My Conclusion about WCDMA technology

picture from: http://www.samsung.com/global/business/telecommunication/productType.do?ctgry_group=11&ctgry_type=17

In this blog, I first introduced evolution of mobile generation networks from 1G to 3G. Second, I analyzed the advantages and disadvantages of GSM, which is still dominant in the worldwide mobile market, and summarized that the migration path from 2.5G to 3G via GPRS and EDGE to UMTS is the path that the majority of mobile carriers worldwide intend to take. Because of various emerging technologies, like GPRS, EDGE, WCDMA, CDMA2000 and so on and other aspects such as potential of new markets, fixed-to-mobile substitution, I believe that the global mobile market will still grow in the future ten years. Hence, I pointed out that the evolution from GSM to 3G would bring more opportunities to this changing industry.

Then I focused on the WCDMA technology, the 3G successor to GSM. After listing the features of WCDMA technology, I made a comparison between WCDMA and its strong competitor CDMA2000 from both technical and economic aspects. Higher volumes permit more attractive prices for network infrastructure, system technology and for mobile end devices. This is already having an effect on the lower end of the market, where unsubsidized cdmaOne terminals cost almost twice as much as GSM/GPRS devices. The expenditure for research and development will also be proportional to the share of the global market, with a positive effect on the speed and time to market. The product portfolio makes this clear: Over 300 GSM handsets are on the market, approximately twice the number of cdmaOne models. Hence, the technologies derived from GSM enjoy the benefits that come from longer periods of development and maturation. The range of value-added services is both wider and more multi-faceted. The return on investment can be achieved faster. Roaming and service continuity also speak out in favor of migration to W-CDMA technology.

In addition, I also talked about HSDPA, the first evolution of WCDMA technology. There were almost 3 times the number of commercial HSDPA network launches compared to CDMA 1x EV-DO from mid-June to mid-September 2006.

At last, I analyzed the possible strategy for GSM operators by integrating GSM and WCDMA as a seamless network to meet the market with respect to the number of subscribers, the way they will use the services, the amount of money customers will spend on telecom services, the amount of money operators will save. All in all, this GSM/WCDMA integrated seamless network adds flexibility in the 3G deployments, enhances system performance, protects network investments through reuse of resources and supports the growth of today’s services as well as the creation and growth of mobile services beyond voice. So my conclusion is that WCDMA/HSDPA will be the leading 3G technology globally in the future.

One of big benefits of WCDMA technology：Great cost savings for GSM operators

Previously, I have mentioned that there are a lot of advantages and benefits of WCDMA technology over other technology in mobile market. This time we will closely look at one of these benefits: cost savings. When evolving from a pure GSM network to an integrated GSM/WCDMA one, two different areas are the sources of cost savings: capital expenditures and operating expenditures. Both will be analyzed below with regard to potential savings.

1. Capital expenditures saving areas
As we can see, the seamless network certainly protects an operator’s GSM investment by reusing GSM resources when evolving toward a 3G network. There are several areas in which operators can realize savings:
(1) The radio access network;
(2) The packet-switched core network;
(3) The circuit-switched core network;
(4) Charging and billing.

For example, the radio access network, one of the most expensive parts of a wireless network, offers several areas for potential savings when building the UTRAN, such as
• Sharing the UTRAN with other operators.
• Co-location and coexistence of GSM and WCDMA
• Using common operations and management subsystems for both GSM and WCDMA
• Having cabinet footprint and installation methods be the same in 2G and 3G.

Additional savings in the operations field are possible because all the established procedures for maintenance, technical support and spare parts management remain the same. What’s more, little to no additional training is required for the field support engineers.

2 operating expenditures saving areas
There are many benefits from operating the GSM and WCDMA networks as a single network, especially when it comes to saving operational costs. With two separate networks, the complexity of running the operator’s business increases exponentially. The operator can also realize significant savings by choosing fewer vendors to provide its network.

Here, we will analyze the major aspects of the single network and the vendor operator relationship with regard to potential savings and ease of operations. They are:
(1) Customer service management: is one of the biggest expenses of running a mobile operator business. Having a common customer care system, a single subscription and one billing system leads to substantial operating expenditures savings, both in terms of personal and training costs. The layered architecture of the seamless network makes it possible to realize these savings.

(2) Technical planning: For every network and vendor, the operator needs to establish an interface team in order to plan and to coordinate ongoing operations. This results in additional costs for highly skilled personnel on both the management and technical levels.

(3) Training: Maintaining two separate networks, each with its specific products, significantly increases the cost of training. Bringing in network equipment from a new vendor automatically leads to new training requirements for operating, maintaining and supporting the new products.

(4) Installation services: especially in the radio access network, comprise a major portion of operational costs. Efforts behind the initial deployment of all network elements are much higher when equipment from different vendors. This smooth evolutionary path enables predefined interconnection and facilitates upgrade procedures. This requires less material and offers smoother installation compared to overlaying equipment from other vendors. It also reduces the human effort and leads to cost reductions.

There are still a lot of other aspects, such as operations, maintenance and support, interoperability testing, processes and human interfaces. The strategy of a GSM/WCDMA seamless network adds flexibility in the 3G deployments, enhances system performance, and protects network investments through reuse of resources. This solution will help the operator secure the satisfaction and loyalty of its great amount of current GSM subscribers. I think every GSM operator will agree that this vital asset must be protected during this GSM to WCDMA transition period, because it is the foundation for future 3G businesses.

Rapid growth ahead for WCDMA/HSDPA mobile market in Europe

The European mobile broadband market is growing exponentially with demand fuelled by declining prices and improving performance. It is said that Vendors’ 2007 financial data indicated an increase in shipments in the range of 40–50 percent and a general price reduction of 20 percent. Until 2011, the mobile broadband market is expected to increase at a compound annual growth rate of 22.9 percent to reach € 3.0 billion. Device revenues are forecasted to increase at a faster rate than network revenues. While the expected high demand from the PC-industry will lead to higher shipment volumes, the vast majority of new subscribers will only be occasional users generating lower network ARPU.

WCDMA/HSDPA and legacy standards are expected to remain the dominant network access technology throughout the entire period with a market share well above 90 percent. We should notice that at the end of 2006, there were about 3.3 million active WCDMA/HSDPA mobile connections in Europe, compared to less than a quarter of a million for all other technologies combined. Although CDMA 450 has achieved some penetration in the Czech Republic, Romania and Scandinavia and will remain an alternative in areas without WCDMA/HSDPA coverage, deployments of WCDMA/HSDPA in lower frequency bands is likely to reduce the traction of EVDO on the European market in the longer term. WCDMA/HSDPA evolves rapidly as a technology, having advanced from peak data rates of 1.8 Mbps for commercial networks in early 2006 to 7.2 Mbps downlink and 2.0 Mbps uplink in the first half of 2007.

Here, I would like to mention that CDMA 450 is a commercially and technically viable technology in operation today providing cellular voice data and WLL services. CDMA450 is a TIA-EIA-IS-CDMA2000 (CDMA-MC) system deployed in 450 MHz which includes a family of standards developed by 3GPP2, published by TIA and approved by ITU for IMT-2000: CDMA2000 1X, CDMA2000 1xEV-DO and CDMA2000 1xEV-DV. Currently, CDMA2000 1X and CDMA2000 1xEV-DO are commercially available for the 450 MHz band and CDMA2000 1xEV-DV is being developed. In my opinion, CDMA 450 is a real competitor for WCDMA/HSDPA. However, the European investment community is ignoring the benefits of CDMA technologies in the 450 and 800MHz frequency bands.

Some people asked question that what are the real market prospects for alternative mobile broadband technologies like CDMA 450 and WiMAX? Frankly speaking, I do not believe that WiMAX will have any major impact on the European market in the coming five years. Any successful alternative network service provider must overcome a number of formidable barriers. These must include securing sufficient radio frequency spectrum, financing and constructing completely new infrastructure and finally gain a competitive edge against three to four established WCDMA/HSDPA network operators, who by that time will offer network speeds of at least 14.4 Mbps at price points comparable to DSL. The prospects for FLASH-OFDM and other 802.20 standard technologies also appear relatively less attractive.

All in all, I think the WCDMA/HSDPA technology would win the majority of mobile market in Europe in the future. Anyway, the popularity of mobile broadband is starting to have an impact on the overall strategies of network operators in many parts of Europe. Of course, we should be clear about which markets have the highest penetration rates and which are lagging behind? There are significant differences in pricing between operators, as well as markets. In addition, study shows that Greece, France and the UK have the highest overall price levels, while the lowest are found in Austria, Sweden, Hungary and Poland.

Evolution of WCDMA

As we can see, the introduction part of WCDMA follows a natural evolution of 2G networks. Then the term "WCDMA Evolved" describes the evolution of WCDMA addressing both operators' need for efficiency and end-user's demand for enhanced experience and simplicity. WCDMA is evolving to handle higher bit rates.

In the first step downlink was improved. WCDMA 3GPP Release 5 extends the specification with HSDPA, which is an enhancement of WCDMA. HSDPA improves the end-user experience by increasing peak data rates to 14 Mbps in the downlink, reducing delay; and providing 2-3 times more system capacity.

In the second step the uplink has been enhanced. Through these capabilities, operators benefit from a technology that provides performance for improved end-user experience for Web access, file download and streaming services. Wireless broadband access to the Internet, intranet and corporate LAN benefits greatly from 'WCDMA Evolved.'

The Concept：In WCDMA 3GPP release 5, WCDMA has been extended with a new transport channel, the high-speed downlink shared channel (HS-DSCH), which provides enhanced support for interactive, background, and to some extent, streaming radio access bearer (RAB) services in the downlink. HS-DSCH transmission facilitates several new features. But to support them with minimum impact on the existing radio interface protocol architecture, a new MAC sub-layer, MAC-hs, has been introduced for HS-DSCH transmission. MAC-hs makes it possible to retain a functional split between layers and nodes from WCDMA 3GPP release 99. A minimum of architectural changes allows a smooth upgrade to HSDPA and ensures HSDPA operation in environments where not all cells have HSDPA functionality.

The Benefits：The primary benefit of HSDPA is the improved end-user experience. In practice, this means shorter download times through higher bit rates (14 Mbps peak rate) and reduced roundtrip time over the air interface. HSDPA also provides advantages for operators by introducing greater system capacity.

Improved end-user experience: HSDPA can reduce the time it takes to download large files by a factor of 20. HDSPA opens up for enhanced end-user experience when using WCDMA for wireless broadband applications such as intranet and Internet access via laptop computers. Here the reduced delay improves the traditional web access. Download of emails and other heavy files are improved by the increased peak data rates.
Improved system capacity: A further benefit of HSDPA is greater system capacity. HSDPA increases capacity in several ways:
1.Shared-channel transmission results in efficient use of available code and power resources in WCDMA
2.The use of a shorter TTI reduces roundtrip time and improves the tracking of fast channel variations
3. Link adaptation maximizes channel usage and enables the base station to operate close to maximum cell power
4.Fast scheduling prioritizes users with the most favorable channel conditions
5.Fast retransmission and soft-combining further increases capacity
6.16QAM yields higher bit rates
Depending on the deployment scenario, the combined gain in capacity is from two to three times that of WCDMA 3GPP release 99. Another benefit of HSDPA is that it is an integral part of WCDMA. Wide-area mobile coverage can be provided with HSDPA. At present, WCDMA can provide simultaneous voice and data services (multi-services) to users on the same carrier. This also applies to HSDPA, which means that spectrum can be used efficiently. HSDPA also makes efficient use of power by employing unused power.

Wide Coverage：WCDMA will be evolved to handle higher bit rates. The first step is to improve the downlink in WCDMA. HSDPA will greatly improve the end-user experience by increasing bit rates to as much as 14 Mbps in the downlink and reducing delay. In addition, no new spectrum / carrier is needed to roll out HSDPA in the network. At present, WCDMA can provide voice and data services on the same carrier simultaneously. This also applies to HSDPA.

Hence, with the advantages of HSDPA, 'WCDMA Evolved' will further enable operators to provide end-users with more advanced wireless broadband applications offering wide area coverage and mobility.

Comparison between WCDMA and CDMA2000 from Market share and economic aspects

The results of comparing the two systems are much clearer when economic aspects are taken into our account. For example, market share, economies of scale in the production of network equipment and end devices as well as the possibilities for international deployment，such as roaming. In this sector, GSM and its successor technologies GPRS, EDGE and UMTS/W-CDMA are dominant.

Data shows that Over 750 million subscribers, at August 2002, in over 175 countries clearly make GSM the leading mobile communication standard worldwide. In 2001, 81 percent of all new subscriptions were for GSM devices, whereas only 13 percent were for cdmaOne devices (EMC Database). The current subscription trend suggests that the gap between market shares for GSM and CDMA will continue to widen.

cdmaOne installations only really played a role in the Americas, particularly in the USA, and to a certain extent in the Asia Pacific Region, in particular in Korea. South Korea provided 70 percent of the cdmaOne customer base in the Asia Pacific Region. In June 2001 this was approximately 28.1 million cdmaOne subscribers which is roughly a third of the entire cdmaOne customer base worldwide. But this customer base is beginning to crumble as the carriers SKT and KT opted for W-CDMA as their 3G path. These two carriers together control 85 percent of the market in Korea.

Let’s look at Japan, NTT DoCoMo and J-Phone (with a combined share of the market amounting to 75.7 percent of all Japanese subscribers) opted for UMTS/W-CDMA as their 3G technology. Based on these facts and analysis, I have to say that WCDMA has the edge over the seriously competitive cdma2000 versions.

Comparison between WCDMA and CDMA2000 from technical aspect

W-CDMA
First let’s look at WCDMA technology. In conjunction with GPRS and EDGE which are evolutionary developments of the GSM technology, W-CDMA can be applied, both cost-effectively and with little need for additional resources. Mobile telephones and other devices used in W-CDMA mode will be able to use GSM, GPRS or EDGE, which ensures a seamless transition within the existing networks. W-CDMA attains its high performance by transmitting signals from the various services which require variable data rates by assigning bandwidth flexibly (bandwidth on demand). Each signal is coded, and then modulated and distributed ("spread") across a 5 MHz transmission bandwidth. The frequency band is available to all subscribers simultaneously. The coding identifies the signals destined for the each individual subscriber. All other users that do not have the appropriate codes will only receive the sum total of all signals in the form of undefined noise.

cdma2000
cdma2000 is a family of mobile technologies that are based on a narrow band (1.25 MHz channel bandwidth) version of CDMA and are derived from the Interim Standard No. 95 (IS-95) which was published in 1993 by the North American trading organization, the TIA. Although a multi-carrier CDMA that is able to handle multiple sequences IS-95 carriers was originally suggested within the framework of IMT-2000, only the single carrier solution of the cdma2000 family has remained (hence the name 1x). The first step takes the form of 1xRTT (also called cdma2000 1x) a slightly improved variant of IS-95 including the integration of a packet-switching core network which delivers similar performance to GPRS. Since the data throughput did not meet the 3G guidelines, the HDR (High Data Rate) system proposed by Qualcomm in 1998 was introduced as an evolution phase and was accepted as a standard known as cdma2000 1xEV-DO in August 2001. 1xEV-DO is designed especially for data services that are not runtime critical, and requires a separate frequency band. This means that transmission capacities are reserved exclusively for data, even if there is no need, which can be a waste of radio resources. In order to eliminate this problem, the new version, cdma2000 1xEV-DV, is designed to handle both voice traffic and data on a single frequency bandwidth. Only this second stage of evolution can be compared to W-CDMA.

Hence, the wider bandwidth of W-CDMA promises to deliver particularly good service quality and proliferation characteristics. The technology of 1xEV systems from cdma2000 appear to be stretched to its limits in terms of additional capacity increases. In contrast, W-CDMA still has potential for increased performance as is made clear by the HSDPA upgrade standard approved in Spring 2002. This allows for a downlink data rate of up to 10 Mbps thanks to improved transmission mechanisms optimized for data transfer.

Although the migration path from GSM to UMTS/W-CDMA also brings about a change in the technology used for transmission, solutions for the reuse of existing network infrastructures appear to be simpler and more cost-effective for this technology than for the cdma2000 system family. Thus, for instance, upgrading to version 1xEV-DO would require huge investment to set up a separate overlay network.

We should notice another problematic issue is the GPS satellite detection of the base stations which is required for cdma2000. Since GPS technology requires an uninterrupted line of sight to the satellites, small cells, for example, inside buildings, or between tall buildings, require additional outlay for installing external GPS receivers. W-CDMA on the other hand operates in asynchronous mode and, as a result, can be used universally without GPS detection.

From the above analysis, we can draw the conclusion that WCDMA outweighs CDMA2000 from a technical aspect.

Standardization activities on WCDMA

In early 1998, to expedite the process of IMT2000/3G standardization and the global acceptance of proposed radio transmission technologies, a concept of a “Partnership Project” was proposed by the European elecommunications Standards Institute (ETSI). This proposal initiated two Third-Generation Partnership Projects (3GPP and 3GPP2) with two different, but related areas of focus.

Each of the 3GPP and 3GPP2 projects involves a number of regional standardization bodies as organizational partners. For 3GPP the original scope was to produce globally applicable and acceptable technical specifications for a Third-Generation Mobile System based on the evolved GSM networks. This scope was subsequently amended to include the maintenance and development of Technical Specifications for GSM and its evolution to General Packet Radio Service (GPRS) and Enhanced Data rates for GSM Evolution (EDGE).

Similarly, the scope of the 3GPP2 work was to harmonize different variations of cdma2000 in a single family of standards. This scope was also expanded to include the development of a data-optimized air interface called the high-rate packet data (HRPD) system. In the development of cdma2000 systems the core network specifications are based on an evolved ANSI-41 and IP network; however, the specifications also include the necessary capabilities for operation with an evolved GSM-MAP-based core network.

As a result of harmonization efforts in 3GPP and 3GPP2, the following three major technologies have been identified and included in the IMT2000 family of standards: The Direct-Sequence mode is based on WCDMA specified by
3GPP (UTRA/FDD), the Multi-Carrier mode is based on cdma2000 Multi-Carrier specified by 3GPP2, and the TDD mode is based on the TDD mode specified by 3GPP (UTRA TDD).

Wideband CDMA (WCDMA) has been chosen as basic radio-access technology for UMTS/IMT-2000 in all major areas of the world. Most GSM operators are planning or have begun deploying IMT2000/UMTS based networks using WCDMA technology. Many IS136/TDMA-based networks have also joined the GSM group and have decided to migrate to WCDMA.

Advantages of GSM and WCDMA integrated network services

It is quite important for subscribers to have a positive experience during the migration to 3G. With a well thought-through seamless network strategy, it is possible to offer generic services on both GSM and WCDMA. In other words, a service that is initially launched on GSM can easily be made available on WCDMA. Subscribers who are accustomed to certain types of service will maintain the same service, such as e-mail account or information service.

On the other hand, GSM operators that deploy WCDMA and evolve to a seamless network have the opportunity to segment their markets and to differentiate services based on the type of service. Because WCDMA handsets will be multi-mode GSM/GPRS/EDGE/WCDMA terminals capable of handling GSM and WCDMA voice and data, users will be able to access services from both networks. The multimode handsets will provide users with seamless services.

There are several good examples of successful segmentation practices when launching new advanced mobile data services. One such example is Turkcell, an operator that currently offers a broad range of mixed voice services, short messaging service (SMS) and GPRS services without focusing on the technology behind them.

Another major strength of this Seamless Network is that it enables flexibility in 3G deployments. The seamless network ensures that services introduced on GSM or WCDMA will work seamlessly on both GSM and WCDMA. The services are only limited by the bandwidth offered at that time. This benefit enables operators to provide mobile services beyond voice using WCDMA in areas where it is commercially beneficial and, at the same time, provide the same types of services nationwide using EDGE on the GSM network.

Our users’ experience in the seamless network

The seamless network is the merger of GSM and WCDMA networks that enables an operator to offer quality service, for voice, data and multimedia, in the most cost-effective and resource-efficient way.

The seamless network solution is comprised of multimode handsets that work on both GSM and WCDMA frequencies and a network that combines the GSM and WCDMA resources. Services are provided over GSM or WCDMA radio access, depending on radio resource availability and service demand.

How will users experience this seamless network? I think users should not take much notice of the network. Just as users today should not notice when a GSM handover from the 1800 MHz to the 900 MHz band occurs, users of a seamless network should not notice whether services are delivered on GSM or WCDMA.

Imagine that a user who boards a train in a large city and heads for the countryside. The user has a multimode GSM/WCDMA handset and has a subscription with an operator having a GSM network with nationwide EDGE coverage. The operator also has a WCDMA network with coverage in all major cities. As the user initially is in an area with WCDMA coverage, he starts his call there. The call begins as a voice call. During the call, the user decides to use a digital camera to show a friend a previously recorded video. This is done by adding a streaming video session while maintaining the voice call. As the train moves out of the WCDMA coverage area, the network moves the call to the GSM network, renegotiates the data transfer with the handset application, and uses EDGE functionality in the GSM network to continue to send both voice and video. The user now experiences the same voice quality as before but lower quality for the streaming video.

Evolution to 3G still bring opportunities to the changing industry

The Western European and some Asian markets have reached a very high level of mobile usage penetration. The same is true for the American market when considering moderate- to high-level spending customers. However, this does not necessarily mean that the growth in number of subscriptions will end, since there is still a large untapped subscriber potential in new markets as well as emerging applications such as machine-to-machine communication. To enable growth in already saturated markets with high penetration figures, the focus for future growth must be on making current subscribers use their telephones more, either by increasing the minutes of use from current voice-centered services or by offering new attractive data services.

Evolution to 3G still bring opportunities to the changing industry. Because the need for capacity and bandwidth will drive the requirements for efficient resource utilization, Ericsson asserts that the seamless network of GSM and WCDMA as one of the most valuable solutions for the future.

Existing GSM operators have several advantages. These include existing network and spectrum, as well as distribution channels. And above all, existing operators already have their own subscribers. Acquiring new subscribers is a huge expense to all operators, and the cost of churn is large. It is much less expensive to keep an existing subscriber than to acquire or “buy” a new one.

Today, most existing subscribers are GSM subscribers. The challenge for an existing GSM operator is how to evolve its 2G network to provide 3G services to subscribers. The key issue will be the ability to implement a quick, cost-effective 3G rollout while retaining profitability with current GSM business. Because based on the enormous success of GSM and the large number of customers using existing GSM networks, GSM investments will continue to be profitable for years to come.

W-CDMA，the 3G successor to GSM

W-CDMA (Wideband Code Division Multiple Access) is a type of 3G cellular network. W-CDMA is the higher speed transmission protocol used in the Japanese FOMA system and in the UMTS system, a third generation follow-on to the 2G GSM networks deployed worldwide.

W-CDMA was developed by NTT DoCoMo as the air interface for their 3G network FOMA. Later NTT DoCoMo submitted the specification to the International Telecommunication Union (ITU) as a candidate for the international 3G standard known as IMT-2000. The 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 the air interface for UMTS, the 3G successor to GSM.

Code Division Multiple Access communication networks have been developed by a number of companies over the years, but development of cell-phone networks based on CDMA was dominated by Qualcomm, the first company to succeed in developing a practical and cost-effective CDMA implementation for consumer cell phones. Qualcomm created an experimental wideband CDMA system called CDMA2000 3x which unified the W-CDMA (3GPP) and CDMA2000 (3GPP2) network technologies into a single design for a worldwide standard air interface. Compatibility with CDMA2000 would have beneficially enabled roaming on existing networks beyond Japan, since Qualcomm CDMA2000 networks are widely deployed, especially in the Americas, with coverage in 58 countries in 2006.

However, divergent requirements resulted in the W-CDMA standard being retained and deployed. Despite incompatibilities with existing air-interface standards, the late introduction of this 3G system, and despite the high upgrade cost of deploying an all-new transmitter technology, W-CDMA has been adopted and deployed rapidly, especially in Japan, Europe and Asia, and is already deployed in over 55 countries as of 2006.

IMT-2000/UMTS break the restriction and bring us opportunities.

As we all know, existing second-generation mobile telecommunications systems were primarily developed for voice telephony. However, the air interfaces only permit simple data services involving transfer rates of up to 9.6 k bit/s. For "Phase 2+" of GSM, higher data transmission rates of up to 115 k bit/s are possible.

With IMT-2000/UMTS, this restriction no longer exists: IMT-2000/UMTS will make it possible to provide personal, mobile, broadband multi-media services with transmission rates of up to 2 M bit/s. The range of services possible with IMT-2000/UMTS will also include new broadband multimedia applications, such as video, as well as the existing voice telephony and data transmission services.

IMT-2000/UMTS satisfies the need of mobile users for access to the various multi-media services that are currently available and those yet to be developed (Internet/intranet, video telephony, online shopping, ecommerce, video-on-demand, etc.), irrespective of location and time of individual users.

As IMT-2000/UMTS is a further development of existing mobile networks and services and not a replacement for them, the step from GSM to IMT-2000/UMTS should be regarded as an evolution of the mobile telecommunications market rather than a revolution. IMT-2000/UMTS offers existing GSM operators a great business opportunity to expand their range of services. The great innovation potential of multi-media applications should also encourage new players onto the market, whether they are operators, service providers or content providers, and not necessarily just from the telecommunications sector, but from other areas affected by IMT-2000/UMTS such as information technology and the media.

Moving from GSM to 3G

The figure is from: dictionary.zdnet.com/definition/WCDMA.html

The evolution from GSM to 3G begins with an upgrade of the GSM network with packet-data capabilities by adding GPRS. This introduces end users to the “always connected” experience.

The next step is the introduction of 3G services, during which the GSM standard is developed in two ways: (1) WCDMA as the 3G radio access for the wideband spectrum and (2) EDGE as the 3G radio access for the existing GSM spectrum WCDMA is a new, highly efficient technology for both packet and circuit-switched traffic. It provides more capacity and higher data rates to enhance the user’s experience of existing voice and data services as well as new advanced mobile services beyond voice.

EDGE is a standardized set of improvements to the GSM radio interface that brings higher data rates and increased spectral efficiency for data services. With EDGE, the operator can have three times more subscribers than with GPRS or triple the data rate. EDGE provides in principle the same type of 3G services as WCDMA, but with lower data transfer rates. Implementing EDGE is fast and cost-efficient. EDGE uses the same channel structure, frequency planning, protocols and coverage as today’s GSM. Operators will be able to achieve more with the same physical resources.

Because the GSM frequency bands are a substantial part of an operator’s total spectrum assets, it will become increasingly important to be able to use the GSM spectrum for 3G services. The choice will not be between WCDMA and EDGE, but how to best utilize both WCDMA and EDGE.

In a word, there will be no revolution to 3G, but rather an evolution and, because of the practical need to re-use the existing infrastructure and to take advantage of new frequency bands as they become available, that evolution will look a bit different depending on where you are.

Third mobile generation networks (3G)

picture from:http://plato.csie.ncku.edu.tw/welcome.htm

All 2G wireless systems are voice-centered. GSM includes short message service (SMS), enabling text messages of up to 160 characters to be sent, received and viewed on the handset. Most 2G systems also support some data over their voice paths, but at painfully slow speeds usually 9.6 Kb/s or 14.4 Kb/s. So in the world of 2G, voice remains king while data is already dominant in wireless communications. And, fixed or wireless, all are affected by the rapid growth of the Internet.

Planning for 3G started in the 1980s. Initial plans focused on multimedia applications such as videoconferencing for mobile phones. When it became clear that the real killer application was the Internet, 3G thinking had to evolve. As personal wireless handsets become more common than fixed telephones, it is clear that personal wireless Internet access will follow and users want broadband Internet access wherever they go.

The second key issue for 3G wireless is that users will want to roam worldwide and stay connected. Today, GSM leads in global roaming. Because of the wide spread of GSM, users can get comprehensive coverage in Europe, parts of Asia and some U.S. coverage. A key goal of 3G is to make this roaming capacity universal.

A third issue for 3G systems is capacity. As wireless usage continues to expand, existing systems are reaching limits. The next step is new technology and new bandwidth.

2.5G, a stepping stone between 2G and 3G cellular wireless technologies

So-called ‘2.5G’ systems recently introduced enhance the data capacity of GSM and mitigate some of its limitations. These systems add packet data capability to GSM networks, and the most important technologies are GPRS (General Packet Radio Service) and WAP (Wireless Application Protocol).

WAP defines how Web pages and similar data can be passed over limited bandwidth wireless channels to small screens being built into new mobile telephones.

At the next lower layer, GPRS defines how to add IP support to the existing GSM infrastructure. GPRS provides both a means to aggregate radio channels for higher data bandwidth and the additional servers required to off-load packet traffic from existing GSM circuits. It supplements today's Circuit Switched Data and Short Message Service. Theoretical maximum speeds of up to 171.2 kilobits per second (kbps) are achievable with GPRS using all eight timeslots at the same time. This is about ten times as fast as current Circuit Switched Data services on GSM networks.

However, it should be noted that it is unlikely that a network operator will allow all timeslots to be used by a single GPRS user. Additionally, the initial GPRS terminals (phones or modems) are only supporting only one to four timeslots. The bandwidth available to a GPRS user will therefore be limited.

The mobile generations from 1G to 2G

The first operational cellular communication system was deployed in the Norway in 1981 and was followed by similar systems in the US and UK. These first generation systems provided voice transmissions by using frequencies around 900 MHz and analogue modulation.

The second generation (2G) of the wireless mobile network was based on low-band digital data signaling. The most popular 2G wireless technology is known as Global Systems for Mobile Communications (GSM). The first GSM systems used a 25MHz frequency spectrum in the 900MHz band. FDMA is used to split the available 25MHz of bandwidth into 124 carrier frequencies of 200 kHz each. Each frequency is then divided using a TDMA (Time Division Multiple Access) scheme into eight timeslots and allows eight simultaneous calls on the same frequency. This protocol allows large numbers of users to access one radio frequency by allocating time slots to multiple voice or data calls. TDMA breaks down data transmission, such as a phone conversation, into fragments and transmits each fragment in a short burst, assigning each fragment a time slot, which the caller can not detect at all.

Today, GSM systems operate in the 900MHz and 1.8 GHz bands throughout the world with the exception of the Americas where they operate in the 1.9 GHz band. Within Europe, the GSM technology made possible the seamless roaming across all countries.
While GSM technology was developed in Europe, CDMA (Code Division Multiple Access) technology was developed in North America. CDMA uses spread spectrum technology to break up speech into small, digitized segments and encodes them to identify each call. CDMA distinguishes between multiple transmissions carried simultaneously on a single wireless signal.

CDMA promises to open up network capacity for wireless carriers and improve the quality of wireless messages and users' access to the wireless airwaves. Whereas CDMA breaks down calls on a signal by codes, TDMA breaks them down by time. The result in both cases is an increased network capacity for the wireless carrier and a lack of interference for the caller.

While GSM and other TDMA-based systems have become the dominant 2G wirelesses technologies, CDMA technology are recognized as providing clearer voice quality with less background noise, fewer dropped calls, enhanced security, greater reliability and greater network capacity.

the evolution of mobile communications

This figure is from the website of International Telecommunication Union:

http://www.itu.int/itunews/issue/2003/06/fig-1.jpg

From the early analog mobile generation (1G) to the last implemented third generation (3G) the paradigm has changed. The new mobile generations do not pretend to improve the voice communication experience but try to enable the users to communicate at any time and everywhere and to provide them with a new set of services.

The growth of the number of mobile subscribers over the last years led to a saturation of voice-oriented wireless telephony. According to International Telecommunication Union Statistics, from a number of 214 million subscribers in 1997 to 1.162 millions in 2002, it is predicted that by 2010 there will be 1700 million subscribers worldwide. It is now time to explore new demands and to find new ways to extend the mobile concept.

The first steps have already been taken by the 2.5G, which gave users access to a data network (e.g. Internet access, MMS – Multimedia Message Service). However, users and applications demanded more communication power. As a response to this demand a new generation with new standards has been developed - 3G. One 3G network exists in commercial use today has been deployed in Japan in 2001 using international standard IMT-2000, with great success.

Benefiting from 3G constant delays, many new mobile technologies were deployed with great success (e.g. Wi-Fi). Now, all this new technologies (e.g. UMTS, Wi-Fi, Bluetooth) claim for a convergence that can only be achieved by a new mobile generation. This new mobile generation to be deployed must work with many mobile technologies while being transparent to the final user.

3 Billion GSM Connections On The Mobile Planet

The GSMA, the global trade group for the mobile industry, announced that total connections to GSM mobile communications networks have now passed the 3 Billion mark globally since April 2008. The third billion landmark has been reached just four years after the GSM industry surpassed its first billion, and just two years from the second billionth connection. The 3 Billion landmark has been surpassed just 17 years after the first GSM network launch in 1991. Today more than 700 mobile operators across 218 countries and territories of the world are adding new connections at the rate of 15 per second, or 1.3 million per day. The world’s biggest GSM markets today are China (509 million), which is growing at a rate of more than 7 million new connections a month and accounts for 14% of the third billion growth; India (193 million), growing at 6 million per month accounts for 12% of the third billion growth, Russia (178 million) and Brazil (93 million) which both contributed 4% of the third billion growth. “The growth of mobile communications continues to soar, not least in emerging markets, which are responsible for 85 percent of new connections today,” said Rob Conway, CEO and Board Member of the GSMA. “One cannot underestimate the importance of mobile as a vital communications tool, connecting so many people, often for the first time in their lives.

About the GSMA:
The GSM Association (GSMA) is the global trade association representing more than 700 GSM mobile phone operators across 218 countries and territories of the world. In addition, more than 200 manufacturers and suppliers support the Association's initiatives as key partners.

The primary goals of the GSMA are to ensure mobile phones and wireless services work globally and are easily accessible, enhancing their value to individual customers and national economies, while creating new business opportunities for operators and their suppliers. The Association's members represent more than 3 billion GSM and 3GSM connections - over 86% of the world's mobile phone connections.

China Netcom to Offer GSM Service from This Month

After one week's study, I have learned some basic knowledge about GSM and its technical details. However, it is quite hard for me to decide which topic should I choose as my main topic. I talked with some of my classmates. They suggested me to look at the development of GSM in China and the market there and try to get some conlusions based on my study and observation. Hence, I decide to focus my study area on the development of GSM market in China. I hope I can find some interesting facts and give my opinions.

Today I heard the news that The China Netcom Group has instructed all employees to use mobile phones that run on China Unicom's GSM network. By May 30 the majority of Netcom employees had received 156-prefix numbers, which are also used by Unicom employees. According to Unicom insiders, the switch to the new numbers has not yet started, but is expected to take place soon. China Netcom's operational targets set at the start of the year will not change.Figures from China Unicom show that 20% of employees in the south of China will move to China Telecom with this figure rising to 30% in the north. Joint CDMA / GSM base station locations will be split 50:50 between the two firms.