Troubleshooting guide

Cingular Communication Manager Help

automatically switches to a roaming provider, the data session will be lost

for a short interval. Disconnects will likely result in interruption of

application functionality and data transfers that are underway. Critical

work that cannot be interrupted should not be performed while moving in

order to minimize this risk.

Note: Signal strength is not the only variable factor in determining the

throughput of your wireless connection. Distance from cell site, network

availability and traffic, device, applications, tasks, file size, transmission

limitations and interference, and other factors also impact the speed of your

connection.

GSM Network Types

Global Systems for Mobile communications (GSM™) is the digital voice

telephone standard that is now used by most of the world. Several

standards exist that allow data connections to be established over a GSM

network. Of these, Cingular offers support for GPRS, EDGE, and 3G

UMTS/HSDPA services. A brief definition will of these services is included

below. However, knowledge of the individual service types is not

necessary to establish connections and all of these will be referred to as

GSM elsewhere in this guide.

GPRS (General Packet Radio Service) is an IP-based service for GSM

cellular networks, and has been deployed worldwide. GPRS/EDGE

supports IP-based applications and provides a mobile extension of the

Internet, or private intranets. More information on GPRS can be found at

http://www.cingular.com/midtolarge/gsm_gprs

EDGE (Enhanced Data Rates for Global Evolution) is a powerful

enhancement to the radio technology used by GPRS. EDGE dramatically

improves national wide area wireless data throughput rates and network

capacity, while providing full backward compatibility for GPRS devices

and applications. More information on EDGE can be found at

http://www.cingular.com/midtolarge/edge

UMTS (

Universal Mobile Telecommunications System) is a third generation (3G)

packet-based standard for the transmission of text, digitized voice, video, and

multimedia. It provides even faster and more versatile connections than its GPRS

and EDGE predecessors.

HSDPA (High Speed Downlink Packet Access) is an enhancement to the

UMTS standard. Both UMTS and HSDPA offer wireless mobility at

broadband speeds. The Cingular HSPDA/UMTS network is currently

available in the greater metropolitan areas of Austin, Baltimore, Boston,

Chicago, Dallas, Houston, Las Vegas, Phoenix, Portland, Salt Lake City, San

Diego, San Francisco, San Jose, Seattle, Tacoma and Washington, D.C. For