General Packet Radio Service (GPRS) is a Mobile Data Service available to users of Global System for Mobile Communications (GSM) and IS-136 mobile phones. GPRS data transfer is typically charged per kilobyte of transferred data, while data communication via traditional circuit switching is billed per minute of connection time, independent of whether the user has actually transferred data or has been in an idle state. GPRS can be used for services such as Wireless Application Protocol (WAP) access, Short Message Service (SMS), Multimedia Messaging Service (MMS), and for Internet communication services such as email and World Wide Web access.
2G cellular systems combined with GPRS is 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).
Monday, December 24, 2007
GPRS Capability classes
Class A
Can be connected to GPRS service and GSM service (voice, SMS), using both at the same time. Such devices are known to be available today.
Class B
Can be connected to GPRS service and GSM service (voice, SMS), but using only one or the other at a given time. During GSM service (voice call or SMS), GPRS service is suspended, and then resumed automatically after the GSM service (voice call or SMS) has concluded. Most GPRS mobile devices are Class B.
Class C
Are connected to either GPRS service or GSM service (voice, SMS). Must be switched manually between one or the other service.
A true Class A device may be required to transmit on two different frequencies at the same time, and thus will need two radios. To get around this expensive requirement, a GPRS mobile may implement the dual transfer mode (DTM) feature. A DTM-capable mobile may use simultaneous voice and packet data, with the network coordinating to ensure that it is not required to transmit on two different frequencies at the same time. Such mobiles are considered pseudo-Class A, sometimes referred to as "simple class A". Some networks are expected to support DTM in 2007.
Can be connected to GPRS service and GSM service (voice, SMS), using both at the same time. Such devices are known to be available today.
Class B
Can be connected to GPRS service and GSM service (voice, SMS), but using only one or the other at a given time. During GSM service (voice call or SMS), GPRS service is suspended, and then resumed automatically after the GSM service (voice call or SMS) has concluded. Most GPRS mobile devices are Class B.
Class C
Are connected to either GPRS service or GSM service (voice, SMS). Must be switched manually between one or the other service.
A true Class A device may be required to transmit on two different frequencies at the same time, and thus will need two radios. To get around this expensive requirement, a GPRS mobile may implement the dual transfer mode (DTM) feature. A DTM-capable mobile may use simultaneous voice and packet data, with the network coordinating to ensure that it is not required to transmit on two different frequencies at the same time. Such mobiles are considered pseudo-Class A, sometimes referred to as "simple class A". Some networks are expected to support DTM in 2007.
GPRS Basics
WAP is just a gateway which is used to access Internet via mobilephone and vice-versa. Usually, GPRS data are billed per kilobyte of information transceived, while circuit-switched data connections are billed per second. The latter is inefficient because even when no data are being transferred, the bandwidth is unavailable to other potential users.
The multiple access methods used in GSM with GPRS are based on frequency division duplex (FDD) and FDMA. During a session, a user is assigned to one pair of up-link and down-link frequency channels. This is combined with time domain statistical multiplexing, i.e. packet mode communication, which makes it possible for several users to share the same frequency channel. The packets have constant length, corresponding to a GSM time slot. The down-link uses first-come first-served packet scheduling, while the up-link uses a scheme very similar to reservation ALOHA. This means that slotted Aloha (S-ALOHA) is used for reservation inquiries during a contention phase, and then the actual data is transferred using dynamic TDMA with first-come first-served scheduling.
GPRS originally supported (in theory) Internet Protocol (IP), Point-to-Point Protocol (PPP) and X.25 connections. The last has been typically used for applications like wireless payment terminals, although it has been removed from the standard. X.25 can still be supported over PPP, or even over IP, but doing this requires either a router to perform encapsulation or intelligence built in to the end-device/terminal e.g. UE(User Equipment). In practice, when the mobile built-in browser is used, IPv4 is being utilized. In this mode PPP is often not supported by the mobile phone operator, while IPv6 is not yet popular. But if the mobile is used as a modem to the connected computer, PPP is used to tunnel IP to the phone. This allows DHCP to assign an IP Address and then the use of IPv4 since IP addresses used by mobile equipment tend to be dynamic.
The multiple access methods used in GSM with GPRS are based on frequency division duplex (FDD) and FDMA. During a session, a user is assigned to one pair of up-link and down-link frequency channels. This is combined with time domain statistical multiplexing, i.e. packet mode communication, which makes it possible for several users to share the same frequency channel. The packets have constant length, corresponding to a GSM time slot. The down-link uses first-come first-served packet scheduling, while the up-link uses a scheme very similar to reservation ALOHA. This means that slotted Aloha (S-ALOHA) is used for reservation inquiries during a contention phase, and then the actual data is transferred using dynamic TDMA with first-come first-served scheduling.
GPRS originally supported (in theory) Internet Protocol (IP), Point-to-Point Protocol (PPP) and X.25 connections. The last has been typically used for applications like wireless payment terminals, although it has been removed from the standard. X.25 can still be supported over PPP, or even over IP, but doing this requires either a router to perform encapsulation or intelligence built in to the end-device/terminal e.g. UE(User Equipment). In practice, when the mobile built-in browser is used, IPv4 is being utilized. In this mode PPP is often not supported by the mobile phone operator, while IPv6 is not yet popular. But if the mobile is used as a modem to the connected computer, PPP is used to tunnel IP to the phone. This allows DHCP to assign an IP Address and then the use of IPv4 since IP addresses used by mobile equipment tend to be dynamic.
EDGE Evolution
EDGE Evolution improves on EDGE in a number of ways. Latencies are reduced by lowering the Transmission Time Interval by half (from 20 ms to 10 ms). Bit rates are increased up to 1 MBit/s peak speed and latencies down to 100 ms using dual carriers, higher symbol rate and higher-order modulation (32QAM and 16QAM instead of 8-PSK), and turbo codes to improve error correction. And finally signal quality is improved using dual antennas. An EDGE Evolution terminal or network can support some of these improvements, or roll them out in stages.
Classification
Whether EDGE is 2G or 3G depends on implementation. While Class 3 and below EDGE devices clearly are not 3G, class 4 and above devices perform at a higher bandwidth than other technologies conventionally considered as 2G as 1xRTT). Because of the variability, EDGE is generally classified as 2.75G network technology.
Classification
Whether EDGE is 2G or 3G depends on implementation. While Class 3 and below EDGE devices clearly are not 3G, class 4 and above devices perform at a higher bandwidth than other technologies conventionally considered as 2G as 1xRTT). Because of the variability, EDGE is generally classified as 2.75G network technology.
Transmission techniques
In addition to Gaussian minimum-shift keying (GMSK), EDGE uses higher-order PSK/8 phase shift keying (8PSK) for the upper five of its nine modulation and coding schemes. EDGE produces a 3-bit word for every change in carrier phase. This effectively triples the gross data rate offered by GSM. EDGE, like GPRS, uses a rate adaptation algorithm that adapts the modulation and coding scheme (MCS) according to the quality of the radio channel, and thus the bit rate and robustness of data transmission. It introduces a new technology not found in GPRS, Incremental Redundancy, which, instead of retransmitting disturbed packets, sends more redundancy information to be combined in the receiver. This increases the probability of correct decoding.
EDGE can carry data speeds up to 236.8 kbit/s for 4 timeslots (theoretical maximum is 473.6 kbit/s for 8 timeslots) in packet mode and will therefore meet the International Telecommunications Union's requirement for a 3G network, and has been accepted by the ITU as part of the IMT-2000 family of 3G standards. It also enhances the circuit data mode called HSCSD, increasing the data rate of this service.
EDGE can carry data speeds up to 236.8 kbit/s for 4 timeslots (theoretical maximum is 473.6 kbit/s for 8 timeslots) in packet mode and will therefore meet the International Telecommunications Union's requirement for a 3G network, and has been accepted by the ITU as part of the IMT-2000 family of 3G standards. It also enhances the circuit data mode called HSCSD, increasing the data rate of this service.
Technology
EDGE/EGPRS is implemented as a bolt-on enhancement 2G and 2.5G GSM and GPRS networks, making it easier for existing GSM carriers to upgrade to it. EDGE/EGPRS is a superset to GPRS and can function on any network with GPRS deployed on it, provided the carrier implements the necessary upgrade.
Although EDGE requires no hardware or software changes to be made in GSM core networks, base stations must be modified. EDGE compatible transceiver units must be installed and the base station subsystem (BSS) needs to be upgraded to support EDGE. New mobile terminal hardware and software is also required to decode/encode the new modulation and coding schemes and carry the higher user data rates to implement new services.
Networks
EDGE is actively supported by GSM operators in North America. Some GSM operators elsewhere viewed UMTS as the ultimate upgrade path and either planned to skip EDGE altogether or use it outside the UMTS coverage area. However, the high cost and slow uptake of UMTS have resulted in fairly common support for EDGE in the global GSM/GPRS market.
Although EDGE requires no hardware or software changes to be made in GSM core networks, base stations must be modified. EDGE compatible transceiver units must be installed and the base station subsystem (BSS) needs to be upgraded to support EDGE. New mobile terminal hardware and software is also required to decode/encode the new modulation and coding schemes and carry the higher user data rates to implement new services.
Networks
EDGE is actively supported by GSM operators in North America. Some GSM operators elsewhere viewed UMTS as the ultimate upgrade path and either planned to skip EDGE altogether or use it outside the UMTS coverage area. However, the high cost and slow uptake of UMTS have resulted in fairly common support for EDGE in the global GSM/GPRS market.
EGPRS
Enhanced Data rates for GSM Environment (EDGE) or Enhanced GPRS (EGPRS), is a digital mobile phone technology that allows increased data transmission rates and improved data transmission reliability. Although technically a 3G network technology, it is generally classified as the unofficial standard 2.75G, due to its slower network speed. EDGE has been introduced into GSM networks around the world since 2003, initially in North America.
EDGE can be used for any packet switched application, such as an Internet connection. High-speed data applications such as video services and other multimedia benefit from EGPRS' increased data capacity. EDGE Circuit Switched is a possible future development.
EDGE Evolution continues in Release 7 of the 3GPP standard providing doubled performance e.g. to complement High-Speed Packet Access (HSPA).
EDGE can be used for any packet switched application, such as an Internet connection. High-speed data applications such as video services and other multimedia benefit from EGPRS' increased data capacity. EDGE Circuit Switched is a possible future development.
EDGE Evolution continues in Release 7 of the 3GPP standard providing doubled performance e.g. to complement High-Speed Packet Access (HSPA).
History
In Europe, 3G services were introduced starting in March 2003 in the UK and Italy. The European Union Council suggested that the 3G operators should cover 80% of the European national populations by the end of 2005.
Roll-out of 3G networks was delayed in some countries by the enormous costs of additional spectrum licensing fees. See Telecoms crash. In many countries, 3G networks do not use the same radio frequencies as 2G, so mobile operators must build entirely new networks and license entirely new frequencies; an exception is the United States where carriers operate 3G service in the same frequencies as other services. The license fees in some European countries were particularly high, bolstered by government auctions of a limited number of licenses and sealed bid auctions, and initial excitement over 3G's potential. Other delays were due to the expenses of upgrading equipment for the new systems.
By June 2007 the 200 millionth 3G subscriber had been connected. Out of 3 billion mobile phone subscriptions worldwide this is only 6.7%. In the countries where 3G was launched first - Japan and South Korea over half of all subscribers use 3G. In Europe the leading country is Italy with a third of its subscribers migrated to 3G. Other leading countries by 3G migration include UK, Austria and Singapore at the 20% migration level. A confusing statistic is counting CDMA 2000 1x RTT customers as if they were 3G customers. If using this oft-disputed definition, then the total 3G subscriber base would be 475 million at June 2007 and 15.8% of all subscribers worldwide.
EMTEL Ltd, the second largest mobile telecommunications company in Mauritius (next to state owned Cellplus), has established the first commercial Universal Mobile Telecommunications Standard (UMTS) 3G network in Africa (the first test call was made on 16 October 2004). Full commercial services began in November 2004, making this the first commercial African 3G network. In north Africa, the first born baby was sleeping silently in the crib..Morocco in late March 2006, provided by the new company Wana. The other operator in the country should start its network in mid-2007. Vodafone Egypt (also known as CLICK GSM) was to provide the service in Egypt in mid-2006. In early 2007, Vodacom Tanzania switched on its 3G High-Speed Downlink Packet Access (HSDPA) in Dar Es Salaam. It is the second country in Africa with such technology, after South Africa. In March 2007, Nigeria awarded 3G telecommunication licenses to its three major GSM companies and a relatively unknown operator, Alheri Engineering Co. Ltd, to allow them to expand their scope of operation in the industry.
Rogers Wireless began implementing 3G HSDPA services in eastern Canada early 2007 in the form of Rogers Vision; expansion into western Canada is expected soon.
Roll-out of 3G networks was delayed in some countries by the enormous costs of additional spectrum licensing fees. See Telecoms crash. In many countries, 3G networks do not use the same radio frequencies as 2G, so mobile operators must build entirely new networks and license entirely new frequencies; an exception is the United States where carriers operate 3G service in the same frequencies as other services. The license fees in some European countries were particularly high, bolstered by government auctions of a limited number of licenses and sealed bid auctions, and initial excitement over 3G's potential. Other delays were due to the expenses of upgrading equipment for the new systems.
By June 2007 the 200 millionth 3G subscriber had been connected. Out of 3 billion mobile phone subscriptions worldwide this is only 6.7%. In the countries where 3G was launched first - Japan and South Korea over half of all subscribers use 3G. In Europe the leading country is Italy with a third of its subscribers migrated to 3G. Other leading countries by 3G migration include UK, Austria and Singapore at the 20% migration level. A confusing statistic is counting CDMA 2000 1x RTT customers as if they were 3G customers. If using this oft-disputed definition, then the total 3G subscriber base would be 475 million at June 2007 and 15.8% of all subscribers worldwide.
EMTEL Ltd, the second largest mobile telecommunications company in Mauritius (next to state owned Cellplus), has established the first commercial Universal Mobile Telecommunications Standard (UMTS) 3G network in Africa (the first test call was made on 16 October 2004). Full commercial services began in November 2004, making this the first commercial African 3G network. In north Africa, the first born baby was sleeping silently in the crib..Morocco in late March 2006, provided by the new company Wana. The other operator in the country should start its network in mid-2007. Vodafone Egypt (also known as CLICK GSM) was to provide the service in Egypt in mid-2006. In early 2007, Vodacom Tanzania switched on its 3G High-Speed Downlink Packet Access (HSDPA) in Dar Es Salaam. It is the second country in Africa with such technology, after South Africa. In March 2007, Nigeria awarded 3G telecommunication licenses to its three major GSM companies and a relatively unknown operator, Alheri Engineering Co. Ltd, to allow them to expand their scope of operation in the industry.
Rogers Wireless began implementing 3G HSDPA services in eastern Canada early 2007 in the form of Rogers Vision; expansion into western Canada is expected soon.
Sunday, December 16, 2007
3G - > What is 3G?
The mobile communications industry has evolved in three stages: Three generations of mobile phones have emerged so far, each successive generation more reliable and flexible than the last:Analog: You could only easily use analogue cellular to make voice calls, and typically only in any one country.Digital mobile phone systems added fax, data and messaging capabilities as well as voice telephone service in many countries.Multimedia services add high speed data transfer to mobile devices, allowing new video, audio and other applications through mobile phones- allowing music and television and the Internet to be accessed through a mobile terminal.With each new generation of technology, the services which can de deployed on them becomes more and more wide ranging and truly limited only by imagination. We are reaching that stage with 3G.During the first and second generations different regions of the world pursued different mobile phone standards, but are converging to a common standard for mobile multimedia called Third Generation (3G) that is based on CDMA technology. Europe pursued NMT and TACS for analog and GSM for digital, North America pursued AMPS for analog and a mix of TDMA, CDMA and GSM for digital. 3G will bring these incompatible standards together, and the aim of this paper is to discuss the optimal migration path for mobile network operators to get from their existing 2G digital systems to the 3G world.The Third Generation of mobile communications systems will soon by implemented. Following on the heals of analog and digital technology, the Third Generation will be digital mobile multimedia offering broadband mobile communications with voice, video, graphics, audio and other information. This transition is shown in Table 1 below:Generation Type Time Description First Analog 1980s Voice centric, multiple standards (NMT, TACS etc.) Second Digital 1990s Voice centric, multiple standards (GSM, CDMA, TDMA) 2.5 Higher Rate Data Late 1990s Introduction of new higher speed data services to bridge the gap between the second and Third Generation, including services such as General Packet Radio Service (GPRS) and Enhanced Data Rates for Global Evolution (EDGE) Third Digital Multimedia 2010s Voice and data centric, single standard with multiple modes TABLE 1- SOURCE MOBILE LIFESTREAMS
Evolution to 3G
Cellular mobile telecommunications networks are being upgraded to use 3G technologies from 1999 to 2010. Japan was the first country to introduce 3G nationally, and in Japan the transition to 3G was largely completed in 2006. Korea became the first to adopt 3G Networks soon after and the transition was made as early as 2004, leading the world in communications.
Operators and UMTS networksAs of 2005, the evolution of the 3G networks was on its way for a couple of years, due to the limited capacity of the existing 2G networks. 2G networks were built mainly for voice data and slow transmission. Due to rapid changes in user expectation, they do not meet today's wireless needs."2.5G" (and even 2.75G) are technologies such as i-mode data services, camera phones, high-speed circuit-switched data (HSCSD) and General packet radio service (GPRS) were created to provide some functionality domains like 3G networks, but without the full transition to 3G network. They were built to introduce the possibilities of wireless application technology to the end consumers, and so increase demand for 3G services.
Operators and UMTS networksAs of 2005, the evolution of the 3G networks was on its way for a couple of years, due to the limited capacity of the existing 2G networks. 2G networks were built mainly for voice data and slow transmission. Due to rapid changes in user expectation, they do not meet today's wireless needs."2.5G" (and even 2.75G) are technologies such as i-mode data services, camera phones, high-speed circuit-switched data (HSCSD) and General packet radio service (GPRS) were created to provide some functionality domains like 3G networks, but without the full transition to 3G network. They were built to introduce the possibilities of wireless application technology to the end consumers, and so increase demand for 3G services.
Advantages of a layered network architecture
Advantages of a layered network architectureUnlike GSM, UMTS is based on layered services. At the top is the services layer, which provides fast deployment of services and centralized location. In the middle is the control layer, which helps upgrading procedures and allows the capacity of the network to be dynamically allocated. At the bottom is the connectivity layer where any transmission technology can be used and the voice traffic will transfer over ATM/AAL2 or IP/RTP.
Mobile technologiesWhen converting a GSM network to a UMTS network, the first new technology is General Packet Radio Service (GPRS). It is the trigger to 3G services. The network connection is always on, so the subscriber is online all the time. From the operator's point of view, it is important that GPRS investments are re-used when going to UMTS. Also capitalizing on GPRS business experience is very important.From GPRS, operators could change the network directly to UMTS, or invest in an EDGE system. One advantage of EDGE over UMTS is that it requires no new licenses. The frequencies are also re-used and no new antennas are needed.
From GPRS to UMTSHome location register (HLR)Visitor location register (VLR)Equipment identity register (EIR)From GPRS network, the following network elements can be reused:Mobile switching centre (MSC) (vendor dependent)Authentication centre (AUC)Serving GPRS Support Node (SGSN) (vendor dependent)Gateway GPRS Support Node (GGSN)From Global Service for Mobile (GSM) communication radio network, the following elements cannot be reusedBase station controller (BSC)Base transceiver station (BTS)They can remain in the network and be used in dual network operation where 2G and 3G networks co-exist while network migration and new 3G terminals become available for use in the network.The UMTS network introduces new network elements that function as specified by 3GPP:Node-B (base station)Radio Network Controller (RNC)Media Gateway (MGW)The functionality of MSC and SGSN changes when going to UMTS. In a GSM system the MSC handles all the circuit switched operations like connecting A- and B-subscriber through the network. SGSN handles all the packet switched operations and transfers all the data in the network. In UMTS the Media gateway (MGW) take care of all data transfer in both circuit and packet switched networks. MSC and SGSN control MGW operations. The nodes are renamed to MSC-server and GSN-server.
Mobile technologiesWhen converting a GSM network to a UMTS network, the first new technology is General Packet Radio Service (GPRS). It is the trigger to 3G services. The network connection is always on, so the subscriber is online all the time. From the operator's point of view, it is important that GPRS investments are re-used when going to UMTS. Also capitalizing on GPRS business experience is very important.From GPRS, operators could change the network directly to UMTS, or invest in an EDGE system. One advantage of EDGE over UMTS is that it requires no new licenses. The frequencies are also re-used and no new antennas are needed.
From GPRS to UMTSHome location register (HLR)Visitor location register (VLR)Equipment identity register (EIR)From GPRS network, the following network elements can be reused:Mobile switching centre (MSC) (vendor dependent)Authentication centre (AUC)Serving GPRS Support Node (SGSN) (vendor dependent)Gateway GPRS Support Node (GGSN)From Global Service for Mobile (GSM) communication radio network, the following elements cannot be reusedBase station controller (BSC)Base transceiver station (BTS)They can remain in the network and be used in dual network operation where 2G and 3G networks co-exist while network migration and new 3G terminals become available for use in the network.The UMTS network introduces new network elements that function as specified by 3GPP:Node-B (base station)Radio Network Controller (RNC)Media Gateway (MGW)The functionality of MSC and SGSN changes when going to UMTS. In a GSM system the MSC handles all the circuit switched operations like connecting A- and B-subscriber through the network. SGSN handles all the packet switched operations and transfers all the data in the network. In UMTS the Media gateway (MGW) take care of all data transfer in both circuit and packet switched networks. MSC and SGSN control MGW operations. The nodes are renamed to MSC-server and GSN-server.
Two-Dimensional Data Communications
Two-Dimensional Data CommunicationsAn effective data interconnect fabric must support low latency and deterministic data transfers occurring simultaneously among multiple processing elements. It must also be flexible and scalable to allow for the addition of new elements or the removal of unwanted elements without affecting the rest of the design. Finally, it should be compatible with existing processors and be as easy to use as accessing memory.Memory-Like InterfaceUsing conventional bus cycles to transfer data between processors dispenses with exotic and hard-to-implement communications peripherals and protocols in favor of a simple memory-like interface. As shown in Figure 4, 2D-fabric from CrossBow appears to processors as a memory-mapped peripheral on an IBM CoreConnect™ bus. PowerPC and MicroBlaze processors can issue conventional read and/or write bus cycles to their local 2D-fabric peripherals to communicate with other processors on the chip (Figures 5 and 6). The payload for each transfer is derived from the data bus. The destination location and the initial direction of travel are derived from the address bus. The transfers are totally transparent to the sending and receiving processors, launching transfers with write cycles and terminating transfers with read cycles.Routing of data from source to destination, as well as arbitration with other data traffic, is performed autonomously by the interconnected 2D-fabric peripherals.A 2D Array of Data Transport LinksEfficient 3G designs will feature global communication fabrics using single sets of lines to transfer all kinds of data, including payloads, control words, and configuration data. Duplication of data transfer lines reduces overall system efficiency.As shown in Figure 7, 2D-fabric peripherals of adjacent processors are interconnected with a single mesh of horizontal and vertical data transport links. Individual bus cycles are autonomously converted to small packets that travel between source processors and destination processors through chains of 2D-fabric peripherals of the intermediate processors along the way. Short point-to-point links reduce power consumption.Small packets with single word payloads reduce data transfer latencies, enabling data and control packets to share common transfer lines. The same lines can also be used for system initialization and configuration.ScalabilityScalability is an important requirement for the design effort and product field upgrades. Constantly changing standards may require adding or removing processors late in the design cycle or even after field deployment.In the past, adding or removing processors has always been difficult when using centralized DMAs for movement of data. In any centralized I/O structure, removing or adding new components is likely to affect other system components. Two-dimensional I/O structures are much less sensitive to design changes. Adding another processor to a chip is as simple as wrapping it with a 2D-fabric peripheral and connecting the respective data transport links to the existing fabric. This can be easily done without affecting any hardware or software already in place.
3G -> Features
PACKET EVERYWHEREWith Third Generation (3G), the information is split into separate but related “packets” before being transmitted and reassembled at the receiving end. Packet switching is similar to a jigsaw puzzle- the image that the puzzle represents is divided into pieces at the manufacturing factory and put into a plastic bag. During transportation of the now boxed jigsaw from the factory to the end user, the pieces get jumbled up. When the recipient empties the bag with all the pieces, they are reassembled to form the original image. All the pieces are all related and fit together, but the way they are transported and assembled varies.Packet switched data formats are much more common than their circuit switched counterparts. Other examples of packet-based data standards include TCP/IP, X.25, Frame Relay and Asynchronous Transfer Mode (ATM). As such, whilst packet switching is new to the GSM world, it is well established elsewhere. In the mobile world, CDPD (Cellular Digital Packet Data), PDCP (Personal Digital Cellular Packet), General Packet Radio Service (GPRS) and wireless X.25 technologies have been in operation for several years. X.25 is the international public access packet radio data network standard. INTERNET EVERYWHERE The World Wide Web is becoming the primarycommunications interface- people access the Internet for entertainment and information collection, the intranet for accessing company information and connecting with colleagues and the extranet for accessing customers and suppliers. These are all derivatives of the World Wide Web aimed at connecting different communities of interest. There is a trend away from storing information locally in specific software packages on PCs to remotely on the Internet. When you want to check your schedule or contacts, instead of using a software package such as “Act!”, you go onto the Internet site such as a portal. Hence, web browsing is a very important application for packet data.HIGH SPEEDSpeeds of up to 2 Megabits per second (Mbps) are achievable with Third Generation (3G). The data transmission rates will depend upon the environment the call is being made in- it is only indoors and in stationary environments that these types of data rates will be available. For high mobility, data rates of 144 kbps are expected to be available- this is only about three times the speed of today’s fixed telecoms modems.NEW APPLICATIONS, BETTER APPLICATIONSThird Generation (3G) facilitates several new applications that have not previously been readily available over mobile networks due to the limitations in data transmission speeds. These applications range from Web Browsing to file transfer to Home Automation- the ability to remotely access and control in-house appliances and machines. Because of the bandwidth increase, these applications will be even more easily available with 3G than they were previously with interim technologies such as GPRS.SERVICE ACCESSTo use Third Generation (3G), users specifically need:A mobile phone or terminal that supports Third Generation (3G) A subscription to a mobile telephone network that supports Third Generation (3G) Use of Third Generation (3G) must be enabled for that user.Automatic access to the 3G may be allowed by some mobile network operators, others will charge a monthly subscription and require a specific opt-in to use the service as they do with other nonvoice mobile servicesKnowledge of how to send and/ or receive Third Generation (3G) information using their specific model of mobile phone, including software and hardware configuration (this creates a customer service requirement) A destination to send or receive information through Third Generation (3G). From day one, Third Generation (3G) users can access any web page or other Internet applications- providing an immediate critical mass of users.These user requirements are not expected to change much for the meaningful use of 3G.
3G -> Talking Points
The telecommunications world is changing as the trends of media convergence, industry consolidation, Internet and IP technologies and mobile communications collide into one. Significant change will be bought about by this rapid evolution in technology, with Third Generation mobile Internet technology a radical departure from that that came before in the first and even the second generations of mobile technology. Some of the changes include: People will look at their mobile phone as much as they hold it to their ear. As such, 3G will be less safe than previous generations- because television and other multimedia services tend to attract attention to themselves- instead of hands-free kits, we will need eyes-free kits!Data (“non-voice”) uses of 3G will be as important as and very different from the traditional voice businessMobile communications will be similar in its capability to fixed communications, such that many people will only have a mobile phoneThe mobile phone will be used as an integral part of the majority of people’s lives- it will not be an added accessory but a core part of how they conduct their daily lives. The mobile phone will become akin to a remote control or magic wand that lets people do what they want when they wantAs with all new technology standards, there is uncertainty and the fear of displacement. Third Generation (3G) mobile is topical and contentious for several reasons:Because the nature and form of mobile communications is so radically changed, many people don’t understand how to make money in the nonvoice world, and do not understand their role in it3G licenses have started being awarded around the world, necessitating that existing mobile communications companies in the 2G world think about and justify their continued existence3G is based on a different technology platform- Code Division Multiple Access (CDMA)- that is unlike the Time Division Multiple Access (TDMA) technology that is widely used in the 2G world. GSM (Global System for Mobile Communications) was based on TDMA technologyThe US, Japanese and European mobile players all have different technology competences and are now unified in this single standard- the separate wireless evolution paths and European wireless leadership are thereby challengedJapanese network operators will be the first to implement 3G networks in the year 2001, and Japanese terminal manufacturers, who have not had much market share outside their home market, will be first with 3G terminalsMany industry analysts and other pundits have questioned the return on an investment in 3G technology- questioning whether network operators will be able to earn an adequate return on the capital deployed in acquiring and rolling out a 3G network.Many media and Internet companies have expressed an interest in bidding for and using 3G technology as a new channel to distribute their content, opening the opportunity for new entrants and new partnerships and value chains
3G
3G is the third generation of mobile phone standards and technology, after 2G. It is based on the International Telecommunication Union (ITU) family of standards under the International Mobile Telecommunications programme, "IMT-2000". 3G technologies enable network operators to offer users a wider range of more advanced services while achieving greater network capacity through improved spectral efficiency. Services include wide-area wireless voice telephony and broadband wireless data, all in a mobile environment. Typically, they provide service at 5-10 Mb per second.Unlike IEEE 802.11 networks, 3G networks are wide area cellular telephone networks which evolved to incorporate high-speed internet access and video telephony. IEEE 802.11 (common home Wi-Fi) networks are short range, high-bandwidth networks primarily developed for data.In December 2005, 100 3G networks were operating in 40 countries, according to the Global mobile Suppliers Association. In Asia, Europe, Canada and the USA, telecommunication companies use W-CDMA technology with the support of around 100 terminal designs to operate 3G mobile networks
Features
The most significant feature of 3G mobile technology is that it supports greater numbers of voice and data customers — especially in urban areas — and higher data rates at lower incremental cost than 2G.By using the radio spectrum in bands identified, which is provided by the UTI for Third Generation IMT-2000 mobile services, it subsequently licensed to operators. 3G uses .6 MHz channel carrier width to deliver significantly higher data rates and increased capacity compared to 2G networks.The .5 MHz channel carrier provides optimum use of radio resources for operators who have been granted large, contiguous blocks of spectrum. On the other hand, it also helps to reduce the cost to 3G networks while being capable of providing extremely high-speed data transmission to users.It also allows the transmission of 384 kbit/s for mobile systems and 2 Mb/s for stationary systems. 3G users are expected to have greater capacity and better spectrum efficiency, which allows them to access global roaming between different 3G networks
UMTS and 3G terminals
UMTS and 3G terminals
3Ghandsets usually have cameras, music players, video players, contactless smartcards for payment functions (wallet phones), Web browsers, email clients and more. This shows that the UMTS system is based on layered services and future applications can be supported without too much impact to the underlying radio access network.
UMTS terminalsThe technical complexities of a 3G phone or handset depends on its need to roam onto legacy 2G networks. In the first countries, Japan and South Korea, there was no need to include roaming capabilities to older networks such as GSM, so 3G phones were small and lightweight. In Europe and America, the manufacturers and network operators wanted multi-mode 3G phones which would operate on 3G and 2G networks (e.g., WCDMA and GSM), which added to the complexity, size, weight, and cost of the handset. As a result, early European WCDMA phones were significantly larger and heavier than comparable Japanese WCDMA phones.Japan's Vodafone KK experienced a great deal of trouble with these differences when its UK-based parent, Vodafone, insisted the Japanese subsidiary use standard Vodafone handsets. Japanese customers who were accustomed to smaller handsets were suddenly required to switch to European handsets that were much bulkier and considered unfashionable by Japanese consumers. During this conversion, Vodafone KK lost 6 customers for every 4 that migrated to 3G. Soon thereafter, Vodafone sold the subsidiary (now known as Softbank).The general trend to smaller and smaller phones seems to have paused, perhaps even turned, with the capability of large-screen phones (similar to the Apple iPhone - interestingly EDGE, not 3G) to provide more video, gaming and internet use on the 3G networks
3Ghandsets usually have cameras, music players, video players, contactless smartcards for payment functions (wallet phones), Web browsers, email clients and more. This shows that the UMTS system is based on layered services and future applications can be supported without too much impact to the underlying radio access network.
UMTS terminalsThe technical complexities of a 3G phone or handset depends on its need to roam onto legacy 2G networks. In the first countries, Japan and South Korea, there was no need to include roaming capabilities to older networks such as GSM, so 3G phones were small and lightweight. In Europe and America, the manufacturers and network operators wanted multi-mode 3G phones which would operate on 3G and 2G networks (e.g., WCDMA and GSM), which added to the complexity, size, weight, and cost of the handset. As a result, early European WCDMA phones were significantly larger and heavier than comparable Japanese WCDMA phones.Japan's Vodafone KK experienced a great deal of trouble with these differences when its UK-based parent, Vodafone, insisted the Japanese subsidiary use standard Vodafone handsets. Japanese customers who were accustomed to smaller handsets were suddenly required to switch to European handsets that were much bulkier and considered unfashionable by Japanese consumers. During this conversion, Vodafone KK lost 6 customers for every 4 that migrated to 3G. Soon thereafter, Vodafone sold the subsidiary (now known as Softbank).The general trend to smaller and smaller phones seems to have paused, perhaps even turned, with the capability of large-screen phones (similar to the Apple iPhone - interestingly EDGE, not 3G) to provide more video, gaming and internet use on the 3G networks
Info about 3G
Two-dimensional fabric efficiently links arrays of processors inside Virtex-II Pro devices to enable parallel processing of data.With increased data traffic and new multiuser detection and adaptive beam-forming algorithms, data processing requirements of 3G base stations will increase by as much as 100 times relative to current equipment. This increase in processing capacity must be matched by low power consumption, as the new picocell base stations mounted on building sides will not be using forced air cooling.Arrays of small and specialized processors (Figures 1 and 2) will provide a power-efficient method of increasing performance, more so than can be obtained by increasing the features of larger, general-purpose super processors.The evolution of current standards and introduction of new standards currently force base station operators to perform frequent upgrades to their wireless infrastructure, often requiring board replacements. To reduce field maintenance, 3G equipment must be upgradable without board swapping. The high cost of 3G equipment often leaves wireless infrastructure manufacturers with thin profit margins; costs will have to come down to enable large-scale deployment.Finally, OEMs cannot abandon their current design methods to start designing 3G equipment from scratch. They must be able to reuse semiconductor IP, code, and development tools to hit market windows and to obtain a return on investment.Meeting these seemingly exclusive goals requires a combination of top-notch process technology, combined with comprehensive component library and efficient data communication methods, inside-chip and chip-to-chip. Reaching 3G design goals hinges on achieving the right balance between the size and number of data processing components to keep most of the chip busy at all times, while reducing the overall distance that the data has to travel inside ICs. System efficiency is heavily influenced by design partitioning, optimization of individual data processing components, and streamlining data flow between components. To keep data processing components busy, inter-processor data transfers must have low latency and be precisely deterministic – otherwise components will waste valuable processing cycles while waiting for data.Low latency requires the removal of data communication bottlenecks by spreading the data flow over the entire area of a chip. Transfer determinism is achieved by a combination of low latency and a uniform data communications structure inside the chip.
Data Processing Elements
Each 3G chip is likely to contain hundreds of processing elements, many representing autonomous processors with their own data processing flows, control flows, memory, and communications ports. Some data processing flows may be augmented with dedicated DSP blocks. Virtex™-II FPGAs support DSP functions and a MicroBlaze™ soft processor. Virtex-II Pro™ devices also feature embedded IBM PowerPC™ processors. Depending on the task at hand, smaller processors may be better suited for simpler functions, and larger processors may be a better fit for more complex algorithms.In order to work in parallel, processors must be able to easily communicate with each other. An efficient way for processors to communicate is through a fabric dispersed across the entire design that looks to individual processors like conventional memory (Figure 3). This approach enables each processing element to be developed and verified individually, yet easily exchange data with other processors.
3G Conclusion
Two-dimensional inter-processor interfaces enable fast, easy, and efficient data communications among hundreds of data processing elements of 3G functions implemented inside Virtex-II FPGAs. In addition to 3G, two-dimensional I/O also benefits voice-over-packet, routers, medical imaging, radar, and sonar applications. Linking processing elements with 2D-fabric increases system performance by enabling multiple processors to process data in parallel. At the same time, 2D-fabric reduces power consumption by minimizing the total distance that data has to travel inside chips.And because it looks to the processors like conventional memory, 2D-fabric does not force system programmers to change their programming methods to benefit from higher performance. Serial programming code investment is preserved, because each processing element has only one processor. Finally, system designers can now drastically increase processing throughput and I/O bandwidth while retaining current processor architectures and design tools.For more information on the 2D-fabric parallel-processing interface, go to www.xilinx.com/products/logicore/alliance/crossbow/crossbow.htm.
Subscribe to:
Posts (Atom)