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UMTS and WCDMA Overview

Mar 28, 2015

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Cellular Mobile Systems and Services (TCOM1010) 2009-April Day-12_UMTS and WCDMA Overview.doc Monzur Kabir, Ph.D., P.Eng Page 1 of 19 UMTS and CDMA Overview 1 BACKGROUND INFORMATION ................................................................................................................................. 2 2 UMTS OVERVIEW.......................................................................................................................................................... 2 2.1 UMTS Releases............................................................................................................................................................. 3 2.2 UMTS Services ............................................................................................................................................................. 4 2.3 UMTS Core Network (CN) Overview.......................................................................................................................... 4 2.4 UMTS Terrestrial Radio Access Network (UTRAN) ................................................................................................... 4 2.5 Frequency Bands ........................................................................................................................................................... 5 2.6 UMTS Technology Overview....................................................................................................................................... 6 3 2G GSM TO 3G UMTS NETWORK ARCHITECTURE.......................................................................................... 8 3.1 UMTS Network Architecture - Evolution: from 2G-GSM to 3G-UMTS R5................................................................ 8 3.2 UMTS Network Architecture -- Evolution: from 2G-GSM to 3G-UMTS R7 ............................................................ 13 4 CDMA AND W-CDMA AN OVERVIEW................................................................................................................. 16 4.1 Multiple Access Technologies .................................................................................................................................... 16 4.2 Channelization Multiple Access Techniques .............................................................................................................. 17 4.3 CDMA Principle ......................................................................................................................................................... 17 4.4 Why CDMA................................................................................................................................................................ 18 4.5 W-CDMA Overview................................................................................................................................................... 19 Cellular Mobile Systems and Services (TCOM1010) 2009-April Day-12_UMTS and WCDMA Overview.doc Monzur Kabir, Ph.D., P.Eng Page 2 of 19 1 Background Information Pre-reading: See the 3G Cellular Mobile Overview document. Three major cellular mobile systems under the hood of IMT-2000 are UMTS (by 3GPP), CDMA2000 (by 3GPP2) and EDGE (also called as EGPRS) (by UWCCC or newly named 3G America). The following figure depicts how the 2G systems are heading towards 3G systems (her UMTS is represented by W-CDMA, which is one but the most prominent system of UMTS). This document gives an overview of W-CDMA and CDMA2000 (UWC-136 or EDGE is covered under GSM/GPRS). http://www.comsec.uwaterloo.ca/~flchiu/CDMA/IMT2000%20standard.pdf 2 UMTS Overview UMTS was formed in 1996 and then joined with few other organizations to form a bigger 3GPP body to carry on the GSM-driven CDMA system (see 3G Cellular Mobile Overview document for a further detail) where it adopts CDMA for the radio interface but keeps GSM technologies as much as it can. The UMTS has three major systems: W-CDMA TD-CDMA and TD-SCDMA. Among them the W-CDMA is the most prominent system. Cellular Mobile Systems and Services (TCOM1010) 2009-April Day-12_UMTS and WCDMA Overview.doc Monzur Kabir, Ph.D., P.Eng Page 3 of 19 2.1 UMTS Releases So far UMTS issued the following Releases (http://www.telecomabc.com/u/umts-releases.html). UMTS Release 3 (also called Release 99) o Based on GSM, Backward compatible with GSM, Interoperation between UMTS and GSM; o Definition of the UTRAN o UTRA UMTS FDD (W-CDMA) o GSM EDGE Radio Access Network (GERAN) UMTS Release 4 o Separation of user data flows and control mechanisms, o UMTS TDD Time Division CDMA (TD-CDMA), High data rate UMTS TDD with 3.84 Mchips/s, Narrowband TDD with 1.28 Mchips/s; o Position location functionality; UMTS Release 5 o End-to-end packet switching based on IP (IMS), o Downlink data rate of over 10 Mbit/s (HSDPA), UMTS Release 6 o IMS "Phase 2" (IMS Messaging, conferencing and Group Management), o High Speed Uplink (HSUPA) o Multimedia Broadcast/Multicast Service (MBMS) o WLAN interworking UMTS Release 7 o Enhanced uplink, other spectrum, o Multiple Input Multiple Output antennas (MIMO), o IMS Emergency call handling. o DSL Access Cellular Mobile Systems and Services (TCOM1010) 2009-April Day-12_UMTS and WCDMA Overview.doc Monzur Kabir, Ph.D., P.Eng Page 4 of 19 2.2 UMTS Services http://www.telecomabc.com/u/umts.html In addition to traditional speech and data communication services, UMTS offers the user full interactive multimedia communications, information and entertainment services with speeds of up to 2 Mbit/s, comparable with the current fixed networks. Further evolutions of UMTS will make even higher transmission speeds possible. In UMTS there are four different kinds of services defined. Each with its own quality of service: Conversational, o Temporal relation preserved, o Weak and rigorous delays, o Services: Telephony, videotelephony, real time video games; Streaming, o Temporal relation preserved, o Services: Multimedia services; Interactive, o Demand of response, o Data integrity preserved, o Services: Internet (web browsing); Background, o No restraints on delays, o Data integrity preserved, o Services: E-mail. 2.3 UMTS Core Network (CN) Overview It was all GSM in 2G, which has a circuit switched (CS) core network (CN). In 2.5G (GPRS and EDGE) another core was added, which is a packet-switched (PS) core with GSNs (GPRS Service Nodes). While continuing with these two (CS and PS) with some as needed enhancements, the UMTS introduced IP Multimedia Sub-system (IMS) for all IP end-to-end multimedia services (including voice-over-IP). UMTS-CN includes network elements: o Legacy GSM: MSC, VLR, HLR, EIR etc. o GPRS/EDGE: SGSN, GGSN etc. o IMS core: CBC, CSCF, MRCF, MGCF, SLF, HSS, AS etc. 2.4 UMTS Terrestrial Radio Access Network (UTRAN) http://www.telecomabc.com/u/utran.html The UMTS Terrestrial Radio Access Network (UTRAN) is the fixed network infrastructure that contains the facilities for the transmission to and from the mobile users over radio. The components of the UTRAN are the base stations, which are called Node B in UMTS, and control nodes, which are called Radio Network Controller (RNC). The Radio Network Controllers are connected to the Core Network (CN). Cellular Mobile Systems and Services (TCOM1010) 2009-April Day-12_UMTS and WCDMA Overview.doc Monzur Kabir, Ph.D., P.Eng Page 5 of 19 The interface for the transmission to and from the mobile users is called the UTRA (UMTS Terrestrial Radio Access). There are two different modes: an UMTS FDD mode and a UMTS TDD mode. The FDD requires a paired band (up and down link) whereas TDD works with an unpaired band. 2.5 Frequency Bands The following bands are available for UMTS, in Europe. DECT UMTS TDD UMTS FDD Sat up UMTS TDD UMTS FDD Sat down 1880 1900 1920 1980 2010 2025 2110 2170 2200 MHz The available spectrum of 155 MHz is divided in: a paired band, FDD: 1920-1980 and 2110-2170 MHz; 2 60 MHz; two unpaired bands, TDD: 1900-1920 MHz and 2010-2025 MHz; in total 35 MHz. The UTRA makes use of W-CDMA in the paired bands. These bands are used the following bit-rates: 144 kbit/s in suburban and rural areas (high-mobility => up to 500 km/h) up to 384 - 512 kbit/s in urban areas (medium-mobility => up to 120 km/h) W-CDMA is officially known as IMT-2000 CDMA Direct Spread (CDMA DS). The main characteristics of W-CDMA are: o Wideband Direct Sequence CDMA; o Frequency Division Duplex; Cellular Mobile Systems and Services (TCOM1010) 2009-April Day-12_UMTS and WCDMA Overview.doc Monzur Kabir, Ph.D., P.Eng Page 6 of 19 o Chip rate: 3.84 Mcps, can be extended to 8.192 or 16.384 Mcps; o No need to synchronize the base stations; o Variable spreading code, Spreading factor from 4 to 256; o Bandwidth between 4.4 and 5 MHz. The UTRA TDD has two types: TD-CDMA and TD-SCDMA, which use unpaired band. These bands are used for high bit rates at hotspots (up to 2 Mbit/s) with low-mobility (less then 10 km/h). All bit rates are based on the first generation of UMTS (Release 1999). Further evolutions of UMTS will make even higher transmission speeds possible 2.6 UMTS Technology Overview IP-based Multimedia Services (IMS) http://www.telecomabc.com/i/ims.html IP-based Multimedia Services (IMS) is a part of the UMTS specification (as of Release 5) that provides IP transport in the core network and the radio access network (UTRAN). IMS enables the convergence of data, speech, and mobile network technology over an IPbased infrastructure. IMS was designed to fill the gap between the existing traditional telecommunications technology and Internet technology. This will allow operators to offer end-to-end IP services. This increases the potential for new innovative services and service integrat

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