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Cellular Internet

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This article covers the practical aspects of wireless access to the Internet via Cellular.

Cellular Internet, also called Mobile Internet is the access to the Internet using a mobile wireless modem, integrated in a mobile phone or in an independent device (USB modem, PCMCIA card ).

Nowadays USB modems are HSPA modems.

Contents

[edit] Introduction to Cellular Internet

[edit] GSM

Global System for Mobile Communications (GSM) is a digital cellular communications technology based on Time Division Multiple Access (TDMA), and is the dominant mobile communications system in most of the world, including Europe, the Middle East, Africa, and Asia, and it now has a strong presence in North America as well. First introduced in 1991, the GSM standard has been deployed in four different frequency bands: 800 (called "850" so as not to be confused with D-AMPS on 800), 900, 1800, and 1900 MHz. GSM 850 and 1900 are primarily used in North America; GSM 900 and 1800 are primarily used outside of North America. GSM uses narrowband TDMA that allows up to eight (or sixteen with Half-Rate Codec1) simultaneous calls on the same radio frequency using different time slots in the same channel. Along with CDMA and D-AMPS (Digital AMPS, often referred to simply as "TDMA"), GSM represents the 2nd generation (2G) of cellular wireless.
1. Initial public perception of Half-Rate Codec quality was so poor that it's not been generally used. However, adaptive encoding has improved quality substantially since then, so it's possible that Half-Rate Codec may be used more widely in the future, particularly in highly cost-sensitive markets (e.g., less developed countries).

[edit] CSD

CSD (Circuit Switched Data) is similar to dialup modem communications. However, a GSM phone has no real modem, just a sort of virtual modem which makes a connection to a carrier's IWU (Inter-Working Unit), located in a service center. The IWU has the actual modem that makes analog data calls and/or fax calls over the PSTN (public switched telephone network). If the carrier doesn't provide the IWU facility, or if the account isn't provisioned for CSD, then a GSM phone cannot make data and/or fax calls.
Speed of CSD is 9.6 Kbps.
A regular dialup modem cannot be made to work over a GSM voice channel because of the audio data compression used.

[edit] HSCSD

[edit] GPRS

With a Class 10 device and good signal, typical download speeds of about 50 Kbps (about 6K Bytes/sec). Available in most GSM service areas.

[edit] EGPRS(EDGE)

With a Class 10 device and good signal, typical download speeds of about 150 Kbps (about 18.5K Bytes/sec). Latency (as measured by ping) of about 300 ms. Widely available. Backward compatible to GPRS.

[edit] UMTS

Typical download speeds of 200-320 Kbps (or about 2x EGPRS). Most (but not all; e.g., Novatel U520) devices are backward compatible to EGPRS and GPRS.

[edit] HSPA

Typical speeds are expected to be upto 3.6 Gbps. Latency (as measured by ping) expected to be about 150 ms (or about 1/2 EGPRS). Backward compatible to UMTS, EGPRS and GPRS.

[edit] CDMA

[edit] 1xRTT

Round-trip latency of about 350 ms.

[edit] EV-DO

[edit] EV-DO Rev. A

[edit] Carriers

Main article: Cellular Internet carriers

[edit] Cingular

[edit] Sprint/Nextel

[edit] T-Mobile

[edit] Verizon

[edit] WAP

Wireless Application Protocol (WAP) is a protocol for wireless Internet access that is designed for small screen cellular phones. Access to the Internet is through a WAP Gateway.

[edit] WAP Gateways

[edit] Cellular Broadband Routers and Modems

You can use:

  • a broadband cellular módem
  • a broadban cellular router
  • a modem-router
  • or plug a modem to a wireless router with USB port.

[edit] Modems

[edit] Routers

[edit] See also

[edit] In other languages

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