Submitted by:
Babulal Chaudhary

---

[attachment=12281]
3G Mobile Communication: Comparisons of 3G Standards
Abstract:
The transition from the 2nd Generation (2G) of mobile cellular networks to the 3rd Generation (3G) was motivated by the introduction of multimedia services. More specifically, the convergence of mobile technologies and Internet allows compelling possibilities for future applications due to the new advancement, constantly growing and personalized services in the mobile communication. There are a lot of standards which support the 3G services and these services make the people’s life convenient. My objective is to compare the 3G standards in which we focus on the two most popular standards i.e. WCDMA & CDMA2000, where WCDMA is an air interface of UMTS.
Keywords: IMT, WCDMA, CDMA, UMTS, UTRAN,
1.0 Introduction
International Mobile Telecommunications-2000 (IMT-2000), better known as 3G or 3rd Generation, is a generation of standards for mobile phones and mobile telecommunications services fulfilling specifications by the International Telecommunication Union. Application services include wide-area wireless voice telephone, mobile Internet access, video calls and mobile TV, all in a mobile environment. Compared to the older 2G and 2.5G standards, a 3G system must allow simultaneous use of speech and data services, and provide peak data rates of at least 200 kbit/s according to the IMT-2000 specification. A new generation of cellular standards has appeared approximately every tenth year since 1G systems were introduced in 1981/1982. Each generation is characterized by new frequency bands, higher data rates and non backwards compatible transmission technology
The following standards are typically in 3G.
 the UMTS system, first offered in 2001, standardized by 3GPP, used primarily in Europe, Japan, China and other regions predominated by GSM 2G system infrastructure. The cell phones are typically UMTS and GSM hybrids. Several radio interfaces are offered, sharing the same infrastructure:
 The original and most widespread radio interface is called W-CDMA.
 The TD-SCDMA radio interface was commercialized in 2009 and is only offered in China.
 The latest UMTS release, HSPA+,( High Speed Packet Access) can provide peak data rates up to 56 Mbit/s in the downlink in theory and 22 Mbit/s in the uplink.
 CDMA2000 system, first offered in 2002, standardized by 3GPP2, used especially in North America and South Korea, sharing infrastructure with the IS-95 2G standard. The cell phones are typically CDMA2000 and IS-95 hybrids.
2.0 Development
2.1 India
The 3G (UMTS and CDMA2000) research and development projects started in 1992. In 1999, ITU approved five radio interfaces for IMT-2000. In 2008, India entered the 3G arena with the launch of 3G enabled Mobile and Data services by Government owned Bharat Sanchar Nigam Ltd. (BSNL). Later, MTNL launched 3G in Delhi and Mumbai. Nationwide auction of 3G wireless spectrum was announced in April 2010. The first Private-sector service provider that launched 3G services is Tata Docomo, on November 5, 2010. And the second is by Reliance Communications, December 13,2010. Other providers like Bharati , Airtel, Vodafone, Idea and Aircel are expected to launch 3G services by January 2011.
2.2 Europe
In Europe, 3G services were introduced starting in March 2003 by 3 Hutchison Whampoa in the UK and Italy. The European Union Council suggested that the 3G operators should cover 80% of the European national populations by the end of 2005.
3.0 Features of 3G
3.1 Data rates
ITU has not provided a clear definition of the data rate users can expect from 3G equipment or providers. Thus users sold 3G service may not be able to point to a standard and say that the rates it specifies are not being met. While stating in commentary that "it is expected that IMT-2000 will provide higher transmission rates: a minimum data rate of 2 Mbit/s for stationary or walking users, and 384 kbit/s in a moving vehicle,"
3.2 Security
3G networks offer greater security than their 2G predecessors. By allowing the UE (User Equipment) to authenticate the network it is attaching to, the user can be sure the network is the intended one and not an impersonator.
4.0 Applications & Services
The bandwidth and location information available to 3G devices gives rise to applications not previously available to mobile phone users. Some of the applications are:
 Mobile TV – a provider redirects a TV channel directly to the subscriber's phone where it can be watched.
 Video on demand – a provider sends a movie to the subscriber's phone.
 Video conferencing – subscribers can see as well as talk to each other.
 Tele-medicine – a medical provider monitors or provides advice to the potentially isolated subscriber.
 Location-based services – a provider sends localized weather or traffic conditions to the phone, or the phone allows the subscriber to find nearby businesses or friends.
5.0 Universal Mobile Telecommunications System (UMTS)
Universal Mobile Telecommunications System (UMTS) is one of the third-generation (3G) mobile telecommunications technologies, which is also being developed into a 4G technology. The first deployment of the UMTS is the release99 (R99) architecture. It is specified by 3GPP and is part of the global ITU IMT-2000 standard. The name UMTS, introduced by ETSI (European Telecommunications Standards Institute), is usually used in Europe. Outside of Europe, the system is also known by other names such as FOMA or W-CDMA. In marketing, it is often referred to as 3G.
The most common form of UMTS uses W-CDMA (IMT Direct Spread) as the underlying air interface but the system also covers TD-CDMA and TD-SCDMA. Being a complete network system, UMTS also covers the radio access network (UMTS Terrestrial Radio Access Network, or UTRAN) and the core network (Mobile Application Part, or MAP), as well as authentication of users via SIM cards (Subscriber Identity Module). Unlike EDGE (IMT Single-Carrier, based on GSM) and CDMA2000 (IMT Multi-Carrier), UMTS requires new base stations and new frequency allocations. However, it is closely related to GSM/EDGE as it borrows and builds upon concepts from GSM. Further, most UMTS handsets also support GSM, allowing seamless dual-mode operation. Therefore, UMTS is sometimes marketed as 3GSM, emphasizing the close relationship with GSM and differentiating it from competing technologies.
5.1 Features & Comparison with GSM
UMTS, using 3GPP, supports maximum theoretical data transfer rates of 45 Mbit/s. Precursors to 3G. In the case of GSM, there is an evolution path from 2G, to GPRS, also known as 2.5G. GPRS supports a much better data rate (up to a theoretical maximum of 140.8 kbit/s, though typical rates are closer to 56 kbit/s) and is packet switched rather than connection oriented (circuit switched). It is deployed in many places where GSM is used. E-GPRS, or EDGE, is a further evolution of GPRS and is based on more modern coding schemes. With EDGE the actual packet data rates can reach around 180 kbit/s (effective). EDGE systems are often referred as "2.75G Systems".
UMTS networks in many countries have been or are in the process of being upgraded with High Speed Downlink Packet Access (HSDPA), sometimes known as 3.5G. Currently, HSDPA enables downlink transfer speeds of up to 21 Mbit/s. Work is also progressing on improving the uplink transfer speed with the High-Speed Uplink Packet Access (HSUPA). Longer term, the 3GPP Long Term Evolution project plans to move UMTS to 4G speeds of 100 Mbit/s down and 50 Mbit/s up, using a next generation air interface technology based upon Orthogonal frequency-division multiplexing.
5.2 Air interfaces
UMTS provides several different terrestrial air interfaces, called UMTS Terrestrial Radio Access (UTRA). All air interface options are part of ITU's IMT-2000. In the currently most popular variant for cellular mobile telephones, W-CDMA (IMT Direct Spread) is used.
5.3 Spectrum of UMTS
6.0 W-CDMA (Wideband Code Division Multiple Access)
W-CDMA, UMTS-FDD, UTRA-FDD, or IMT-2000 CDMA Direct Spread is an air interface standard found in 3G mobile telecommunications networks. It is the basis of Japan's NTT DoCoMo's FOMA service and the most-commonly used member of the UMTS family and known as WCDMA. It utilizes the DS-CDMA channel access method and the FDD & TDD duplexing method to achieve higher speeds and support more users compared to most time division multiple access (TDMA) schemes used today.
6.1 Development
The world's first commercial W-CDMA service, FOMA, was launched by NTT DoCoMo in Japan in 2001. In the late 1990s,. ITU eventually accepted W-CDMA as part of the IMT-2000 family of 3G standards, as an alternative to CDMA2000, EDGE, and the short range DECT system. Later, W-CDMA was selected as an air interface for UMTS. W-CDMA transmits on a pair of 5 MHz-wide radio channels, while CDMA2000 transmits on one or several pairs of 1.25 MHz radio channels. Though W-CDMA does use a direct sequence CDMA transmission technique like CDMA2000, W-CDMA is not simply a wideband version of CDMA2000. The W-CDMA system is a new design by NTT Docomo, and it differs in many aspects from CDMA2000. From an engineering point of view, W-CDMA provides a different balance of trade-offs between cost, capacity, performance, and density; it also promises to achieve a benefit of reduced cost for video phone handsets. W-CDMA may also be better suited for deployment in the very dense cities of Europe and Asia.
6.2 Technical features
 Radio channels are 5 MHz wide.
 Chip rate of 3.84 mcps
 Supported mode of duplex: frequency division (FDD), Time Division (TDD)
 Employs coherent detection on both the uplink and downlink based on the use of pilot symbols and channels.
 Supports inter-cell asynchronous operation.
 Frame Length : 10ms
 Multicode transmission.
 Adaptive power control based on SIR (Signal-to-Interference Ratio).
 Multiuser detection and smart antennas can be used to increase capacity and coverage.
 Multiple types of handoff (or handover) between different cells including soft handoff, softer handoff and hard handoff.
 1:1 frequency reuse scheme
 Multiple Service with different Quality of Service.
7.0 CDMA2000 System
CDMA2000 also known as IMT Multicarrier (IMT MC)) is a family of 3G mobile technology standards, which use CDMA channel access, to send voice, data, and signaling data between mobile phones and cell sites. The set of standards includes: CDMA2000 1X, CDMA2000 EV-DO Rev. 0, CDMA2000 EV-DO Rev. A, and CDMA2000 EV-DO Rev. B. All are approved radio interfaces for the ITU's IMT-2000. CDMA2000 has a relatively long technical history and is backward-compatible with its previous 2G iteration IS-95 (cdmaOne).
7.1 Development & Data Rate:
CDMA2000 is developed by Qualcomm and is direct evolution from the previous generations to prove the CDMA systems and it provides the easiest way to migrate to 3G networks. CDMA2000 1X increases the voice capacity of the CDMA One networks and delivers the packets data rate speed of 307 Kbps. The approach that is used is the wideband for the high data rates which is the CDMA2000 3X. The 3X standard has now been past it by a two phase strategy called CDMA2000 1xEV, where 1xEV stands for 1X evolution, or evolution using 1.25 MHz Today CDMA2000 1X systems are based on a standard 1.25 MHz carrier for delivering high data rates and increased voice capacity and the total is 3times the 1X capacity (means 3.75 MHz).
7.1 1X
CDMA2000 1X (IS-2000), also known as 1x and 1xRTT (Radio Transmission technology), is the core CDMA2000 wireless air interface standard. The designation "1x", meaning 1 times Radio Transmission Technology, indicates the same RF bandwidth as IS-95. i.e. a duplex pair of 1.25 MHz radio channels. 1xRTT almost doubles the capacity of IS-95 by adding 64 more traffic channels to the forward link. The 1X standard supports packet data speeds of up to 153 kbps with real world data transmission averaging 60–100 kbps in most commercial applications. IMT-2000 also made changes to the data page link layer for the greater use of data services, including medium and page link access control protocols and QoS. The IS-95 data page link layer only provided "best effort delivery" for data and circuit switched channel for voice i.e., a voice frame once every 20 ms
7.2 1xEV-DO
CDMA2000 1xEV-DO (Evolution-Data Optimized), often abbreviated as EV-DO or EV, is a telecommunications standard for the wireless transmission of data through radio signals, typically for broadband Internet access. There are two phases of this technology which are labeled as 1xEV-DO and 1xEV-DV. DO stands for the data only and DV for the data and voice. CDMA2000 1xEV-DO is standardized by the TIA (Telecommunication Industry Association) in October 2000 and recognized by the ITU as IMT-2000 standard. 1xEV-DO can provide customers with peak data rates of 2.4 Mb/s . It uses multiplexing techniques including code division multiple access (CDMA) as well as time division multiple access (TDMA) to maximize both individual user's throughput and the overall system throughput. It is standardized by 3rd Generation Partnership Project 2 (3GPP2) as part of the CDMA2000 family of standards and has been adopted by many mobile phone service providers around the world, particularly those previously employing CDMA networks. It is also used on the Global star satellite phone network.