Mobile phone standards

Just as there are several different types of mobile messaging (SMS, EMS, MMS, etc.) there are also several different mobile phone standards:

Each mobile phone standard is described below.

AMPS (Analog)

Analog cellular phone systemAMPS is an acronym which stands for "Analog Mobile Phone Service" or sometimes also known as "Advanced Mobile Phone System". The AMPS standard was the most prevalent analog mobile phone standard used throughout the 1980s. (However, it was not the very first mobile phone standard, hence the term "Advanced" in the name.)

AMPS is still in use today for certain high-reliability voice applications including GM's On*Star service and certain very-low-bandwidth industrial data applications. Although there is a data element to AMPS which is used to send the date, time of day, and other low-bandwidth data to mobile phones, AMPS phones cannot do text or picture messaging.

AMPS phones do not support the creation of text or picture messages and thus AMPS is of no use to IMU.


TDMA: Time Division Multiple Access

How TDMA works - click for larger imageTDMA is an acronym which stands for "Time Division Multiple Access". It is a digital standard which allows for each cellular "channel" to be divided into time slots, thus providing a gain in capacity over AMPS. Given the higher capacity per cell tower and the fact that it is a digital standard, TDMA was the obvious follow-on replacement to AMPS.

Currently TDMA is highly used in the US and a few other parts of the world, but its use is quickly being phased out in favor of GSM and CDMA.

Modern TDMA phones support the creation of text messaging and even Nokia Smart Messages and thus these messages can be processed and displayed by IMU.


GSM: Global System for Mobile

GSM is an acronym which stands for "Global System for Mobile". The GSM standard is the most-used mobile standard in the world, with the largest deployment being in Europe.

GSM is a digital standard which is internally based on Time Division Multiple Access (TDMA) techniques. Newer GSM phones also support digital transmission through GPRS, which allows packets of data to be sent and received at moderate rates. It is this GPRS extension which allows new features such as MMS and WAP/web browsing capability.

The GSM standard has been around for a relatively long time. Its popularity continues to grow because of the addition of GPRS and integration of cameras, MP3 players and other gadgets into GSM phones. Because of these additions, this relatively old standard is actually being phased in within the US.

Modern GSM phones support the creation of text and picture messages and thus these messages can be processed and displayed by IMU. In fact, GSM is the preferred standard for use with IMU.


CDMA: Code Division Multiple Access

How CDMA works - click for larger imageCDMA is an acronym which stands for Code Division Multiple Access. Of the three digital standards mentioned above, CDMA is the newest and allows for the highest capacity and highest mobile data throughput. Theoretically CDMA provides many times the channel capacity of TDMA. Proponents of CDMA also claim that there are fewer dropped calls when crossing cell boundaries.

Due to the newness of CDMA and extended standards such as CDMA-2000 and W-CDMA, the CDMA standard is rapidly growing in popularity in the US, South America and certain parts of Asia.

Modern CDMA phones support the creation of text and picture messages and thus these messages can be processed and displayed by IMU.



Another standard worth mentioning is the NTT DoCoMo standard. This standard is found only in Japan. NTT DoCoMo phones are very advanced and support text and picture messaging. Currently IMU does not support NTT DoCoMo but Pangolin is working on this and will surely have DoCoMo support at some point in the future.


Other standards

Aside from the major mobile phone standards mentioned above, there are other standards that are used far less frequently including NAMPS, iDEN/Nextel, NMT, TETRA/Dolphin, Iridium and Globalstar. IMU has no direct support for these standards, but may still be able to receive messages sent by one of these, provided that the carriers have inter-operability agreements with GSM or CDMA operators, or provided that IMU can be directly connected to a message server on one of these networks.


Types of mobile messaging
Mobile phone standards
 IMU-supported phone standards
What is Pangolin's IMU?
Connecting the modem
Moderating the content
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