UMTS/HSDPA technology allows operators to control the proportion of networking resources allocated for voice and for data. Normally, voice has precedence over data, but the operator can designate a minimum level of data capacity for each.
4G Americas reports that UMTS/HSDPA, the third generation evolution for the GSM family of technologies, having already added 33 million customers since the end of 2004, serves close to 50 million customers today.
UMTS (WCDMA) is the leading global 3G technology choice in service today by 270 operators in 117 countries worldwide, up from 61 operators offering commercial UMTS/HSDPA service at the end of 2004. Another 59 networks are either in deployment or in pre-commercial or planned stages. In addition, eight operators have been awarded 3G UMTS licenses and there are 72 potential licenses yet to be awarded.
UMTS and GSM (including GPRS/EDGE) use fundamentally different radio technologies, with UMTS based on wideband CDMA and GSM based on TDMA. However, the international standards body designed UMTS to complement and co-exist with GSM networks. With multimode devices, users can access either GSM or UMTS, and can even do handover over from one network to the other. Meanwhile, operators can manage a common core network that controls both the GSM and UMTS radio access networks.
UMTS/HSDPA is an IP-based network. Based on service options, The AT&T UMTS/HSDPA network dynamically assigns mobile stations either a public or private IP address. The network then routes IP packets between user devices and external networks such as the Internet. Above the IP layer, user applications can use standard Internet protocols such as TCP, UDP, HTTP, FTP, HTTP, POP, IMAP, etc.
High Speed Downlink Packet Access is a software upgrade to UMTS that increases peak rates from 2 Mbps to 10 Mbps and average speeds to close to 1 Mbps. In the same way that EDGE uses dynamic modulation and error control to increase speeds over GPRS, HSDPA employs these same techniques, as well as others, to increase the speed of UMTS data channels.
Higher speed accomplishes two important things. First, it reduces the amount of time it takes for applications to communicate data, making them more responsive. Second, it makes feasible new applications that demand high throughput and/or low latency, such as video streaming or client/server applications.
GPRS cards will not operate on the UMTS radio link. However, many UMTS devices (e.g., mobile telephones) will be dual mode, allowing them to use UMTS when available, and GPRS in other areas. In GPRS mode, devices run at GPRS speeds.
AT&T has deployed UMTS/HSDPA in most major American metropolitan areas. For details, check out the wireless coverage map.
UMTS outperforms any other cellular technology planned for global deployment. AT&T UMTS service provides average speeds of 220-320 Kbps with burst speeds up to 384 Kbps.
UMTS/HSDPA and Wi-Fi are complementary services. UMTS/HSDPA is a wide-area wireless data service. Wi-Fi is a local-area wireless service and currently is only available to the public in select locations such as hotels and airports.
UMTS/HSDPA provides average speeds of 220-320 / 400-700 Kbps. Public Wi-Fi provides effective throughput rates up to 6 Mbps (though actual speeds depend on backhaul and number of users).
UMTS devices use the same types of SIM cards as GSM/GPRS/EDGE devices. AT&T has provisioned new SIM cards for UMTS devices, and these newer SIMs can be used with GSM/GPRS/EDGE devices. However, if a GSM SIM is used in a UMTS/GSM device, the customer will not have access to UMTS-specific content or the UMTS home deck.
UMTS/HSDPA is an asymmetrical system. Since most of the information flow is from an Internet Web site or corporate server to the mobile device, the system is architected to provide higher download speeds than upload speeds. UMTS/HSDPA average upload speeds are 220-320 Kbps.
The latency of UMTS/HSDPA, as measured by round trip time from the mobile station to a node immediately external to the UMTS/HSDPA network, is expected to be 200 to 300 msec.
UMTS/HSDPA has significantly lower latency than GPRS/EDGE, which can be up to 600 msec.
The UMTS/HSDPA network does not support transmission of fax protocols. However, third-party fax services (such as E-Fax) can provide a gateway between e-mail and fax which will allow you to send and receive faxes over UMTS/HSDPA using an e-mail client.
UMTS/HSDPA is independent of Java. However, most UMTS/HSDPA mobile telephones will support Java. Java applications such as interactive gaming will be able to take advantage of higher UMTS/HSDPA speeds. Users will also be able to download Java applications over the air faster.
For more information about UMTS/HSDPA coverage, check out AT&T BroadbandConnect.
AT&T has roaming partners worldwide, many of whom have deployed, or are planning to deploy UMTS/HSDPA service.
AT&T UMTS/HSDPA service is available in most greater metropolitan areas.
UMTS/HSDPA allows mobile workers to be more productive by allowing them to use familiar hardware (e.g., laptops) and the same networking applications that they use in their office. The broadband capabilities of UMTS/HSDPA enables a network-computing experience that almost indistinguishable from being in the office.
UMTS/HSDPA does support voice over IP. However, for reliable high-quality VoIP, the network also needs to implement IP quality-of-service mechanisms. These capabilities are part of the UMTS/HSDPA specifications, but are not available in current AT&T UMTS/HSDPA service.
Initial UTMS coverage emphasizes areas with higher subscriber densities such as metropolitan areas.
UMTS/HSDPA can operate in a variety of bands. In Europe and Asia, operators are deploying UMTS/HSDPA in 3G spectrum at 2100 MHz. In the US AT&T is deploying UMTS/HSDPA in the 1900 and 850 MHz bands.
Sockets are supported in the sense that sockets (including Windows Sockets) are the primary interface between applications and TCP/IP protocol stacks. Since UMTS/HSDPA is an IP network that uses TCP/IP protocols, applications typically use sockets interfaces.
The same Web optimization system that is available for GPRS/EDGE is available for UMTS/HSDPA.
Yes, custom APNs are available for UMTS/HSDPA.
UMTS/HSDPA is highly compatible with EDGE and GPRS. Almost any application that functions on GPRS/EDGE will function on UMTS/HSDPA. In addition, UMTS/HSDPA mobile telephones also support GPRS (and in some cases EDGE), so that users can obtain GPRS connectivity when out of the UMTS/HSDPA coverage area.
GSM, GPRS and EDGE will continue to be supported for a long time. Most GSM operators deploying UMTS/HSDPA intend to operate both GSM/GPRS and UMTS/HSDPA networks in combination. In fact, UMTS/HSDPA has been designed so that a common core network can support both types of radio access networks.
Like EDGE, almost any application that works over the Internet or your private IP network is a good candidate for UMTS/HSDPA. But because UMTS/HSDPA offers higher throughput rates and lower network latency, you can transfer large files faster and even access "chatty" client/server applications. UMTS/HSDPA makes the following types of mobile applications feasible: e-mail with even larger attachments, Web browsing with streaming video, complex database transactions, multimedia (video/audio streaming and downloading), picture and video messaging, WAP-based applications with rich content, and access to latency-sensitive enterprise applications.
UMTS/HSDPA and CDMA2000 are the two principle global 3G cellular technologies. UMTS/HSDPA has similar performance to CDMA2000 1xEV-DO, both from a throughput and latency perspective. However, far more operators globally have committed to UMTS/HSDPA technology than EV-DO.
With UMTS/HSDPA, you can use the same applications as with GPRS/EDGE, including e-mail, group collaboration, Web-browsing, instant messaging, picture messaging, virtual private networking, Intranet access to enterprise applications, and SMS. UMTS/HSDPA provides higher throughput rates, enabling you to transfer larger files faster and to make your applications even more responsive. UMTS/HSDPA enables e-mail with large attachments, complex database transactions, multimedia (video/audio streaming and downloading), video messaging, rich WAP content, and Web-based (even "chatty") client/server enterprise applications.
UMTS/HSDPA is independent of higher level services such as WAP. However, the higher throughput and lower latency of UMTS/HSDPA will allow content developers to deliver richer WAP content. Sessions will also be more responsive.
Not at this time. However, UMTS/HSDPA specifications do include comprehensive quality-of-service mechanisms with which applications can request specific performance parameters. AT&T may implement these in the future.
UMTS/HSDPA mobile telephones allow you to initiate a call on UMTS/HSDPA, and if you move out of a UMTS/HSDPA coverage area, to continue your call on the GSM network.
UMTS/HSDPA data service is very effective while the user is mobile, whether in a car or in a train, so long as the user remains in a coverage area. The UMTS/HSDPA radio interface is particularly adept at adjusting to rapid changes in the radio environment that are typical when mobile.
UMTS/HSDPA is targeted to mobile workers who travel primarily in the UMTS/HSDPA coverage area. This includes:
- Field sales/service (e.g., pharmaceutical sales rep or HVAC technician)
- Real estate (commercial and residential)
- Property appraisal (commercial and residential)
- Public service, utilities, building inspection
- Professional service (engineering, construction, legal, management consulting)
- Telecom, IT support
Improved latency can dramatically increase the speed of applications, especially those that involve a lot of back and forth traffic, such as database and other client/server applications and browsing of complex web pages. Some applications however, such as FTP file transfer, are not sensitive to latency due to the use of windowing protocols.
More than likely you will be able to run the application unchanged. Both CDMA2000 1X and UMTS/HSDPA are IP-based networks. Carrier networks do differ in some respects, however, such as how long data sessions are maintained in the absence of data traffic and IP addressing options, so you may have to investigate these aspects. However, nearly any application based on IP will work on UMTS/HSDPA.
Tethering options in the handsets include Bluetooth, cable and IR. Bluetooth will be available in many, though not necessarily all devices.
UMTS/HSDPA will have no impact on the installed base of GPRS and EDGE devices. Existing GPRS/EDGE devices can continue to access the GPRS/EDGE network with no change.
The AT&T UMTS/HSDPA network provides access to its content servers, the Internet, and corporate networks. The network supports all consumer and business APNs.
Yes. For UMTS/HSDPA connections, AT&T uses UMTS Encryption Algorithm1 (UEA1), which is based on a mode of operation of a block cipher called Kasumi, and employs a 128-bit key. Authentication is similar to the authentication used in GSM/GPRS/EDGE, and is based on the credentials in the SIM card.
AT&T interconnects its UMTS/HSDPA network to customer networks via the Internet or direct connection such as frame relay.
UMTS/HSDPA provides sophisticated authentication and encryption similar to GPRS/EDGE service:
- User credentials. Requires SIM card containing identity information.
- Authentication. Based on challenge/response mechanism against SIM credentials.
- 128-bit encryption between mobile device and the Radio Network Controller (RNC). Protects a significant portion of the UMTS/HSDPA infrastructure against eavesdropping.
In addition, companies can augment security using Virtual Private Network (VPN) technology, providing a secure tunnel from the device, over the Internet and through to the corporate data center.
UMTS/HSDPA is well suited for video and multimedia applications, including streaming and downloaded content.
MEdia Net will work noticeably faster on UMTS/HSDPA mobile phones. In addition, AT&T has developed richer, more graphical content and video for UMTS/HSDPA.
In general, WAP 2.0 content developers do not have to do anything different to support UMTS/HSDPA versus GPRS/EDGE. However, faster download speeds and reduced latency allow you to create richer (e.g., more graphical or multimedia-based) content. The network will provide a service indication of whether a user has a GPRS/EDGE connection or UMTS/HSDPA connection, allowing the content server to adjust content accordingly.
The nature of all wireless networks is that packets can be lost under difficult radio conditions. UMTS/HSDPA uses robust modulation and error-correcting techniques to mitigate packet loss, allowing for reliable data transmissions in most usage scenarios.
The network allocates voice and data independent traffic channels. Voice does not directly affect data performance except that if there is little voice traffic, the network can assign more, or faster data channels.
Both use a radio technology called direct sequence spread spectrum, where streams of data are "spread" into a much larger number of transmitted bits using spreading codes—hence the name Code Division Multiple Access. However, other than using the same spreading approach, nearly all other implementation aspects are different, including the width of radio channels where CDMA2000 uses 1.25 MHz radio channels and WCDMA uses 5 MHz radio channels.
GSM and UMTS/HSDPA technologies will co-exist, and many GSM operators will offer both GSM and UMTS/HSDPA networks. Eventually, operators could phase out their GSM networks and only operate UMTS/HSDPA, but that will take many years.
Most IR connection speeds are limited to 115 Kbps. Bluetooth or cable connections will provide the highest throughput rates.
UMTS networks do indeed support peak speed of 2 Mbps and with later versions of the technology, even higher rates. Current devices, however, have peak rates of 384 Kbps, and do not support the 2 Mbps rate. Even when they do, these will be burst rates, and average speeds will be lower due to multiple users sharing the network. At this time, AT&T UMTS service supports provides average speeds of 220-320 Kbps with burst speeds up to 384 Kbps. With HSDPA, average speeds of 400-700 Kbps can be expected.
UMTS/HSDPA is a powerful and complex new technology. As such, it has taken time to get every aspect to work reliably. However, commercial UMTS/HSDPA deployments are now gathering momentum globally, with a large array of handset and infrastructure suppliers.
Other features for UMTS/HSDPA mobile telephones include multimedia support (voice and video), large color displays, Java, WAP2, voice handover between UMTS/HSDPA and GSM, SMS, and MMS.
Yes. There are currently over 60 operators that allow AT&T UMTS customers to roam onto their network.
Yes. UMTS/HSDPA mobile telephones can engage in simultaneous voice and data sessions. This means you can be talking on the phone while using the microbrowser or while using the phone as a modem to a computer.
The UMTS/HSDPA network makes sense for both business and consumer users who want to use a high-performance cellular network. Business users could be those with demanding office productivity applications and consumers could be those wanting to take advantage of features such as streaming video.