Table of Contents. The scope of this document is focused on the basic EPS domain. The remainder of this document is organized as follows. Chapter 3 will describe the protocol stacks and then Chapter 4 will explain traffic flows over the LTE network. Table 3 lists the reference points of the LTE network reference model and gives a description of interfaces between EPS entities. Figure 1. LTE network reference model. LTE Protocol Stacks. Figure 2 shows the user plane protocol stacks for the LTE network reference model shown in Figure 1.
The functions of the key layers of the protocol stacks are briefly described below. Figure 2. LTE user plane protocol stacks. Figure 3 shows the control plane protocol stacks for the LTE network reference model. Figure 3. LTE control plane protocol stacks.
On S11 interface, does it provide GTP tunnel per bearer?? We have fixed it and posted the updated file. Thank you again for your kine comment and sorry for the late reply. They use interface Gz incluce Ga and Rf.
IP Multimedia Subsystem
Please check again! This is srilakshmi. This introduction was well done. Please help us with more insight with topic like DRX, Power, scheduling and others more.
LTE Network Architecture
All rights reserved. English Korean About Us. Samsung Cloud Native 5G Core. Download PDF File. The RLC protocol has three operational modes i. Therefore, the MAC protocol supports multiplexing and de-multiplexing between logical channels and transport channels.
Higher layers use different logical channels for different QoS metrics. The eNB scheduler makes sure radio resources are dynamically allocated to UEs and performs QoS control to ensure each bearer is allocated the negotiated QoS. It also performs functions required for efficient management of the radio resources.
For SON functions, eNBs exchange resource status information, traffic load information and eNB configuration update information, and coordinate each other to adjust mobility parameters using the X2AP protocol.Flexibility and expandability would allow Operators to bring new services on-line as those services emerge and evolve.
IMS is designed to offer unprecedented convenience for individual and business users. They had seen it as far too expensive and burdensome to introduce and maintain.
VoLTE Building blocks. There are primarily 3 types of SIM Cards This testing is required as handset manufacturers and operators will be seeking to assure themselves that the underlying protocol features are present and functioning correctly. Operator want to ensure that the underlying IMS and protocol is functioning, and performing as intended, in order to deliver the expected quality of service.
Its time to demystify IMS Core network. This is connected over sGi Interface. Function of SIP Server. It also handles Transcoding of the media plane.
The CSCF performs all the signaling operations, manages SIP sessions and coordinates with other network entities for session control, service control and resource allocation.
We need similar App servers for other Multimedia services such as VideoGaming etc. This allows third party providers an easy integration and deployment of their value added services to the IMS infrastructure.
This prioritization helps Voice call to pass thru even in case of Radio Congestion. MRF stands for Media resource function. B Number routing Table. The IMS architecture gives service providers the opportunity to deliver new and better services, with reduced operating costs, across wireless, wireline, and broadband networks. IMS unifies applications enabled by the Session Initiation Protocol SIP to connect traditional telephony services and non-telephony services, such as instant messaging, voicevideo streaming, and multimedia messaging.
The IMS architecture involves a clear separation of three layers Hope this information is useful for you. Please feel free to Mail me vikas. Skip to Content.A protocol is a system of digital rules for message exchange between telecom Nodes in order for one Node to communicate with another. SCTP is used to provide guaranteed message delivery.
SCTP provides a reliable transport service that operates at message level. Key features of UDP Include SIP : Session Initiation Protocol SIP is a communications protocol that is widely used for managing multimedia communication sessions such as voice and video calls.
SIP, therefore is one of the specific protocols that enable voice communication over IP. Key features of SIP Includes Diameter : Diameter is an authentication, authorization, and accounting protocol for Telecom networks. Key features of Diameter includes Whether User can use Internet services or Not? Whether these services are allowed on Roaming or Not? This is used for QOS Management. We are going to understand each and every link in detail here.
We will starting with Diameter links and take this journey to SIP links. This Rx Interface is used to control the establishment of any type of Incoming or Outgoing Callsand thereby authorize and control resource usage in the access networks. Rx uses Diameter protocol. Other Messages getting exchanged on Cx Interfaces are Cx uses Diameter protocol. Sh uses Diameter protocol. For any voice callThe charging function needs to perform credit control before allowing call to mature.
Ro Interface also works on Diameter protocol. Gm Interface is key to all User based communication. For security reasons, the Gm and Mw Interfaces are physically separate.
This Interface also carries Authentication, encryption, and complete session control. It plays vital role for the interworking with another IMS network.
These interfaces allow interaction with the media resource for specific supplementary services e.The evolved packet core communicates with packet data networks in the outside world such as the internet, private corporate networks or the IP multimedia subsystem.
The interfaces between the different parts of the system are denoted Uu, S1 and SGi as shown below:. The mobile equipment comprised of the following important modules:. This keeps information about the user's phone number, home network identity and security keys etc. Each eNB is a base station that controls the mobiles in one or more cells. The base station that is communicating with a mobile is known as its serving eNB. LTE Mobile communicates with just one base station and one cell at a time and there are following two main functions supported by eNB:.
The eBN sends and receives radio transmissions to all the mobiles using the analogue and digital signal processing functions of the LTE air interface. The eNB controls the low-level operation of all its mobiles, by sending them signalling messages such as handover commands. Each eBN connects with the EPC by means of the S1 interface and it can also be connected to nearby base stations by the X2 interface, which is mainly used for signalling and packet forwarding during handover.
A home eNB HeNB is a base station that has been purchased by a user to provide femtocell coverage within the home. There are few more components which have not been shown in the diagram to keep it simple. Each packet data network is identified by an access point name APN. This has two slightly different implementations, namely S5 if the two devices are in the same network, and S8 if they are in different networks. Previous Page. Next Page. Previous Page Print Page.Next generation networks utilize an exhaustive list of architectural components that need to work seamlessly to enable end-to-end services for customers that demand connectivity and content at any-time, any-place and on any device.
The following is a list of select interfaces, network nodes and acronyms to better navigate the technical aspects of modern service delivery networks. Interfaces Nodes Acronyms.
Find Out More. Dialogic Service Provider Solutions. TS This is the roaming version of the Gmb interface. Cloud optimized real-time communications solutions.
IMS VoLTE and 3GPP Interfaces
All rights reserved. Conveys media control requests, responses and notifications as well as documents scripts, announcement files, and other resources between the MRFC and an Application Server. Conveys control plane messages for establishing and managing tunnels for providing packet data network access. Provides user plane control and mobility support between the mobile packet core and WLAN access networks. Supports transfer of subscription and authentication data for authenticating and authorizing user access.
Provides user plane tunneling and control plane tunnel management for inter-PLMN traffic roaming. Enables dynamic control over applications through detection, monitoring and reporting procedures. Supports exchange of User Profile information such as service related information, user location information or charging function info.
Supports secure transport of access authentication, authorization, mobility parameters and charging-related information. Provides support for intra-LTE handovers, context transfer, load management, and user plane bearer transport control between eNode Bs. Conveys intra-operator application specific user security settings and key information to the NAF.The home network's P-GW allows the user to access the home operator's services even while in a visited network.volte call flow - SIP Call Flow - IMS Call procedure
A P-GW in the visited network allows a "local breakout" to the Internet in the visited network. This has two slightly different implementations, namely S5 if the two devices are in the same network, and S8 if they are in different networks.
The complexities of the new charging mechanisms required to support 4G roaming are much more abundant than in a 3G environment. Few words about both pre-paid and post-paid charging for LTE roaming is given below:. Prepaid Charging - The CAMEL standard, which enables prepaid services in 3G, is not supported in LTE; therefore, prepaid customer information must be routed back to the home network as opposed to being handled by the local visited network.
Operators do not have the same amount of visibility into subscriber activities as they do in home-routing scenarios in case of local breakout scenarios because subscriber-data sessions are kept within the visited network; therefore, in order for the home operator to capture real-time information on both pre- and postpaid customers, it must establish a Diameter interface between charging systems and the visited network's P-Gateway.
In case of local breakout of ims services scenario, the visited network creates call detail records CDRs from the S-Gateway showever, these CDRs do not contain all of the information required to create a TAP 3.
Next Page. Previous Page Print Page.Releases 9, 10 and 11 bring new features and enhancements, such as: carrier aggregation, enhanced downlink control channel, advanced MIMO technique and more. While FDD makes use of separate bands to transmit uplink and downlink data, TDD uses time slots on the same frequency for both uplink and downlink.
It is comprised of components that have the following functions: mobility management, authentication, quality of service, routing upload and download IP packets, IP address allocation, and more. It connects to the HSS and requests the authentication information for the subscriber trying to connect to the network. The MME is also responsible for allocating a gateway router to the Internet if there are more available.
The MME also supports lawful interception of signaling. The P-GW handles policy enforcement, user by user packet filtering, charging support, lawful interception and packet screening. The functions of the HSS include mobility management, call and session establishment support, user authentication and access authorization. These policies are enforced in the eNodeB. The PCEF enforces rules that allow data packets to pass through the gateway.
To learn more about these interfaces go to the section Interfaces of the eNodeB hyperlink here. The X2 interface provides connectivity between two or more eNodeBs. Two or more eNodeBs can exchange signalling information through the X2 interface. The main roles of the X2 interface are the following:. These indicators allow the network to offer subscribers a better service quality, and ensures an efficient resource allocation. The eNodeB reports performance measurements.
Network element managers calculate and analyze the performance measurements into KPIs. The UE can be a device such as: mobile phone, laptop, tablet, computer, etc.
The E-UTRA enables a latency decrease, allows high bandwidth capabilities and is optimized for packet data.
OFDM splits data into small sub-carriers on neighboring frequencies, over a single channel. OFDM handles phenomena such as interference, noise or multipath significantly more efficiently than other modulation methods. Its main advantage is a lower peak-to-average power ration, which is proven to be more efficient in networks where the transmit power is most important.
The element management system EMS is responsible of the functions of each network element. However, the EMS does not manage the traffic between network elements. KPIs are indicators allow the network to offer subscribers a better service quality, and ensures an efficient resource allocation. Accessibility is a measurement that allows operators to know information related to the mobile services accessibility for the subscriber.
Retainability measures how many times a service was interrupted or dropped during use, thus preventing the subscriber to benefit from it or making it difficult for the operator to charge for it.
Therefore, a high retainability is very important from a business stand point. The measurement is performed by determining the percentage of time that the service was available for the subscribers served by a specific cell.
The measurement can also aggregate data from more cells or from the whole network. General Praporgescuet 6, ap. LTE Architecture Concepts. The LTE network overview.