Monday, August 24, 2009
AAL2
AAL2 provides bandwidth-efficient transmission of low-rate, short and variable packets in delay sensitive applications. It supports VBR and CBR. AAL2 also provides for variable payload within cells and across cells. AAL type 2 is subdivided into the Common Part Sublayer (CPS ) and the Service Specific Convergence Sublayer (SSCS ).
Third Generation Cellular Networks
Third Generation Cellular Networks (commonly referred to as 3G) represent the next phase in the evolution of cellular technology, evolution from the analog systems (1st generation) and digital systems (2nd generation). 3G networks will represent a shift from voice-centric services to converged services, including voice, data, video, fax and so forth.
UMTS is the dominant 3G solution being developed, representing an evolution from the GSM network standards, interoperating with a GSM core network. The 3G will implement a new access network, utilizing both improved radio interfaces and different technologies for the interface between the access network and the radio network.
UMTS will use a wideband CDMA technology for transmission, and a more efficient modulation than GSM. This will allow UMTS to reach higher utilization, and offer higher bandwidth to the end-user. UMTS also implements an ATM infrastructure for the wireline interface, using both AAL2 and AAL5 adaptations; AAL2 for real-time traffic and AAL5 for data and signaling.
UMTS is the dominant 3G solution being developed, representing an evolution from the GSM network standards, interoperating with a GSM core network. The 3G will implement a new access network, utilizing both improved radio interfaces and different technologies for the interface between the access network and the radio network.
UMTS will use a wideband CDMA technology for transmission, and a more efficient modulation than GSM. This will allow UMTS to reach higher utilization, and offer higher bandwidth to the end-user. UMTS also implements an ATM infrastructure for the wireline interface, using both AAL2 and AAL5 adaptations; AAL2 for real-time traffic and AAL5 for data and signaling.
2008 Global Digital Economy - M-Commerce, E-Commerce & E-Payments
E-commerce is now an important part of the economy, particularly in the developed markets. While e-commerce is still in its infancy in many emerging markets, this is set to change in the coming years especially in China. In 2008 China now has the highest number of Internet users in the world, overtaking the USA. E-commerce growth in the USA remains strong however, with China also offering significant opportunities for those operating in the e-commerce space.
Worldwide the number of Internet users has now reached around 1.4 billion and billions will be spent by consumers during 2008 on online retail. While the economic slowdown will most likely curb e-commerce growth somewhat over the next couple of years, particularly spending on online advertising, there is evidence that so far the online retail market has remained steady due mostly to the lower prices offered via online shopping.
Internet banking has slowly become more popular around the world, with 30% or more of Internet users utilising such services in some markets. However many online banking websites have at least one potential design weakness that could leave users vulnerable to cyber attacks. Improved bank security measures over the last couple of years, such as the introduction of home chip and pin devices is helping to combat this issue.
In the next few years the total entertainment and publishing industry (including offline and online) is expected to be worth more than $2 trillion – driven in particular by a wave of growth in online video games, gambling, music, social networking/UGC, and online video. In recent times sales of digital music, mostly via the Internet, have increased by more that 30%; in contrast sales of CD and DVDs continue to decline. Online video consumption is also beginning to produce promising results and advertisers have begun to seriously take note. Pay-to-own downloading is particularly popular and new business models in this area are expected to emerge over the next few years. Travel and adult content services are also popular with more growth expected ahead.
Mobile commerce is potentially important for a wide range of industries, including telecommunications, IT, finance, retail and the media, as well as for end-users. It will work best in those areas where it can emphasise the core virtue of mobile networks – convenience. However while there are good applications, the technologies and business models to date have not been well suited to mass market applications. The regulatory environment has also held this market up. This is beginning to change as banks and merchants collaborate with mobile operators. Applications around contactless cards using Near Field Communications are also being developed around the world. Focus has also turned to the developing markets, where mobile phones are being viewed as an opportunity to reach the masses that would not otherwise use m-payment or m-banking services.
In countries such as Kenya and India, national mobile banking systems are thriving and they are literally popping up around the world as well. In Kenya, 3 million out of Vodafone's 10 million subscribers are using mobile banking services and Vodafone is rapidly rolling the service out in other countries as well.
This annual report provides an insight and analyses into the trends and developments taking place in the m-commerce and e-commerce sectors. The report provides analyses of the trends and issues impacting upon the growth of e-commerce, including e-banking, e-payments and online advertising sectors. Analyses of the developments taking place in mobile commerce are also provided, along with information on m-payment and m-banking. Statistics and forecasts for both the e-commerce and m-commerce markets are provided. The report also includes valuable insights and statistics on the developments taking place on a regional level including North America, Latin America, Europe, Middle East, Africa and Asia Pacific.
Worldwide the number of Internet users has now reached around 1.4 billion and billions will be spent by consumers during 2008 on online retail. While the economic slowdown will most likely curb e-commerce growth somewhat over the next couple of years, particularly spending on online advertising, there is evidence that so far the online retail market has remained steady due mostly to the lower prices offered via online shopping.
Internet banking has slowly become more popular around the world, with 30% or more of Internet users utilising such services in some markets. However many online banking websites have at least one potential design weakness that could leave users vulnerable to cyber attacks. Improved bank security measures over the last couple of years, such as the introduction of home chip and pin devices is helping to combat this issue.
In the next few years the total entertainment and publishing industry (including offline and online) is expected to be worth more than $2 trillion – driven in particular by a wave of growth in online video games, gambling, music, social networking/UGC, and online video. In recent times sales of digital music, mostly via the Internet, have increased by more that 30%; in contrast sales of CD and DVDs continue to decline. Online video consumption is also beginning to produce promising results and advertisers have begun to seriously take note. Pay-to-own downloading is particularly popular and new business models in this area are expected to emerge over the next few years. Travel and adult content services are also popular with more growth expected ahead.
Mobile commerce is potentially important for a wide range of industries, including telecommunications, IT, finance, retail and the media, as well as for end-users. It will work best in those areas where it can emphasise the core virtue of mobile networks – convenience. However while there are good applications, the technologies and business models to date have not been well suited to mass market applications. The regulatory environment has also held this market up. This is beginning to change as banks and merchants collaborate with mobile operators. Applications around contactless cards using Near Field Communications are also being developed around the world. Focus has also turned to the developing markets, where mobile phones are being viewed as an opportunity to reach the masses that would not otherwise use m-payment or m-banking services.
In countries such as Kenya and India, national mobile banking systems are thriving and they are literally popping up around the world as well. In Kenya, 3 million out of Vodafone's 10 million subscribers are using mobile banking services and Vodafone is rapidly rolling the service out in other countries as well.
This annual report provides an insight and analyses into the trends and developments taking place in the m-commerce and e-commerce sectors. The report provides analyses of the trends and issues impacting upon the growth of e-commerce, including e-banking, e-payments and online advertising sectors. Analyses of the developments taking place in mobile commerce are also provided, along with information on m-payment and m-banking. Statistics and forecasts for both the e-commerce and m-commerce markets are provided. The report also includes valuable insights and statistics on the developments taking place on a regional level including North America, Latin America, Europe, Middle East, Africa and Asia Pacific.
Mobile Communications and Mobile Data Technologies
This report is a technical introduction, for people without an engineering background, to digital cellular mobile technologies. These are the basis of huge and growing industries for voice and increasingly data communications, with cellular handsets becoming the most widely used electronic product in history.
We begin with an introduction to the 1G and early digital technologies AMPS, IS-136 TDMA and IS-95 CDMA. We discuss GSM and its high speed data enhancements, including HSCSD GPRS and EDGE. We discuss the UMTS (Universal Mobile Telecommunications Service) Wideband Code Division Multiple Access (WCDMA) 3G technologies. These are based on the GSM network architecture and together with GSM are the most widely used technologies on a global basis.
We also discuss the Japanese FOMA WCDMA system, which was the basis for UMTS WCDMA, and CDMA2000 and its high speed data enhancement EV-DO (Evolution Data Only) which are the dominant 3G technologies in North America and many other non-European countries. We provide tutorials on convolutional coding and the spreading and scrambling processes which are at the heart of Code Division Multiple Access (CDMA) spread-spectrum techniques.
We discuss services which operate similarly or identically over all 2.5G and 3G networks, including SMS text messaging, Multimedia Messaging Service (MMS) and Wireless Application Protocol (WAP). We discuss the IP Media Subsystem (IMS) – a centrally managed network architecture which is the basis for providing a number of services including instant messaging with presence, Push-to-Talk over Cellular (PoC), VoIP and location based services, irrespective of the underlying 2.5G or 3G network technology.
Base-stations and their backhaul network are the most expensive part of cellular systems. We discuss the various approaches to base-stations, including the conventional large, tower-based ‘macro-node’, and alternatives for smaller areas and enclosed spaces, including ‘micro-nodes’ and ‘pico-nodes’. We conclude this discussion with a detailed evaluation of the emerging ‘femtocell’ technology: the ability to place a small base-station in a home or office, using the owner’s ADSL or HFC cable modem service for backhaul. This is based on the new Generic Access Network (GAN) standards, which arose initially from the desire to achieve Fixed Mobile Convergence (FMC) via unlicensed frequencies, with Bluetooth and WiFi approaches.
We discuss the long-term development of the two major 3G technologies into 4G mobile systems, with similar OFDM-based modulation schemes and performance to fixed and mobile WiMAX. We consider the challenge the 4G development of UMTS poses to CDMA2000’s 4G Ultra Mobile Broadband and to the widespread adoption of WiMAX.
Broadcasting or multicasting to handheld devices can be achieved with a unidirectional system with separate frequencies such as Eureka 147 Terrestrial Digital Mobile Broadcasting (T-DMB), DVB-H or Qualcomm’s FLO (Forward Link Only). Alternatively, it can be achieved with data packets within the cellular technology, perhaps with OFDM modulation to increase data density, as is possible with EV-DO. We discuss these and other approaches to this important addition to mobile technology.
We also discuss the major audio visual coding technologies, otherwise known as data compression, for sound, video and multimedia material. An increasing number of these technologies are utilised in 3G services and in mobile broadcasting.
Cellular mobile technology is a complex and rapidly developing field. This report is intended to give non-specialists a comprehensive technical introduction to current and emerging mobile cellular technologies. This report is intended to enable readers to understand current usage and foresee likely developments relevant to their own domains, such as telecommunications regulation, investment and management.
We begin with an introduction to the 1G and early digital technologies AMPS, IS-136 TDMA and IS-95 CDMA. We discuss GSM and its high speed data enhancements, including HSCSD GPRS and EDGE. We discuss the UMTS (Universal Mobile Telecommunications Service) Wideband Code Division Multiple Access (WCDMA) 3G technologies. These are based on the GSM network architecture and together with GSM are the most widely used technologies on a global basis.
We also discuss the Japanese FOMA WCDMA system, which was the basis for UMTS WCDMA, and CDMA2000 and its high speed data enhancement EV-DO (Evolution Data Only) which are the dominant 3G technologies in North America and many other non-European countries. We provide tutorials on convolutional coding and the spreading and scrambling processes which are at the heart of Code Division Multiple Access (CDMA) spread-spectrum techniques.
We discuss services which operate similarly or identically over all 2.5G and 3G networks, including SMS text messaging, Multimedia Messaging Service (MMS) and Wireless Application Protocol (WAP). We discuss the IP Media Subsystem (IMS) – a centrally managed network architecture which is the basis for providing a number of services including instant messaging with presence, Push-to-Talk over Cellular (PoC), VoIP and location based services, irrespective of the underlying 2.5G or 3G network technology.
Base-stations and their backhaul network are the most expensive part of cellular systems. We discuss the various approaches to base-stations, including the conventional large, tower-based ‘macro-node’, and alternatives for smaller areas and enclosed spaces, including ‘micro-nodes’ and ‘pico-nodes’. We conclude this discussion with a detailed evaluation of the emerging ‘femtocell’ technology: the ability to place a small base-station in a home or office, using the owner’s ADSL or HFC cable modem service for backhaul. This is based on the new Generic Access Network (GAN) standards, which arose initially from the desire to achieve Fixed Mobile Convergence (FMC) via unlicensed frequencies, with Bluetooth and WiFi approaches.
We discuss the long-term development of the two major 3G technologies into 4G mobile systems, with similar OFDM-based modulation schemes and performance to fixed and mobile WiMAX. We consider the challenge the 4G development of UMTS poses to CDMA2000’s 4G Ultra Mobile Broadband and to the widespread adoption of WiMAX.
Broadcasting or multicasting to handheld devices can be achieved with a unidirectional system with separate frequencies such as Eureka 147 Terrestrial Digital Mobile Broadcasting (T-DMB), DVB-H or Qualcomm’s FLO (Forward Link Only). Alternatively, it can be achieved with data packets within the cellular technology, perhaps with OFDM modulation to increase data density, as is possible with EV-DO. We discuss these and other approaches to this important addition to mobile technology.
We also discuss the major audio visual coding technologies, otherwise known as data compression, for sound, video and multimedia material. An increasing number of these technologies are utilised in 3G services and in mobile broadcasting.
Cellular mobile technology is a complex and rapidly developing field. This report is intended to give non-specialists a comprehensive technical introduction to current and emerging mobile cellular technologies. This report is intended to enable readers to understand current usage and foresee likely developments relevant to their own domains, such as telecommunications regulation, investment and management.
3G and UMTS Technology
Mobile data communications is evolving quickly because of Internet, Intranet, Laptops, PDAs and increased requirements of workforce mobility. 3G UMTS will be the commercial convergence of fixed line telephony, mobile, Internet and computer technology. New technologies are required to deliver high speed location and mobile terminal specific content to users. The emergence of new technologies thus provides an opportunity for a similar boom what the computer industry had in 1980s, and Internet and wireless voice had in 1990s.
The main IMT-2000 standardisation effort was to create a new air interface that would increase frequency usage efficiency. The WCDMA air interface was selected for paired frequency bands (FDD operation) and TDCDMA (TDD operation) for unpaired spectrum. 3G CDMA2000 standard was created to support IS-95 evolution.
The UMTS transport network is required to handle high data traffic. A number of factors were considered when selecting a transport protocol: bandwidth efficiency, quality of service, standardisation stability, speech delay sensitivity and the permitted maximum number of concurrent users. In the UMTS network, ATM (Asynchronous Transfer Mode) is defined for the connection between UTRAN and the core network and may also be used within the core network. In addition to the IMT-2000 frame many new standards will be integrated as part of the next generation mobile systems. Bluetooth and other close range communication protocols and several different operating systems will be used in mobiles. Internet will come to mobiles with WAP, i-mode and XML protocols. 3G development has helped to start the standardisation and development of large family of technologies.
This section covers some of the core UMTS technologies and it will be updated regularly
The main IMT-2000 standardisation effort was to create a new air interface that would increase frequency usage efficiency. The WCDMA air interface was selected for paired frequency bands (FDD operation) and TDCDMA (TDD operation) for unpaired spectrum. 3G CDMA2000 standard was created to support IS-95 evolution.
The UMTS transport network is required to handle high data traffic. A number of factors were considered when selecting a transport protocol: bandwidth efficiency, quality of service, standardisation stability, speech delay sensitivity and the permitted maximum number of concurrent users. In the UMTS network, ATM (Asynchronous Transfer Mode) is defined for the connection between UTRAN and the core network and may also be used within the core network. In addition to the IMT-2000 frame many new standards will be integrated as part of the next generation mobile systems. Bluetooth and other close range communication protocols and several different operating systems will be used in mobiles. Internet will come to mobiles with WAP, i-mode and XML protocols. 3G development has helped to start the standardisation and development of large family of technologies.
This section covers some of the core UMTS technologies and it will be updated regularly
3G and UMTS Technology
Mobile data communications is evolving quickly because of Internet, Intranet, Laptops, PDAs and increased requirements of workforce mobility. 3G UMTS will be the commercial convergence of fixed line telephony, mobile, Internet and computer technology. New technologies are required to deliver high speed location and mobile terminal specific content to users. The emergence of new technologies thus provides an opportunity for a similar boom what the computer industry had in 1980s, and Internet and wireless voice had in 1990s.
The main IMT-2000 standardisation effort was to create a new air interface that would increase frequency usage efficiency. The WCDMA air interface was selected for paired frequency bands (FDD operation) and TDCDMA (TDD operation) for unpaired spectrum. 3G CDMA2000 standard was created to support IS-95 evolution.
The UMTS transport network is required to handle high data traffic. A number of factors were considered when selecting a transport protocol: bandwidth efficiency, quality of service, standardisation stability, speech delay sensitivity and the permitted maximum number of concurrent users. In the UMTS network, ATM (Asynchronous Transfer Mode) is defined for the connection between UTRAN and the core network and may also be used within the core network. In addition to the IMT-2000 frame many new standards will be integrated as part of the next generation mobile systems. Bluetooth and other close range communication protocols and several different operating systems will be used in mobiles. Internet will come to mobiles with WAP, i-mode and XML protocols. 3G development has helped to start the standardisation and development of large family of technologies.
This section covers some of the core UMTS technologies and it will be updated regularly
The main IMT-2000 standardisation effort was to create a new air interface that would increase frequency usage efficiency. The WCDMA air interface was selected for paired frequency bands (FDD operation) and TDCDMA (TDD operation) for unpaired spectrum. 3G CDMA2000 standard was created to support IS-95 evolution.
The UMTS transport network is required to handle high data traffic. A number of factors were considered when selecting a transport protocol: bandwidth efficiency, quality of service, standardisation stability, speech delay sensitivity and the permitted maximum number of concurrent users. In the UMTS network, ATM (Asynchronous Transfer Mode) is defined for the connection between UTRAN and the core network and may also be used within the core network. In addition to the IMT-2000 frame many new standards will be integrated as part of the next generation mobile systems. Bluetooth and other close range communication protocols and several different operating systems will be used in mobiles. Internet will come to mobiles with WAP, i-mode and XML protocols. 3G development has helped to start the standardisation and development of large family of technologies.
This section covers some of the core UMTS technologies and it will be updated regularly
3G and UMTS Technology
Mobile data communications is evolving quickly because of Internet, Intranet, Laptops, PDAs and increased requirements of workforce mobility. 3G UMTS will be the commercial convergence of fixed line telephony, mobile, Internet and computer technology. New technologies are required to deliver high speed location and mobile terminal specific content to users. The emergence of new technologies thus provides an opportunity for a similar boom what the computer industry had in 1980s, and Internet and wireless voice had in 1990s.
The main IMT-2000 standardisation effort was to create a new air interface that would increase frequency usage efficiency. The WCDMA air interface was selected for paired frequency bands (FDD operation) and TDCDMA (TDD operation) for unpaired spectrum. 3G CDMA2000 standard was created to support IS-95 evolution.
The UMTS transport network is required to handle high data traffic. A number of factors were considered when selecting a transport protocol: bandwidth efficiency, quality of service, standardisation stability, speech delay sensitivity and the permitted maximum number of concurrent users. In the UMTS network, ATM (Asynchronous Transfer Mode) is defined for the connection between UTRAN and the core network and may also be used within the core network. In addition to the IMT-2000 frame many new standards will be integrated as part of the next generation mobile systems. Bluetooth and other close range communication protocols and several different operating systems will be used in mobiles. Internet will come to mobiles with WAP, i-mode and XML protocols. 3G development has helped to start the standardisation and development of large family of technologies.
This section covers some of the core UMTS technologies and it will be updated regularly
The main IMT-2000 standardisation effort was to create a new air interface that would increase frequency usage efficiency. The WCDMA air interface was selected for paired frequency bands (FDD operation) and TDCDMA (TDD operation) for unpaired spectrum. 3G CDMA2000 standard was created to support IS-95 evolution.
The UMTS transport network is required to handle high data traffic. A number of factors were considered when selecting a transport protocol: bandwidth efficiency, quality of service, standardisation stability, speech delay sensitivity and the permitted maximum number of concurrent users. In the UMTS network, ATM (Asynchronous Transfer Mode) is defined for the connection between UTRAN and the core network and may also be used within the core network. In addition to the IMT-2000 frame many new standards will be integrated as part of the next generation mobile systems. Bluetooth and other close range communication protocols and several different operating systems will be used in mobiles. Internet will come to mobiles with WAP, i-mode and XML protocols. 3G development has helped to start the standardisation and development of large family of technologies.
This section covers some of the core UMTS technologies and it will be updated regularly
Circuit Switching vs. Packet Switching
Traditional connections for voice communications require a physical path connecting the users at the two ends of the line, and that path stays open until the conversation ends. This method of connecting a transmitter and receiver by giving them exclusive access to a direct connection is called circuit switching.
Most modern networking technology is radically different from this traditional model because it uses packet data. Packet data is information which is:
1.chopped into pieces (packets),
2.given a destination address,
3.mixed with other data from other sources,
4.transmitted over a line with all the other data,
5.reconstituted at the other end.
Packet-switched networks chop the telephone conversation into discrete "packets" of data like pieces in a jigsaw puzzle, and those pieces are reassembled to recreate the original conversation. Packet data was originally developed as the technology behind the Internet.
A data packet.
The major part of a packet's contents is reserved for the data to be transmitted. This part is called the payload. In general, the data to be transmitted is arbitrarily chopped-up into payloads of the same size. At the start of the packet is a smaller area called a header. The header is vital because the header contains the address of the packet's intended recipient. This means that packets from many different phone users can be mixed into the same transmission channel, and correctly sorted at the other end. There is no longer a need for a constant, exclusive, direct channel between the sender and the receiver.
Packet data is added to the channel only when there is something to send, and the user is only charged for the amount of data sent. For example, when reading a small article, the user will only pay for what's been sent or received. However, both the sender and the receiver get the impression of a communications channel which is "always on".
On the downside, packets can only be added to the channel where there is an empty slot in the channel, leading to the fact that a guaranteed speed cannot be given. The resultant delays pose a problem for voice transmission over packet networks, and is the reason why internet pages can be slow to load.
Most modern networking technology is radically different from this traditional model because it uses packet data. Packet data is information which is:
1.chopped into pieces (packets),
2.given a destination address,
3.mixed with other data from other sources,
4.transmitted over a line with all the other data,
5.reconstituted at the other end.
Packet-switched networks chop the telephone conversation into discrete "packets" of data like pieces in a jigsaw puzzle, and those pieces are reassembled to recreate the original conversation. Packet data was originally developed as the technology behind the Internet.
A data packet.
The major part of a packet's contents is reserved for the data to be transmitted. This part is called the payload. In general, the data to be transmitted is arbitrarily chopped-up into payloads of the same size. At the start of the packet is a smaller area called a header. The header is vital because the header contains the address of the packet's intended recipient. This means that packets from many different phone users can be mixed into the same transmission channel, and correctly sorted at the other end. There is no longer a need for a constant, exclusive, direct channel between the sender and the receiver.
Packet data is added to the channel only when there is something to send, and the user is only charged for the amount of data sent. For example, when reading a small article, the user will only pay for what's been sent or received. However, both the sender and the receiver get the impression of a communications channel which is "always on".
On the downside, packets can only be added to the channel where there is an empty slot in the channel, leading to the fact that a guaranteed speed cannot be given. The resultant delays pose a problem for voice transmission over packet networks, and is the reason why internet pages can be slow to load.
TDMA vs. CDMA
We have considered how a mobile phone can send and receive calls at the same time (via an uplink and a downlink). Now we will examine how many users can be multiplexed into the same channel (i.e., share the channel) without getting interference from other users, a capability called multiple access. For 3G technology, there are basically two competing technologies to achieve multiple access: TDMA and CDMA.
TDMA is Time Division Multiple Access. It works by dividing a single radio frequency into many small time slots. Each caller is assigned a specific time slot for transmission. Again, because of the rapid switching, each caller has the impression of having exclusive use of the channel.
CDMA is Code Division Multiple Access. CDMA works by giving each user a unique code. The signals from all the users can then be spread over a wide frequency band. The transmitting frequency for any one user is not fixed but is allowed to vary within the limits of the band. The receiver has knowledge of the sender's unique code, and is therefore able to extract the correct signal no matter what the frequency.
This technique of spreading a signal over a wide frequency band is known as spread spectrum. The advantage of spread spectrum is that it is resistant to interference - if a source of interference blocks one frequency, the signal can still get through on another frequency. Spread spectrum signals are therefore difficult to jam, and it is not surprising that this technology was developed for military uses.
Finally, let's consider another robust technology originally developed by the military which is finding application with 3G: packet switching.
TDMA is Time Division Multiple Access. It works by dividing a single radio frequency into many small time slots. Each caller is assigned a specific time slot for transmission. Again, because of the rapid switching, each caller has the impression of having exclusive use of the channel.
CDMA is Code Division Multiple Access. CDMA works by giving each user a unique code. The signals from all the users can then be spread over a wide frequency band. The transmitting frequency for any one user is not fixed but is allowed to vary within the limits of the band. The receiver has knowledge of the sender's unique code, and is therefore able to extract the correct signal no matter what the frequency.
This technique of spreading a signal over a wide frequency band is known as spread spectrum. The advantage of spread spectrum is that it is resistant to interference - if a source of interference blocks one frequency, the signal can still get through on another frequency. Spread spectrum signals are therefore difficult to jam, and it is not surprising that this technology was developed for military uses.
Finally, let's consider another robust technology originally developed by the military which is finding application with 3G: packet switching.
Achievements at 3G Mobile
Currently capable of making live TD-SCDMA voice and data calls, the SoftFone-LCR chipset is also featured as the core component in the DTivy(TM)--A Series reference design from Datang Mobile, the developer of the TD-SCDMA standard. Designed through a collaborate effort between Analog Devices and Datang Mobile, the DTivy--A Series reference design is a complete hardware and software solution providing significant BOM savings and faster time-to-market to manufacturers of next-generation 3G TD-SCDMA products such as high-end camera phones, camcorder phones, multimedia phones, and video phones.
Also at the summit, Lining Wang of Analog Devices RF and wireless systems group, will lead a technical presentation on delivering next-generation mobile devices through software and semiconductor innovation. Mr. Wang's presentation will cover challenges faced by handset designers and highlight technology solutions that incorporate reconfigurable analog functions and software-based radio architectures. The presentation will take place on Wednesday, June 29 at 4:40 p.m. local time.
"We are very excited with the industry momentum that is continuing to build around the TD-SCDMA standard as well as our SoftFone-LCR chipset," said Christian Kermarrec, vice president, RF and wireless systems, Analog Devices, Inc. "Because TD-SCDMA uses unpaired frequency bands and is very efficient in its use of spectrum, we believe that it is a good underlying technology for 3G cellular networks in China."
The China 3G Mobile International Summit & Exhibition is intended to bring together leading mobile operators and service providers, infrastructure providers, chipset suppliers, handset developers, content providers and application developers from China and around the world. Discussions will focus on the hottest issues for China in launching 3G, including policies and regulatory initiatives for the 3G market, case studies and lessons from leading international 3G operator deployments, as well as strategies for developing the market for new 3G mobile services and applications in China.
Also at the summit, Lining Wang of Analog Devices RF and wireless systems group, will lead a technical presentation on delivering next-generation mobile devices through software and semiconductor innovation. Mr. Wang's presentation will cover challenges faced by handset designers and highlight technology solutions that incorporate reconfigurable analog functions and software-based radio architectures. The presentation will take place on Wednesday, June 29 at 4:40 p.m. local time.
"We are very excited with the industry momentum that is continuing to build around the TD-SCDMA standard as well as our SoftFone-LCR chipset," said Christian Kermarrec, vice president, RF and wireless systems, Analog Devices, Inc. "Because TD-SCDMA uses unpaired frequency bands and is very efficient in its use of spectrum, we believe that it is a good underlying technology for 3G cellular networks in China."
The China 3G Mobile International Summit & Exhibition is intended to bring together leading mobile operators and service providers, infrastructure providers, chipset suppliers, handset developers, content providers and application developers from China and around the world. Discussions will focus on the hottest issues for China in launching 3G, including policies and regulatory initiatives for the 3G market, case studies and lessons from leading international 3G operator deployments, as well as strategies for developing the market for new 3G mobile services and applications in China.
CDMA 3G Variants (in the IMT-2000 Family)
The primary CDMA variants that will be used in IMT-2000 3G networks are W-CDMA (Wideband CDMA) and cdma2000, which are similar but not the same, so that W-CDMA handsets will not work with cdma2000 handsets and visa versa.
W-CDMA (Wideband CDMA)
W-CDMA is the competitor to cdma2000 and one of two 3G standards that makes use of a wider spectrum than CDMA and therefore can transmit and receive information for faster and more efficiently. Co-developed by NTT DoCoMo, it is being backed by most European mobile operators and is expected to compete with cdma2000 to be the de facto 3G standard
W-CDMA (Wideband CDMA)
W-CDMA is the competitor to cdma2000 and one of two 3G standards that makes use of a wider spectrum than CDMA and therefore can transmit and receive information for faster and more efficiently. Co-developed by NTT DoCoMo, it is being backed by most European mobile operators and is expected to compete with cdma2000 to be the de facto 3G standard
Outdoor wireless mesh technology
Outdoor wireless mesh technology addresses the growing municipal Wi-Fi market. Municipalities, service providers, universities and multi-site commercial organizations are revolutionizing they way they move voice, video and data traffic by incorporating wireless mesh networks into their overall IP networking strategies. Wireless Mesh networks are resilient, in that there are no single points of failure. Based on the mature 802.11 wireless standard, mesh networks are highly reliable and capable of communicating with millions of wireless devices currently in use. Finally, mesh networks feature dynamic route capability and are “self-healing”. Thus, they are easy to deploy and manage – and affordable. Their inherent mesh architecture eliminates the line-of-sight requirement of older outdoor wireless technologies.
Cisco Wireless Mesh ATP’s are “selected” by Cisco and must have a proven track record in integrating RF/Radio solutions with IP networks. Venture’s 22-year track record of engineering, deploying and supporting complex networks and information systems coupled with Venture’s extensive Cisco networking certifications makes Venture a strong player in the Wireless Mesh arena.
Cisco Wireless Mesh ATP’s are “selected” by Cisco and must have a proven track record in integrating RF/Radio solutions with IP networks. Venture’s 22-year track record of engineering, deploying and supporting complex networks and information systems coupled with Venture’s extensive Cisco networking certifications makes Venture a strong player in the Wireless Mesh arena.
Monday, August 17, 2009
General Packet Radio Service(GPRS)
General packet radio service (GPRS) is a packet oriented mobile data service available to users of the 2G cellular communication systems global system for mobile communications (GSM), as well as in the 3G systems. In the 2G systems, GPRS provides data rates of 56-114 kbit/s.
GPRS data transfer is typically charged per megabyte of traffic transferred, while data communication via traditional circuit switching is billed per minute of connection time, independent of whether the user actually is using the capacity or is in an idle state. GPRS is a best-effort packet switched service, as opposed to circuit switching, where a certain quality of service (QoS) is guaranteed during the connection for non-mobile users.
2G cellular systems combined with GPRS are often described as 2.5G, that is, a technology between the second (2G) and third (3G) generations of mobile telephony. It provides moderate speed data transfer, by using unused time division multiple access (TDMA) channels in, for example, the GSM system. Originally there was some thought to extend GPRS to cover other standards, but instead those networks are being converted to use the GSM standard, so that GSM is the only kind of network where GPRS is in use. GPRS is integrated into GSM Release 97 and newer releases. It was originally standardized by European Telecommunications Standards Institute (ETSI), but now by the 3rd Generation Partnership Project (3GPP).
GPRS was developed as a GSM response to the earlier CDPD and i-mode packet switched cellular technologies
GPRS data transfer is typically charged per megabyte of traffic transferred, while data communication via traditional circuit switching is billed per minute of connection time, independent of whether the user actually is using the capacity or is in an idle state. GPRS is a best-effort packet switched service, as opposed to circuit switching, where a certain quality of service (QoS) is guaranteed during the connection for non-mobile users.
2G cellular systems combined with GPRS are often described as 2.5G, that is, a technology between the second (2G) and third (3G) generations of mobile telephony. It provides moderate speed data transfer, by using unused time division multiple access (TDMA) channels in, for example, the GSM system. Originally there was some thought to extend GPRS to cover other standards, but instead those networks are being converted to use the GSM standard, so that GSM is the only kind of network where GPRS is in use. GPRS is integrated into GSM Release 97 and newer releases. It was originally standardized by European Telecommunications Standards Institute (ETSI), but now by the 3rd Generation Partnership Project (3GPP).
GPRS was developed as a GSM response to the earlier CDPD and i-mode packet switched cellular technologies
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