scheduling algorithms in the literature for
Heterogeneous LTE-A Networks, and for Femtocells LTE-A Networks. And finally, we provide some
concluding remarks in the last section.
QoS-based Packet Scheduling Algorithms for Heterogeneous LTE-Advanced Network...ijwmn
The number of LTE (Long-Term Evolution) users and their applications has increased significantly in the last decade, which increased the demand on the mobile network. LTE-Advanced (LTE-A) comes with many features that can support this increasing demand. LTE-A supports Heterogeneous Networks (HetNets) deployment, in which it consists of a mix of macro-cells, remote radio heads, and low power nodes such as Pico-cells, and Femto-cells. Embedding this mix of base-stations in a macro-cellular network allows for achieving significant gains in coverage, throughput and system capacity compared to the use of macrocells only. These base-stations can operate on the same wireless channel as the macro-cellular network, which will provide higher spatial reuse via cell splitting. Also, it allows network operators to support higher data traffic by offloading it to smaller cells, such as Femto-cells. Hence, it enables network operators to provide their growing number of users with the required Quality of Service (QoS) that meets with their service demands. In-order for the network operators to make the best out of the heterogeneous LTE-A network, they need to use QoS-based packet scheduling algorithms that can efficiently manage the spectrum resources in the HetNets deployment. In this paper, we survey Quality of Service (QoS) based packet scheduling algorithms that were proposed in the literature for the use of packet scheduling in Heterogeneous LTE-A Networks. We start by explaining the concepts of QoS in LTE, heterogeneous LTE-A networks, and how traffic is classified within a packet scheduling architecture for heterogeneous LTE-A networks. Then, by summarising the proposed QoS-based packet scheduling algorithms in the literature for Heterogeneous LTE-A Networks, and for Femtocells LTE-A Networks. And finally, we provide some concluding remarks in the last section.
Long-Term Evolution (LTE), an emerging and promising fourth generation mobile technology, is expected
to offer ubiquitous broadband access to the mobile subscribers. In this paper, the performance of Frame
Level Scheduler (FLS), Exponential (EXP) rule, Logarithmic (LOG) rule and Maximum-Largest Weighted
Delay First (M-LWDF) packet scheduling algorithms has been studied in the downlink 3GPP LTE cellular
network. To this aim, a single cell with interference scenario has been considered. The performance
evaluation is made by varying the number of UEs ranging from 10 to 50 (Case 1) and user speed in the
range of [3, 120] km/h (Case 2). Results show that while the number of UEs and user speed increases, the
performance of the considered scheduling schemes degrades and in both case FLS outperforms other three
schemes in terms of several performance indexes such as average throughput, packet loss ratio (PLR),
packet delay and fairness index.
Two-level scheduling scheme for integrated 4G-WLAN network IJECEIAES
In this paper, a novel scheduling scheme for the Fourth Generation (4G)-Wireless Local Area Network (WLAN) network is proposed to ensure that end to end traffic transaction is provisioned seamlessly. The scheduling scheme is divided into two stages; in stage one, traffic is separated into Actual Time Traffic (ATT) and Non-Actual-Time Traffic (NATT), while in stage two, complex queuing strategy is performed. In stage one, Class-Based Queuing (CBQ) and Deficit Round Robin(DRR) are used for NATT and ATT applications, respectively to separate and forward traffic themselves according to source requirements. Whereas in the stage, two Control Priority Queuing (CPQ) is used to assign each class the appropriate priority level. Evaluation of the performance of the integrated network was done according to several metrics such as end-to-end delay, jitter, packet loss, and network’s throughput. Results demonstrate major improvements for AT services with minor degradation on NAT applications after implementing the new scheduling scheme.
Multiple Downlink Fair Packet Scheduling Scheme in Wi-MaxEditor IJCATR
IEEE 802.16 is standardization for a broadband wireless access in network metropolitan area network (MAN). IEEE 802.16
standard (Wi-Max) defines the concrete quality of service (QoS) requirement, a scheduling scheme and efficient packet scheduling
scheme which is necessary to achieve the QoS requirement. In this paper, a novel waiting queue based on downlink bandwidth
allocation architecture from a number of rtps schedule has been proposed to improve the performance of nrtPS services without any
impaction to other services. This paper proposes an efficient QoS scheduling scheme that satisfies both throughput and delay guarantee
to various real and non-real applications corresponding to different scheduling schemes for k=1,2,3,4. Simulation results show that
proposed scheduling scheme can provide a tight QoS guarantee in terms of delay for all types of traffic as defined in WiMax standards.
This process results in maintaining the fairness of allocation and helps to eliminate starvation of lower priority class services. The
authors propose a new efficient and generalized scheduling schemes for IEEE 802.16 broadband wireless access system reflecting the
delay requirements.
Survey on scheduling and radio resources allocation in lteijngnjournal
- The document discusses scheduling and radio resource allocation in LTE networks. It focuses on the radio resource manager (RRM) element in LTE that performs admission control and packet scheduling.
- Several scheduling algorithms are proposed for both uplink and downlink directions, including proportional fair, EXP-PF, round robin, max-min fair, and algorithms that aim to maximize throughput or support quality of service requirements.
- The paper provides an overview of these scheduling algorithms, evaluates their performance, and offers criticism on how to best allocate radio resources in LTE networks.
Packet and message coalescing techniques can improve energy efficiency. Packet coalescing groups packets into bursts before transmission to reduce overhead from transitioning network links like Ethernet interfaces between active and sleep modes. Message coalescing does a similar grouping at the message level. Evaluating coalescing for Energy Efficient Ethernet, smaller buffers had lower energy usage but increased delay, while larger buffers improved energy savings with higher delay. Message coalescing was also studied for InfiniBand clusters to reduce memory usage.
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.
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Ericsson interview
1. Step Description Value (30 % HARQ)
1 eNBProcessingDelay(S1-U->Uu) 1 ms
2 Frame Alignment 1,022 ms
3 TTI for DL DATA PACKET 0,675 ms
4 HARQ Retransmission 0,3 * 5 ms
5 UE ProcessingDelay 1 ms
6 S1-U TransferDelayand aGW 7 ms (Note)
Total one way delay 12,2 ms
NOTE: The delaybudgetwasmeasuredinproductionenvironments,The S1-Udelayisbandwith
depended.
Speech pathdelay
Jitter is defined as a variation in the delay of received packets. The sending side
transmits packets in a continuous stream and spaces them evenly apart. Because of network
congestion, improper queuing, or configuration errors, the delay betweenpackets can vary
instead of remaining constant, as shown in the figure.
n the RRC you can increase jtter buffer size and delay. Try to use larger RTP package, test with
40ms. Lower audio quality = 0 can be a solution. That's about what you can do locally in the
RRCs
ncrease rx jitter buffer to min 12+
- increase rx jitter delay to min 10+
- audio packet size 20 or 40
Jitter is a variation in packet transit delay caused by queuing, contention and serialization
effects on the path through the network. In general, higher levels ofjitter are more likely to occur
on either slow or heavily congested links.
2. Delay and latency are similar terms that refer to the amount of time it takes a bit to be
transmitted from source to destination. Jitter is delay that varies over time. One way to
view latency is how long a system holds on to a packet. ... The speed of a system is affected by
congestion and delays.
Jitter in IP networks is the variation in the latency on a packet flow between two systems, when
some packets take longer to travel from one system to the other.Jitter results from network
congestion, timing drift and route changes
Handover interruption delay
HybridARQ enabledRate adaptationbasedonCQIfeedbackRLCAMmode Multiple bearersQoS
scheduler
Duringhandoverprocess,forsome period,userequipments cannotexchangeuserplane packetswith
any of the base stations.Thisperiodisknownashandoverinterruptiontime.Itincludesthe time
requiredtoexecute anyradioaccessnetworkprocedure,radioresourcecontrol signaling,orother
message exchanges betweenthe userequipmentandthe radioaccessnetwork.The impactof intraLTE-
Advancedhandoversoninterruptiontimeislessthanorequal to that providedbyhandoversinLTE.In
LTE-Advanced,sub-framesize,alsoknownasTransmissionTime Interval (TTI),of 1msmakesitcapable
of adaptingtofast changingradiolinkconditionsandallowsexploitationof multiuserdiversity[7].In
LTE-Advanced,processingdelaysindifferentnodesandRACHschedulingperiodare reducedin
comparisontoLTE. RACH cycle isdecreasedfrom5.0ms to1.0ms. Thistutorial outlinesthe procedures
involvedinhandoverprocessandanalyzesthe performance of handoverinterruptiontimeforbothFDD
and TDD modes.The paperis organizedasfollows:SectionIIexplainsthe minimumrequirementssetby
IMT-Advancedandassumptionsof analysis.SectionIII
presentsthe analysisof handoverinterruptiontimebeforethe conclusionsare drawninSectionIV.II.
REQUIREMENTS & ASSUMPTIONSA.MinimumRequirementsThe IMT-Advancedproposal shallbe able
to supporthandoverinterruptiontimesspecifiedinTable I[8].TABLE I IMT-A REQUIREMENTS Handover
Type InterruptionTime (ms) Intra-Frequency27.4Inter-FrequencyWithinaspectrumband40.0
Betweenspectrumbands60.0 B. AssumptionsHandoverInterruptiontime forintra-frequencyand
interfrequencyisthe same asitdoesnot dependonthe frequencyof the targetcell aslongas the cell
has alreadybeenmeasuredbythe UserEquipment(UE),whichisatypical scenario[8].Forthe purposes
of determininghandoverinterruptiontime,interactionswiththe core network(i.e.,networkentities
beyondthe radioaccessnetwork) are assumedtooccur in zerotime.Itis alsoassumedthatall
3. necessaryattributesof the targetchannel (thatis,downlinksynchronizationisachievedanduplink
access procedures,if applicable,are successfullycompleted) are knownatinitiationof the handover
fromthe servingchannel tothe targetchannel [9].ForanalysisRACHand PUCCH cycle istakenas 1ms.
The RACH and PUCCH waitingtimesinTDDcases are calculatedbasedonthe UL/DL sub-frame locations
inthe respective frame configurations.InTDDmode analysis,frame configuration1isconsidered.III.
ANALYSISThe intra- andinter-frequencyhandoverinterruptiontime iscalculatedbasedonthe
handoverprocedure showninfigure 3.The stepsinvolvedinhandoverinterruptionare:1) Radio
Synchronizationtothe targetcell.2) Average delaydue toRandomAccessCHannel (RACH) scheduling
period.3) RACH Preamble Transmission.4) Preamble detectionatTargeteNodeB.5) Transmissionof
RandomAccess(RA) - Time betweenthe RA responsetransmissionandUE’s receptionof scheduling
grant. 6) Decodingof schedulinggrantandtimingalignmentatUE. 7) Transmissionof data.Radio
synchronizationdelayisthe sumof the delaycausedbyfrequencysynchronizationanddownlink
synchronization.Frequencysynchronizationdelaydependsonwhetherthe targetcell isoperatingon
the same carrier frequencyasthe servingcell.Butsince the UE has alreadyidentifiedand
When the phone at the opposite end of the connection receives the RTP packets, it must
reassemble them back into an audio signal. If packets are missing, the audio signal will contain
gaps. This packet loss can be caused by a number of network problems. One
common cause of packet loss is congested WAN links.
There are two types of EPS bearers: default and dedicated. In the LTE network, the
EPS bearer QoS is controlled using the following LTE QoS parameters:
▶ Resource Type: GBR or Non-GBR
▶ QoS Parameters
QCI
ARP
GBR
MBR
APN-AMBR
UE-AMBR
Every EPS bearer must have QI and ARP defined. The QCI is particularly important
because it serves as reference in determining QoS level for each EPS bearer. In case
of bandwidth (bit rate), GBR and MBR are defined only in GBR type EPS bearers,
whereas AMBR (APN-AMBR and UE-AMBR) is defined only in Non-GBR type EPS
bearers.
Below, we will explain the LTE QoS parameters one by one.
Resource Type = GBR (Guaranteed Bit Rate)
For an EPS bearer, having a GBR resource type means the bandwidth of the bearer is
4. guaranteed. Obviously, a GBR type EPS bearer has a "guaranteed bit rate" associated
(GBR will be further explained below) as one of its QoS parameters. Only a dedicated
EPS bearer can be a GBR type bearer and no default EPS bearer can be GBR type. The
QCI of a GBR type EPS bearer can range from 1 to 4.
Resource Type = Non-GBR
For an EPS bearer, having a non-GBR resource type means that the bearer is a best
effort type bearer and its bandwidth is not guaranteed. A default EPS bearer is always
a Non-GBR bearer, whereas a dedicated EPS bearer can be either GBR or non-GBR.
The QCI of a non-GBR type EPS bearer can range from 5 to 9.
QCI (QoS Class Identifier)
QCI, in an integer from 1 to 9, indicates nine different QoS performance
characteristics of each IP packet. QCI values are standardized to reference specific
QoS characteristics, and each QCI contains standardized performance characteristics
(values), such as resource type (GBR or non-GBR), priority (1~9), Packet Delay
Budget (allowed packet delay shown in values ranging from 50 ms to 300 ms), Packet
Error Loss Rate (allowed packet loss shown in values from 10-2 to 10-6. For more
specific values, search on Google for "3GPP TS 23.203" and see Table 6.1.7 in the
document. For example, QCI 1 and 9 are defined as follows:
QCI = 1
: Resource Type = GBR, Priority = 2, Packet Delay Budget = 100ms, Packet Error
Loss Rate = 10-2 , Example Service = Voice
QCI = 9
: Resource Type = Non-GBR, Priority = 9, Packet Delay Budget = 300ms, Packet Error
Loss Rate = 10-6, Example Service = Internet
QoS to be guaranteed for an EPS bearer or SDF varies depending on the QCI values
specified.
QCI, though a single integer, represents node-specific parameters that give the details
of how an LTE node handles packet forwarding (e.g. scheduling weights, admission
thresholds, queue thresholds, link layer protocol configuration, etc). Network
operators have their LTE nodes pre-configured to handle packet forwarding according
to the QCI value.
By pre-defining the performance characteristics of each QCI value and having them
standardized, the network operators can ensure the same minimum level QoS
required by the LTE standards is provided to different services/applications used in an
LTE network consisting of various nodes from multi-vendors.
QCI values seem to be mostly used by eNBs in controlling the priority of packets
delivered over radio links. That's because practically it is not easy for S-GW or P-GW,
in a wired link, to process packets and also forward them based on the QCI
characteristics all at the same time (As you may know, a Cisco or Juniper router would
not care about delay or error loss rate when it processes QoS of packets. It would
merely decide which packet to send first through scheduling (WFQ, DWRR, SPQ, etc.)
based on the priority of the packets (802.1p/DSCP/MPLS EXP)).
ARP (Allocation and Retention Priority)
5. When a new EPS bearer is needed in an LTE network with insufficient resources, an
LTE entity (e.g. P-GW, S-GW or eNB) decides, based on ARP (an integer ranging from
1 to 15, with 1 being the highest level of priority), whether to:
remove the existing EPS bearer and create a new one (e.g. removing an EPS bearer
with low priority ARP to create one with high priority ARP); or
refuse to create a new one.
So, the ARP is considered only when deciding whether to create a new EPS bearer or
not. Once a new bearer is created and packets are delivered through it, the ARP does
not affect the priority of the delivered packet, and thus the network node/entity
forwards the packets regardless of their ARP values.
One of the most representative examples of using the ARP is an emergency VoIP call.
So, an existing EPS bearer can be removed if a new one is required for a emergency
119 (911 in US, 112 in EC, etc) VoIP call.
GBR (UL/DL)
This parameter is used for a GBR type bearer, and indicates the bandwidth (bit rate)
to be guaranteed by the LTE network. It is not applied to a non-GBR bearer with no
guaranteed bandwidth (UL is for uplink traffic and DL is for downlink traffic).
MBR (UL/DL)
MBR is used for a GBR type bearer, and indicates the maximum bit rate allowed in the
LTE network. Any packets arriving at the bearer after the specified MBR is exceeded
will be discarded.
APN-AMBR (UL/DL)
As you read the foregoing paragraph, you may wonder why a non-GBR type bearer
does not have a "bandwidth limit"? In case of non-GBR bearers, it is the total
bandwidth of all the non-GBR EPS bearers in a PDN that is limited, not the individual
bandwidth of each bearer. And this restriction is controlled by APN-AMBR (UL/DL). As
seen in the figure above, there are two non-GBR EPS bearers, and their maximum
bandwidths are specified by the APN-AMBR (UL/DL). This parameter is applied at UE
(for UL traffic only) and P-GW (for both DL and UL traffic).
UE-AMBR (UL/DL)
In the figure above, APN-AMBR and UE-AMBR look the same. But, please take a look
at the one below.
A UE can be connected to more than one PDN (e.g. PDN 1 for Internet, PDN 2 for VoIP
using IMS, etc.) and it has one unique IP address for each of its all PDN connections.
Here, UE-AMBR (UL/DL) indicates the maximum bandwidth allowed for all the non-
GBR EPS bearers associated to the UE no matter how many PDN connections the UE
has. Other PDNs are connected through other P-GWs, this parameter is applied by
eNBs only.
How SRVCC works
6. The SRVCC implementation controls the transfer of calls in both directions.
LTE to legacy network handover
Handover from LTE to the legacy network is required when the user moves out of the LTE coverage
area. Using SRVCC, the handover is undertaken in two stages.
Radio Access Technology transfer: The handover for the radio access network and this
is a well-established protocol that is in use for transfers from 3G to 2G for example.
Session transfer: The session transfer is the new element that is required for SRVCC. It is
required to move the access control and voice media anchoring from the Evolved Packet
Core, EPC of the packet switched LTE network to the legacy circuit switched network.
During the handover process the CSCF within the IMS architecture maintains the control of the
whole operation.
Voice handover using SRVCC on LTE
The SRVCC handover process takes place in a number of steps:
1. The handover process is initiated by a request for session transfer from the IMS CSCF.
2. The IMS CSCF responds simultaneously with two commands, one to the LTE network, and
the other to the legacy network.
3. the LTE network receives a radio Access Network handover execution command through the
MME and LTE RAN. This instructs the user device to prepare to move to a circuit switched
network for the voice call.
4. The destination legacy circuit switched network receives a session transfer response
preparing it to accept the call from the LTE network.
5. After all the commands have been executed and acknowledged the call is switched to the
legacy network with the IMS CSCF still in control of the call.
Legacy network to LTE
When returning a call to the LTE network much of the same functionality is again used.
To ensure the VoLTE device is able to return to the LTE RAN from the legacy RAN, there are two
options the legacy RAN can implement to provide a swift and effective return:
7. Allow LTE information to be broadcast on the legacy RAN so the LTE device is able to
perform the cell reselection more easily.
Simultaneously release the connection to the user device and redirect it to the LTE RAN.
SRVCC interruption performance
One of the key issues with VoLTE and SRVCC is the interruption time when handing over from an
LTE RAN to a legacy RAN.
The key methodology behind reducing he time is to simultaneous perform the redirections of RAN
and session. In this way the user experience is maintained and the actual interruption time is not
unduly noticeable.
It has been found that the session redirection is the faster of the two handovers, and therefore it is
necessary for the overall handover methodology to accommodate the fact that there are difference
between the two.