800/850/900/1800/1900 Wait, that is more than Quad

[VoiceMobil]

Yeah, so basically my question is why am I hearing about 800mHz GSM? Is there such a thing? I thought 800mHz was only Nextel's iDEN, which is a variation of TDMA? Or am I wrong? I know that T-Mobile UK has a roaming agreement with Nextel, so that leads me to believe that Nextel has some form of 800mHz GSM, or are European handsets still TDMA capable?

[ZaphodB]

800MHz GSM is a reality. 850MHz is a subset of 800MHz, thus "quad" refers to 800/900/1800/1900. Some of Rogers AT&T's towers are 800MHz though I believe the majority are 1900MHz. AT&T (US) GSM is on 850MHz, which is secretly part of the 800MHz band. Cingular and T-Mobile GSM (as well as Fido in Canada) are all 1900MHz GSM.

All AMPS (Analog) is 800MHz.

Much of Verizon, Telus, Bell Mobility, and Alltel's CDMA coverage is 800MHz.

Nextel's iDEN uses 800MHz and 900MHz frequency (which may be part of the explanation for European roaming).

I believe AT&T's TDMA coverage is in the 800MHz band as well.

Thus, you see that 800MHz is quite crowded.

[Kenny]

Some info I pulled off the web....

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It's the closest thing there is to an "international" standard -- GSM systems are used in nearly 200 countries (with 600 million subscribers) worldwide, from Europe (where the standard originated) throughout Africa, Asia and Australia. Coverage in these areas is for the most part excellent; in some cities the use of picocells even makes it possible to use phones on moving subway trains. Though a latecomer to North America, GSM is now making some substantial gains there, though with a different flavor than used elsewhere. Originally utilizing the 900 Mhz spectrum, GSM providers in parts of Europe, Africa, and Asia later added additional capacity at 1800 Mhz. In North America, however, GSM service is currently available only at 1900 Mhz. The good news for world travelers is that most cell phone manufacturers offer dual-band (900 and 1900 Mhz) or tri-band (900, 1800 and 1900 Mhz) phones that will work in most places GSM systems are found. The bad news is that a fourth GSM system -- GSM 800, operating at 850 Mhz -- may soon join the fray in the US. I'm only aware of one "quad-band" (GSM 800, 900, 1800, 1900) phone so far, but if the standard achieves widespread use I'm sure we'll see more.

While growing rapidly, in the US and Canada GSM service can be scarce outside of larger urban areas. In Latin America, coverage currently exists only in parts of Argentina, Bolivia, Chile, El Salvador, Paraguay and Peru (all at GSM 1900) along with Venezuela (GSM 900). Other notable non-GSM countries include South Korea and Japan. GSM is a feature-rich technology that includes fax capability and SMS (short messaging service). Most providers offer e-mail to SMS gateways, making it possible to receive flight updates and breaking news alerts over the phone. Many providers also offer quick connect data services through ISDN lines, and the latest generation GPRS (Global Packet Radio Service) promises high-speed "always on" data connections much faster than the traditional 9600 bps. If you can't tell, I'm a big fan of GSM and hope that it soon is available everywhere. My principal mobile phone is a tri-band "world" phone with service from VoiceStream, one of the largest GSM providers in the US with roaming agreements with GSM carriers worldwide .


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Nokia is to further expand on the global success of GSM with the introduction of GSM 800 technology. This enables both TDMA and TDMA/GSM operators to launch GSM services on 800 MHz frequencies, with an evolution path to 3G services with EDGE and WCDMA. Offering GSM enhanced with EDGE brings in new 3G opportunities in the 800 MHz band with full global roaming between the Americas, Europe and Asia.

With this announcement Nokia brings benefits to operators and mobile users around the world, enabling global GSM/EDGE 800/900/1800 and 1900 MHz coverage and roaming. In addition to GSM/EDGE on the 800 MHz band Nokia has already committed to GSM/EDGE deliveries for the 900, 1800 and 1900 MHz bands.

The introduction of GSM 800 means operators can offer voice and highly successful GSM services on the 800 MHz band. GSM and TDMA networks using 800MHz can be enhanced with EDGE (Enhanced Data Rates for Global Evolution) for the evolution to 3G services. 800MHz system deliveries are expected to start during the second half of this year. 800MHz based TDMA is currently deployed in the Americas and parts of Asia.

"GSM800 will be ideal for wide coverage areas where 800MHz bands are available. GSM 800 will open up completely new markets through expanding the GSM technology to all major frequency bands. In addition, it brings the era of true mobile multimedia a step closer, by offering evolution to EDGE and WCDMA capabilities," says Jukka Auramo, Vice President, Marketing and Sales, IP Mobility Networks, Nokia Networks.

As the same GPRS core technology and service creation platforms will be used on 800MHz as well as on other GSM bands, applications and services created globally are easy to adopt, in order ensure fast revenue generation.

A major benefit of GSM 800 is that it enables existing TDMA operators as well as new GSM entrants to benefit from the global success of GSM. In addition, current GSM 1800 and 1900 operators can reduce their network expenditures by reduced coverage and capacity costs on the 800 MHz band. Standardization work for GSM and EDGE on 800 MHz has been completed by all major standardisation bodies.


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Chip makers are putting together designs for handset transceivers that can handle all four GSM bands, but few are showing enthusiasm for the idea of a true quad-band phone.

The fourth band comes from the decision by a number of TDMA operators in the US to migrate their networks to GSM and GPRS and then to GSM-Edge to offer higher data rates. The operators intend to use their existing 850MHz networks to support the new GSM-based services, requiring changes to existing handset designs.

Sony Semiconductor recently unveiled a dedicated design for a direct-conversion, quad-band transceiver. Other suppliers say supporting the additional band is not a major problem for existing transceivers and that they are working on integrated products.

But they are focusing the bulk of their efforts on tri-band phones that primarily support either the two US frequencies or the two frequencies used in Europe and Asia.

Etienne Delhaye, RF market sector team manager for Philips Semiconductors, said: "We currently supply a device that has three RF inputs. You can use two high-frequency bands and one low band. You can add switches and filters for the [extra] low band.

"We are working on future products that could have four input pins.

"We don't see a market before the beginning of next year for real quad-band phones. And is there a real requirement for roaming across four bands? There will be high-end phones but the market will not be huge."

Tim Ridgers, development manager for RF products at Philips, added: "Depending on the market [that manufacturers] are addressing, they require a combination of three out of the four bands.

"A 900MHz design will work fairly well at 850MHz. It is a question of RF performance as the [US] cellular band is occupied by other modulation schemes. Designers may trade off filter performance against the transceiver design."

Stephen Graham, RF product manager at Hitachi Microelectronics, said: "All of Hitachi's existing transceivers will handle quad-band subject to external switches and filters.

"We are seeing a demand for quad-band capability but it is more about flexibility than a need for high volume. Phones with three out of the four bands are the most likely [products]. Quad-band phones will be high end."

A spokeswoman for Silicon Laboratories says the company's existing transceiver will work with four bands given the presence of a front-end switch and a filter for the 850MHz band.

[VoiceMobil]

Thanks, that cleared things up for me.