Digital Wireless Standards (Cellular):

Japan (PDC)
Personal Digitial Cellular is the 2G TDMA-based protocols used in Japan, owned by NTT DoCoMo. PDC services operate in the 800 and 1500 MHz bands. PDC is the Japanese equivalent of GSM but is incompatible with other systems. It is operated by NTT DoCoMo, as well as by all the other Japanese operators, but the technology was developed by NTT DoCoMo. Previously known as PHP (Personal HandyPhone) and Japanese Digital Cellular (JDC)

US (IS-54, IS-136, IS-95)
IS-54: Interim Standard 54 is the dual mode (analog and digital) standard for cellular phone service in North America. In its analog form, it conforms to the AMPS standard. IS-54 is an EIA/TIA (Electronics Industries Association/Telecommunications Industries Association) standard, developed with the involvement of the CTIA. Since 1995, IS-54 enhancements fall under IS-136.

IS-136: Also known as DigitalAMPS (D-AMPS). The EIA/TIA Interim Standard which succeed IS-54, and which addresses digital cellular systems employing TDMA (Time Division Multiple Access). IS-136 also specifies a DCCH (Digital Control CHannel) in support of new features controlled by a signaling and control channel between the cell site and the terminal equipment. IS-136 also allows analog AMPS (Advanced Mobile Phone System) to coexist with North America TDMA on the same cellular network, sharing frequency bands and channels, which supports a smooth transition from analog to digital cellular. IS-136 gave rise to a high-tier standard for PCS (Personal Communications Services), developed by a Joint Technical Committee (JTC) comprising representatives from ATIS and the TIA. High-Tier PCS supports fast-moving vehicular traffic, much like traditional cellular.

IS-95: A TIA standard for North American cellular systems based on CDMA (Code Division Multiple Access), and is widely deployed in North America and Asia. IS-95a defines what generally is known as cdmaOne, which supports voice and 14.4 Kbps data rates. IS-95b supports data rates up to 115 Kbps.

Europe (GSM)
GSM originally stood for Groupe Speciale Mobile but now is known as Global System for Mobile Communications. It is the standard digital cellular (also called mobile) phone service you will find in Europe, Japan, Australia and elsewhere – a total of 85 countries! Most countries decided to pick a single, standard wireless phone technology years ago, and they settled on GSM. The U.S. refused to settle on a standard and that has resulted in a patchwork of multiple, incompatible technologies. GSM exists in the U.S., and is gaining ground in the U.S. though it uses a different frequency than the system used in Europe and elsewhere. In the U.S. it is used by companies including VoiceStream and AT&T.

*Although this is an abbreviated definition, we will explore GSM in more detail in future WOTD’s.