Q and A: UMTS (WCDA)
Q&A: UMTS
What is UMTS?
Is UMTS the same as WCDMA?
Are there different types of UMTS systems?
What are the advantages of UMTS?
How does a GSM operator deploy UMTS?
How does an analog or TDMA operator deploy UMTS?
What is the average cost of deploying UMTS?
Does UMTS affect voice capacity?
What companies offer UMTS products?
Where does UMTS fit in the Americas market?
What is UMTS?
Universal Mobile Telecommunications System (UMTS) is a voice and high-speed data technology that is part of the International Telecommunication Union’s (ITU) IMT-2000 family of third-generation (3G) wireless standards. Wideband CDMA (WCDMA) is the radio technology used in UMTS. As a result, the terms “UMTS” and “WCDMA” are often used interchangeably.
UMTS is based on Internet Protocol (IP) technology and supports packetized voice and data at theoretical peak data rates of up to 2 Mbps, with average speeds of 200-300 Kbps when the user is walking or driving. UMTS is designed to support bandwidth-intensive applications such as streaming multimedia, large file transfers and videoconferencing. UMTS also is designed to support delay-sensitive applications such as Virtual Private Networks (VPNs) and real-time, multiplayer gaming. UMTS’ other key benefits include high spectral efficiency for voice and data, support for simultaneous voice and data, low infrastructure costs, global roaming and a broad selection of handsets and other user devices.
Industry groups that endorse UMTS include the Association of Radio Industries and Businesses ( ARIB) in Japan, European Telecommunications Standards Institute ( ETSI), Global mobile Suppliers Association ( GSA), GSM Association, the ITU, the Third Generation Partnership Project ( 3GPP), 3G Americas and the UMTS Forum.
UMTS builds on GSM, which is the world’s most widely used wireless technology. GSM has more than 82% of the global wireless market and is used by more than 2.1 billion people worldwide, as of 3Q 2006. UMTS is available from 142 operators in 61 countries, as of October 2006. Nearly 300 operators worldwide have committed to deploying UMTS. This combination of commitments and commercial deployments means that like other members of the GSM family of technologies, UMTS enjoys a global cost structure, equipment selection and user adoption unmatched by any other 3G technology.
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Is UMTS the same as WCDMA?
Wideband CDMA (WCDMA) is the radio technology used within UMTS. As a result, the terms "UMTS" and "WCDMA" are often used interchangeably, although UMTS refers to the complete system.
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Are there different types of UMTS systems?
There are two types of UMTS systems: frequency division duplex (FDD) wideband code division multiple access (FDD/WCDMA) and time division duplex (TDD) wideband code division multiple access (TDD/WCDMA). FDD/WCDMA uses two frequencies, which allows separate transmission and reception on two different frequencies. TDD/WCDMA allows for duplex transmission on the same frequency by assigning different time slots in a single frame for transmission and reception. TD-SCDMA is a type of TDD/WCDMA and is expected to be used primarily in China.
Most UMTS deployments thus far use FDD. One reason is spectrum; in countries such as the United States, limited spectrum is available for TDD. However, vendors such as IPWireless have helped successfully commercialize UMTS TDD in some countries.
For more details about the different types of UMTS systems, see the 3G Americas white paper published in September 2006: “Mobile Broadband: EDGE, HSPA and LTE”.
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What are the advantages of UMTS?
The advantages of UMTS can be divided into two categories: user benefits and operator benefits.
The key user benefits include:
Speed: UMTS supports user achievable peak data rates of 350 Kbps, theoretical peak data rates of up to 2 Mbps, with average speeds of 200-300 Kbps when the user is walking or driving. That throughput is fast enough to support bandwidth-intensive applications such as streaming multimedia, large file transfers and videoconferencing. An “always-on” connection: Like cable broadband and DSL, UMTS provides a constant Internet connection, so users do not have to log on each time they want access, and they can receive “pushed” services, such as stock alerts. Value: UMTS is packet-based, which is a more efficient way for operators to provide service. That savings can be passed on to users in the form of lower rates. Packetized services also mean that users pay only for the data that they send and receive instead of additionally paying for the airtime used when setting up a connection and waiting for a server to respond. Availability: UMTS is available from 142 operators in 61 countries, as of October 2006. Nearly 300 operators worldwide have committed to deploying UMTS. Compatibility: UMTS is backward-compatible with EDGE and GPRS. When users move out of an area with UMTS coverage, their device automatically switches to an EDGE or GPRS network, depending on factors such as network availability and how much bandwidth their application requires. As a result, UMTS users are always assured of having some level of packet-data service at home and when traveling. Roaming: As mentioned above, UMTS was commercially available in 61 countries as of October 2006. Nearly 300 operators in 112 countries worldwide have committed to deploying UMTS. This adoption means that UMTS provides the most roaming options of any 3G technology. and where UMTS is not available, customers will fall back to EDGE or GPRS services. Quality of service (QoS): UMTS includes sophisticated quality of service (QoS) mechanisms, which ensure that each type of data service gets exactly the amount of spectrum and infrastructure resources it needs. For example, delay-sensitive applications such as streaming videos are given priority over e-mail and other applications that can tolerate some delay. This design helps ensure a good user experience.
The key operator benefits include:
Ease of upgrade: UMTS re-uses major previous investments, particularly the packet data network infrastructure deployed for GPRS and EDGE. Depending on the manufacturer, upgrading can be as simple as adding UMTS software and channel cards to the existing GSM/GPRS/EDGE radio infrastructure, which continues to serve customers using those technologies. This modular architecture reduces the cost of the UMTS upgrade, allowing operators to price their 3G services much more competitively than if the upgrade required replacing major infrastructure elements. Spectrally efficient and flexible: UMTS works in a variety of spectrum bands, including the existing 850 and 1900 MHz bands and the new 1700/2100 MHz spectrum bands being auctioned in the U.S. and other countries in the Western Hemisphere. That flexibility is particularly important to operators in the Americas, where, unlike Europe, most countries’ regulators don’t require new licenses for 3G-only spectrum bands. Some UMTS user devices sold in the Americas, such as PC card modems, will support multiple spectrum bands thereby providing additional roaming options. Over the years, the GSM community has worked to expand the UMTS standard so it is capable for use in additional bands. Currently, the UMTS standard is available worldwide for use in 850, 900, 1700, 1800, 1900, 2100 and 2600 MHz bands. Additionally, it is expected the standard will be expanded for uses in the 450 MHz and 700 MHz bands. Currently, there is UMTS TDD equipment available for the 450 MHz spectrum band. A wide selection of bands benefits operators because it provides more flexibility. For example, signals travel farther at lower frequencies, so a UMTS network at 850 or 900 MHz is a good fit for covering sparsely populated rural areas. UMTS also makes highly efficient use of spectrum due to a combination of Code Division Multiple Access (CDMA) and Time Division Multiple Access (TDMA) technologies. For example, a single 5 MHz radio channel can handle more than 100 simultaneous WCDMA voice calls. The number of simultaneous data sessions is even higher. Compatibility: UMTS is backward-compatible with EDGE and GPRS. When users move out of an area with UMTS coverage, their device automatically switches to an EDGE or GPRS network, depending on factors such as network availability and how much bandwidth their application requires. As a result, UMTS users are always assured of having some level of packet-data service at home and when traveling. This flexibility and compatibility are particularly important for enterprise customers. This design also gives operators the flexibility to launch UMTS in certain parts of their footprint, such as major cities, before expanding to other areas. An operator might also choose to have GSM, GPRS, EDGE and UMTS all deployed in the same market. This approach is not wasteful nor is it redundant. Instead, it lets the operator route each type of traffic over the network that’s best equipped to handle it. For example, low-bandwidth text message could run on the GPRS network, freeing the UMTS network to concentrate on high-bandwidth services such as streaming video. Volumes: UMTS is the third generation for GSM’s evolution, which represents more than 2.1 billion customers today. Nearly 300 operators worldwide have committed to deploying UMTS including 142 networks that are commercial today. That market size translates into high volumes of UMTS infrastructure and user devices, and one rule of business is that higher volumes drive down costs. So, as with GSM, UMTS operators enjoy a wide selection of affordable infrastructure and user devices, such as handsets. Research & Development: By virtue of its scope and scale, UMTS has a leading role for R&D. The investment into building the technology and evolving for the future is assured by the base of billions of customers. Quality control: UMTS includes sophisticated QoS mechanisms, which ensure that each type of data service gets exactly the amount of spectrum and infrastructure resources it needs. For example, delay-sensitive applications such as streaming videos are given priority over e-mail and other applications that can tolerate some delay. This design helps ensure a good user experience.
UMTS’ QoS mechanisms cover every step of a data application’s journey, from the device, into the cell site, through the network and at the gateway to the Internet. QoS is key for a service targeting enterprise users, and it helps retain customers and reduces the need for cut-rate pricing to attract customers to replace those who have churned.
Forward-looking design: UMTS’ QoS mechanisms also can support Voice over Internet Protocol (VoIP), the final stage of the UMTS vision, where voice and data travel over the same packet infrastructure. That design reduces the need for, and cost of, a separate infrastructure for circuit-switched voice. Through the use of session initiation protocol (SIP), which governs the traffic flows, UMTS ensures that voice avoids delays and delivers a toll-quality experience.
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How does a GSM operator deploy UMTS?
All next-generation wireless networks, regardless of technology, have three main components:
The radio infrastructure, which includes the cell sites. The packet core infrastructure, which handles only the packet-data traffic. This set of components is added when the operator deploys GPRS. The circuit-switched infrastructure, which includes the mobile switching centers (MSCs) and handles circuit-switched voice traffic.
UMTS re-uses major previous investments, particularly the packet data network infrastructure deployed for GPRS and EDGE. Depending on the manufacturer, upgrading can be as simple as adding UMTS software and channel cards to the existing GSM/GPRS/EDGE radio infrastructure, which continues to serve customers using those technologies. This modular architecture reduces the cost of the UMTS upgrade, allowing operators to price their 3G services much more competitively than if the upgrade required replacing major infrastructure elements.
Depending on the operator’s market and business model, it may initially deploy UMTS in urban areas, with EDGE or GPRS serving rural areas. As demand for UMTS grows, the operator then may expand UMTS to rural areas. Even so, its EDGE and GPRS customers can continue to use their devices and services after UMTS is expanded to their markets.
Although UMTS requires a new radio-access network (RAN), several factors reduce the cost and speed of deployment. First, most UMTS RAN equipment can be collocated in GSM cell sites, facilitated by multi-radio cabinets that can simultaneously accommodate GSM, GPRS, EDGE and UMTS equipment. Second, most of the GSM/GPRS core network can be re-used for UMTS.
Once deployed, operators can achieve additional cost savings by using the same tools to manage their GSM, GPRS, EDGE and UMTS networks. That is because these technologies share many of the same aspects, including:
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How does an analog or TDMA operator deploy UMTS?
An analog or TDMA operator’s migration to UMTS begins by deploying a GSM/GPRS network in parallel with their existing network. This approach allows the operator to continue generating revenue from existing customers while signing up new customers for GSM/GPRS.
In each cell site, GSM/GPRS radios are be deployed alongside the existing analog or TDMA radios. Many vendors sell GSM/GPRS radio infrastructure that can be easily reconfigured to support multiple combinations of GSM, GPRS, EDGE and UMTS. In some cases, the old and new radios may be able to share the same antennas and reduce the cost of deployment. As in a GSM network being upgraded to GPRS, a packet core also is added.
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What is the average cost of deploying UMTS?
The cost varies significantly by factors such as the size, age and design of the existing network. For example, if the operator’s existing radio infrastructure can be upgraded to UMTS, the cost is relatively minimal. In networks that are older than five years, the radio infrastructure may not be upgradeable, increasing the cost of deploying UMTS. If the operator needs additional spectrum or a higher density of cell sites, the cost of deploying UMTS will be higher.
Upgrading a 2G base station to 3G increases its total capacity by a factor of up to 10 times. Also, since all 2G base stations eventually come to the end of their working lives, it generally makes good economic sense to evolve a 2G base station to 3G rather than try to upgrade it. Operators will get substantially more voice capacity at incremental cost.
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Does UMTS affect voice capacity?
UMTS lets infrastructure and spectrum handle more simultaneous voice calls and data sessions. UMTS is highly efficient because the operator can match each traffic type to the appropriate system, including GSM, GPRS, EDGE and WCDMA.
Suppose that several users are on a UMTS network. Some are using it to send and receive e-mails, some for video calls, while others are in voice calls. Each of these traffic types has different needs. A voice call, for example, uses a fairly constant amount of bandwidth, whereas many data applications need a large amount of bandwidth for a brief period.
UMTS gives operators an elegant way for these traffic types to co-exist through a technique called spreading, where the network shrinks and expands each channel’s capacity based on the traffic type. For example, the network would expand a channel to make room for a video call by shifting a voice call to another channel.
This approach makes more efficient use of available infrastructure and spectrum than other technologies that dedicate an entire channel to only high-speed data. As a result, UMTS provides the flexibility for operators to efficiently utilize their spectrum for both voice and data during critical time of capacity needs for each. The bottom line is that UMTS handles nearly three times as many simultaneous calls as a basic GSM network.
UMTS also sets the foundation for voice over IP (VoIP). For example, when UMTS operators deploy High Speed Uplink Packet Access ( HSDPA), they gain the upload speeds necessary to provide a good VoIP user experience. UMTS also provides the low latency and QoS mechanisms necessary to provide a good VoIP user experience.
For more details on the voice capabilities of UMTS technology, including VoIP, see the September 2006 white paper “Mobile Broadband: EDGE, HSPA and LTE”
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What companies offer UMTS products?
Alcatel, Ericsson, Lucent Technologies, Motorola, Nokia, Nortel Networks and Siemens are among the major manufacturers that already offer a wide range of UMTS infrastructure products, such as base stations.
UMTS devices for use in the Americas include multimedia handsets from Motorola and Nokia and PC card modems from Sierra Wireless.
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Where does UMTS fit in the Americas market?
There are at least three major reasons why UMTS is an ideal 3G choice for operators in the Americas:
New services: UMTS is designed for high-bandwidth 3G services that are not practical or cost-effective on other networks. A joint analysis by 3G Americas’ members, published by Rysavy Research in September 2006, found that UMTS has the greatest spectral efficiency for data rates above 100 Kbps. The ability to offer a wide range of innovative high-bandwidth services cost-effectively gives UMTS operators a competitive advantage. UMTS also provides operators the ability to compete with dial-up, DSL and cable operators for broadband users. Flexibility: Unlike many Asian and European regulators, Canadian and U.S. regulators do not require operators to obtain 3G spectrum licenses before they can launch 3G. UMTS works in existing spectrum bands, including 850 and 1900 MHz, the two most widely used wireless bands in North America. The UMTS design also lets operators roll out 3G at their own pace, such as initially focusing on major cities before expanding into smaller cities and outlying areas. Global roaming: UMTS is particularly attractive to North American enterprises and business users who need 3G while traveling abroad. UMTS is available from 142 operators in 61 countries, as of October 2006. Nearly 300 operators worldwide have committed to deploying UMTS. In areas without UMTS coverage, the phone or modem automatically switches to GPRS or EDGE. As a result, UMTS customers always have access to high-speed packet data.
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