 | Issue: | Europe II 2007 |
| Article no.: | 9 | |
| Topic: | Keep on moving: the evolution of 3G | |
| Author: | Mikael Bäck | |
| Title: | Vice President, Product and Portfolio Management, Business Unit Networks | |
| Organisation: | Ericsson AB | |
| PDF size: | 464KB |
About author
Mikael Bäck is the Vice President of Product and Portfolio Management of Ericssonís Business Unit Networks. Prior to this position Mr Bäck was Vice President and Head of the Product Area for WCDMA Radio Networks. Prior to joining the WCDMA group, he was responsible for Japanese standards within the PDC Business Unit. Mikael Bäck holds a Masters degree in Electrical Engineering from the Royal Institute of Technology in Stockholm.
Article abstract
It has only been a decade or so since most user connections to the Internet were via a fixed analogue modem operating at 28.8kbit/s. The first data connections via GSM, Global System for Mobile Communications, phones were a patience-stretching 9.6kbit/s. Today, the latest commercial releases of 3G WCDMA radio networks support download speeds of up to 14.4Mbit/s – more than a match for most fixed broadband connections – and they are set to get faster still as WCDMA radio networks evolve to meet growing demand for mobile broadband.
Full Article
Over the years, some industry commentators have questioned whether investment in WCDMA, Wideband Code Division Multiple Access, mobile technology is worthwhile and wondered whether a succession of alternative technologies would render 3G mobile networks obsolete. Meanwhile, GSM/WCDMA operators have been steadily building their WCDMA businesses – rolling out networks, adding subscribers and delivering ever-enhanced functionality. Now WCDMA is undergoing one of its most significant transformations to date, and there is much more to come. The advanced and growing capabilities of WCDMA, in combination with its global adoption, make it the most attractive technology choice for mobile operators who want to deploy voice services and beyond. These capabilities are now on a par with those currently offered by wireline DSL – with the complementary advantage of true global mobility. Enhancing WCDMA in this way will enable mass-market mobile broadband services, such as mobile email, online music, high-speed Internet access, true mobile office and mobile TV anywhere. Unlike competing mobile TV technologies, WCDMA does not require operators to build new, separate networks to start offering broadcast and interactive mobile TV services. An evolving global success story When it comes to technology choices for delivering mobile broadband services, the market has already voted. WCDMA has been selected as 3G technology by eight out of the worldís ten largest operators. It already serves more than 100 million subscribers, and that number is growing daily. Today, more than 80 per cent of all mobile subscribers are served by the GSM/WCDMA family, and this market share is growing month by month. The health of the WCDMA market is testament to industry efforts to ensure openness and interoperability. The scale of the WCDMA market has meant well-funded R&D programmes with a large pool of technical expertise, with economies in manufacturing, supply and logistics. This volume advantage benefits the development of handsets and network equipment, and drives down manufacturing costs. It also helps maintain competitive advantage for the standard, distributed across a large volume of manufactured units. WCDMA was always intended to be an evolutionary technology, and it has continuously evolved to meet the needs of a changing world and of ever more universal wireless communications. It gives GSM operators a standardized route to 3G service capabilities, and provides a continuous evolutionary path into the future. While there are other wireless technologies that may offer higher data rates, none can claim the mobility features, global reach or economies of scale provided by WCDMA. Perhaps WCDMAís strongest hand is its ability to keep growing as a technology, to offer ever-improving mobile broadband service capabilities. Letís take a look at the most significant developments of the standard. Higher speeds in both directions As end-user devices get ever more sophisticated, with the ability to handle high resolution images, video calls and emails with attachments, the need for faster downlink and uplink speeds continues to grow. WCDMA is evolving to stay ahead of the curve. The most immediate enhancement of WCDMA is High Speed Packet Access, HSPA. The downlink version, HSDPA, is currently being deployed globally and will soon be followed by its uplink HSPA sibling, EUL, enhanced uplink, or HSUPA. HSDPA offers unprecedented mobile download speeds – up to 14.4Mbit/s – and short response times for users, as well as more than double the system capacity for mobile operators compared with earlier releases. According to the latest information from the GSM Suppliersí Association, nearly 200 HSDPA devices have already been launched by over 50 suppliers, including: 86 mobile phones; 39 PC cards; and, 34 notebooks. Nearly 100 HSDPA networks have been commercially launched in over 50 countries. Based on the 3GPP Release 6 standard, HSUPA represents the second step of HSPA. Initially, HSUPA will provide uplink speeds approaching 1.4Mbit/s – more than three times the uplink data speed in WCDMA networks. This will add a new mobile dimension to things such as online communities and video-sharing services. Later HSUPA phases will deliver uplink speeds approaching 5.8Mbit/s. Combined, HSPAís faster downlink and uplink speeds will further enhance end-usersí experiences with reduced delay and quicker responses when using interactive applications such as mobile office or fast Internet access with support for gaming or audio and video downloads. Additionally, the uplink will improve the userís experience of mobile broadband services such as video conferencing, email with attachments and file sharing. Several HSPA devices are already available, and the first commercial launches are imminent. Several laptop manufacturers have announced plans to integrate HSPA modems. HSPA offers very low latency – the time it takes for a message to travel from the end-user device to a server on the Internet and back. This means it can provide a user experience equivalent to that from fixed connections. Low latency is important when downloading web pages with a lot of different objects, or when playing games online when users need to react fast. WCDMA with HSPA provides an ideal access platform for services based on IMS and, ultimately, all-IP. A multitude of consumer and enterprise mobile multimedia services will be enabled by this combination. HSPA will continue to evolve, for example with the addition of higher-order modulation schemes and MIMO, Multiple Input Multiple Output, to deliver even higher bit-rates per carrier. Initially, 2×2 MIMO will deliver up to 28Mbit/s. Rather than transmitting a single data stream from a single antenna, this transmits two different data streams from two antennas. By combining the two different data streams at the user terminal, the data speed can be doubled (2x14Mbit/s). The introduction of 2×2 MIMO is relatively straightforward, since virtually every WCDMA base station installed today already has two antennas per sector. Today, two modulation schemes are supported, known as 16QAM, Quadrature Amplitude Modulation, and QPSK, Quadrature Phase Shift Keying. A third modulation scheme, 64QAM, will be introduced to enable data speeds of up to 21Mbit/s. Bit rates will be increased even further in forthcoming system releases, which will combine 64QAM and 2×2 MIMO, which delivers speeds of up to 42Mbit/s – double the speed of a single stream with 64QAM. Even higher speeds will be possible in the future with the introduction of 4×4 MIMO. Looking to the future A standard initiative known as Long Term Evolution, LTE, provides a clear evolutionary path to meet future demands for a system that supports different spectrum allocations. Defined by 3GPP, Third Generation Partnership Project, and set for release later this year, LTE enables efficient spectrum utilization for both legacy and future wireless frequency bands. It provides smooth migration for 2G, 3G and other spectrum (such as TV bands) for use in future mobile communication networks. The large wireless industry behind LTE ensures economies of scale and very cost-efficient solutions. The standard, sometimes referred to as ëSuper 3Gí, is specified to provide data rates of over 100Mbit/s in the downlink, and over 50Mbit/s in the uplink, with latency of around 10ms. LTE enhances WCDMAís single 5MHz carrier transmission scheme with support for spectrum allocations ranging from 1.25MHz to 20MHz, according to the allocation of subcarriers. LTE supports both unpaired Time Division Duplex, TDD, and paired Frequency Division Duplex, FDD, spectrum. This enables operators to expand in new frequency bands or to migrate smoothly into legacy bands to support fixed, mobile and broadcast applications. Looking beyond LTE, the International Telecommunication Union, ITU, defines ë4Gí as network technology with throughput of 100Mbit/s for wide-area mobile use and 1Gbit/s for hotspot coverage to be applied in new spectrum bands with 100MHz channels. Such systems will be commercially available for deployment well beyond 2010. There was a live demonstration of an LTE system at 3GSM World Congress in Barcelona in February 2007. The demonstration encompassed a variety of applications, with speeds of up to 144Mbit/s supported by MIMO antenna technology on a 20MHz carrier in the 2.6GHz frequency band. With the advantages of HSPA and LTE, WCDMA will further enable operators to provide users with more advanced applications with wide-area coverage and mobility and create a true mass market for mobile broadband services. New operator opportunities As well as offering GSM operators a well-defined path to the future, WCDMA is now being seen as an attractive evolution option for CDMA operators. As these operators consider their next technology step, they recognise the secure development path, enhanced revenue opportunities, lower total cost of ownership and global support that come with the economies of scale offered by a truly global standard such as GSM/WCDMA. Many network operators have successfully run – and still are running – multiple network standards in parallel for as long as it takes to get subscribers to migrate and to ensure there is sufficient coverage and capacity during the migration. As 3G mobile services enter a new phase of growth and development, GSM/WCDMA is well placed to help operators succeed in the mobile broadband mass market.
