Topic 4 Broadband Internet - The Basic for NGN (Full) + LO PDF

TOPIC 4: BROADBAND INTEREST: THE BASIC FOR NGN  PART A (4.1): ITU’S WORK ON BROADBAND  Learning Outcomes: Upon completion of this course, students should be able to: 4.1 Remember ITU’s Work on Broadband i. Identify the following items: a. ITU-T Work on Broadband...

TOPIC 4: BROADBAND INTEREST: THE BASIC FOR NGN  PART A (4.1): ITU’S WORK ON BROADBAND  Learning Outcomes: Upon completion of this course, students should be able to: 4.1 Remember ITU’s Work on Broadband i. Identify the following items: a. ITU-T Work on Broadband b. ITU-R Work on Broadband c. ITU-D Work on Broadband International Telecommunication Union (ITU) The world’s largest organization for telecommunications An agency of the United Nations (UN) whose purpose is to coordinate telecommunication operations and services throughout the world. Originally founded in 1865, as the International Telegraph Union, the ITU is the oldest existing international organization. ITU headquarters are in Geneva, Switzerland. Nowadays highlights the importance of broadband. Timeline of ITU  Sectors in ITU ITU is covered by its three sectors: – ITU-T: International Telecommunication Union Telecommunication standardization sector – ITU-R: International Telecommunication Union Radiocommunication sector – ITU-D: International Telecommunication Union Development sector  Radiocommunication (ITU-R) -- ensures optimal, fair and rational use of the radio frequency (RF) spectrum Telecommunication Standardization ( ITU-T ) -- formulates recommendations for standardizing telecommunication operations worldwide Telecommunication Development (ITU-D) -- assists countries in developing and maintaining internal communication operations  ITU-T (Standardization)  ITU-T Work on Broadband Crucial role in defining operation and interoperability of technologies that underpin global communications network 200 - 300 new global standards approved every year, with over 4,000 in use today Standards enable global communications by ensuring ICT networks and devices speak the same language globally. To ensure the efficient and timely production of standards covering all fields of telecommunications and Information Communication Technology (ICTs) on a worldwide basis, as well as defining tariff and accounting principles for international telecommunication services.  APPLICATIONS ITU-T is performing standardization in several other areas related to the broadband Internet, such as IPTV, Internet of Things, cloud computing, IPv4 to IPv6 transition, and so on.  ITU-R (Radiocommunication)  ITU-R Work on Broadband Global management of radio-frequency spectrum and satellite orbits. Ensures equal and efficient use of radio-frequency spectrum to accommodate huge growth in demand for spectrum. ITU-R coordination of orbital slots prevents radio interference preventing malfunctioning of satellite services  APPLICATIONS ITU-R developed the IMT-2000 (International Mobile Telecommunications-2000) umbrella of mobile standards commonly known as 3G (third generation) ITU-R also set the requirements for 4G mobile systems (i.e., next generation mobile networks) All mobile standards that comply with all IMT-Advanced requirements are referred to as 4G (e.g., LTE-Advanced from 3GPP, IEEE 802.16m, a.k.a. Mobile WiMAX 2.0).  ITU-D (Radiocommunication)  ITU-D Work on Broadband Spread equitable and affordable access to telecommunications to help stimulate social and economic development Human capacity-building in developing and least developed countries (LDCs) Helps to ensure that people everywhere are empowered to reap the benefits that connectivity delivers Assistance to countries in the creation of broadband strategies and policies, as well as the regulation of broadband networks and services.  Application ITU-D helps via building local or regional capacity for investments and deployment of broadband technologies and applications, with aim to allow people around the world to benefit from it in personal lives and in the society in general. The final goal of ITU-D is connecting everyone everywhere via broadband, including developed and developing countries in the world.  PART B (4.2): DSL AND CABLE ACCESS NETWORKS  Learning Outcomes: Upon completion of this course, students should be able to: 4.2 Apply DSL and Cable Access Networks i. Show the following items: a. ADSL Access Architecture b. ADSL Frequency Bands and Modulation c. ADSL Network Architecture d. Cable Access Network  4.2.1 a. ADSL Access Architecture Illustrate the architecture of DSLAM in the direction from the network toward  ADSL Access Architecture Components that participate within ADSL architecture: 1. ADSL transceiver remote unit ADSL transceiver remote unit (at the user) is splitters which is for providing both the telephone service (i.e., POTS – Plain Old Telephony Service) and the ADSL service 2. DSLAM DSLAM is a multiplexer of DSLs on the side of the operator  ADSL Access Architecture The terminal (downlink), the telephone (i.e., POTS) signals and ADSL signals are transferred to the users. Splitters on both sides of the subscriber line (i.e., local loop) are used for frequency multiplexing/demultiplexing of POTS and ADSL signals. This is achieved by using a low pass filter with upper frequency boundary around 4 kHz (frequency range of the POTS subscriber line is 0–4 kHz). The splitter is used to ensure the operation of POTS services even in case of failure of ADSL service.  ADSL Access Architecture In the uplink direction, POTS and ADSL signals are multiplexed on the side of the user (again with the splitter) and the signals are transmitted by the same twisted pair telephone line to the ADSL network elements on the operator’s side On the side of the operator, multiplexed POTS and ADSL signals are transmitted to the DSLAM, which first uses a splitter to separate (i.e., to demultiplex) POTS and ADSL signals. There are two outputs of the splitter: one is for POTS signal and the other for ADSL signal that is carried  4.2.1. b. ADSL Frequency Bands and Modulation ADSL Frequency Bands  ADSL Frequency Bands and Modulation ADSL Frequency Bands The physical layer (i.e., OSI-1) of ADSL is designed to be able to coexist with standard POTS spectrum. The two services can coexist because ADSL is using a higher frequency spectrum than the baseband spectrum used for POTS. In fact, the frequency band dedicated for voice in POTS is 0.3–3.4 kHz, but the bandwidth between 3.4 and 4.0 kHz is needed as guard band (to avoid interference) for dial-up modem communication specified in V.90 standard. ADSL is full duplex communication achieved either by FDD (Frequency Division Duplex), TDD (Time Division Duplex), or ECD (Echo-Canceling Duplex). However, the implementations of ADSL equipment by vendors usually are based on FDD approach.  ADSL Frequency Bands and Modulation ADSL Frequency Bands In this case, the ADSL uses spectrum between 25 and 1104 kHz. – The lower band between 25 and 138 kHz is used for upstream communication (i.e., uplink) – The higher band between 138 and 1104 kHz is used for the downstream communication (i.e., downlink).  ADSL Frequency Bands and Modulation ADSL Modulation DMT (discrete multitone) modulation is used in ADSL Discrete multitone (DMT) is a method of separating a Digital Subscriber Line (DSL) signal so that the usable frequency range is separated into 256 frequency bands (or channels) of 4.3125 KHz each. Within each channel, modulation use quadratude amplitude modulation (QAM). By varying the number of bits per symbol within a channel, the modem can be rate-adaptive.  4.2.1.c. ADSL Network Architecture  ADSL Network Architecture In the access network, on the network’s side (on the other end of the local loop) is located the DSLAM. Several local loops end into single DSLAM, which provides aggregation of the traffic from users, and vice versa (toward the end users). Network node between the access part and the core network is ADSL Broadband Remote Access Server (BRAS). In fact, BRAS is a router which is responsible for routing traffic between the DSLAM-enabled access network and the core IP network of the operator (e.g., the Internet Service Provider). It performs aggregation of user sessions from the access network, and vice versa.  ADSL Network Architecture The core network for ADSL usually includes two servers, one proxy server and one AAA server (for Authentication, Authorization, and Accounting). The proxy server is so-called access registrar server, while the AAA server in ADSL networks is RADIUS server (Remote Authentication Dial In User Service). RADIUS is a client–server protocol standardized by IETF (Internet Engineering Task Force) for AAA functionalities in dial-up access to the Internet. It is based on the client-server model. The RADIUS client is located in the BRAS router. There are two possible implementations depending on whether the ADSL device works in bridged mode or routing mode.  4.2.1 d. Cable Access Network The cable networks, which use coaxial cables as their media, initially were designed to deliver broadcast TV services, first analog TV and then digital TV over the cable. However, with the development of the Internet on a global scale the focus of cable networks has shifted from networks dedicated for TV broadcast over cable to end users, toward triple-play networks which can deliver telephony (VoIP), TV, and data Internet services. The coaxial cable as a medium has better transmission characteristics (much wider frequency spectrum for signal transmission on one side) than twisted-pair, and such bandwidth was needed because TV as a service demands more bandwidth (either frequency bandwidth or bit rates) than voice. On the other side, cable networks were initially designed to carry the TV in downstream direction, which can cause problem for two-way communications (downstream and upstream) as used for all Internet services (e.g., most Internet services are based on a client–server paradigm which uses the request–response principle in opposite directions of the communication path).  Cable Access Network There are different models of network access to the Internet through cable networks. Basically, such models differ regarding the implementation of data transmission in the downstream and upstream directions. One approach is a hybrid network, where data in the downstream direction (i.e., toward the end user) is sent via cable TV network, and for the upstream direction is used another network such as dial-up access via a telephone line. In this approach the bit rate in the downstream can be several tens of megabits per second and cable network continues to operate with unidirectional amplifiers that normally exist in the cable networks to enhance the TV signals.  Cable Access Network In such case there is no need for additional investments in the cable network, but there is a need for alternative connection for the upstream. Additionally, another drawback of this approach is that the data is received by all users on the same cable in the downstream direction. Approach which is most used nowadays for Internet services over cable access network is two-way data transmission over the cable network, based on DOCSIS (Data-Over-Cable Service Interface Specifications) Cable Network Architecture Figure: The architecture of the integrated wired network  Cable Network Architecture The integrated network with cable access can be divided into several segments, and they are (going from user’s side toward the core network of the cable operator): home IP network, DOCSIS, PacketCable, and core IP network, which constitute a functional environment that provides transparent transfer of various types of data from different services, as well as implementation of new services in the future over the same access network.  PART C (4.3): MOBILE BROADBAND: NEXT GENERATION MOBILE NETWORKS  Learning Outcomes: Upon completion of this course, students should be able to: 4.2 Understand Mobile Broadband: Next Generation Mobile Networks i. Explain the following items: a. Evolution of Mobile Broadband b. 4G Standard by 3GPP : LTE/LTE-Advanced c. 4G Standard by IEEE : Mobile WiMAX 2.0 d. IP Multimedia Subsystem (IMS) for NGN e. Next Generation Mobile Services A) EVOLUTION OF MOBILE BROADBAND  The ITU is setting the definition for the next generation mobile networks referred to as 4G. They are targeted to provide higher data rates to mobile users, and therefore can be referred to as mobile broadband networks and technologies. The requirements for 4G radio interface are specified in ITU-R (International Telecommunication Union Radiocommunication) report M.2134 and are referred to as IMT-Advanced (International Mobile Telecommunications- Advanced). Similar approach was used for the definition of the third generation of mobile networks (3G) which was named IMT-2000. When 3G was already on the ground, with its first implementations, the future development of mobile networks (beyond 3G) was specified in the ITU-R recommendation M.1645  B) 4G STANDARD BY 3GPP: LTE/LTE-ADVANCED LTE Advanced is a mobile communication standard, formally submitted as a candidate 4G system to ITU-T in late 2009. It was approved into ITU,IMT-Advanced and was finalized by 3GPP in March 2011. Standardized by the 3GPP as a major enhancement of the LTE standard. It was commercially implemented in October 2012 by Russian network Yota.  LTE Advanced Key Features Peak data rates: downlink - 1 Gbps; uplink - 500 Mbps. Spectrum efficiency: 3 times greater than LTE. Peak spectrum efficiency: downlink - 30 bps/Hz; uplink - 15 bps/Hz. Spectrum use: the ability to support scalable bandwidth use and spectrum aggregation where non-contiguous spectrum needs to be used. Latency: from Idle to Connected in less than 50 ms and then shorter than 5 ms one way for individual packet transmission.  LTE Advanced Key Features Cell edge user throughput to be twice that of LTE. Average user throughput to be 3 times that of LTE. Mobility: Same as that in LTE Compatibility: LTE Advanced shall be capable of interworking with LTE and 3GPP legacy systems. Comparison between LTE & Advanced LTE The main new functionalities introduced in LTE-Advanced Carrier Aggregation (CA). Enhanced use of multi-antenna techniques. Support for Relay Nodes (RN).  Carrier Aggregation Each aggregated carrier is referred to as a component carrier. Use maximum of five component carriers. Each of BW of 1.4Mhz, 3MHz,5MHz, 10MHz, 15MHz or 20 MHz. The individual component carriers can also be of different bandwidths.  Channel BW per CCs can be different b/w UL & DL. The individual component carriers can also be of different bandwidths.  Three Different Scenarios Spectrum allocation in 4G can be characterized as follows: – Intra-band adjacent/ contiguous component carriers; – Intra-band non-adjacent/ non-contiguous component carriers; – Inter-band component carriers.  Intra Band, Contiguous – The CCs are allocated within the same operating band and they are contiguous. Intra Band, Non Contiguous – The CCs are allocated within the same operating band and they are not contiguous. Inter Band, Non Contiguous – The CCs allocated in different operating bands. – The CCs will experience different pathloss, which increases with increasing frequency  C) 4G Standard by IEEE: WiMAX 2.0 Mobile WiMAX is a mobile version of the fixed WiMAX used for fixed broadband wireless access. But, Mobile WiMAX is still lacking behind 3GPP mobile technologies. For example, such compatibility was given in 3G mobile systems from 3GPP (i.e. UMTS/HSPA) by having CS domain as in 2G mobile system (2G). Also, such compatibility is given in LTE and LTE- Advanced by having already evolved core architecture and services continuity.  4G Standard by IEEE: WiMAX 2.0 Mobile WiMAX 2.0, has many similarities in the radio access part with LTE- Advanced. Both technologies are almost at the same time period approved as 4G by ITU. However, this is a different progress compared to the 3G development where Mobile WiMAX entered the 3G umbrella later (in October 2007), and had no significant impact on the 3G mobile networks on a global scale. But, at the same time it was an indication of a “serious intention” of another mobile technology to provide more competition and more possibilities for mobile broadband world.  4G Standard by IEEE: WiMAX 2.0 On the other side, the wireless interfaces of Mobile WiMAX 2.0 and LTE- Advanced as well as all-IP core architecture in both standards lead to a convergence of these technologies in some way. That provides possibility to offer both radio access technologies (LTE-Advanced and Mobile WiMAX 2.0, defined over the same frequency bands and having similar radio interfaces) to be integrated in single mobile terminals in cost-effective manner. However, that is dependent upon the regulation (i.e., spectrum management) and business strategies of vendors and mobile operators. Mobile WiMAX Architecture Network  Mobile WiMAX Architecture Network In general, the architecture for the MobileWiMAX1.x releases (based on IEEE 802.16e radio interface) and MobileWiMAX 2.x releases (based on IEEE 802.16m radio interface) is similar. It is consisted of three main parts: – Access Service Network (ASN), – Connectivity Service Network (CSN), – Mobile Stations (MSs).  Mobile WiMAX Architecture Network The ASN is the RAN of Mobile WiMAX, consisted of BSs and Access Service Network Gateway (ASN-GW). The CSN provides the means for IP connectivity between the ASN (and MSs connected to the ASN) and the Internet. The ASN-GW provides two main entities: Data path entity: This is used for transfer of user data between the MSs (in ASN) and public Internet. Control entity: This is used for control and context management per MS, including authentication, accounting, key distribution, QoS provisioning, MM with CSN as anchor point, as well as for connection with the CSN and its server Quality of Service in WiMAX Networks D) IP Multimedia Subsystem (IMS) for NGN IMS uses SIP as signaling and control protocol for different services, including multimedia session services and some non-session services such as presence services and message exchange services. So, NGN IMS supports SIP-based services, but also PSTN/ISDN simulation services IP Multimedia Subsystem (IMS) for NGN  The core part of IMS A) Breakout Gateway Control Function (BGCF) B) Media Gateway Controller Function (MGCF) C) Multimedia Resource Function Controller (MRFC):  Breakout Gateway Control Function (BGCF) This is used for processing of user requests for routing from an S-CSCF for the situations when the S-CSCF has determined that it cannot use session routing by using DNS (Domain Name System) or ENUM(E.164 Number Mapping)/DNS (e.g., cases with PSTN termination of a given call from an IMS user). So, BGCF determines the next hop for routing of a given SIP message. If a breakout occurs in the same IMS network then BGCF selects a MGCF (Media Gateway Controller Function) for interworking with the PSTN. If the routing in BGCF results in breakout into another network, then BGCF forwards the request to the I-CSCF node in the other IMS network. In the given cases when BGCF is involved it also can generate charging records.  Media Gateway Controller Function (MGCF) This performs signaling translation between SIP and ISUP (Integrated Services Digital Network User Part, from SS7 signaling system in PSTN). In SAE it interfaces the S-GW by using SCTP/IP protocol (Stream Control Transmission Protocol) stack.  Multimedia Resource Function Controller (MRFC): This is part of the Multimedia Resource Function (MRF), which is split into two parts: – Multimedia Resource Function Controller (MRFC) – Multimedia Resource Function Processor (MRFP). The MRFC is a signaling node that interprets the information coming from the AS and S-CSCF and using that information for control of the media stream in the MRFP. On the other side, MRFP is a user plane node that provides mixing of media streams (e.g., for multiple receiving parties). Also, it can be a source for media stream (e.g., for multimedia announcements), and provides media streams processing as well as floor control (i.e., management of access rights to shared resources in conferencing environments).  Other entities or nodes for interconnection of the IMS i) Home Subscriber Server (HSS) ii) Subscriber Location Function (SLF) iii) Application Server (AS) iv) Interconnection Border Control Function (IBCF)  Home Subscriber Server (HSS) This is the main user database in the IMS architecture that contains home subscriber profiles (and subscription information), provides authentication and authorization of the users (via CSCF entities of the IMS) and contains information about the network location of the user (i.e., IP address). In fact, it merges the Home Location Register (HLR) and AuC functions that exist in GSM. It is the same HSS node given in SAE.  Subscriber Location Function (SLF) This is a resolution function in IMS that provides information on HSS that has information for a given IMS user (upon a query from I-CSCF or S-CSCF, or from an AS). Hence, this function is not required in networks that have single HSS.  Application Server (AS) This is a server that hosts and executes given service. AS is using SIP for communication with the S-CSCF, which contacts AS in the order supplied by the HSS (in a case of multiple AS). Multiple AS can be any combination of AS, such as SIP AS, OSA (Open Service Access) server, or IP Multimedia Service Switching Function (IM-SSF).  Interconnection Border Control Function (IBCF) This is used as a gateway to external networks. It is in fact a Session Border Controller (SBC) and provides firewall and NAT (Network Address Translation) functionalities in the IMS architecture.  E) Next Generation Mobile Services - Mobile TV IPTV over WiMAX and WiFi To provide TV streaming service in WiMAX, there is a need to use certain QoS class. WiFi also can be used for IPTV transmission, especially in home environments. WiFi operates in unlicensed frequency bands, which may be congested by many users havingWiFi networks operational (i.e., in a residential building or corporate offices). IPTV  Next Generation Mobile Services- Mobile TV Multicast and Broadcast Multimedia System 3GPP has started with standardization of Multicast and Broadcast Multimedia System (MBMS) It is aimed to provide the same multimedia content transmitted to multiple users in a same cell or multiple cells. So, MBMS is a point-to-multipoint service in which data is transmitted from a single source entity to multiple recipients. Transmitting the same data to multiple recipients allows network resources to be shared between multicast and broadcast and other services  Next Generation Mobile Services-Location-Based Services LBSs provide users of mobile devices personalized services customized to their current location in the mobile network. There are two basic approaches to implement LBS regarding the positioning of the users: Process location data in a server and deliver results to the device; Obtain location data for a device-based application that uses it directly.