NETWORK TELECOMMUNICATION A BEGINNER'S GUIDE: Ts. Norbaiti Adzlina binti Basharudin Harison binti Hussain Dr. Nui A/P Din Keraf
A BEGINNER'S GUIDE: Ts. Norbaiti Adzlina binti Basharudin Harison binti Hussain Dr. Nui A/P Din Keraf TELECOMMUNICATION NETWORK
Copyright © 2023 http://polimas.mypolycc.edu.my e ISBN 978-967-0055-23-7 Electrical Engineering Department Politeknik Sultan Abdul Halim Muadzam Shah (POLIMAS) Bandar Darul Aman. 06000 Jitra, Kedah DR. NUI A/P DIN KERAF [email protected] [email protected] [email protected] TS. NORBAITI ADZLINA BINTI BASHARUDIN Senior Lecturer Electrical Engineering Department Politeknik Sultan Abdul Halim Muadzam Shah All rights reserved. No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the publisher, except in the case of brief quotations embodied in critical reviews and certain other noncommercial uses permitted by copyright law. HARISON BINTI HUSSAIN Senior Lecturer Electrical Engineering Department Politeknik Sultan Abdul Halim Muadzam Shah Principal Lecturer Electrical Engineering Department, Politeknik Sultan Abdul Halim Muadzam Shah
This book provides an overview of modern telecommunications networks, covering the latest technologies and industry developments. It aims to offer a comprehensive guide for students, professionals, and anyone interested in understanding the underlying principles, design, and operation of these networks. From basic concepts to advanced topics, this book provides a wealth of knowledge on the subject, including the architecture, protocols, and key technologies used in telecommunications networks. Whether you are just starting out or looking to expand your knowledge, this book is an essential resource for anyone looking to build a career in this exciting field PREFACE
07 CONTENTS T a bl e of CHAPTER 1 INTRODUCTION TO NEXT GENERATION NETWORK (NGN) "Anything worth having takes time." – @reallygreatsite The History of Telephony Public Switched Telephone Network Signalling Network Transmission Systems Time Division Multiplexing in PSTN The convergence of the Two Worlds: Next Generations Networks (PSTN) 08 08 10 16 20 23 CHAPTER 2 38 INTERNET FUNDAMENTALS BY IETF Internet Architecture of IETF Standardization Fundamental Internet Protocols 39 39 43 27
INTRODUCTION TELECOMMUNICATION NETWORK provides students with the basic knowledge of telecommunication network of Next Generation Networks (NGN). This course focuses on NGN architectures, protocols and services, including technologies and regulation. Students are also expose to NGN convergence between the traditional telecommunications and the internet to facilitate voice and data communications. SYNOPSIS
INTRODUCTION CHAPTER 1 TO NEXT GENERATION NETWORK (NGN)
1 2 3 4 5 6 Telecommunication network - digital Local loop (subscriber line) - Switching was done with digital system (SPC- stored programme control switches) remain analog 1990S Replacement ISDN with the xDSL (Digital Subscriber Line) technologies. Most widespread DSL was ADSL (Asymmetric DSL) 2000 - 2010 The digitalization of the subscriber line began with ISDN (for internet and voice) ISDN could not satisfy such requirements for higher data rates for emerging internet services 1990S Step by step replaced by Crossbar switches. Crossbar stayed in operation worldwide until the 1990s (transition from analog to digital telephony) FIRST HALF OF 20TH CENTURY First automatic switching used base one step by step switches called Strowger switches (analog system) END OF 19TH CENTURY Started 19th Century Invention of the telephone by Alexander Graham Bell Manual switching (based on operator) 1876 HISTORY OF TELEPHONY TRADITIONAL TELECOM WORLD
TODAY TELEPHONE ERA 2020 With new technology and ideas, VoIP has become the telephony of choice in an ever changing marketplace, both for businesses and consumers there is so much potential in what these systems can do that the sky’s the limit or should we say the cloud.
PUBLIC SWITCHED TELEPHONE NETWORK (PSTN) PSTN is a combination of telephone networks used worldwide, including telephone lines, fiber optic cables, switching centers, cellular networks, satellites and cable systems. PSTN is referred as circuit-switched technology which consists of transmission path and nodes. PSTN lets users make landline telephone calls to one another. It is a traditional telephone network that was widely used before the advent of digital and internet-based communication technologies Consists of telecommunication instruments, that interconnected by switching center (in central office). A systematic set of interconnecting transmission lines arranged. The PSTN network consists of a complex network of switches, trunks, and other equipment that connect telephone lines and enable users to make telephone calls.
PULSE CODE MODULATION (PCM) Pulse Code Modulation (PCM) is a method of digitally representing an analog signal by taking regular samples of the signal and converting the samples into a series of numerical values. . The resulting numerical values are then encoded into a digital signal using a method such as binary encoding. The digital signal can then be transmitted or stored for later use. PCM involves quantization of the analog signal, which involves mapping a continuous range of values to a finite set of discrete values. Used in digital audio and video applications and is the standard format for digital audio in the compact disc (CD) and digital versatile disc (DVD) formats.
THREE (3) STEP OF PCM to digitize an analog signal Sampling is process of taking samples of analog voice signal at regular time intervals, Ts. The function of sampling circuit is to periodically sample the continually changing analog input voltage and convert those samples to a series of constant amplitude pulses. PULSE CODE MODULATION (PCM) Quantizer will quantize the signal coming from sampler. The quantizer will determine the amplitude (voltage) of each sampling instant according to its magnitude. For voice it is set to 256 levels which can be presented using 8-bit codes (28 = 256). Binary Encoder will convert each quantized sample into 8 binary code. (A) SAMPLING (B) QUANTIZATION (C) BINARY ENCODING
Telephone Network consist of end users who have phone handsets (i.e telephones) connected via twisted pairs (local loop) which connect the telephone in the home (or office) to local exchange (central office). Local exchanges are interconnected with transmission systems, following certain network hierarchy (PDH/SDH etc). When all switching and transmission is accomplished by using digital signals then it is refer as Digital Network. ARCHITECTURE OF THE TELEPHONE NETWORK
SWITCHING TECHNIQUE IN TELEPHONE NETWORK Packet switching is the process of segmenting or broken down a message/data to be transmitted into several smaller packets. Each packet is enveloped with address or labeled with its destination and other overhead information to ensure that it travels to the correct destination without errors. In packet switching, instead of being dedicated to one communication session at a time, network links are shared by packets from multiple competing communication sessions, resulting in the loss of the quality of service guarantees that are provided by circuit switching. Packet switching shares available network bandwidth between multiple communication sessions. (a) Packet Switching
SWITCHING TECHNIQUE IN TELEPHONE NETWORK A softswitch is a component used in the core network of a telecom network operator to provide call control and signalling as well as processing of media streams. It is software-based device in a telecommunications network which provides managing of voice, fax, data and video traffic, routing of a call within the network, and can process the signaling for all types of packet protocols. Traditional switch is the hardware, with physical switchboards to route the calls. Softswitch is the VoIP software solution which is installed on servers and has the same functionality. A softswitch combines two elements: a call agent or call feature server for call control, routing and signalling, and a media gateway or access gateway for processing media streams. These two elements can be co-located on a single piece of hardware, or located on separate hardware where one call agent or call feature server can control one or more gateways. (b) Softswitch
The exchange of control information in the establishment of a telephone call on a telecommunications circuit. SIGNALLING NETWORK signaling information from many users is multiplexed over a common channel and can be carried separately from the voice traffic. COMMON CHANNEL SIGNALLING (CCS) CHANNEL ASSOCIATED SIGNALING (CAS) certain signaling information is associated with the voice channels over the same transmission medium Definition Definition Definition analog signal (eg. electrical signal) or digital signals (eg. bits, bytes or packets) Signaling can be done using General classification of signaling in PSTN is divide into two (2) groups:
SIGNALLING SYSTEM NO.7 (SS7) STP is a router and/or signaling gateway in the SS7 network STP has main task to route signaling message between so-called signaling points in the network STP who act as gateway nodes actually connect signaling network of one telecomunication network with signaling network (ie. belonging to a telecom operator) which signaling network of another telecommunication network (ie. belonging to another telecom operator SIGNAL TRANFER POINT SERVICE SWITCHING POINT SS7 is integrated with local telephone exchanges (with -attached subscriber lines to them) SS7 converts dialed number into SS7 signaling messages and established signaling connection with the SSP of the called user SS7 establishes, manages and terminates voice connections It send signaling messages to another SSP via the STP node to which it is connected. SSP STP ARCHITECTURE
SIGNALLING SYSTEM NO.7 (SS7) SIGNALING POINTS DIAGRAM SCP can be viewed as a database with an appropriate interface for database access by other signaling points in SS7 Usage of SCP is for special B-numbers such as the 0800 series or for provisioning of roaming in PLMN SCP SERVICE CONTROL POINT ARCHITECTURE
SIGNALLING SYSTEM NO.7 (SS7) SS7 is composed of multiple protocols which are layered according to OSI (Open System for Interconnection) model standardize by ITU. PROTOCOL MODEL OSI Model SS7 Protocol Model
electrical signals (over copper cables) optical signals (fiber) and radio signals (over wireless links) Signals are carried from one node to another node in the network by using transmission system, which are carrying signals, such as Transmission systems carry many signals from many users (to reduce cost) by using multiplexing technique. Different frequencies or frequency bands are assigned to different channels over the same transmission medium. TRANSMISSION SYSTEMS (A) FREQUENCY DIVISION MULTIPLEXING (FDM)
Different time intervals, called time slots, are assigned to different users over the same transmission medium and using the same frequency in the case of copper cables or radio transmission, or the same wavelength in the case of fiber. TRANSMISSION SYSTEMS (B) TIME DIVISION MULTIPLEXING (TDM) (C) CODE DIVISION MULTIPLEXING (CDM) Based on using different code sequence for different signals over the same frequency bands and during the same time intervals. CDM is not used in transmission system, but mainly used in wireless and mobile networks
Based on carrying user data on different wavelengths over the same fiber cable Individually signal to be transmitted are assigned a different wavelength within a common bandwidth. TRANSMISSION SYSTEMS (D) WAVELENGTH DIVISION MULTIPLEXING (WDM)
30 time slots are used for voice (in telephone network) First time slot, TS -0 is used for synchronization. TS-16 is mainly used for signaling related to voice connections Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, Compact Discs, digital telephony and other digital audio applications. ITU-T has standardized the hierarchy for bit rates in digital transmission systems. First hierarchy level (E1) in Europe and most of world is 2048 kbit/s Bit rates for E1 = fs x no of bits x no channel = 8000 Hz x 8 bit x 32 channel = 2048 kbit/s 32 channel = 32 time slots (TS) Time slot are numbered as TS-0 to TS-31 In America the first hierarchy level is 1544 kbit/s and it is consisted of 24 channels, multiplexed with TDM TIME DIVISION MULTIPLEXING (TDM) (A) PULSE CODE MODULATION TIME DIVISION MULTIPLEXING (PCM-TDM) in
The first internationally standardized form of digital higher-order multiplexing and was deployed over a variety of cable and radio systems, as well as optical fiber cable around the world. Plesiohronous’ meaning nearly synchronous relates to the situation where the individual 2Mbit/s tributaries that are to be multiplexed over the PDH system are operating at close-but slightlyvarying rates ‘Stuffing’ or ‘justification’ is need to be added to the TDM highway at each stage of multiplexing Bit stuffing in a PDH system is applied to ensure that the TDM frame is filled tightly, irrespective of the actual number of bits sampled from each tributary. The digital hierarchy rates in fact from the PDH, where the bit rate is controlled by a clock in the local equipment (e.g exchange) TIME DIVISION MULTIPLEXING (TDM) (B) PLESIOCHRONOUS DIGITAL HIERARCHY (PDH) in
Synchronous Digital Hierarchy (SDH) is a group of fiber optic transmission rates that transport digital signals with different capacities. SDH technology enables low-bit rate data streams to combine with high-rate data streams. Furthermore, as the whole network is synchronous, it enables users to embed and extract individual bit streams from high-rate data streams relatively easily. SDH is the International Telecommunication Union's Telecommunication (ITU-T) Standardization Sector version of the Synchronous Optical Network (SONET) standard. Both technologies provide faster and cheaper network interconnections than traditional Plesiochronous Digital Hierarchy (PDH) equipment. SDH is used in transmission systems for broadband Integrated Services Digital Network (ISDN) and for transporting Asynchronous Transfer Mode cells, Ethernet aggregations, PDH signals, storage area network signals and other communication signals. SDH systems were developed in the late 1980s and early 1990s to replace PDH technology. The primary goal was to eliminate potential synchronization issues for bulk data and telephone exchanges. The data transfer rate also increased in a simple and more flexible optical fiber-based network infrastructure. TIME DIVISION MULTIPLEXING (TDM) (C) SYCHRONOUS DIGITAL HIERARCHY (SDH) in
CWDM (course WDM) – a few wavelengths used on a single fiber. DWDM (Dense WDM) – many wavelengths used on a single fiber. DWDM is targeted for usage in the transport network. (which are migrating from SDH/SONET toward IP/MPLS networks over DWDM). Possibility to multiplex voice, video and data on the same wavelength or to carry different types of traffic on different wavelength (e.g voice on one wavelength, TV on another, etc) through a single fiber. TIME DIVISION MULTIPLEXING (TDM) (D) DENSE WAVELENGTH DIVISION MULTIPLEXING in The optical fiber is the best medium to be deployed at backbones of very high data rates To increase the bandwidth, SDH is used by laying more and more fibers but mean while an enormous amount of bandwidth of fiber is being wasted To utilize the maximum bandwidth, DWDM is only solution Why move to DWDM? 1 2 3
CONVERGENCE IN TWO (2) WORLDS: NEXT GENERATION NETWORKS NGN Qos support for real time services Provision of terminating calls in the Internet Need broadband access to the Internet that give possibility of new services (eg. IPTV) Signaling is required for conversational services, such as VoIP, video telephony, conferencing and so on. value-added services, by using data sharing, combining existing real-times services (eg. VoIP, IPTV, etc) and non-real time services (eg. Web, email and peerto-peer) Convergence is the process of interconnection of tradisional switched network (PSTN and mobile network) and packet base networks that use IP (Internet Protocol). However by having Internet, would provide possibility for convergence, leads to transition of all service to the Internet. Such process create challenges; Convergence toward the Internet provides possibilities for Following years coming, the voice make significant step toward the VoIP transition by using the standardized IMS (IP Multimedia Subsystem). For mobile networks, for example, 4G mobile networks are all-IP because that is mandatory requirements for 4G in the IMT-Advanced
CONVERGENCE IN TWO (2) WORLDS: NEXT GENERATION NETWORKS NGN MAIN DRIVERS FOR NETWORK EVOLUTION EVOLUTION TOWARDS CONVERGED NETWORKS
CONVERGENCE IN TWO (2) WORLDS: NEXT GENERATION NETWORKS NGN CONVERGED COMMUNICATIONS TRENDS IN TELECOM AND BROADCASTING
CONVERGENCE IN TWO (2) WORLDS: NEXT GENERATION NETWORKS NGN WHERE IS "CONVERGENCE" HAPPENING? CONVERGENCE OF THE NETWORK
Traditional circuit-switching telephony is being replaced by VoIP (including fixed and mobile ones) Traditional SS7 signaling is being carried over IP and replaced by SIP signaling When willNGN merge? CONVERGENCE IN TWO (2) WORLDS: NEXT GENERATION NETWORKS NGN
CONVERGENCE IN TWO (2) WORLDS: NEXT GENERATION NETWORKS NGN FIXED - MOBILE CONVERGENCE TOWARDS FIXED - MOBILE CONVERGENCE
CONVERGENCE IN TWO (2) WORLDS: NEXT GENERATION NETWORKS NGN NETWORK CONVERGENCE DEVICE CONVERGENCE
CONVERGENCE IN TWO (2) WORLDS: NEXT GENERATION NETWORKS NGN APPLICATION CONVERGENCE SERVICE CONVERGENCE
CONVERGENCE IN TWO (2) WORLDS: NEXT GENERATION NETWORKS NGN Next Generation Network (NGN): A packet-based network able to provide telecommunication services and able to make use of multiple broadband, QoS-enabled transport technologies and in which service-related functions are independent from underlying transport-related technologies. It enables unfettered access for users to networks and to competing service providers and/or services of their choice. It supports generalized mobility which will allow consistent and ubiquitous provision of services to users. Fundamental characteristics for defining NGN: Packet based transfer. Separation of control functions for bearer capabilities, call/session – service. Decoupling of service and network, and provision of open interfaces (I/F). A wide range of services like (Real Time(RT)/ streaming/ non Real Time (RT)/ multimedia). Interworking with legacy networks via open I/F. Support of Generalized mobility. Support to unrestricted access by users to different service providers.
Key Features of NGN functions CONVERGENCE IN TWO (2) WORLDS: NEXT GENERATION NETWORKS NGN https://www.itu.int/en/ITU-T/studygroups/2013-2016/03/Documents/201405- miniworkshop/05-Chaesub-Lee.pdf
NGN architecture CONVERGENCE IN TWO (2) WORLDS: NEXT GENERATION NETWORKS NGN https://www.itu.int/en/ITU-T/studygroups/2013-2016/03/Documents/201405- miniworkshop/05-Chaesub-Lee.pdf
INTERNET FUNDAMENTALS CHAPTER 2 IETF by
INTERNET PROTOCOL ARCHITECTURE Internet protocols and technologies are positioned in upper layers of the protocol layering model, from network layer (OSI-3 layer) up to the application layer. Main protocols in the IP stack are protocols at the network layer and transport layer (OSI-4 layer). Main protocol in Internet is the IP, which exists currently in two standardized versions, IP version 4 (IPv4) and IP version 6 (IPv6). Further, on the transport layer there are two fundamental protocols, namely User Datagram Protocol (UDP) and Transmission Control Protocol (TCP). Comparison OSI Model & IP Model
INTERNET NETWORK ARCHITECTURE The Internet architecture is a matter of network design. The Internet is standardized by the Internet Engineering Task Force (IETF). In general, IP (Internet Protocol) trafficl can be transferred over many access and transmission technologies, then the network architecture can be diverse. However, main rules for the Internet architectures concepts and designs are supervised by the Internet Architecture Board (IAB), which is a committee of the IETF. EXAMPLE OF NETWORK ARCHITECTURE (A) BASIC HOME NETWORK DIAGRAM
INTERNET NETWORK ARCHITECTURE EXAMPLE OF NETWORK ARCHITECTURE (B) HOME NETWORK DIAGRAM WITH MODEM AND ROUTER (C) ROUTER SWITCH NETWORK DIAGRAM
INTERNET PROTOCOL VERSION 4 (IPv4) The Internet Protocol version 4 (IPv4) is the delivery mechanism used by the TCP/IP protocols. IPv4 is an unreliable and connectionless datagram protocol-a best-effort delivery service. The term best-effort means that IPv4 provides no error control or flow control. If reliability is important, IPv4 must be paired with a reliable protocol such as TCP IPv4 is also a connectionless protocol for a packet switching network that uses the datagram approach. This means that each datagram is handled independently, and each datagram can follow a different route to the destination.
IPv4 or Internet Protocol version 4, address is a 32-bit string of numbers separated by periods. It uniquely identifies a network interface in a device. IP is a part of the TCP/IP (Transmission Control Protocol/Internet Protocol) suite, where IP is the principal set of rules for communication on the Internet. An IP address is needed to be allocated on the devices, such as PCs, printers, servers, routers, switches, etc., to be able to communicate with each other in the network and out the Internet. IPv4 Address Format IPv4 addresses are expressed as a set of four numbers in decimal format, and each set is separated by a dot. Thus, the term ‘dotted decimal format.’ Each set is called an ‘octet’ because a set is composed of 8 bits. The figure below shows the binary format of each octet in the 192.168.10.100 IP address: INTERNET PROTOCOL VERSION 4 (IPv4) A number in an octet can range from 0 to 255. Therefore, the full IPv4 address space goes from 0.0.0.0 to 255.255.255.255. The IPv4 address has two parts, the network part and the host part. A subnet mask is used to identify these parts.
Static – static IP address is set manually on the device. It is best practice to set static IP addresses on network devices, such as routers and switches, and on servers as well. Dynamic – dynamic IP address can be automatically allocated to a device via Dynamic Host Configuration Protocol (DHCP). Dynamic IP addresses are best to be used on end devices, such as PCs. Public IP address – used to route Internet traffic. This is used on the Internet and is given out by Internet Service Providers (ISPs) to their customers. Private IP address – used in private networks for internal traffics within the LAN. Private addresses are not routable out the Internet. IPv4 Address Allocation The Internet Protocol address can be allocated to hosts or interfaces either manually or dynamically. Types of IPv4 Addresses there are two types of IP addresses, namely public IP addresses and private IP addresses. INTERNET PROTOCOL VERSION 4 (IPv4)
Class A Public & Private IP Address Range Class B Public & Private IP Address Range Class C Public & Private IP Address Range Class D IP Address Range Class E IP Address Class The Five (5) IPv4 Classes INTERNET PROTOCOL VERSION 4 (IPv4) https://www.meridianoutpost.com/resources/articles/index.php
Most routers can support IPV6. The address space of IPv6 is defined with 128 bits, which has enabled the existence of a huge number of addresses compared to 32 bits for addresses in IPv4. INTERNET PROTOCOL VERSION 6 (IPv6) Berkeley Software Distribution (BSD), 1970 and Linux 2.2 Solaris 8. Available with new versions of most operating systems such as The address scheme of IPv6 is new and is based to serve demographic and modern networks. Also an option to operating system with Windows 2000/NT, 1993
HEADER FORMAT IPV4 IPV6
KEY COMPARISON IPV4 IPV6
COMPARISON ADDRESSING IPV4 IPV6
UDP is a communications protocol that facilitates the exchange of messages between computing devices in a network. In a network that uses the Internet Protocol (IP), it is sometimes referred to as UDP/IP. User Datagram Protocol is an alternative to the transmission control protocol (TCP) — UDP enables process-to-process communication, while TCP supports host-to-host communication. UDP divides messages into packets, called datagrams, which can then be forwarded by the devices in the network – q switches, routers, security gateways — to the destination application/server. While UDP does not number or reassemble the datagrams, it does include port numbers in the datagram header that help distinguish different user requests and an optional checksum capability that can help verify the integrity of the data transferred. UDP speeds up transmissions by enabling the transfer of data before an agreement is provided by the receiving party. As a result, UDP is beneficial in time-sensitive communications, including voice over IP (VoIP), domain name system (DNS) lookup, and video or audio playback. USER DATAGRAM PROTOCOL (UDP)